Decomposition and Crystallization of Intermetallics by High-Energy Mechanical Milling

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.