tailieunhanh - Kinetics of Materials - R. Balluff_ S. Allen_ W. Carter (Wiley_ 2005) Episode 3

Tham khảo tài liệu 'kinetics of materials - r. balluff_ s. allen_ w. carter (wiley_ 2005) episode 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 68 CHAPTER 3 DRIVING FORCES AND FLUXES FOR DIFFUSION 17. J. Hoekstra . Sutton . Todorov and . Horsfield. Electromigration of vacancies in copper. Phys. Rev. B 62 13 8568-8571 2000. 18. p. Shewmon. Diffusion in Solids. The Minerals Metals and Materials Society Warrendale PA 1989. 19. . Larché and . Voorhees. Diffusion and stresses basic thermodynamics. Defect and Diffusion Forum 129-130 31-36 1996. 20. . Hirth and J. Lothe. Theory of Dislocations. John Wiley Sons New York 2nd edition 1982. 21. F. Larché and . Cahn. The effect of self-stress on diffusion in solids. Acta Metall. 30 10 1835-1845 1982. 22. . Cottrell. Dislocations and Plastic Flow. Oxford University Press Oxford 1953. 23. . Darken. Diffusion of carbon in austenite with a discontinuity in composition. Trans. AIME 180 430-438 1949. 24. u. Mehmut . Rehbein and . Carlson. Thermotransport of carbon in two-phase V-C and Nb-C alloys. Metall. Trans. 17A 11 1955-1966 1986. 25. . Cottrell and . Bilby. Dislocation theory of yielding and strain ageing of iron. Proc. Phys. Soc. A 49 49-62 1949. EXERCISES Component 1 which is unconstrained is diffusing along a long bar while the temperature everywhere is maintained constant. Find an expression for the heat flow that would be expected to accompany this mass diffusion. What role does the heat of transport play in this phenomenon Solution. The basic force-flux relations are Ji L11W1 Liq VT _ 1 __ Jq TqiV Ui Lqq VT Under isothermal conditions Ji LuVgi z Jq LqiV 11 Therefore using Eqs. and Jq Tãi Ji QĨ SJ1 nil The heat flux consists of two parts. The first is the heat flux due to the flux of entropy which is carried along by the mass flux in the form of the partial atomic entropy 81. Because 81 dS dNi a flux of atoms will transport a flux of heat given by Jq TJs Tsiĩỵ. The second part Is a cross effect proportional to the flux of mass with the proportionality factor being the heat of transport. As .