Materials, Their Properties and Uses 960 TINPLATE LT-125 is a water-soluble organo-trialkyl-tin used as a bacteriocide in paper and textile processing It can be used over a wide pH range Soft-steel plate containing a thin coating of pure tin on both sides A large proportion of the tinplate used goes into the manufacture of food containers because of its resistance to the action of vegetable acids and its nonpoisonous character It solders easily, and also is easier to work in dies than terneplate, so that it is preferred over terneplate for making toys and other cheap articles in spite of a higher cost Commercial tinplate comes in boxes of 112 sheets, 14 by 20 in (0.36 by 0.51 m), and is designated by the net weight per box when below 100 lb (45 kg) Heavy tinplate above 100 lb (45 kg) goes by number, as steel does, or by letter symbols The weight of tin may be as high as 1.7% of the total weight of the sheet Coke plates carry as little tin as is necessary to protect and brighten the plate for temporary use The tin of the coat forms compounds of FeSn2, Fe2Sn, and FeSn with the iron of the plate, and on a coke plate this compound is 0.00006 to 0.00015 in (0.00015 to 0.00038 cm) thick Best cokes carry more tin than the standard cokes Charcoal plates have heavier coats of tin designated by the letter A The AAAAAA, or 6A, has the heaviest coating Tinplate is made by the hot-dip process using palm oil as a flux, or by a continuous electroplating process A base box contains 31,360 in2 (20 m2) of tinplate, and standard-dip tinplate has 1.5 lb (0.7 kg) of tin per base box, while electrolytic plate has only 0.25 lb (0.1 kg) of tin per base box and much electrolytic tinplate for container use has only 0.10 lb (0.05 kg) of tin per base box Electrotinning gives intimately adherent coatings of any desired thickness, and the plate may have a serviceable coat as thin as 0.00003 in (0.00008 cm), or about one-third that of the thinnest possible dipped plate A slight cold rolling of electrolytic tinplate gives a bright, smooth finish Taggers was originally a name for tinplate that is undersized, or below the gage of the plate in the package, but the name taggers tin is also applied to light-gage plate These sizes are No 38 gage, 55 lb (25 kg); No 37, 60 lb (27 kg); and No 36, 65 lb (29 kg) Ductilite, of Wheeling-Pittsburgh Steel Corp., is a tinplate that is not made by hot rolling in packs, but is cold-rolled from single hot-rolled strip steel It is of uniform gage and does not have the thin edges of pack-rolled plate It also has a uniform grain structure Weirite, of Weirton Steel Corp., is cold-reduced coke tinplate Black plate, used for cans in place of tinplate where the tin protection is not necessary, is not black, but is any sheet steel other than tinplate or terneplate in tinplate sizes It may be chemically treated to resist rust or corrosion TINPLATE Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses TITANATES 961 Electroplated tin-zinc coatings, developed at the International Tin Research Institute (ITRI) in England in the late 1940s, are more corrosion-protective of steel than zinc alone However, bath control is difficult, and the sodium stannate and cyanide systems of the original bath are toxic In the early 1990s, ITRI developed the Stanzec process, which is cyanide-free, nontoxic, and more controllable The electrolyte, or bath, is a mixture of sodium or potassium stannate, sodium or potassium zincate, sodium or potassium hydroxide, plus complexing and stabilizing agents, brighteners, and grain refiners Any alloy composition can be deposited by barrel, brush, or rack plating, and deposits of 70 to 80% tin with the balance zinc combine solderability with good corrosion resistance A 75Sn–25Zn plate has a Vickers hardness of 37, and the coatings are typically ductile and suitable for painting They also can be plated to brasses and high-copper alloys and are considered alternatives to plating with toxic cadmium in many applications Compounds made by heating a mixture of an oxide or carbonate of a metal and titanium dioxide High dielectric constants, high refractive indices, and ferroelectric properties contribute primarily to their commercial importance Barium titanate crystals, BaTiO3, are made by die-pressing titanium dioxide and barium carbonate and sintering at high temperature This crystal belongs to the class of perovskite in which the closely packed lattice of barium and oxygen ions has a barium ion in each corner and an oxygen ion in the center of each face of a cube with the titanium ion in the center of the oxygen octahedron Because of their high dielectric constant and compatibility with high-temperature superconductors, thin perovskite oxide films are candidates for tunable microwave devices For piezoelectric use the crystals are subjected to a high current, and they give a quick response to changes in pressure or electric current They also store electric charges and are used for capacitors Glennite 103, of Gulton Industries Inc., is a piezoelectric ceramic molded from barium titanate modified with temperature stabilizers Bismuth stannate, Bi2(SnO3) и 5H2O, a crystalline powder that dehydrates at about 284°F (140°C), may be used with barium titanate in capacitors to increase stability at high temperatures Ceramelex is molded polycrystalline barium titanate Lead zirconate–lead titanate is a piezoelectric ceramic that can be used at higher temperatures than barium titanate Lead titanate, PbTiO3, is used as a less costly substitute for titanium oxide It is yellowish and has only 60% of the hiding power, but is very durable and protects steel from rust Butyl titanate is a yellow, viscous liquid used in anticorrosion varnishes TITANATES Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses 962 TITANIUM AND TITANIUM ALLOYS and for flameproofing fabrics It is a condensation product of the tetrabutyl ester of ortho-titanic acid, and contains about 36% titanium dioxide Calcium titanate, CaTiO3, occurs in nature as the mineral perovskite As a ceramic, it has a room-temperature dielectric constant of about 160 It is frequently used as an addition to barium titanate or by itself as a temperature-compensating capacitor Magnesium titanate, MgTiO3, crystallizes as an ilmenite rather than a perovskite structure It is not ferroelectric, and is used with titanium dioxide to form temperature-compensating capacitors It has also been used as an addition agent to barium titanate Strontium titanate, SrTiO3, has a cubic perovskite structure at room temperature It has a dielectric constant of about 230 as a ceramic, and it is commonly used as an additive to barium titanate to decrease the Curie temperature By itself, it is used as temperature-compensating material because of its negative temperature characteristics Strontium titanate, used as a brilliant diamondlike gemstone, is a strontium mesotrititanate Stones are made up to carats The refractive index is 2.412 It has a cubic crystal similar to the diamond, but the crystal is opaque in the X-ray spectrum Crystalline silicotitanate, developed at Texas A&M University and Sandia National Laboratories, has potential use in the cleanup of radioactive wastes As an inorganic ion-exchange agent, it promotes exchange of resident sodium ions for ions of radioactive elements It has proved effective in removing cesium from neutral and highly acidic waste solutions Titanate fibers can be used as reinforcement in thermoplastic moldings The fibers, called Fybex, produced by LNP Engineering Plastics, Inc., can also be used in plated plastics to reduce thermal expansion, warpage, and shrinkage Titanate fibers in plastics also provide opacity TITANIUM AND TITANIUM ALLOYS A metallic element, symbol Ti, occurring in a great variety of minerals It was first discovered as an element in 1791 in a black magnetic sand at Manachin, Cornwall, England, and called menachite, from the name of the sand, menachinite Its chief commercial ores are rutile and ilmenite In rutile it occurs as an oxide It is an abundant element but is difficult to reduce from the oxide High-purity titanium (99.9%) has a melting point of about 3034°F (1668°C), a density of 0.163 lb/in3 (4,512 kg/m3), and tensile properties at room temperature of about 34,000 lb/in2 (234 MPa) ultimate strength, 20,000 lb/in2 (138 MPa) yield strength, and 54% elongation It is paramagnetic and has low electrical conductivity and thermal expansion The commercial metal is produced from sponge titanium, which is made by converting the oxide to titanium tetrachloride followed by Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses TITANIUM AND TITANIUM ALLOYS 963 reduction with molten magnesium The metal can also be produced in dendritic crystals of 99.6% purity by electrolytic deposition from titanium carbide Despite its high melting point, titanium reacts readily in copper and in other metals and is much used for alloying and for deoxidizing It is a more powerful deoxidizer of steel than silicon or manganese An early German deoxidizing alloy known as Badin metal