Handbook of Lubrication Episode 2 Part 1 pdf

calcium and ferrosilicon as deoxidizing materials. Aresulting low-melting ternary inclusion then spreads over the tool face in high-speed machining and acts as a diffusion barrier. Coated Tools In the late 1960s crater formation was found to be retarded by the vapor phase deposition of a very thin (0.0002 in., 5 µm) coating of TiC on a steel cutting grade carbide tool. It was later found that such coatings also tended to reduce the wear-land wear. The TiC coating provides a material in contact with the iron surface of the chip that is less likely to give up its carbon than WC. Use of such a coating avoids the tool-weakening effect associated with relatively large additions of TiC or TaC to the tool in bulk. Tools have also been coated with A1 2 O 3 and this material is thought to function as a diffusion barrier which is one of the mechanisms believed responsible for the success of the specially deoxidized steels. In addition to TiC, other coating materials is use include TiN, HfC and HfN. All of these appear to provide a more stable material relative to decomposition in the presence of hot iron and at the same time act as diffusion barriers. ATiN coating gives lower tool-face friction than TiC when cutting a low-alloy steel. Although TiC is more stable than WC there will be some decomposition of TiC. The carbon that is released will be absorbed by the low-carbon steel, thus strengthening it and causing an increase in tool-face friction. TiN does not appear to be as good a diffusion barrier as TiC, but when it decomposes the nitrogen released does not have as great a strengthening action on the steel as does carbon. This results in lower tool-face friction for a TiN coating than for a TiC coating. 13 Tools have also been coated with A1 2 O 3 which also acts as a diffusion barrier. The subject of tool coating is a rapidly developing and further important developments are expected. Cutting Fluids Cutting fluids have a dual role — cooling and lubrication. In high-speed cutting operations where the tool remains buried in the cut most of the time, such as in turning, the function of the fluid is primarily one of cooling. In low-speed operations involving intermittent cutting, such as in broaching or tapping, lubrication is important. Both water-base and oil base lubricants are used, the former are generally better coolants while the latter are better lubricants. There are many secondary considerations associated with cutting fluids such as chip disposal, corrosion prevention, health and safety considerations, etc. Adiscussion of these aspects of cutting fluid technology is to be found in Reference 14 and in the next chapter of this handbook. It is unlikely that anything but a vapor can penetrate the interface between chip and tool during a continuous cutting operation. This is due to the near perfect contact between chip and tool and the normally high-speed motion of the chip counter to fluid penetration. From the latter point of view it is unlikely that any penetration will be from the side of the tool (i.e., parallel to the cutting edge). CHIPFORMATION AND CHIPCONTROL Figure 15 shows several types of chips formed under different operating conditions. Discontinuous chip formation is shown at (a) and cutting with a large BUE is shown at (b). Cutting with the continuous ribbon-like chip previously discussed is illustrated at (c). When the work material is very soft and extensive, strain-hardening occurs during cutting or when the friction between chip and tool is high, the narrow shear zone shown in (c) assumes a fan shape as shown at (d). Cooling the back of the chip will frequently cause the chip to curl away from the tool (e) resulting in a decrease in the contact length between chip and tool. There is an optimum Volume II 349 335-356 4/11/06 12:34 PM Page 349 Copyright © 1983 CRC Press LLC MACHINING ECONOMICS In a single-tool turning operation, the machining cost per part will depend upon the rate of metal removal (Z · , in. 3 /min) or (mm 3 /min). (24) where V = cutting speed, fpm (m/mm); b = depth of cut, in. (m); t = feed rate, in./r (mm/v) = undeformed chip thickness. The depth of cut will normally be fixed by the amount of material to be removed, but the operator may select the values of speed (V) and feed (t). The cost to make a cut of ᐉin.