EFFECT OF AMBIENT-TEMPERATURE ON THE MA AND MG PROCESSES IN NI-ZR ALLOY SYSTEM

The mechanical alloying and mechanical grinding were carried out at three representative temperatures, i.e., one at low temperatures -180-120, the second at 25°C and the third at a high temperature of 200°C, using the mixture of pure Ni and Zr powders at 50 at.% proportion and the NiZr2 intermetallic compound, respectively. The higher the ambient temperature, the faster the amorphization proceeds in the case of the MA process. This is attributed to the increasing interdiffusion rate at the interface of the two metals. An increase in ambient temperature is found to be effective also in the amorphization due to the MG process. The defects, which are produced and equilibrate under the milling at high temperatures, are the likely cause for the energization and amorphization of the intermetallic compound NiZr2. © 1990 The Japan Society of Applied Physics.