contained about 9% aluminum, 19 silicon, titanium, and the balance iron Titanium copper, used for deoxidizing nonferrous metals, is made by adding titanium to molten copper The congealed alloy is broken into lumps One of the chief uses of the metal has been in the form of titanium oxide as a white pigment It is also valued as titanium carbide for hard facings and for cutting tools Small percentages of titanium are added to steels and alloys to increase hardness and strength by the formation of carbides or oxides or, when nickel is present, by the formation of nickel titanide The first titanium alloys in the United States were produced in 1945 by the Bureau of Mines Titanium is one of the few allotropic metals (steel is another); that is, it can exist in two different crystallographic forms At room temperature, it has a close-packed hexagonal structure, designated as the alpha phase At around 1625°F (884°C), the alpha phase transforms to a body-centered cubic structure, known as the beta phase, which is stable up to titanium’s melting point of about 3050°F (1677°C) Alloying elements promote formation of one or the other of the two phases Aluminum, for example, stabilizes the alpha phase; that is, it raises the alpha to the beta transformation temperature Other alpha stabilizers are carbon, oxygen, and nitrogen Beta stabilizers, such as copper, chromium, iron, molybdenum, and vanadium, lower the transformation temperature, therefore allowing the beta phase to remain stable at lower temperatures, and even at room temperature Titanium’s mechanical properties are closely related to these allotropic phases For example, the beta phase is much stronger, but more brittle, than the alpha phase Titanium alloys therefore can be usefully classified into three groups on the basis of allotropic phases: alpha, beta, and alpha-beta alloys Titanium and its alloys have attractive engineering properties They are about 40% lighter than steel and their moderate weight and high strengths, up to 200,000 lb/in2 (1,379 MPa), gives titanium alloys the highest strength-to-weight ratios of any structural metal Furthermore, this exceptional strength-to-weight ratio is maintained from Ϫ420°F (Ϫ216°C) up to 1000°F (538°C) A second outstanding property of titanium materials is their corrosion resistance The presence of a thin, tough, oxide surface film provides excellent resistance to atmospheric and sea environments as well as a wide range of Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses 964 TITANIUM AND TITANIUM ALLOYS chemicals, including chlorine and organics containing chlorides Being near the cathodic end of the galvanic series, titanium performs the function of a noble metal Titanium and its alloys, however, can react pyrophorically in certain media Explosive reactions can occur with fuming nitric acid containing less than 2% water or more than nitrogen dioxide and, on impact, with liquid oxygen Pyrophoric reactions also can occur in anhydrous liquid or gaseous chlorine, liquid bromine, hot gaseous fluorine, and oxygen-enriched atmospheres Fabrication is relatively difficult because of titanium’s susceptibility to hydrogen, oxygen, and nitrogen impurities, which cause embrittlement Therefore elevated-temperature processing, including welding, must be performed under special conditions that avoid diffusion of gases into the metal Heat is usually required in most forming operations Commercially pure titanium and many of the titanium alloys are now available in most common wrought mill forms, such as plate, sheet, tubing, wire, extrusions, and forgings Castings can also be produced in titanium and some of the alloys, investment casting and graphite-mold (rammed graphite) casting being the principal methods Because of titanium’s highly reactive nature in the presence of such gases as oxygen, the casting must be done in a vacuum furnace Because of their high strength-to-weight ratio primarily, titanium and titanium alloys are widely used for aircraft structures requiring greater heat resistance than aluminum alloys Because of their exceptional corrosion resistance, however, they (unalloyed titanium primarily) are also used for chemical processing, desalination, and power generation equipment; marine hardware; valve and pump parts; and prosthetic devices There are several grades of commercially pure titanium, also called unalloyed titanium They are distinguished by their impurity content, that is, the maximum amount of carbon, nitrogen, hydrogen, iron, and oxygen permitted Regardless of grade, carbon and hydrogen contents are 0.10 and 0.015% maximum, respectively Maximum nitrogen is 0.03%, except for 0.05 in Grades and Iron content ranges from as much as 0.20% in Grade 1, the most pure (99.5) grade, to as much as 0.05 in Grade 4, the least pure (98.9) Maximum oxygen ranges from 0.18% in Grade to 0.40 in Grade Grade 7, 99.1% pure based on maximum impurity content, is actually a series of alloys containing 0.12 to 0.25% palladium for improved corrosion resistance in hydrochloric, phosphoric, and sulfuric acid solutions Palladium content has little effect on tensile properties, but impurity content, especially oxygen and iron, has an appreciable effect Minimum tensile yield strengths range from 25,000 lb/in2 (172 Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses TITANIUM AND TITANIUM ALLOYS 965 MPa) for Grade to 70,000 lb/in2 (483 MPa) for Grade Grade 16, from Oremet–Wah Chang, has only 0.05% palladium and, thus is less costly than Grade alloys Titanium-ruthenium alloy Ti-0.2Ru, developed by the research group Mintek of South Africa, is said to match the corrosion resistance of Grade alloys at lower cost Its ultimate tensile strength is 84,000 lb/in2 (579 MPa) and the elongation is about 23%, both greater than those of Grade There are three principal types of titanium alloys: alpha or near-alpha alloys, alpha-beta alloys, and beta alloys All are available in wrought form and some of each type for castings as well In recent years, some also have become available in powder compositions for processing by hot isostatic pressing and other powder-metallurgy techniques Titanium alpha alloys typically contain aluminum and usually tin Other alloying elements may include zirconium, molybdenum, and, less commonly, nitrogen, vanadium, columbium, tantalum, or silicon Though they are generally not capable of being strengthened by heat treatment (some will respond slightly), they are more creep-resistant at elevated temperature than the other two types, are preferred for cryogenic applications, and are more weldable but less forgeable Ti-5Al-2Sn, which is available in regular and ELI grades (extra-low interstitial) in wrought and cast forms, is the most widely used In wrought and cast form, minimum tensile yield strengths range from 90,000 lb/in2 (621 MPa) to 115,000 lb/in2 (793 MPa) and tensile modulus is on the order of 15.5 ϫ 106 to 16 ϫ 106 lb/in2 (106,873 to 110,320 MPa) It has useful strength to about 900°F (482°C) and is used for aircraft parts and chemical processing equipment The ELI grade is noted for its superior toughness and is preferred for containment of liquid gases at cryogenic temperatures Other alpha or near-alpha alloys and their performance benefits include Ti-8Al-1Mo-1V (high creep strength to 900°F), Ti-6Al-2Sn-4Zr-2Mo [creep resistance and stress stability to 1100°F (593°C)], Ti-6Al-2Cb-1Ta-0.8Mo (toughness, strength, weldability), and Ti-2.25Al-11Sn-5Zr-1Mo [high tensile strength—135,000 lb/in2 (931 MPa) yield, superior resistance to stress corrosion in hot salt media at 900°F] Another alpha alloy, Ti-0.3Mo-0.8Ni, also known as TiCode 12, is noted for its greater strength than commercially pure grades and equivalent or superior corrosion resistance, especially to crevice corrosion in hot salt solutions The near alpha alloy Ti-5Al1Sn-1Zr-1V-0.8Mo combines good toughness and weldability, corrosion and stress-corrosion resistance, and room-temperature creep resistance Developed by Titanium Metals Corp., it has longitudinal tensile yield strength of 103,000 to 116,000 lb/in2 (710 to 800 MPa), depending on sheet and plate thickness, and elongation of 10 to 15% Machinability Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses 966 TITANIUM AND TITANIUM ALLOYS and forgeability are quite similar to those of the alpha-beta Ti-6Al-4V alloy The alloy is said to be ideal for marine fasteners Titanium alpha-beta alloys, which can be strengthened by solution heat treatment and aging, afford the opportunity of parts fabrication in the more ductile annealed condition and then can be heat-treated for maximum strength Ti-6Al-4V, which is available in regular and ELI grades, is the principal alloy, its production alone having accounted for about half of all titanium and titanium-alloy production In the annealed condition, tensile yield strength is about 130,000 lb/in2 (896 MPa) and 13% elongation Solution treating and aging increase yield strength to about 150,000 lb/in2 (1,034 MPa) Yield strength decreases steadily with increasing temperature, to