Decomposition and Crystallization of Intermetallics by High-Energy Mechanical Milling

Abstract

Structural transformations induced by high-energy ball-milling were studied in this work. It was found that amorphous Fe₉₀Zr₁₀ ribbons undergo crystallization into BCC α-Fe(Zr) under milling in a high-energy planetary ball-mill. Analyses of samples milled at different speeds suggested that the observed crystallization is a deformation-induced process rather than a thermally induced one. In addition, milling-induced structural transformations of CoSn and CoIn₂ intermetallics were studied. High-energy milling led to the decomposition of the CoSn phase into the high-temperature polymorph of Co₃Sn₂ and Sn(Co), whereas no evidence of the decomposition of CoIn₂ was found. These results may be attributed to high local stress during ball collisions which may make only those decomposition processes favorable, with which negative volume changes are associated.