metals and alloys for high temperature applications

... of thermophilic and mesophilic proteins at room temperature and increases with temperature, so as to allow for enzymatic activity near 100 °C It is only upon achieving these high temperatures that ... biotechnological and biocatalytic applications, where the opportunities are relevant to (a) how we might employ hyperthermostable enzymes for applications where extreme temperatures are required and (b) ... thermodynamics (i.e for endothermic reactions) would result in increased yields when the reaction is performed at high temperatures; (e) the reactions kinetics are faster at high temperatures; (f)...

Ngày tải lên: 07/03/2014, 05:20

... architecture for a bandgap based temperature sensor without an explicit bandgap reference is proposed It is power and area efficient and achieves excellent performance in the high temperature ... Pathrose, C Liu, K.T.C Chai and Y.P Xu, "A Time-Domain Bandgap Temperature Sensor for High Temperature Applications, ” (Accepted for publication in IEEE Transactions on Circuits and Systems II: Express ... reference forms the temperature sensor front-end Several topologies have been proposed for BGR with high performance Two BGR designs, one in the conventional temperature [27] and one in the high temperature...

Ngày tải lên: 09/09/2015, 11:33

... parts; piping applications; pipe fittings, steel; pressure containing parts; steel flanges; steel valves; temperature service applications, elevated; temperature service applications, high 16 Certification ... manufacturer and purchaser S11 Fatigue Acceptance Test S11.1 For alloy steel, except UNS K91560, components intended for service above 800°F (425°C), and for UNS K91560 components intended for service ... analysis for carbon, boron, columbium, and calcium shall conform to Table B A This table does not apply to heat analysis Product analysis limits for cobalt under 0.05 % have not been established and...

Ngày tải lên: 08/09/2016, 00:53

... materials, energy, technology, and information Metals and alloys are materials, which have been widely used by mankind for thousands of years, and this is no mere chance: metals have many remarkable ... Strain at High Temperatures Physical Model and Theory 43 Velocity of Dislocations 45 Dislocation Density 49 Rate of the Steady-State Creep 51 43 High Temperature Strain of Metals and Alloys, Valim ... Volume Plastic Deformation and Fracture of Materials 710 pages with 436 figures and 19 tables 1992 Hardcover ISBN 3-527-26819-7 Valim Levitin High Temperature Strain of Metals and Alloys Physical...

Ngày tải lên: 10/08/2014, 12:21

... by the X-ray method at high temperatures Pure metals, solid solutions and nickel-based superalloys have been studied 25 Structural Parameters in High- Temperature Deformed Metals 3.1 Evolution ... vanadium, niobium and molybdenum Nickel and iron are two of the most important materials for practical use and are applied as the base for numerous alloys for high- temperature operation Vacuum-melted ... values Qin and QT because the increase in temperature influences Q and the fraction in Eq (2.9) in opposite directions Measurements of Iin and Id as well as Iin and IT are performed for the same...

Ngày tải lên: 10/08/2014, 12:21

... substructure formation These peculiarities are seen well in Figs 3.4 and 3.5 27 28 Structural Parameters in High- Temperature Deformed Metals Fig 3.5 Structural parameters versus time and creep curve for ... kinks and loops that have been observed in this work for different metals show convincingly that the formation of jogs takes place during high- temperature deformation Assuming that the kinks and ... size and the subgrain misorientation at the beginning of the steady-state stage for face-centered metals are listed in Table 3.1 29 30 Structural Parameters in High- Temperature Deformed Metals...

Ngày tải lên: 10/08/2014, 12:21

... 42 Structural Parameters in High- Temperature Deformed Metals pure metals Larger values of η are observed in solid solutions as compared with metals Most of the dislocations in specimens ... Mechanism and Structural Model of Strain at High Temperatures 4.1 Physical Model and Theory It follows from the obtained data that complex processes occur in the crystal lattice at high- temperature ... compare these energies The values of Ev and Es are expressed as [18] Ev ≈ Es ≈ ρµb2 4π ρµb2 8π ln ln L b (4.1) F ρb2 (4.2) High Temperature Strain of Metals and Alloys, Valim Levitin (Author) Copyright...

Ngày tải lên: 10/08/2014, 12:21

... heat-resistant metals, steels and alloys operate at temperatures between 0.40 and 0.75 Tm The area of temperature and stress where the proposed mechanism of hightemperature deformation takes ... significance in the process of hightemperature strain for pure metals and solid solutions The upper stress limit of the sub-boundary stability depends upon the metal properties and temperature The lower ... Herring-Nabarro) at higher temperatures and relatively lower stresses It is necessary to emphasize that an adequate understanding of dislocation processes in these ranges of temperature and stress is...

Ngày tải lên: 10/08/2014, 12:21

... λ and increased value of D lead to the strain rate decreasing when the applied stress is relatively low 81 83 High- temperature Deformation of Superalloys 6.1 γ Phase in Superalloys The high- temperature ... relatively long tertiary deformation, which results in rupture The representative curves of high- temperature tests for two superalloys are shown in Figs 6.4 and 6.5 For superalloys it is often preferred ... resistance to high- temperature deformation This has created a need for alloys that can withstand higher stresses and temperatures for the hot zones of modern gas turbines The development has led,...

Ngày tải lên: 10/08/2014, 12:21

... stress and high temperature the rafting of particles occurs and the deforming dislocations can bow between the obstacles This results in accelerating tertiary creep and rupture 93 94 High- temperature ... ˙ stress for five superalloys are presented in Fig 6.16, where ln ε is plotted ˙ against σ Results for three alloys are shown in Fig 6.17 A linear dependence is observed for all superalloys Hence, ... 3.3W + 5Fe T = 1023K Data from Ref [32] 95 96 High- temperature Deformation of Superalloys Fig 6.17 Logarithm of strain rate versus stress for superalloys: B, Ni + 9Cr + 5.0Al + 2.0Ti + 1Nb + 12W...