about 70,000 lb/in2 (483 MPa) at about 950°F (510°C) for the aged alloy At 850°F (454°C), aged bar has a 1,000-h stress-rupture strength of about 50,000 lb/in2 (345 MPa) Uses range from aircraft and aircraft turbine parts to chemical processing equipment, marine hardware, and prosthetic devices The alloy is also the principal alloy used for superplastically formed, and superplastically formed and simultaneously diffusion-bonded, parts At 1650 to 1700°F (899 to 927°C) and low strain rates, the alloy exhibits tensile elongations of 600 to 1,000%, a temperature range also amenable to diffusion-bonding the alloy SP700, from Japan’s NKK Corp., exhibits some 2,000% elongation at about 1420°F (770°C) Although Ti-6Al-4V and Ti-6Al-4V ELI have served for armor plate—the latter being superior—less expensive titanium armor alloys have been introduced by Oremet–Wah Chang They contain 2.5 to 5.4% aluminum, 2.0 to 3.4 vanadium, 0.2 to iron, and 0.2 to 0.3 oxygen Following are other alpha-beta alloys and their noteworthy characteristics Ti-6Al-6V-2Sn: high strength to about 600°F (315°C) but low toughness and fatigue resistance Ti-8Mn: limited use for flat mill products, not weldable Ti-7Al-4Mo: a forging alloy mainly, but limited use; and a 150,000 lb/in2 (1,034 MPa) yield strength in the aged condition Ti-6Al-2Sn-4Zr-6Mo: high strength, 170,000 lb/in2 (1,172 MPa) yield strength, decreasing to about 110,000 lb/in2 (758 MPa) at 800°F (427°C); for structural applications at 750 to 1000°F (400 to 540°C) Ti-5Al-2Sn-2Zr-4Mo-4Cr and Ti-6Al-2Sn-2Zr-2Mo2Cr: superior hardenability for thick-section forgings; high modulus—about 17 ϫ 106 to 18 ϫ 106 lb/in2 (117,215 to 124,110 MPa), respectively; tensile yield strength of about 165,000 lb/in (1,138 MPa) Ti-6Al-2Sn-2Zr-2Mo-2Cr castings of the same nominal composition as the wrought alloy except for a reduction of silicon to 0.1% by weight also exhibit good mechanical performance after hot isostatic Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses TITANIUM AND TITANIUM ALLOYS 967 pressing Tensile properties for several duplex and triplex heat treatments, and thicknesses of 0.5 to 1.5 in (12.5 to 37.5 mm), demonstrate ultimate strengths of 142,000 to 154,000 lb/in2 (979 to 1,062 MPa), yield strengths of 127,000 to 135,000 lb/in2 (876 to 931 MPa), elongations of 6.7 to 11.9%, and average fracture toughness of 97,800 to 125,000 lb/in2 in0.5 (108 to 140 MPa m0.5) Ti-10V-2Fe-3Al: best of the alloys in toughness at a yield strength of 130,000 lb/in2 (896 MPa); can also be aged to a yield strength of about 172,000 lb/in2 (1,186 MPa); intended for use at temperatures to about 600°F (315°C) Ti-3Al-2.5V: a tubing and fastener alloy primarily, moderate strength and ductility, weldable Beta titanium alloys, fewest in number, are noted for their hardenability, good cold formability in the solution-treated condition, and high strength after aging On the other hand, they are heavier than titanium and the other alloy types, their density ranging from about 0.174 to 0.175 lb/in3 (4.84 g/cm3) for Ti-13V-11Cr-3Al, Ti-8Mo-8V-2Fe3Al, and Ti-3Al-8V-6Cr-4Zr-4Mo to 0.183 lb/in3 (5,065 kg/m3) for Ti11.5Mo-6Zr-4.5Sn, which is also known as Beta III They are also the least creep-resistant of the alloys Ti-13V-11Cr-3Al, a weldable alloy, can be aged to tensile yield strengths as high as 195,000 lb/in2 (1,345 MPa) and retains considerable strength at temperatures to 600°F, but has limited stability at prolonged exposure to higher temperatures Timetal 21S, of Titanium Metals Corp., is a metastable beta alloy of composition Ti-15Mo-3Al-2.7Cb-0.3Fe-0.2Si-0.13O with maximum amounts of 0.05% carbon, 0.05 nitrogen, 0.015 hydrogen, and 0.4 residual elements It is unique among titanium and titanium alloys in its resistance to Skydrol, a widely used aircraft hydraulic fluid Also, its oxidation resistance at 1200°F (649°C) is far superior to that of commercially pure titanium Aging at 1000°F (538°C) results in tensile yield strengths of 179,000 to 187,000 lb/in2 (1,234 to 1,289 MPa) The alloy can be rolled to thin foil, a form useful for metalmatrix composites Timetal 15-3, of the nominal composition Ti-15V3Al-3Cr-3Sn, is another metastable beta alloy It is a high-strength, cold-formed strip alloy with ultimate tensile strength of 145,000 to 180,000 lb/in2 (1,000 to 1,241 MPa), tensile yield strengths of 140,000 to 170,000 lb/in (965 to 1,172 MPa) and elongations of to 7%, depending on aging temperature and time after solution heat-treatment and air cooling Timetal LCB (low-cost beta), a Ti-6.8Mo-4.5Fe-1.5Al alloy of the same company, reduces formulating cost because iron need not be removed from the ore It is a candidate for replacing steel spring wire and requires processing temperatures of only 300 to 400°F (149 to 204°C) The alloy has a tensile strength of 150,000 lb/in2 (1,034 MPa) Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses 968 TITANIUM AND TITANIUM ALLOYS and a tensile modulus of 16.5 ϫ 10 lb/in (113,768 MPa) Oremet–Wah Chang’s Tiadyne 3515, also known as Titanium Alloy C and Ti-1270, contains 50% titanium, 35 vanadium, and 15 chromium It is noted for high-temperature strength and the ability to resist combustion in air at temperatures and pressures far greater than for Ti-6Al-4V alloy The average tensile yield strength is 137,000 lb/in2 (945 MPa), 98,000 lb/in2 (676 MPa) at 1000°F (538°C) It is available in rod, various flat products, and powder, and is also castable Tiadyne 3510 contains about 35% zirconium, 10.5 columbium, and 0.07 to 0.13 oxygen Though rather heavy (density is 0.19 lb/in3, 5,300 kg/m3) and having a low modulus (10.4 ϫ 106 lb/in2, 71,700 MPa), tensile yield strength is 160,000 lb/in2 (1,103 MPa), weldability is good and the alloy can be surface hardened by oxidation for high wear resistance It is also superplastic at certain elevated temperatures and is at least as corrosion resistant as commercially pure titanium Prosthetic devices, firearm firing mechanisms, and springs are potential uses Ti-45Cb, of this company, features superior resistance to oxidizing environments and combustion in pure oxygen The alloy has a density of 0.206 lb/in3 (5,702 kg/m3), an ultimate tensile strength of 80,000 lb/in (552 MPa), a tensile yield strength of 70,000 lb/in (483 MPa)—29,000 lb/in (200 MPa) at 752°F (400°C)—23% elongation, and a modulus of elasticity of ϫ 106 lb/in2 (62,055 MPa) Its corrosion resistance may be slightly better than that of titanium in sulfuric acid and in hydrochloric acid at concentrations of less than 20% Ti-45Cb has been used for autoclave vent lines in processing gold ores, for parts of oxygen injectors exposed to pure oxygen, and, for hot wet-oxidation equipment used in wastewater processing Applications include aerospace rivets, high-pressure oxygenated gas vents, oxygen lances for pressure oxidation reactors, valves for corrosive oxygenated processes, and superconducting wire In an effort to spur nonaerospace uses, manufacturers have introduced several low-cost titanium alloys which are roughly similar in strength to aerospace alloy Ti-6Al-4V but which may sacrifice certain performance features required in aerospace applications These alloys include titanium alloy Auto-grade, of Allvac, titanium alloys RM and VM of RMI Titanium Co., and Timetal-62S of Titanium Metals Corp To reduce cost, Auto-grade is initially forged and rolled in the beta region, then rolled in the alpha-beta range RM, made of recycled material, has a nominal Ti-6Al-4V composition VM, for virgin metal, is Ti-6.4Al-1.2Fe, the iron substituting for more-costly vanadium Timetal-62S, Ti-6Al-1.7Fe-0.1Si, also uses iron instead of vanadium and costs about 25% less than the aerospace alloy Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses TITANIUM ORES 969 Titanium alloys are leading candidates for metal-matrix composites, primarily for aircraft and aircraft engine applications Silicon carbide fiber is a leading reinforcement One approach, developed by Howmet Corp and General Electric Aircraft Engines, is called bicasting Preforms of alloys reinforced with the fiber are cast within a matrix alloy A hard, crystalline powder of composition TiC made by reacting titanium dioxide and carbon black at temperatures above 3272°F (1800°C) It is compacted with cobalt or nickel for use in cutting tools and for heat-resistant parts It is lighter in weight and less costly than tungsten carbide, but in cutting tools it is more brittle When combined with tungsten carbide in sintered carbide tool materials, however, it reduces the tendency to cratering in the tool A general-purpose cutting tool of this type contains about 82% tungsten carbide, titanium carbide, and 10 cobalt binder Kentanium, of Kennametal, Inc., is titanium carbide in various grades with up to 40% either cobalt or nickel as the binder, used for high-temperature, erosion-resistant parts For highest oxidation resistance, only about 5% cobalt binder is used Kentanium 138, with 20% cobalt, is used for parts where higher strength and shock resistance are needed, and