(m) axial length on a bar of D in.(mm) diameter will be (25) where x = value of machine, operator and overhead (¢/min), T c = cutting time (min), T d = down time to change the tool (min), y = mean value of cutting edge (¢), T = tool life (min), and T w = work changing time (min). Item I = machine and labor cost per part, item II = tool and tool changing cost per part, and item III = work changing cost per part. Certain values of V and t will give a minimum cost per part and since an increase in t will cause a smaller decrease in tool life (T) than will an increase in V, it is advantageous to adjust t relative to machining cost before adjusting V. However, the cost optimum value of t usually lies beyond the practical range in turning. That is, the cost per part will decrease with increase in t, but before the cost optimum value can be reached, (t*), a constraint will be encountered such as finish, power, force on tool (breakage), chatter, surface integrity, etc. On the other hand, the cost optimum value of V (V*) usually lies within the practical range. For a constant value of t, the Taylor Equation 21 relates tool life (T) in min and the cutting speed (V) in fpm VT n = C, where n and C are constants. The value of cutting time (T c ) will be (26) where ᐉ, = axial length of cut, in. (m), D = diameter of work, in. (mm), and C 1 = a constant for a constant value of t. Volume II 351 FIGURE 16. Carbide chip curler used to pe- riodically break chips to simplify chip disposal. I = tungsten carbide insert. 335-356 4/11/06 12:34 PM Page 351 Copyright © 1983 CRC Press LLC Substituting Equations 21 and 26 into Equation 25: (27) The quantity (xT w ) may be considered independent of V. The cost per part (¢) will be a minimum when ∂¢/∂V = 0. This occurs when the cost optimum value of tool life is (28) For a carbide tool n ~ _ 0.2 and, therefore, T* = 4R if x = 10 ¢/min, T d = 10 min, and y = 100¢. Then, R = 20 min –1 and T* = 80 min. For a HSS tool, n ~ _ 0.1 while for a ceramic tool n ~ _ 0.4 and the corresponding values of T* in the above example would be 180 min (HSS) and 30 min (ceramic). When more than one tool is used, the value of R to be used is approximately the sum of the values of R for the individual tools. This results in the cost optimum tool life (T*) being greater the greater the number of tools used at one time. Manual Adaptive Control 18 is a technique for adaptiveiy controlling a machine tool with practically no investment in capital equipment beyond that required for ordinary machining. In this case, the operator acts as the group of sensors required in adaptive control and also serves as the interface between the machine tool and the low cost (~ $250) computer. After each tool change, he enters the time elapsed from the last tool change and the number of parts produced. The programed computer then tells the operator to increase or decrease the production rate in order to approach minimum cost per part. GRINDING Grinding is one of the most versatile methods of removing material from machine parts to provide precise geometry. However, the process is very complex and difficult to study because of the small size of the individual chips produced by hard abrasive particles having a wide range of shape, spacing, and relative elevation. Grinding operations may conveniently be classified in terms of whether the wheel is dressed or whether the wear of the wheel is sufficiently high that it is self-dressing. In form- and-finishing grinding (FFG), individual chips are relatively small and wear flats develop on the active grains in the surface. Periodically the dull grains are removed or “sharpened” by dressing the wheel with a diamond tool. Typical FFG operations are horizontal spindle surface grinding, internal grinding, cylindrical grinding, and centerless grinding. In stock removal grinding (SRG) wheel wear is relatively high and the wheel is self-dressing. Ex- amples of SRG are abrasive cut off processes, conditioning of slabs and billets in a steel mill and vertical spindle surface grinding. The rate of wear of a grinding wheel is usually important to the economics and performance of the process. In the case of SRG wear is usually expressed in terms of a grinding ratio (G). In such cases, the rate of change of wheel diameter is relatively large and G may easily be measured. In