high temperature chemistry of silicates and other oxide systems

... Composition of Superalloys 12 9 Rafting 13 0 Effect of Composition and Temperature on γ/γ Misfit Other Creep Equations 13 7 Summary 14 1 11 1 13 6 VII 8 .1 8.2 8.3 Deformation of Some Refractory Metals The Creep ... Mechanism of Strain at High Temperatures Physical Model and Theory 43 Velocity of Dislocations 45 Dislocation Density 49 Rate of the Steady-State Cr...

Ngày tải lên: 10/08/2014, 12:21

... 0. 02 0.05 – – 20 .1 14.0 9.5 19.8 12. 64 9 .29 0.70 1.65 4.47 2. 14 – – 2. 52 2.70 – 1. 42 – 9.90 – – 5 .26 9.10 – – – 2. 99 9. 82 4.54 – – – – 5. 12 – – – 0.006 0.003 0. 020 0.008 – – – 2. 04 – – 87.36 ... equal to gQ, where g= √ (2. 4) πη Q= e2 mc2 λ3 + cos2 2 |F |2 a6 sin 2 (2. 5) where η is the mean angle of misorientation of neighboring subgrains, Q is the reflectivity...

Ngày tải lên: 10/08/2014, 12:21

... 1 .3 6 .3 8.8 20.6 2.2 9.6 Metal T, K 137 0 Nb 1508 V 1096 σ, MPa N , 1011 m−2 24.9 29.4 35 .3 17.2 28.4 1.6 3. 1 3. 8 2.9 5 .3 29.4 34 .3 1.6 1.4 3. 6 Vacancy Loops and Helicoids 3. 6 Vacancy Loops and ... 2.1 2.6 3. 1 7.8 9.8 11.8 1.6 1 .3 1.1 2.2 2.7 3. 2 0.50 1096 5 .3 6 .3 7.4 24.5 29.4 34 .3 1.9 1.5 0.8 3. 6 4.1 4.4 0.55 1206 2.6 3. 7 4.2 12.8 17.2 19.6 2.2 1.6 1...

Ngày tải lên: 10/08/2014, 12:21

... (4. 1) F ρb2 (4. 2) High Temperature Strain of Metals and Alloys, Valim Levitin (Author) Copyright c 2006 WILEY-VCH Verlag GmbH & Co KGaA, Weinheim ISBN: 3-527-313389-9 44 Physical Mechanism of ... distinguishing feature of the high- temperature strain Fig 4. 1 The physical model of the steady-state strain at high temperature The sub-boundaries are built of t...

Ngày tải lên: 10/08/2014, 12:21

... of great practical importance Most 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 ... mechanism of Herring-Nabarro) at higher temperatures and relatively lower stresses It is necessary to emphasize that an adequate understanding of dislocation processes in the...

Ngày tải lên: 10/08/2014, 12:21

... value of 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 ... representative curves of high- temperature tests for two superalloys are shown in Figs 6. 4 and 6. 5 For superalloys it is often preferred to measure t...

Ngày tải lên: 10/08/2014, 12:21

... used the results of measurements of the particle sizes and the data of the strain rate tests 99 100 High- temperature Deformation of Superalloys Finally, the minimum strain rate of a superalloy ... particles and then cut them Hence, the thermally activated overcoming of particles is the process that controls the constant strain rate However, under the effect of appl...

Ngày tải lên: 10/08/2014, 12:21

... 33.5 8. 8 20.4 19 .8 20.0 20.6 30.9 23 .8 25.1 25.7 27.6 26.5 38. 1 38. 0 18. 3 18. 6 42.4 14 .8 10.2 14.4 21.4 58. 0 64.0 88 .3 103.0 106.0 1 18. 0 143.3 162 .8 163.3 2 28. 0 113 114 Single Crystals of Superalloys ... strength High Temperature Strain of Metals and Alloys, Valim Levitin (Author) Copyright c 2006 WILEY-VCH Verlag GmbH & Co KGaA, Weinheim ISBN: 3-527-313 38...

Ngày tải lên: 10/08/2014, 12:21

... mechanism of strain of the investigated superalloys There exists a competition between the Orowan mechanism of bowing of the dislocations between the γ particles and the cutting of particles by partial ... the high- temperature and low-stress creep of single crystals 7.4 On the Composition of Superalloys Some data about the influence of alloying elements on the streng...

Ngày tải lên: 10/08/2014, 12:21

... The minimum strain rate of niobium and molybdenum is dependent exponentially on the applied stress at high temperatures The mean value of the activation energy of the high- temperature strain for ... 0.3Hf The microstructure of extruded and recrystallized material consists of a solid solution and of particles of titanium carbide, TiC The particle sizes are between...

Ngày tải lên: 10/08/2014, 12:21

... 117 120 , 123 125 – influence of orientation on 114–119 Index – influence of stress on 120 – influence of temperature on 116–118, 120 – dislocation mechanisms of strain 119 127 , 129 – properties ... refractory alloys 151, 152 – in refractory metals 143–145, 147–150, 152 – in solid solutions 54 – in superalloys 86, 87, 95, 96, 116 120 , 124 , 125 – at higher temperatures...

Ngày tải lên: 10/08/2014, 12:21

... Cardona and others [1–5] studied the Raman and Infrared spectra of the superconductivity cuprate perovskites and reported the origin of phonon softening and the systematic vibrations of phonon ... Phonon Spectra of High Temperature Superconductor 54 An attempt has been made in this paper to study phonon frequencies in Bi2Sr2Ca2Cu3O10 high temperature supercondu...

Ngày tải lên: 07/08/2014, 14:20

... languages from all corners of the world, from the Fuegian of southernmost Chile to the Inuit of northernmost Alaska, and from the Maori of the remote Cook Islands to Siberian Yakut Some of them describe, ... (ntumpane) of the Kele in Congo, the xylophones used by the Northern Chin of Burma, the banging on the roots of trees practised by the Melan...

Ngày tải lên: 15/01/2014, 10:51

... credit opinion of a more narrow scope, including interest strips and return of principal Fitch Ratings – Definitions of Ratings and Other Forms of Opinion – Nov 2012 A.1 International Issuer and ... section Understanding Credit Ratings - Limitations and Usage for further information on the limitations of the agency’s ratings Fitch Ratings – Definitions...

Ngày tải lên: 16/02/2014, 03:20