where temperatures are below about 1800°F (982°C) This material has a tensile strength of 45,000 lb/in (310 MPa), compressive strength of 550,000 lb/in2 (3,792 MPa), and Rockwell A hardness 90 Kentanium 151A, for resistance to molten glass or aluminum, has a binder of 20% nickel Titanium-carbide alloy, of Ford Motor Co., for tool bits, has 80% titanium carbide dispersed in a binder of 10 nickel and 10 molybdenum The material has a Rockwell A hardness of 93 and a dense, fine-grained structure Ferro-Tic, of Chromalloy Corp., has titanium carbide bonded with stainless steel It has a Rockwell C hardness of 55 Machinable carbide is titanium carbide in a matrix of Ferro-Tic C tool steel Titanium carbide tubing is produced in round or rectangular form 0.10 to in (0.25 to 7.6 cm) in diameter, by TEEG Research, Inc It is made by vapor deposition of the carbide without a binder The tubing has a Knoop hardness above 2,000 and a melting point of 5880°F (3249°C) Grown single crystals of titanium carbide of Linde Co have composition TiC0.94, with 19% carbon The melting point is 5882°F (3250°C), specific gravity 4.93, and Vickers hardness 3,230 TITANIUM CARBIDE The most common titanium ores are ilmenite and rutile Ilmenite is an iron-black mineral having a specific gravity of about 4.5 and containing about 52% titanic oxide, or titania, TiO2 TITANIUM ORES Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses WATER REPELLENTS 1025 Rain is a source of freshwater, and freshwater is considered potable water if it contains less than 500 ppm of dissolved solids Heavy water is a form of water in which the hydrogen atoms are replaced by the heavy stable isotope of hydrogen deuterium Heavy water has a molecular weight of 20.028, melting point of 38.9°F (3.81°C), boiling point of 214.6°F (101.4°C), and a viscosity of 1.107 MPa и s At the energy level of solidification the water molecules arrange themselves in precise order close together, and the frozen water, or ice, can be split in straight cleavage from a line scratched on the surface In the solid assembly of molecules, there is no available space, and the contained impurities of water are thrown out in freezing, except in the dendritic snow molecule Ice has load-bearing capacity, and thus the term structural ice Ice bridges across frozen lakes and rivers in the Arctic have been made of ice reinforced with ferry cable and wood Ice reinforced with random distribution of glass fibers, wood, sawdust, and other materials is called icecrete Continuous strands of glass yarn add rigidity and, if prestressed, load-carrying capacity Ice crystals serve as the blasting medium to clean surfaces of dirt and grease or for paint removal in a system developed at the Penn State University Gas Dynamics Laboratory Chemicals used for treating textiles, leather, and paper such as washable wallpaper, to make them resistant to wetting by water They are different from waterproofing materials in that they are used where it is not desirable to make the material completely waterproof, but to permit the leather or fabric to “breathe.” Water repellents must not form acids that would destroy the material, and they must set the dyes rather than cause them to bleed on washing There are two basic types: a durable type that resists cleaning and a renewable type that must be replaced after the fabric is dry-cleaned Zelan, a pyridinium-resin compound of Du Pont, is representative of the first type Quilon, of the same company, is used for paper, textiles, and glass fabric and forms a strong chemical bond to the surface of the material by an attachment of the chromium end of the molecule through the covalent bond to the negatively charged surface It is a stearotochromic chloride The second type is usually an emulsion of a mineral salt over which a wax emulsion is placed; the treatment may be a one-bath process, or it may be by two separate treatments Aluminum acetate is one of the most common materials for this purpose Basic aluminum acetate is a white, amorphous powder of composition Al(OH)(OOC и CH3) It is only slightly soluble in water but is soluble in mineral acids Niaproof, of Niacet Corp., is a concentrated aluminum acetate for waterproofing textiles, and WATER REPELLENTS Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses 1026 WATER SOFTENERS Ramasit and Migasol are similar materials Zirconium acetate, a white, crystalline material of composition ZrOH(C2H3O2)3, and its sodium salt are used as water repellents Zirconyl acetate, ZrO(C2H3O2)2, a light-yellow solution containing 13% ZrO2, is used for both water repellancy and flame resistance of textile fibers Intumescent agents are repellent coatings that swell and snuff out fire when they become hot Latex 744B, of Dow Chemical Co., is a repellent of this type It is a vinyl water emulsion compounded with pentaerythritol, dicyandiamide, and monosodium phosphate, and is used on textiles, wallboard, and fiber tile Silicones have established their value as water-repellent finishes for a range of natural and synthetic textiles The silicone polymers may be added as a solution, an emulsion, or by spraying a fine mist; alternatively, intermediates may be added that either polymerize in situ or attach themselves to the fibers These techniques result in the pickup of to 3% of silicone resin on the cloth Commercially, dichloromethylsilane polymer is added as a solution or emulsion to a fabric; this is heated in the presence of a catalyst, such as a zinc salt of an organic acid or an organotin compound, to condense the polymer and form a water-repellent sheath around each fiber Soluol Chemical Co.’s Aquagard 170 is a nonionic organopolysiloxane in the form of a white emulsion; it is cured at low temperatures by its catalyst Curade 170, a cationic metallic compound, producing a finish that is highly durable to dry cleaning Similar techniques are employed for imparting water repellency to leather Silicones containing SiᎏH groups are used for paper treatment The treated paper has a measure of water repellency and, in addition, some antiadhesive properties Fluorine-based polymers are also employed for treating fabrics Gore-Tex, produced by W L Gore, is a polytetrafluoroethylene coating on nylon fabric; garments fashioned from this treated nylon are weatherproof and breathable Scotchgard, from 3M, is a polymer containing fluoroalkyl groups that is effective for repelling both water and oil Scotchban, from the same company, provides water, oil, and grease repellency to paper Zepel B, from Du Pont Co., is a fluoropolymer dispersion in water that does not promote yellowing or discoloration of coated outerware The Quillon series, also from Du Pont, consists of greenish solutions of chrome complexes in isopropanol that are water-repellent agents for packaging materials, nonwoven fabrics, and adhesive tapes Vinsol MM from Hercules Inc is a dark brown, free-flowing powder that is a sodium soap of a blend of Vinsol resin and a fatty acid It was specially developed for use in masonry cements Chemical compounds used for converting soluble, scale-forming solids in water into insoluble forms In the latter WATER SOFTENERS Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses WATER SOFTENERS 1027 condition they are then removed by setting or filtration The hardness of water is due chiefly to the presence of carbonates, bicarbonates, and sulfates of calcium and magnesium; but many natural waters also contain other metal complexes which need special treatment for removal Temporary hard waters are those that can be softened by boiling; permanent hard waters are those that require chemicals to change their condition Sodium hydroxide is used to precipitate magnesium sulfate Caustic lime is employed to precipitate bicarbonate of magnesium, and sodium aluminate is used as an accelerator Barium carbonate may also be used Prepared water softeners may consist of mixtures of lime, soda ash, and sodium aluminate, the three acting together Sodium aluminate, Na2Al2O4, is a water-soluble, white powder melting at 3002°F (1650°C), which is also used as a textile mordant, for sizing paper, and in making milky glass Reynolds Metals Co produces this material in flake form with iron content below 0.0056% for paints, water softeners, and paper coatings Alum is used in settling tanks to precipitate mud, and zeolite is used extensively for filtering water The liquids added to the washing water to produce fluffier textiles are fabric softeners and not water softeners They are usually basic quaternary ammonium compounds such as distearyl dimethyl ammonium chloride with 16 and 18 carbon atoms, which are cationic, or positively charged A thin coating is deposited on the negatively charged fabric, giving a lubricated cloth with a fluffy feel Water is also softened and purified with ion-exchange agents, which may be specially prepared synthetic resins Cation-exchange agents substitute sodium for calcium and magnesium ions and produce soft waters When the water is treated with a hydrogen derivative of a resin, the metal cations