the case of FFG there is usually a negligible change in wheel volume during grinding and essentially all of the wheel consumption is associated with dressing. In such cases, the G = volume of work removed volume of work consumed 352 CRC Handbook of Lubrication 335-356 4/11/06 12:34 PM Page 352 Copyright © 1983 CRC Press LLC grinding ralio is not a convenient way of measuring wheel life. Instead, some means of accurately measuring the change in wheel radius, or alternatively some means of measuring the development of wear flats on the active abrasive grains must be devised. Such meas- urements are very difficult to make on a complete grinding wheel. Grinding Mechanics The mechanics of grinding is discussed in detail in Reference 19 and, therefore, only a few essentials will be reviewed here. Figure 17a shows a plunge surface grinding operation. The term plunge infers that there is no cross feed in the direction of the wheel axis. The wheel width is greater than the work width (b) and the wheel and work speeds are V and v, respectively. The wheel depth of cut is d. The mean undeformed shape of the chip is shown in Figure 17b, while Figure 17c shows the cross section of an undeformed chip at its midpoint. The maximum undeformed chip thickness (t) may be found as follows: (29) where C is the effective number of cutting points per square inch. The volume of a single chip can also be found by assuming the shape of the chip to be a long slender triangle, in which case Volume of single chip = 1 / 2 A _ ᐉ (30) where A _ is the mean cross-section of the chip (= b′t/2) and b′ is the effective chip width. It is convenient to define b′ in terms of the ratio (r) of chip width (b′) to chip thickness (t), thus (31) Substituting Equations 31 into 30 and equating the chip volumes from Equations 29 and 30: (32) Volume II 353 FIGURE 17. Undeformed chip shape in grinding. abc 335-356 4/11/06 12:34 PM Page 353 Copyright © 1983 CRC Press LLC The quantity t has been shown to be the most important quantity relative to grinding performance 20 and can be readily estimated if C, r′and ᐉare known. The difficulty in estimating C and some of the techniques used can be found in References 21 to 23. The length of scratch (ᐉ, Figure 17a) may be estimated as follows, if local wheel and work deflection are negligible (33) The value of t in FFG is generally about 100 µin. For such small cuts a very small part of the abrasive grain is active and the removal mechanism differs substantially from that of the concentrated shear mechanism that pertains in cutting (as shown in Figure 2). In fine grinding, the removal mechanism is more akin to that of an indentation hardness test. 24 Figure 18a shows the plastic zone that develops beneath a spherical indenter. 25 Figure 18b shows a typical blocky abrasive grain. Only a small percentage of such a grain produces a chip in fine grinding and the effective rake angle will be even more negative than that corresponding to the inclined faces at the lowest point on the grain of Figure 18b. Actually, the very small radius at the active point on the grain will be responsible for the effective rake angle as shown in Figure 18c. Here the action is likened to that of a spherical indenter subjected to an inclined load. The effective radius of this indenter will of course be much smaller than that of the dotted circle shown in Figure 18b. Material to the front of the indenter of Figure 18c will be plastic but unsupported and will flow upward to generate the chip. The consequences of the chip-forming mechanism shown in Figure 18c are the following: 1.Deformation of a much larger volume of material than escapes as a chip. 2.Considerably greater subsurface flow than with the cutting mechanism shown in Figure 2, leading to a greater tendency for subsurface cracking and for residual stresses in grinding than in cutting. 3.Agreater proportion of the total energy in fine grinding will end up in the workpiece surface than in metal cutting. In high speed cutting, 90% or more of the energy consumed ends up in the chip, while in fine grinding most of the energy ends up in the work (~80%). The fact that the specific energy in fine grinding is 50 times or more greater than that for cutting the same material is in agreement with the extrusion-like mechanism shown in Figure 354CRC Handbook of Lubrication abc FIGURE 18. Chip-forming mechanism in fine grinding and its relation to hardness indentation. 