Ngày tải lên: 10/08/2014, 12:21

... increase 107 108 High- temperature Deformation of Superalloys Fig 6.21 Predicted and actual relation between creep rupture stress for IN939 superalloy and its rupture life, tr Temperature of tests ... 7.2 Deformation of Single-crystal Superalloys at Lower Temperatures and Higher Stress Single-crystal superalloys have salient features in response to the applied stress conditions The deformation ... 110 High- temperature Deformation of Superalloys In a phase of type B3 A (Ni3 Al) Ti atoms occupy places in sublattice A Cr, Fe and Co atoms are located mostly in sublattice B Atoms of Mo, Nb and...

Ngày tải lên: 10/08/2014, 12:21

... γ/γ interface 123 124 Single Crystals of Superalloys 7.3 Deformation of Single-crystal Superalloys at Higher Temperatures and Lower Stress Increase in temperature up to 1223K results in a change ... for superalloys which must withstand high stresses at temperatures from 1273 to 1373K (GMSX-4, GMSX-10, TMS-138, Rene N6 and others) The reason for the positive influence of the Re and Ru additions ... typical for ther superalloys in the higher temperature, lower stress regime Macroscopic shear loading of the CMSX-6 superalloy results in slip in several microscopic systems of type {111} < 110 > and...

Ngày tải lên: 10/08/2014, 12:21

... to the highest stress level The development of superalloys for operation at temperatures up to 2073 K continues New classes of alloys attract investigators and engineers Refractory superalloys ... carbide possesses the highest melting point Tungsten–rhenium–hafnium carbide alloys seem to be promising for operation at high temperatures Fig 8.11 Effect of annealing temperature on applied ... Refractory Metals Fig 8.7 The measured activation energy of high- temperature strain for molybdenum Fig 8.8 The strain rate map for molybdenum with a grain size of 100µm Reprinted from Ref [26] 8.2 Alloys...

Ngày tải lên: 10/08/2014, 12:21

... experiments I am grateful to Dr V.I Babenko for his participation in the development of equipment for in situ X-ray studies High Temperature Strain of Metals and Alloys, Valim Levitin (Author) Copyright ... 35 – theory 157 – for metals 43–45, 67, 68 – for superalloys 95–97 – shear deformation 124, 125 e evolution of structural parameters – in matrix of superalloys 88, 89 – in metals 25–33 r rafting ... peculiarities 40 d deformation map – iron 64 – molybdenum 150 – nickel 63 – niobium 145 density of dislocations – differential equation 49–51, 77, 78 High Temperature Strain of Metals and Alloys, Valim...

Ngày tải lên: 10/08/2014, 12:21

... Oxide Thickness of high- k dielectric, εSiO2 and high- k are the permittivity of SiO2 (3.9) and the high- k dielectrics, respectively, and Thigh-k,phy is the physical thickness of the high- k film In ... Kcal/mol), and large band gap (5.7 eV) [2.22] The excellent 17   Chapter 2: Literature and Technology Review thermal stability and high band gap make it a promising candidate for high- κ dielectric ... voltage linearity and leakage current density The intermixing of HfO2 and Al2O3 to form Hf-Al-O dielectrics is investigated for the merits of high permittivity of HfO2 and high energy band-gap of Al2O3...

Ngày tải lên: 12/09/2015, 11:24

... Opportunities in Protection Materials Science and Technology for Future Army Applications Summary • Penetration mechanisms in metals and alloys, ceramics and glasses, and polymeric materials (Chapter 3) ... Materials Science and Technology for Future Army Applications OVERVIEW armor for face shields, vehicle windows, and other applications requiring transparency For each of these applications, system-level ... of material deformation and failure, as well as the necessary high- performance computing infrastructure; • Experimental facilities and capabilities to assess and certify the performance of new...

Ngày tải lên: 05/03/2014, 12:20

... that to be the case for most list and newsbrief documents and for many transcripts Beyond news data, this holds for case law documents, many types of financial documents, and others matic Condensation ... acceptability rate for magazine LEADs climbed to 92.50/0, still lower than for any other source Document length was a factor for LEAD acceptability for the entire test corpus, but list, newsbrief and transcript ... rating and assigning attributes to the 2,727 test corpus documents and LEADs I would also like to thank Breck Baldwin, Afsar Parhizgar, David Schmeer and Paul Zhang for their comments and suggestions...

Ngày tải lên: 17/03/2014, 07:20

... boundaries, and screw dislocations Particularly relevant to high- temperature environments is the bandgap energy of SiC At room temperature, the bandgap of 4H-SiC (the most attractive SiC polytype for ... C-face/SiC and MWCNTs and between the Ti layer and the MWCNTs where strong Ti-C bonds can form The reasons for the poorer adhesion between MWCNTs and the Si-face/SiC substrates are not entirely clear and ... SiC-Ag interface) and recording both thermocouple readings at each tested temperature and pressure For all experiments, the samples were allowed to dwell at the set temperature for 30 to ensure...

Ngày tải lên: 06/05/2014, 08:53

... in applications such as electronic and optical devices Metals and alloys have high- melting temperatures because of the heavy bonding between the atoms There are a variety of applications for metals ... some significant metals and important alloys have been analyzed and reported in this book This introduction chapter deals with the significance and applications of metals, alloys and semiconductors ... magnesium and its alloys suitable for use in missiles and automotive industry Magnesium alloys have low density (1.5–1.8 g/cm3) and high strength in relation to their weight (Kainer 2000) Magnesium alloys...

Ngày tải lên: 30/05/2014, 00:31

Ngày tải lên: 29/06/2014, 09:21