form acids from the salts The carbonates are converted to carbonic acid which goes off in the air When it is treated again with a basic resin derivative, or anionexchange agent, the acids are removed Water receiving this double treatment is equal to distilled water Salt-cycle anion exchange substitutes chloride ions for other anions in the water, and when combined with cation exchange, it produces sodium chloride in the water in place of other ions BiQust, from Purolite Ltd., is an anion-exchange resin developed at Oak Ridge National Laboratories to remove radioactive pertechnetate from groundwater It can also be used to treat perchlorate anion in industrial discharge waters Ion-exchange resins are also being used to remove metals from metal-plating and electronics wastewaters In electrolytic ion exchangers for converting seawater to freshwater, the basic cell is divided into three compartments by two membranes, one permeable only to cations and the other only to anions Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses 1028 WAX The sodium ions migrate toward the cathode, and the chlorine ions go toward the anode, leaving freshwater in the center compartment Ion-exchange membranes for electrodialysis (salt splitting or separation), and also used in fuel cells, are theoretically the same as powdered exchange resins but with an inorganic binder Such a membrane resin of the Armour Research Foundation is made by the reaction of zirconyl chloride and phosphoric acid, giving a chain molecule of zirconium-oxygen with side chains of dihydrogen phosphate Zeo-Karb, a sulfonated coat, and Zeo-Rex, a sulfonated phenolformaldehyde resin, are cation exchangers of Permutit Co., while De-Acidite and Permutit A of the same company are anion exchangers Amberlite IRA-400, of Rohm & Haas, is a strongly basic alkyl amine which will split neutral salts in the water and also remove silica The German Wofatit P exchanger is a sodium salt of a phenol-formaldehyde resin Ion-exchange agents are also used for refining sugar, glycerin, and other products, and for the purification of acids and the separation of metals An eluting agent is a solvent used to elutriate the resin beds in the separation of metals, that is, to separate the heavier from the lighter particles, causing a metal ion on the resin to change place with hydrogen or with an ammonium group in the elutriant Zeolites are crystalline aluminosilicates that display cation-exchange properties The most common zeolite for softening uses is zeolite 4A, a sodium aluminosilicate made by Union Carbide Corp Zeolex is a similar product from J M Huber Corp EZA Zeolite A is a white powder from Ethyl Corp that is employed as a replacement for sodium phosphates in laundry detergents WAX A general name for a variety of substances of animal and veg- etable origin, which are fatty acids in combination with higher alcohols instead of with glycerin, as in fats and oils They are usually harder than fats, less greasy, and more brittle, but when used alone, they not mold as well Chemically, the waxes differ from fats and oils in being composed of high-molecular-weight fatty acids with highmolecular-weight alcohols The most familiar wax is beeswax from the honeybee, but commercial beeswax is usually greatly mixed or adulterated Another animal wax is spermaceti from the sperm whale Vegetable waxes include Japan wax, jojoba oil, candelilla, and carnauba wax These are sold under the trade name Stralpitz by Strahl & Pitsch, Inc Mineral waxes include paraffin wax from petroleum, ozokerite, ceresin, and montan wax The mineral waxes differ from the true waxes and are mixtures of saturated hydrocarbons The animal and vegetable waxes are not plentiful materials, and are often blended with or replaced by hydrocarbon waxes or waxy synthetic resins But waxes can be made from common oils and fats Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses WAX 1029 by splitting off the glycerin and reesterifying selected mixtures of the fatty acids with higher alcohols Hywax 122 is a self-emulsifiable wax composed of cetyl, myristyl, and stearyl esters derived from animal and vegetable oils Mazawax and Macol, from Mazer Chemicals, are fatty alcohol blends with various emulsifiers; they are all-purpose waxes for creams, lotions, hair relaxants, and hair dipilatory formulations Opalwax, of Du Pont, is a synthetic wax produced by the hydrogenation of castor oil It has about the same hardness as carnauba, specific gravity of 0.98, and melting point of 187 to 190°F (86 to 88°C), but it lacks the luster of carnauba It is odorless and has a pearl-white color It is very resistant to most solvents and is used for insulation, coatings, candles, and carbon paper Acrawax, of Lonza, Inc., is a somewhat similar substitute for carnauba with higher melting point Stroba wax, of the same company, is a synthetic wax with a base of stearic acid and lime The melting point is 217 to 223°F (103 to 106°C) It is used in polishes, insulation, and as a flatting agent Synthetic wax under the name of Pentawax 286 is a true wax in that it is a combination of fatty acids with an alcohol It is made from the long-chain acids of vegetable oils with pentaerythritol It has a higher melting point than carnauba, 110°F (43°C), but does not form a self-polishing liquid wax as carnauba does Wax R21 is a metal-containing synthetic wax used in liquid floor waxes, temporary corrosion protection, release agents, and as a melting point booster Other brands from the same manufacturer, Hoechst Celanese Corp., are Hostalub and Ceridust, which are specialty waxes based on polyolefins, paraffins, chemically modified montan, and micropowders Sheerwax is made by catalytic hydrogenation of vegetable oils It has the hardness and high melting point of carnauba wax and can be had in white color Waxes are employed in polishes, coatings, leather dressings, sizings, waterproofing for paper, candles, and varnishes They are softer and have lower melting points than resins, are soluble in mineral spirits and in alcohol, and are insoluble in water Some plastics have wax characteristics and may be used in polishes and coatings or for blending with waxes Polyethylene waxes are light-colored, odorless solids of low molecular weight, up to about 6,000 Mixed in solid waxes to the extent of 50%, and in liquid waxes up to 20%, they add gloss and durability and increase toughness In emulsions they add stability Acumist is a micronized polyethylene wax that is a processing and performance additive for adhesives, coatings, color concentrates, cosmetics, inks, lubricants, paints, plastics, and rubber It can also be constituted from low-molecular-weight homopolymer, oxidized homopolymer, or as a copolymer Acumist is from Allied-Signal, Inc Marlex 20, of Phillips Petroleum Co., is a Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses 1030 WEAR-RESISTANT STEEL methylene polymer used to blend with vegetable or paraffin waxes to increase the melting point, strength, and hardness Santowax R, of Monsanto, is a mixture of terphenyls It is a light-buff, waxy solid, highly soluble in benzene, and with good resistance to heat, acids, and alkalies It is used to blend with natural waxes in candles, coatings, and insulation Epolene wax, of Eastman Chemical Products, Inc., is a polyethylene Waxes are not digestible, and the so-called edible waxes used as water-resistant coatings for cheese, meats, and dried fruits are not waxes, but are modified glycerides Monocet is such a material It is a white, odorless, tasteless, waxy solid melting at 104°F (40°C) and is an acetylated monoglyceride of fatty acids Many types of steel have wear-resistant properties, but the term usually refers to high-carbon, high-alloy steels used for dies, tooling, and parts subject to abrasion and for wear-resistant castings They are generally cast and ground to shape They are mostly sold under trade names for specific purposes The excess carbon of the steels is in spheroidal form rather than as graphite One of the earlier materials of this kind for drawing and forming dies, Adamite, was a chromium-nickel-iron alloy with up to 1.5% chromium, nickel equal to half that of the chromium, and from 1.5 to 3.5 carbon with silicon from 0.5 to The Brinell hardness ranges from 185 to 475 as cast, with tensile strengths to 125,000 lb/in2 (862 MPa) The softer grades can be machined and then hardened, but the hard grades are finished by grinding Kinite has about 13% chromium, 1.5 carbon, 1.1 molybdenum, 0.70 cobalt, 0.55 silicon, 0.50 manganese, and 0.40 nickel It is used for blanking dies, forming dies, and cams Martin steel has 13% chromium, about molybdenum, 0.80 cobalt, 0.35 vanadium, and 1.5 carbon T15 tool steel, for extreme abrasion resistance in cutting tools, is classified as a super-high-speed steel It has 13.5% tungsten, 4.5 chromium, cobalt, 4.75 vanadium, 0.50 molybdenum, and 1.5 carbon Its great hardness comes from the hard vanadium carbide and the complex tungsten-chromium carbides, and it has full red-hardness The property of abrasion