335-356 4/11/06 12:34 PM Page 354 Copyright © 1983 CRC Press LLC 18 as are other experimental observations. Also adding to the specific grinding energy is the fact that metal is pushed from side to side several times before leaving as achip. As the undeformed chip thickness (t) increases, a greater percentage of the abrasive particle is active and the effective rake angle increases. For SRG where chips are quite large, the removal mechanism approaches that of Figure 2 and there is much less danger of overheating the work since more energy consumed ends up in the chip rather than in the workpiece. In the abrasive cut-off operation, chips are relatively large and the specific grinding energy will be only about 1 × 10 6 in.lb/in. 3 (6.9 × 10 6 kPa) instead of about 30 × 10 6 in.lb/ in. 3 (207 × 10 6 kPa) for horizontal surface grinding and as much as 100 x 10 6 in.lb/in. 3 (690 × 10 6 kPa) for internal grinding. SURFACE INTEGRITY In many cases the quality of the finished surface is an item of major concern. This involves items such as 1. Surface finish 2. Residual surface stresses 3. Thermally induced damaged: oxidation and burning, overtempering, surface cracks 4. Mechanically induced surface cracks and highly strained areas (BUE) From the standpoint of brittle fracture and fatigue, any residual surface stresses should be compressive. When surface integrity is a problem, the use of sharp tools and cutting conditions to avoid BUE formation or overheating the surface are principal items for con- sideration. Since the cutting temperature varies as (V) 1/2 , high temperature problems are more apt to occur in grinding since V will normally be 6000 fpm (30 m/sec) or greater. When excess grinding temperatures are a problem, a shift to a lower wheel speed (~ 2000 fpm or 10 m/sec), use of a sharp wheel (frequent dressing), lower removal rates and an active oil-base lubricant will usually be helpful. In addition to the references cited above, References 26 to 35 provide further background concerning material removal operations. REFERENCES 1. Shaw, M. C., Metal Cutting Principles, MIT Press, Cambridge, 1954. 2. Merchant, M. E., Mechanics of the cutting process, J. Appl. Phys., 16, 267, 1945. 3. Piispanen, V., Lastumuodosiumisen teoriaa, Tek. Aikak., 27, 315, 1937. 4. Trent, E. M., Advances in machine tool design and research, Proc. 8th Machine Tool Design Res. Conf., Tobias S. A. and Koenigsberger, F. M., Eds., Pergamon Press, Oxford, 1967, 629. 5. Opitz, H., DerHeutige Stand der Zerspannungsforschung, WerkstatistechnikMaschinenbau, 46, 210, 1956. 6. Shaw, M, C., Wear mechanisms in metal processing, Proc. Int. Tribology Conf., MIT Press, Cambridge, 1979. 7. Taylor, F. W., On the art of metal cutting, Trans. ASME, 28, 31, 1907. 8. Vilenski, D. and Shaw, M. C., The importance of workpiece softening on machinability, Ann. CIRP, 18, 623, 1969. 9. McKenna, P. W., U.S. Patent 2,113,353, 1938. 10. Opitz, H. and Koenig, W., Ind. Anzieger, 87, 46 (Part I), 26, 1965; Ind. Anzeiger. 87, 845 (Part II); 43, 1965; Ind. Anmger, 87, 1033 (Part III), 51, 1965. 11. Sata, T., Chairman, Working Group on Machinability in Japan, Bull. 3(1), Japan Society of Precision Engineers, Tokyo, 1969. Volume II 355 335-356 4/11/06 12:34 PM Page 355 Copyright © 1983 CRC Press LLC 12. Tipnb, V. A. and Joseph, R. A., J. Eng. Ind., Trans. ASME, 93, 571, 1971. 13. Rao, S. B., Kumar, K. V., and Shaw, M. C., Friction characteristics of coated tungsten carbide cutting tools, Wear, 49, 353, 1978. 14. Shaw, M. C., Grinding fluids, Manuf. Eng. Trans., 1, 1972. 15. Henriksen, E. K., Balanced design will fit the chip breaker to the job, Am. Machinist, April 26, 1954. 16. Nakayama, K., A study on chip breaker, Bull, Jpn. Soc. Mech. Eng., 5(17), 142, 1962. 17. Subramanian, K. L. and Bhattacharya, A., Mechanics of chip breakers. Int. J. Prod. Res., 4(1), 37, 1965. I8. Shaw, M. C. and Komanduri, R., Manual adaptive control, Am. Much., 121, 205, 1977. 19. Shaw, M. C., Fundamentals of grinding, keynote paper, 1st Int. Grinding Conf., Carnegie Mellon Univ., April 1972, in New Developments in Grinding, Carnegie Press, Pittsburgh, 1972. 20. Snoeys, R., The significance of chip thickness in grinding, Ann. CIRP. 23(2), 227, 1974. 