Peculiarities of plastic deformation of filamentary crystals

Keywords

thick single crystals, whisker crystals, plastic deformation, two-phase struc¬ture, stress, shear resistance.

Cite as

Kozak L. Yu. Peculiarities of plastic deformation of filamentary crystals. Physico­chemical Mechanics of Materials. 2022. 58(4), 037-044.

Abstract

The process of plastic deformation of single crystals at the atomic level according to the previously proposed discrete model is described. The single crystals are considered as a two-phase structure consisting of surface layers and inner regions of a perfect crystalline lattice. The effect of surface on the strength of single crystals of perfect structure is analyzed. As the proportion of the surface layer in the total volume of thick single crystals is small, the influence of the surface on their strength is very low. Increase of the number of defects after plastic deformation significantly increases their strength. On the other hand, due to the small size of whisker crystals, the surface has a significant influence, which makes them very strong. It is concluded that the mechanisms of plastic deformation at the atomic level are the same for both thin and thick crystals, despite the differences in their tensile diagrams.

 

References

1. Whisker Crystals: https://web.posibnyky.vntu.edu.ua/fmbt/suvak_novi_materiali_kompoziti/1-7.html
2. G. V. Berezhnova, Whisker Crystals[in Russian], Nauka, Kyiv (1969).
3. E. M. Nadgornyi, “Properties of whisker crystals,” Uspekhi Fiz. Nauk, 77, No. 2, 227 (1962).
4. L. Yu. Kozak, “New discrete model of plastic deformation of solid bodies,” Mater. Sci., 55, No. 4, 461–468 (2020).
5. L. Yu. Kozak, Alternative Concept of Solids’ Plasticity[in Ukrainian], Nation. Techn. Univ. Oil and Gas, Ivano-Frankivsk (2020).
6. V. I. Likhtman, P. A. Rebinder, and H. V. Karpenko, The Influence of Surface-Active Environment on Deformation Processes of Metals[in Russian], Publ. House of the USSR Acad. Sci., Moscow (1954).
7. Ya. I. Frenkel, Introduction into Theory of Metals[in Russian], Nauka, Leningrad (1972).
8. E. Shmidt, and V. Boas, Plasticity of Crystals, Especially of Metal Ones[in Russian], Publ. House of Foreign Lit., Moscow-Leningrad (1938).
9. W. H. Bragg, and W. L. Bragg, Crystal State[in Russian], Nauch. Tech. Publ. House of the USSR, Moscow (1938).
10. D. Gough Hanson, and S. J. Wright, “The behavior of single crystals of aluminum under static and repeated stresses,” Philos. Transact. Royal Soc., 226, 1–30 (1927).
11. F. R. N. Nabarro, Z. S. Bazinski, and D. B. Holt, Plasticity of Pure single Crystals[in Russian], Metallurgiya, Moscow (1967).
12. M. V. Klassen-Nekliudova, and T. A. Kontorova, “Nature of inercrystalline layers,” Uspekhi Fiz. Nauk, 22, No. 3, 143–151 (1939).
13. V. I. Arkharov, Yu. G. Skripka, and E. S. Markhasin, “The importance of the mechanism of forming interatomic bonds in alloys for their strength and plastic properties,” Sov. Mater. Sci., 14, No. 2, 151–154 (1978).
14. L. Y. Kozak, “Investigation of the instability of crystal lattices by using discrete models,” Mater. Sci., 53, No. 3, 424–430 (2017).
15. L. Y. Kozak, Plasticity of Metals and Instability of Crystal Lattice[in Ukrainian], Fakel Publ. House, Ivano-Frankivsk (2004).
16. S. Z. Bokstein, S. T. Kishkin, M. P. Nazarova, and I. L. Swetlow, Features of Hardening of Metallic and Non-Metallic Whisker Single Crystals[in Russian], Naukova Dumka, Kyiv (1972).
17. A. M. Belikov, Plastic Deformation of Whisker Crystals[in Russian], Voronezh Univ. Publ. House, Voronezh (1991).
18. T. Ogata, K. Ishikawa, K. Nagai, and T. Yuri, “Time-dependent deformation of austenitic stainless steels at cryogenic temperatures,” Cryogenics, 26, No. 6, 365–369 (1986).
19. S. N. Zhurkov, “Kinetic concept of solids’ strength,” Vestnik Acad. Nauk USSR, No. 3, 46–52 (1968).
20. U. F. Kocks, Kinetics of Nonuniform Deformation, Progress in Materials Science, Chalmers Anniversary Volume, Pergamon Press, Oxford, 19, 185–241 (1981).
21. G. A. Malygin, “Low-temperature instability of plastic deformation of metals,” Physics of Metals and Metallography, 40, No. 1, 21–28 (1975).
22. B. J. Brindley, and P. J. Worthington, “Yield-point phenomena in substitutional alloys,” Metallurg. Rev., 15, Is. 1, 101–114 (1970).
23. V. P. Alekhin, Physics of Strength and Plasticity of Surface Layers of Materials[in Russian], Nauka, Moscow (1983).
24. A. F. Ioffe, Physics of Crystalls[in Russian], Gosizdat, Leningrad (1929).