or wear resistance in steels generally comes from the hard carbides, and is thus inherent with proper heat treatment in many types of steel WEAR-RESISTANT STEEL WELDING METALS AND ALLOYS Materials in the form of rod, wire, or powder for welding or surfacing, such as hardfacing metals and alloys Rod and wire are also called electrodes and, if used to fill the joint, filler metals American National Standards Institute (ANSI) and/or American Welding Society (AWS) specifications pertain to particular welding processes and electrode material For example, for Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses WELDING METALS AND ALLOYS 1031 shielded metal arc welding covered electrodes, ANSI/AWS A5.1 pertains to carbon steels, A5.5 (low-alloy steels), A5.4 (corrosion-resistant steels), A5.15 (cast irons), A5.3 (aluminum and aluminum alloys), A5.6 (copper and copper alloys), A5.11 (nickel and nickel alloys), and A5.13 and A5.21 (surfacing) Depending on the type of electrode, the covering may serve to protect the weld metal from excessive contamination and grain growth; establish the electrical characteristics of the electrode; and improve, directly or by adding alloying elements, mechanical properties of the weld Electrodes in each of these specifications are further defined more specifically For example, in A5.1, E6010 designates an electrode (E) for 60,000 psi (414 MPa) minimum undiluted weld-metal tensile strength as welded According to A5.5, a suffix following the five-unit designation indicates the kind of alloy steel, such as carbon-molybdenum, chromium-molybdenum, nickel, or manganese-molybdenum type Stainless-steel designations (A5.4) reflect composition of the undiluted weld metal, applicable positioning of the welding operation, and the type of welding current suitable with the electrode Nonferrous metal and alloy specifications indicate by metal or alloy numerical designation or chemical symbol the metal or alloy Electrodes for cast iron (A5.15) include nickel, nickel-iron, and nickel-copper alloys and an alloy steel Phosphor bronze and aluminum bronze are also used for welding cast iron but the weld is said to be a braze weld Gas tungsten arc welding electrodes are tungsten or tungsten alloys as specified in ANSI/AWS A5.12 Electrode classifications, and color identifications applied by band or other means on electrode, are EWP for tungsten (green), EWCe-2 (for tungsten with 2% by weight cerium oxide (orange), EWLa-1 for tungsten with 1% lanthanum oxide (black), EWTh-1 for tungsten with 1% thoria (yellow), EWTh-2 for tungsten with 2% thoria (red), EWZr-1 for tungsten with 0.25% zirconia (brown), and EWG for tungsten with rare-earth oxide and nominal content specified by manufacturer Gas metal arc welding electrodes are designated by AWS A5.18 for carbon steels, A5.28 (lowalloy steels), A5.10 (aluminum and aluminum alloys), A5.7 (copper and copper alloys), A5.19 (magnesium and magnesium alloys), A5.14 (nickel and nickel alloys), A5.9 (300 and 400 Series stainless steels), and A5.16 (titanium and titanium alloys) Electrode compositions for welding some aluminum alloys, copper alloys, and steels may differ from that of the base metals Electrode classifications within the specifications indicate the electrode alloy or alloy type Flux-cored arc welding electrodes generally consist of a hollow steel sheath surrounding a core of fluxing and alloying ingredients Core ingredients stabilize the arc and/or deoxidize, shield, alloy, and Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses 1032 WELDING METALS AND ALLOYS improve the properties of the weld metal Most electrodes are in accordance with ANSI/AWS A5.20, which classifies 12 for mild steel (EXXT-1 to EXXT-11, plus EXXT-G and EXXT-GS); ANSI/AWS A5.29, which classifies five for low-alloy steels (EXXT1-X, EXXT4-X, EXXT5X, EXXT-8X, and EXXTX-G); ANSI/AWS A5.22, which classifies four for stainless steels (EXXXT-1, -2, -3, and -G); and AWS A5.34, which classifies electrodes for nickel alloys ANSI/AWS A5.25 classifies electroslag welding electrodes and ANSI/AWS A5.26 classifies electrogas welding electrodes Flux-cored arc welding electrodes are also available for hardfacing, or surfacing, metals for superior heat and corrosion resistance or to restore worn or damaged parts Welding metals and alloys or their forms are known by many trade names Intensarc is one for carbon steels Flexarc rods include a range of stainless steels Aluminum weld is a 5% silicon aluminum alloy for welding aluminum-silicon alloys Croloy welding rods, of Babcock & Wilcox, can weld alloy steels without preheating They are low-alloy chromium-molybdenum steels Chromang, for welding high-alloy steels, is an “18-8” stainless steel modified with 2.5 to manganese An iron-base alloy with 25 nickel, 21 chromium, manganese, molybdenum, 1.6 copper, 0.19 nitrogen, 0.015 phosphorus and sulfur, and 0.01 oxygen provides austenitic welds that stay tough at temperatures of Ϫ450°F (Ϫ270°C) Developed at the National Institute of Standards and Technology for welding superconducting magnets, it offers about twice the fracture toughness of 308 and 316 stainless steels Chromend 9M, for arc welding hard deposits, contains to 10 chromium and 1.5 molybdenum and results in welds of Brinell hardness 400 Elkonite is a group of welding alloys made especially for welding machines In general, they are sintered tungsten or molybdenum carbides combined with copper or silver and used for spot rather than continuous welds Tungsten electrodes can be pure tungsten, thoriated tungsten, or zirconium tungsten, the latter two being for direct-current welding Thoriated tungsten gives high arc stability, and thoria also increases machinability Zirconium tungsten provides adhesion between the electrode and molten metal for weld uniformity Thermit is a mixture of aluminum powder and iron oxide for welding large sections of iron or steel or for filling large cavities Thermit welding, developed by Goldschmidt Thermit Co., involves burning the aluminum to react with the oxide, setting free the iron in molten form Cast-iron thermit, for welding cast iron, is thermit with ferrosilicon and 20 steel Red thermit is made with red oxide, black thermit with black oxide Railroad thermit is thermit with additions of nickel, manganese, and steel Cast-iron welding electrodes, wire, or rod from Washington Alloy Co include Alloy Nickel Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses WELDING METALS AND ALLOYS 1033 55 and 99, Alloy EST, and Cascade 17A, 17M, 17T, 18A, 18M, 18T, and RC1 Depending on alloy, weld-metal tensile properties range from ultimate strengths of 50,000 to 84,000 lb/in2 (345 to 579 MPa), yield strengths of 40,000 to 63,000 lb/in2 (276 to 434 MPa), and elongations of to 33% Inco-Weld A, welding wire for stainless steels and overlays, has 70 nickel, 16 chromium, iron, manganese, titanium, and a maximum of 0.07 carbon Annealed welds have a tensile strength of 80,000 lb/in2 (552 MPa) and 12% elongation Nickel welding rod is much used to join cast iron but the operation is brazing, the base metal not being melted Colmonoy 23 A is a nickel-alloy welding powder for welding cast iron and for filling blow holes in iron castings by torch application It contains 2.3 silicon, 1.25 boron, 0.1 carbon, 1.5 maximum iron, the balance nickel, and melts at 1950°F (1066°C) Hardfacing alloys, which increase wear resistance, are also numerous Tungweld rods comprise steel tubes with fine tungsten carbide particles Kennemetal KT-200, which has a tungsten carbide core and steel sheath, gives Rockwell C surface hardness of 63 The high-manganese-steel Amsco welding rods provide Brinell 500 to 700 hardnesses Toolface is a high-speed-steel-rod for facing worn cutting tools Superloy, for facing surfaces of extreme hardness, has alloy granules in a soft steel tube The deposit contains 30 chromium, cobalt, molybdenum, tungsten, 0.05 boron, and 0.2 carbon Tungalloy, Resisto-Loy and Isorod are other hardfacing rods, Resisto-Loy having a nonferrous content Stoodite is a high-manganese-steel rod and Rockide refers to metal oxide rods for hardfacing Weartech alloys, of Weartech International and designated WT hardfacing alloys, are a wide range of iron-, nickel-, and cobalt-base hardfacing alloys, many of which are similar to Colmonoy, Stellite, Tribaloy, and other trade-name grades The iron alloys include Ni-Res alloy for a surface hardness of Brinell 160; Norem-02A, -04A, and -04B alloys, for 32 to 42 Rockwell C hardnesses; and WT590 and -595 alloys for Rockwell C 58 Except for Ni-Res, which is high in nickel (29%), all these alloys are high (22 to 30%) in chromium The nickel alloys are similar to Colmonoy alloys 4, 5, 6, or 56; Tribaloy 700; Hastelloy C; Ni-60 or Nucalloy 45 They contain 11 to 16 chromium and provide Rockwell C hardnesses of 23 to 62, depending on the alloy The cobalt alloys, the most in quantity, include alloy L-605, many Stellite alloy grades, and two Tribaloy grades Most of these alloys are quite high in chromium content and, depending on alloy, provide 