21. Brecker, J. N. and Shaw, M. C., Measurement of the effective number of cutting points in the surface of a grinding wheel, Proc. Int. Conf. Prod. Eng. Tokyo, 1974, 740. 22. Peklenik, J., Ermittlung von geometrischen und physikalischen Kenngrossen fur die Grundlagen des Schleifens, Dissertation T.H. Aachen, 1957. 23. Nakaysmua, K. and Shaw, M. C., Study of the finish produced in surface grinding. II. Analytical, Proc, Inst. Mech. Eng. (London), 182(3K), 182, 1967-1968. 24. Shaw, M. C., A New Theory of Grinding, Institution of Engineers, Australia, 1972, 73. 25. Shaw, M. C. and DeSalvo, G. J., The role of elasticity in hardness testing, Metals Eng. Quart., 12, 1, 1972. 26. Amarego, E. J. A., and Brown, R. H., The Machining of Metals, Prentice-Hall, Englewood Cliffs, N. J., 1966. 27. Boothroyd, G., Fundamentals of Metal Machining, McGraw-Hill, New York, 1975. 28. Ernst, H. et al., Machine Theory and Practice, American Society of Metals, Metals Park. Ohio, 1950. 29. Kronenberg, M., Machining Science and Applications, Pergamon Press, Oxford, 1966. 30. Trent, E. M., Metal Cutting, Butterworths, London. 1977. 31. Shaw, M. C., Ed., International Research in Production Engineering, American Society of Mechanical Engineers, New York, 1963. 32. Zorev, N. N., Metal Cutting Mechanics, Pergamon Press, Oxford, 1966. 33. CIRP, Yearly Proc. Int. Inst., Prod, Eng, Res., Paris, Ann. CIRP, 1952 to Present. 34. Machine Tool Design and Research - Yearly Proceedings of Conference held in Great Britain UMIST, Manchester, 1962 to Present. 35. Proceedings of Yearly North American Metal Working Research Conferences (NAMRC) Society of Man- ufacturing Engineers, Dearborn, Mich., 1972 to Present. 356 CRC Handbook of Lubrication 335-356 4/11/06 12:34 PM Page 356 Copyright © 1983 CRC Press LLC CUTTING FLUIDS Ralph Kelly and Gregory Foltz INTRODUCTION The primary function of any cutting fluid is to control heat. 1 A cutting tool generates temperatures of 375 to 750°C and the resulting chip as it slides up the tool face creates tremendous pressures (up to 1,379,000 kPa). About 75% of the heat is generated by de- formation of the metal, the other 25% by friction between the chip and the tool. By controlling the temperature generated in the cut zone, tool wear can be controlled and tool life increased. 2 As the cutting tool cuts (or the grinding wheel grinds), metal deforms by shear or plastic flow along a shear plane extending from the top of the tool to the surface of the metal (Figure 1). Below the shear plane is undisturbed metal; above it, the deformed metal forms a chip. Reduced friction at the chip-tool interface increases the shear angle, produces a thin chip, and deforms less metal. Where a tool face is examined under a microscope, rough peaks and valleys can be seen (Figure 2). These tiny projections collide with the chip as it slides up the tool face and weld to the chip under the conditions of very high heat and pressure. Continuous shearing of these welds results in tool wear, the tip of the tool becomes cratered, and heat concentrates at this point. Small pieces of sheared-off metal form a built-up edge on the face of the tool, a major cause of poor surface finish. When a cutting fluid is introduced between the tool and chip, friction is reduced, the shear angle increases, the chip becomes thinner, the power requirement is reduced, and less heat is generated. Also, the built-up edge disappears, the finish smooths out, and size control improves. The nascent metal exposed under the high temperature and pressure conditions reacts with chemicals in the cutting fluid to form a low shear strength solid between the chip and the tool. The chip slides freely up the tool face, tools last much longer, speeds and feeds can be stepped up, and more work can be done with each tool. The cooling and lubricating mechanisms are dependent on the job: slow-speed, slow-feed operations need more lubrication while high-speed, high-feed operations need more cooling. TYPES OF CUTTING FLUIDS 3 Cutting Oils A cutting oil contains mineral oil, fatty oil, or a combination of these. Mineral oils are petroleum derivatives; fatty oils are derived from animal or vegetable sources. Extreme pressure (EP) sulfur, chlorine, or phosphorus additives are employed to improve antiweld properties for heavy-duty applications. Sulfur forms a better lubricant, but chlorine is