AMORPHIZATION OF TRANSITION METAL-SI ALLOY POWDERS BY MECHANICAL ALLOYING

Amorphization of TM-Si (TM: trasition metal) alloy powders by mechanic al alloying has been systematically investigated. Pure element powder mixtures were mechanically alloyed for ten hours with a high energy ba ll mill. The results show that amorphous metallic silicide powders wer e successfully synthesized in Ti-Si, Zr-Si, Nb-Si, and Ta-Si systems. Prediction of the amorphization range of mechanically alloyed TM-Si po wders by the Miedema model is inappropriate. The possible criteria for the amorphization of TM3Si powders after mechanical alloying 10 h in a shaker ball mill are (a) the free energy of amorphous state of TM3Si powders is less than - 31.95 kJ/mole, and (b) the silicon to trasitio n metal atomic radius ratio is less