SUSPENSION EFFECT OF NANOCRYSTALLINE GRAIN-GROWTH UNDER ELECTROPULSING

The effect of electropulsing on nanocrystalline grain growth in amorph ous material is considered. A size-dependent growth rate of a nanoscal e grain is revealed, which is due to the size-dependent electrical res istivity. A suspension effect is found when the density of electric cu rrent is at a critical value j(c). The formed grain may shrink when th e density of applied electric current is higher than j(c). Numerical c alculation shows that j(c) is about 2.59 x 10(3) A/mm(2) for nanocryst alline Ni80P20 alloy with grain size of 13 nm. (C) 1998 Acta Metallurg ica Inc.