more reactive than sulfur and breaks down to form the EP lubricant at lower temperatures. Phosphorus is not as effective as either sulfur or chlorine and its use is less common. Cutting oils are often classified as active or inactive; an inactive oil will not darken a copper strip immersed in it for 3 hr at 100°C while an active oil will. Inactive oils are straight mineral oils, containing sulfurized fatty oils. Active oils are sulfurized or sulfochlorinated mineral or fatty oils. Straight mineral oil — Used for light-duty machining of ferrous or nonferrous metals, its major function is as the base fluid for the blends and additive oils listed below. Straight fatty oils — Very limited use because of their expense and frequent odor problems. They find their greatest application in blends with mineral oils. Palm oil, lard oil, and coconut oil are the most popular. Volume II 357 357-369 4/10/06 2:13 PM Page 357 Copyright © 1983 CRC Press LLC film in the machining process. This reduces friction and built-up edge, and provides antiweld properties. These oils are useful for machining tough, ductile metals. Reactivity of the sulfur makes them unsuitable for copper or copper alloys. Sulfo-chlorinated mineral oil — Combination of sulfur and chlorine additives produces products with exceptional antiweld properties over a wide temperature range. They are used for machining (especially threading) tough, low-carbon steels. Fatty oils added to this type of product produce a cutting oil for a wide range of heavy-duty and slow-speed operations. Cutting oils generally provide the excellent lubrication needed in low-clearance, low- speed operations; especially where a high quality surface finish is required. They have good rust control. Sump life is long since rancidity-causing bacteria do not grow in pure oil unless it is contaminated with water. The straight-oil cutting fluids do allow buildup of excessive heat, since oil dissipates heat only half as fast as water and because it is much more viscous than water-based fluids. These oils are also somewhat of a safety hazard in that they smoke and burn. In addition, their high misting properties cause the parts and surrounding area to become slippery and dirty. Emulsified Oils (Soluble Oils) These mixtures of mineral oil and emulsifiers (Figure 3) are supplied as concentrates which are added to water at the ratio of 1 part concentrate to 5 to 20 parts water. The oil is made soluble by emulsifying agents, primarily sulfonates. The emulsified particles range in size from 200 to 80 μm, large enough to reflect light and create a milky, opaque appearance when mixed with water. Premium grades may contain bactericides and corrosion inhibitors. Addition of fatty oils, fatty acids, or esters produces a superfatted emulsion for heavy-duty use on both ferrous and nonferrous metals. Sulfur, chlorine, or phosphorous, in addition to the fat, form an extreme pressure emulsion for very heavy-duty operations, including re- placement of straight cutting oil in some applications. Used as general-purpose products, soluble or emulsified oils offer lubrication because they contain oil, and the water aids in dissipating heat. Speeds and feeds can be stepped up and better size control obtained. Soluble oils have several disadvantages. When mixed with hard water, some soluble oils form a precipitate which is deposited on parts and machines, and which can interfere with filtration. In extreme cases, the emulsion may be broken. At strong concentrations, mist from a soluble oil can leave machines and work areas in a messy, slippery condition. Depending on the amount of rust preventives added, rust can be a problem. The water can support bacterial growth, leading to rancid odors and short sump life if proper bactericides are not present. Volume II 359 FIGURE 3. Emulsified oils (soluble oils). 357-369 4/10/06 2:13 PM Page 359 Copyright © 1983 CRC Press LLC [...]