000202880 001__ 202880
000202880 005__ 20181203023641.0
000202880 0247_ $$2doi$$a10.1088/0965-0393/12/5/003
000202880 022__ $$a0965-0393
000202880 037__ $$aARTICLE
000202880 245__ $$aModelling diffusion in crystals under high internal stress gradients
000202880 260__ $$c2004
000202880 269__ $$a2004
000202880 336__ $$aJournal Articles
000202880 520__ $$aDiffusion of vacancies and impurities in metals is important in many processes occurring in structural materials. This diffusion often takes place in the presence of spatially rapidly varying stresses. Diffusion under stress is frequently modelled by local approximations to the vacancy formation and diffusion activation enthalpies which are linear in the stress, in order to account for its dependence on the local stress state and its gradient. Here, more accurate local approximations to the vacancy formation and diffusion activation enthalpies, and the simulation methods needed to implement them, are introduced. The accuracy of both these approximations and the linear approximations are assessed via comparison to full atomistic studies for the problem of vacancies around a Lomer dislocation in Aluminium. Results show that the local and linear approximations for the vacancy formation enthalpy and diffusion activation enthalpy are accurate to within 0.05 eV outside a radius of about 13 Angstrom (local) and 17 Angstrom (linear) from the centre of the dislocation core or, more generally, for a strain gradient of roughly up to 6 x 10(6) m(-1) and 3 x 10(6) m(-1), respectively. These results provide a basis for the development of multiscale models of diffusion under highly non-uniform stress.
000202880 6531_ $$acores
000202880 6531_ $$adislocation
000202880 6531_ $$asolids
000202880 700__ $$aOlmsted, D. L.
000202880 700__ $$aPhillips, R.
000202880 700__ $$0246474$$aCurtin, W. A.$$g211624
000202880 773__ $$j12$$q781-797$$tModelling And Simulation In Materials Science And Engineering
000202880 909C0 $$0252513$$pLAMMM$$xU12614
000202880 909CO $$ooai:infoscience.tind.io:202880$$pSTI$$particle
000202880 937__ $$aEPFL-ARTICLE-202880
000202880 970__ $$aolmsted_modelling_2004/LAMMM
000202880 973__ $$aOTHER$$rREVIEWED$$sPUBLISHED
000202880 980__ $$aARTICLE