High-temperature creep

Energies of the vacancy generation Ey and vacancy diffusion Uy in crystal lattice turn out to be a controlling factor of a material resistance to strain at high temperatures. These factors are affected by strength of interatomic bonding. 

Interatomic Bonding in Solids Fundamentals,Simulation,andAppUcations, First Edition. Valim Levitin. 

I would like to show compactly in this chapter stages of a physical research  

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Superalloys high temperature creep-resisting alloys based on Ni, Co, and including (here) the Nimonic series. 

Kohlstedt D. L. and Goetze C. (1974). Low-stress high-temperature creep in olivine single crystals. J. Geophys. Res., 79 2045-2051. 

Tubes seldom fail because of external oxidation, and tubes rarely burn up. They fail because of high-temperature creep, which causes the tube to expand and burst. Thus, the fundamental cause of tube failure is a high localized temperature, which is called a hot spot. ... 

Identification of hot spots. Localized overheating of a tube causes localized high-temperature creep. This leads to the plastic deformation of a tube, and hence thin tube walls. Such hot spots are indicated by the color of the tube, as shown in Table 21.1. This chart is not a function of... 

Dislocation climb only becomes of practical significance at elevated temperatures because of its dependence upon vacancies whose number and mobility depend very strongly on the temperature. Dislocation climb is important in high temperature creep and recovery phenomena. See Fig. 13. 

Tins concept of a liquid as an iin wr)eci crystal requires that the molecules ill a liquid are packed sufficiently loosely for comparatively free movement, i.e. the energy required to move a molecule from a lattice site to a vacant space is not large compared with thermal energies. Under these conditions, shear (low ol the liquid resembles closely Ihe high temperature creep of crystalline solids. A number of theories of the liquid state have this concept as their Mailing point. 

Yoshida, H., Okada, K., Ikuhara, Y., and Sakuma, T., Improvement of high-temperature creep resistence in fine-grained A1203 by Zr4 segregation in grain boundaries , Phil. Mag. Lett., 1997, 76, 9-14. 

HP microalloys were developed during the 1990s. The microalloys enhanced carburization resistance and improved high-temperature creep-rupture resistance.88... 

D. A. Koester, R. D. Nixon, S. Chevacharoenkul, and R. R. Davis, High Temperature Creep of SiC Whisker-Reinforced Ceramics, in Proceedings of the International Conference on Whisker- and Fiber-Toughened Ceramics, eds. R. A. Bradley, D. E. Clark, D. C. Larsen, and J. O. Stiegler, ASM International, Metals Park, OH, 1988, pp. 139-145. 

R. Morrell and K. H. G. Ashbee, High Temperature Creep of Lithium Zinc Silicate Glass-Ceramics, Part 1, General Behavior and Creep Mechanisms, /. Mater. Sci., 8, 1253-1270 (1973). 

Stress Distribution and High Temperature Creep Rate of Discontinuous Fiber Reinforced Metals, Acta Metallurgies et Materialia, 38, 1941-1953 (1990). 26. A. G. Evans, J. W. Hutchinson, and R. M. McMeeking, Stress-Strain Behavior of Metal Matrix Composites with Discontinuous Reinforcements, Scripta Metallurgica et Materialia, 25, 3-8 (1991). 

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