... Applicability of RCRA regulations is dependent on individual situations .25 Many additional state and local standards exist, covering all facets of the metalworking industry Responsibility for compliance lies with both the manufacturers and the users Copyright © 19 83 CRC Press LLC 357-369 4 /10 /06 2: 13 PM Page 369 Volume II 369 REFERENCES 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Cookson,... Society of Mechanical Engineers, New York, 19 72 Suskind, R., Occupational skin problems, J Occup Med., No 1, 39, 19 59; No 2, 11 9, 19 59; No 4, 23 0, 19 59 Ciesko, R., The Effects of Water Soluble Cutting Fluids on Operating Conditions in Machining, Tech Pap EM75-380, American Society of Mechanical Engineers, New York, 19 75 Russ, G A., Coolant control of a large central system, J ASLE, Preprint No 79-AM-2A -1, ... Reading, Mass., 19 71 Priest, W., Treatment of waste oil emulsions by ultrafiltration, Water Waste Treat., 21 , 42, 19 78 Vaughn, R L and Miller, H B., Cutting Fluids and Environmental Compatibility, Tech Pap MR70 714 , American Society of Mechanical Engineers, New York, 19 70 Bennett, E O., The biology of metalworking fluids, Lubr Eng., 28 , 23 7, 19 72 Rossmore, H W., Microbiological Causes of Cutting Fluid... Dearborn, Mich., 19 67 Joseph, J J., Cleaning metalworking fluids, Am Mach., 75, March 19 71 Brandt, R H., Fluid Longevity and Central Clarification Systems, Tech Pap MR74 -17 1, American Society of Mechanical Engineers, New York, 19 74 Bennett, E O., Water quality and coolant life, J ASLE, 30, 549, 19 74 Bennett, E O., The Effect of Water Hardness on the Deterioration of Cutting Fluids, Tech Pap MR 722 26, American... February 19 77 Merchant, M E., Fundamentals of cutting fluid action, Lubr Eng., 16 3, August 19 50 Dwyer, J J., Cutting fluids, Special Rep 548, Am Mach., 10 5, March 19 64 Kelly, R., Selection and Maintenance of Cutting Fluids, Tech Pap MR73 -11 0, American Society of Mechanical Engineers, New York, 19 73 Springborn, R K., Cutting and Grinding Fluids: Selection and Application, American Society of Tool and... grinding wheel and the work Copyright © 19 83 CRC Press LLC 357-369 4 /10 /06 368 2: 13 PM Page 368 CRC Handbook of Lubrication Only when a large volume of clean fluid bathes the tool and reaches the cutting zone are full benefits obtained from cutting fluids Relatively simple, inexpensive modifications to existing machine tools will often increase tool life as much as 10 0%, improve surface finish, give greater... production rates, and good size control Chemical solutions are stable, even in hard water Although they contain no oil, the chemical lubrication afforded through wetting agents does supply sufficient Copyright © 19 83 CRC Press LLC 357-369 4 /10 /06 3 62 2 :13 PM Page 3 62 CRC Handbook of Lubrication with products having low to moderate friction -reducing properties Some grinding can be performed with cutting fluids... tramp oil Copyright © 19 83 CRC Press LLC 357-369 4 /10 /06 366 2: 13 PM Page 366 CRC Handbook of Lubrication CUTTING FLUID APPLICATION Improved tool life, better surface finish, lower power consumption, greater accuracy, and efficient chip flushing can be achieved when clean fluid floods the cutting zone Generally, a large volume of cutting fluid at low pressure is most effective .22 Higher fluid pressures... Deterioration, Tech Pap MR74 -16 9, American Society of Mechanical Engineers, New York, 19 74 Mason J W., Cost Savings Through Cutting Fluid Selection, Tech Pap MR69 -25 9, American Society of Mechanical Engineers, New York, 19 69 ASME, Machine Design Considerations for Improving Metalworking Fluid Performance, Tech Pap MR7 625 2, American Society of Mechanical Engineers, New York, 19 76 Gettelman, K and Fisher,... Preprint No 79-AM-2A -1, 19 79 Tomko, J., Cutting Fluid Maintenance, Tech Pap MR 71- 804, American Society of Mechanical Engineers, New York, 19 71 McCoy, J S., A practical approach to central system control, J ASLE, preprint No 77-AM-1E-l, 19 79 Kulowiec, J J., Techniques for removing oil and grease from industrial wastewater, Pollut Eng., 49, February 19 79 Nemerow, N L., Liquid Waste of Industry, Theories, . Patent 2, 11 3,353, 19 38. 10 . Opitz, H. and Koenig, W., Ind. Anzieger, 87, 46 (Part I), 26 , 19 65; Ind. Anzeiger. 87, 845 (Part II); 43, 19 65; Ind. Anmger, 87, 10 33 (Part III), 51, 19 65. 11 . Sata,. Society of Mechanical Engineers, New York, 19 72. 10 . Suskind, R., Occupational skin problems, J. Occup. Med., No. 1, 39, 19 59; No. 2, 11 9, 19 59; No. 4, 23 0, 19 59. 11 . Ciesko, R., The Effects of Water. Pittsburgh, 19 72. 20 . Snoeys, R., The significance of chip thickness in grinding, Ann. CIRP. 23 (2) , 22 7, 19 74. 21 . Brecker, J. N. and Shaw, M. C., Measurement of the effective number of cutting