21 to 63 Rockwell C hardnesses Stellite alloys and Tribaloy alloys are products of Deloro Stellite, Colmonoy alloys are products of Wall Colmonoy, and Norem alloys are products of the Electric Power Research Institute Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses 1034 WETTING AGENTS Chemicals used in making solutions, emulsions, or compounded mixtures, such as paints, inks, cosmetics, starch pastes, oil emulsions, dentifrices, and detergents, to reduce the surface tension and give greater ease of mixing and stability to the solution In the food industries, chemical wetting agents are added to the solutions for washing fruits and vegetables to produce a cleaner, bacteria-free product Wetting agents are described in general as chemicals having a large hydrophilic group associated with a smaller hydrophilic group Some liquids naturally wet pigments, oils, or waxes, but others require a proportion of a wetting agent to give mordant or wetting properties Pine oil is a common wetting agent, but many are complex chemicals They should be powerful enough not to be precipitated out of solutions in the form of salts, and they should be free of odor or any characteristic that would affect the solution Aerosol wetting agents, of American Cyanamid Co., are in the form of liquids, waxy pellets, or free-flowing powders Aerosol OS is a sodium salt of an alkyl naphthalene sulfonic acid It is a yellowishbrown powder soluble in most organic solvents This salt was called Nekal in Germany The Cyanamers are also free-flowing powders from the same company; basically modified polyacrylates, they are soluble in water and less so in alcohol The Dresinols of Hercules, Inc., are sodium or ammonium dispersions of modified rosin, with 90% of the particles below 39 in (1 m) in size Polyfon is a sodium lignosulfonate produced from lignin waste liquor It is used for dye and pigment dispersion, oil-well drilling mud, ore flotation, and boiler feedwater treatment WETTING AGENTS WHALE OIL An oil extracted by boiling and steaming the blubber of several species of whale that are found chiefly in the cold waters of the extreme north and south Whales are mammals and are predaceous, living on animal food The blubber blanket of fat protects the body, and the tissues and organs also contain deposits of fat Most whale oil is true fat, namely, the glycerides of fatty acids, but the head contains a waxy fat In the larger animals the meat and bones yield more fat than the blubber Both the whalebone whales and the toothed whales produce whale oil The bluehead whales of the south, Silbaldus musculus, are the largest and yield the most oil per weight The whaling industry is under international control, and allocations are made on the basis of blue whale units averaging 20 tons (18 metric tons) of oil each The blue whale is about 25 ft (8 m) long at birth and reaches 70 ft (21 m) in years This species often reaches 100 ft (30 m) with a weight of about 150 tons (136 metric tons) and will yield about 27 tons (24 metric tons) of oil The gray whale, or California whale, of the northern Pacific, is a small 50-ft (15-m) Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses WHALE OIL 1035 species The Greenland whale of the north, Balaena mysticetus, and the finback whale of the south, Balaenoptera physalus, produce much oil The beluga, or white whale, Delphinapterus leucas, and the narwhal, Monodon monoceros, of the north polar seas, produce porpoise oil Both species of porpoise measure up to 20 ft (6 m) in length Whale oil is sold according to grade, which depends upon its color and keeping qualities The latter in turn depends largely upon proper cooking at extraction Grades and are fine, pale-yellow oils, grade is amber, grade is pale brown, and grade is the darkest oil Grade has less than 1% free fatty acids, while grade has from 15 to 60% with a strong, fishy odor The specific gravity is 0.920 to 0.927, saponification value 180 to 197, and iodine value 105 to 135 Whale oil contains oleic, stearic, palmitic, and other acids in varying amounts But whales are now so scarce that the former uses of the oils and meat are restricted, particularly in the United States Whale oils of the lower grades were used for quenching baths for heat-treating steels, and in lubricating oils The best oils are used in soaps and candles, or for preparing textile fibers for spinning, or for treating leather In Europe whale oil is favored for making margarine because it requires less hydrogen than other oils for hardening, and the grouping of 16 to 22 carbon atom acids gives the hardened product greater plasticity over a wider temperature range Sod oil is oil recovered from the treatment of leather in which whale or other marine mammal oil was used It contains some of the tannins and nitrogenous matter which make it more emulsifiable and more penetrant than the original oil Whale meat was used for food in Japan and in dog food in the United States When it is cured in air, the outside is hard and black, but the inside is soft In young animals the flesh is pale; in older animals it is dark red It has a slight fishy flavor, but when cooked with vegetables is almost indistinguishable from beef It contains 15 to 18% proteins Whale-meat extract is used in bouillon cubes and dehydrated soups It is 25% weaker than beef extract Whale liver oil is used in medicine for its high vitamin A content It also contains kitol, which has properties similar to vitamin A but is not absorbed in all animal metabolism Whalebones are the elastic, hornlike strips in the upper jaw of the Greenland whale and some other species The strips are generally from to 10 ft (2 to m) long and number up to 600 Those from the bowhead whale of the Arctic Ocean are the longest slabs, measuring up to 13 ft (4 m) in length to 10 to 12 in (25 to 30 cm) wide at the bottom Finback whalebone is less than ft (1 m) in length The humpback whale, Megaptera longimana, of the northern Pacific, is a baleen whale with no teeth Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses 1036 WHEAT and with plates of baleen in the mouth to act as a sieve It grows to a length of 50 ft (15 m) Whalebone is lightweight, very flexible, elastic, tough, and durable It consists of a conglomeration of hairy fibers covered with an enamellike fibrous tissue It is easily split and when softened in hot water is easily carved Whalebone has a variety of uses in making whips, helmet frames, ribs, and brush fibers Baleen is a trade name for strips of whalebone used for whips, and for products where great flexibility and elasticity are required The edible seed grains of an annual grass of the genus Triticum, of which there are many species and thousands of varieties Wheat was the basic food grain of the early civilizations of the Near East, and has remained the chief grain of the white races except in cold climates where rye grows better The plains of the United States, Canada, Argentina, Australia, southern Russia, the Danube Valley, and northern India are the great wheat areas The types grown commercially are chiefly common wheat and durum wheat Common wheat, T vulgare, is the chief source of wheat flour It has a stout head from which the grains can be separated easily The hundreds of varieties are divided roughly into hard wheats and soft wheats, and red wheats and white wheats The hard wheats usually have smaller grains, but are richer in proteins Spring wheat is wheat that is sown in the spring and harvested in late summer Winter wheat is sown in the fall to develop a root system before winter and is then harvested in early summer It is more resistant and gives a higher yield Durum wheat, T durum, has a thick head with long beards, and large, hard grains rich in gluten The plant is hardy and drought-resistant, but the flour is too glutenous for U.S bread and is much used for macaroni and in mixtures Seven classes of wheat are designated in the official grain standards of the U.S Department of Agriculture: hard red spring wheat; durum wheat; red durum wheat; hard red winter wheat; soft red winter wheat; white winter wheat; and mixed wheat Each class permits mixtures of varieties The minimum test weight of wheat is required to be 60 lb/bu (778 kg/m3) Most of the wheat production is ground for edible flour Since wheat varies with the variety, climate, and soil, uniformity in the flour could formerly be obtained only by blending wheats from different areas to obtain an average; but uniformity is now obtained by an air-spinning process which separates the milled flour into fractions according to protein-starch ratios and then combining for the flour of uniform ratio These are called turbo-flours Wheat flour is not normally a uniform product even from one area, as it is made up of starch granules, fractured endosperm cells, and protein fragments WHEAT Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses WHITE BRASS 1037 Pregelatinized flour is used for canned goods to reduce the time needed for dextrinizing Wheat-flour paste, for textile coatings, is hydroxyethylated flour made by treating wheat flour with ethylene oxide It requires little cooking to form a starchy product Wheat is also used for making beer, and at times is employed for producing starch and alcohol Some wheat is used for stock feed, but most of the wheat for this purpose is of lower and condemned grades Buckwheat consists of the seed grains of Fagopyrum esculentum, a plant of the same family as the rhubarb and dock It is native to Asia and is one of the chief foods in Russia, but is used only in mixed flours in the United States The flour is more starchy and has less protein than wheat It is also darker in color and has a different flavor WHETSTONE Stones of regular fine grains composed largely of chal- cedony silica, often with minute garnet and rutile crystals They are used as fine abrasive stones for the final sharpening of edge tools Whetstones are also sometimes selected, fine sandstones from the grindstone quarries The chocolate whetstone from New Hampshire is mica schist The finest whetstones are called oilstones A fine-grained honestone, known as coticule, comes from Belgium and is used for sharpening fine-edged tools It is compact, yellow in color, and contains minute crystals of yellow manganese garnet, with also potash mica and tourmaline Coticule is often cut double with blue-gray phyllite rock adhering to and supporting it Scythestones are made from Ohio and Indiana sandstones and from the schist of Vermont Rubbing stones are fine-grained Indiana sandstones Very fine, single-crystal fibers that range from 118 to 394 in (3 to 10 m) in diameter and have length-to-diameter ratios of 50 to 10,000 Since they are single crystals, their strengths approach the calculated theoretical strengths of the materials Alumina whiskers, which have received the most attention, have tensile strengths up to ϫ 106 lb/in2 (20,700 MPa) and a modulus of elasticity of 62 ϫ 106 lb/in2 (427,000 MPa) Other whisker materials are silicon carbide, silicon nitride, magnesia, boron carbide, and beryllia WHISKERS WHITE BRASS A bearing metal which is actually outside of the range of the brasses, bronzes, or babbitt metals It is used in various grades, the specification adopted by SAE being tin, 65%; zinc, 28 to 30; and copper, to It is used for automobile bearings and is close-grained, hard, and tough It also casts well A different alloy is known under the name of white brass in the cheap jewelry and novelty trade It has no tin, small proportions of copper, and the remainder zinc It is a Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses 1038 WHITE GOLD high-zinc brass and varies in color from silvery white to yellow, depending upon the copper content An old alloy formerly used for casting buttons, known as Birmingham platina, or platina, contained 75% zinc and 25 copper It had a white color but was very brittle A yellowish metal known as bath metal, once widely used for casting buttons, candlesticks, and other articles, was a brass containing 55% copper and 45 zinc White nickel brass is a grade of nickel silver The white brass used for castings where a white color is desired may contain up to 30% nickel The 60:20:20 alloy is used for white plaque castings for buildings The high-nickel brasses not cast well unless they also contain lead Those with 15 to 20% nickel and lead are used for casting hardware and valves White nickel alloy is a copper-nickel alloy containing some aluminum White copper is a name sometimes used for copper-nickel alloy or nickel brass Nickel brasses known as German silver are copper-nickel-zinc white alloys used as a base metal for plated silverware, for springs and contacts in electrical equipment, and for corrosion-resistant parts The alloys are graded according to the nickel content Extra-white metal, the highest grade, contains 50% copper, 30 nickel, and 20 zinc The lower grade, called fifths, for plated goods, has a yellowish color It contains 57% copper, nickel, and 36 zinc All of the early German silvers contained up to 2% iron, which increased the strength, hardness, and whiteness, but is not desirable in the alloys used for electrical work Some of the early English alloys also contained up to 2% tin, but tin embrittles alloys The Federal Trade Commission prohibits the use of the term German silver in the marketing of silver-plated ware, but the name still persists in other industries The name of a class of jewelers’ white alloys used as substitutes for platinum The name gives no idea of the relative value of the different grades, which vary widely Gold and platinum may be alloyed together to make a white gold, but the usual alloys consist of 20 to 50% nickel, with the balance gold Nickel and zinc with gold may also be used for white golds The best commercial grades of white gold are made by melting the gold with a white alloy prepared for this purpose This alloy contains nickel, silver, palladium, and zinc The 14-karat white gold contains 14 parts pure gold and 10 white alloy A superior class of white gold is made of 90% gold and 10 palladium High-strength white gold contains copper, nickel, and zinc with the gold Such an alloy, containing 37.5% gold, 28 copper, 17.5 nickel, and 17 zinc, when aged by heat treatment, has a tensile strength of about 100,000 lb/in2 (690 MPa) and an elongation of 35% It is used for making jewelry; has a fine, white color; and is easily worked into intricate shapes Two nickel-free white gold alloys, developed by Handy and WHITE GOLD Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website Materials, Their Properties and Uses WHITE METALS 1039 Harmon, contain about 51% silver, palladium, and either zinc or germanium They were developed because some people are allergic to nickel leaching from 10-karat white gold alloys White-gold solder is made in many grades containing up to 12% nickel, up to 15 zinc, with usually also copper and silver, and from 30 to 80 gold The melting points of eight grades range from 1283 to 1553°F (695 to 845°C) Although a great variety of combinations can be made with numerous metals to produce white or silvery alloys, the name usually refers to the lead-antimony-tin alloys employed for machine bearings, packings, and linings; to the low-melting-point alloys used for toys, ornaments, and fusible metals; and to the type metals Slush castings, for ornamental articles and hollow parts, are made in a wide variety of soft white alloys, usually varying proportions of lead, tin, zinc, and antimony, depending on cost and the accuracy and finish desired These castings are made by pouring the molten metal into a metal mold without a core, and immediately pouring the metal out, so that a thin shell of the alloy solidifies against the metal of the mold and forms a hollow product A number of white metals are specified by the ASTM for bearing use These vary in a wide range from to 91% tin, 4.5 to 15 antimony, up to 90 lead, and up to copper The alloy containing 75% tin, 12 antimony, 10 lead, and copper melts at 363°F (184°C), is poured at about 707°F (375°C), and has an ultimate compressive strength of 16,150 lb/in2 (111 MPa) and a Brinell hardness of 24 The alloy containing 10% tin, 15 antimony, and 75 lead melts at 464°F (240°C) and has a compressive strength of 15,650 lb/in2 (108 MPa) and a Brinell hardness of 22 The first of these two alloys contains copper-tin crystals; the second contains tin-antimony crystals A white bearing metal produced under the name of Asarcoloy is composed of cadmium with 1.3% nickel It contains NiCd crystals, is harder and has higher compressive strength than babbitt, and has a low coefficient of friction It has a melting point of 604°F (317°C) SAE Alloy 18 is such a cadmiumnickel alloy with also small amounts of silver, copper, tin, and zinc A bismuth-lead alloy containing 58% bismuth and 42 lead melts at 254°F (123.5°C) It casts to exact size without shrinkage or expansion and is used for master patterns and for sealing Various high-tin or reverse bronzes have been used as corrosionresistant metals, especially before the advent of the chromium, nickel, and aluminum alloys for this purpose Trabuk was a corrosion-resistant, high-tin bronze with about 5% nickel Fahry’s alloy was a reverse bronze containing 90% tin and 10 copper, used as a bearing metal, and the Jacoby metal used for machine parts had 85% tin, 10 antimony, and copper The scarcity and high cost of tin WHITE METALS Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website ... g/cm3) for Ti-13V-11Cr-3Al, Ti-8Mo-8V-2Fe3Al, and Ti-3Al-8V-6Cr-4Zr-4Mo to 0.183 lb/in3 (5,065 kg/m3) for Ti11.5Mo-6Zr-4.5Sn, which is also known as Beta III They are also the least creep-resistant... near-alpha alloys and their performance benefits include Ti-8Al-1Mo-1V (high creep strength to 900°F), Ti-6Al-2Sn-4Zr-2Mo [creep resistance and stress stability to 1100°F (593°C)], Ti-6Al-2Cb-1Ta-0.8Mo... structural applications at 750 to 1000°F (400 to 540°C) Ti-5Al-2Sn-2Zr-4Mo-4Cr and Ti-6Al-2Sn-2Zr-2Mo2Cr: superior hardenability for thick-section forgings; high modulus—about 17 ϫ 106 to 18 ϫ 106