The microstructure of Ti-50at%Ni vacuum-sintered compact was investigated in relation to the particle size of powders and the sintering temperature. The green compacts of [TiH2+Ni] powders ball-milled for various times were sintered in vacuum of 10m-3Pa at 1273-4473K for 3.6ks.
It was found that the sintered compact obtained was almost free from micropores, when the particle size of TiHm2 in the milled powders was smaller than about 3 μm (particle size of Ni was 2 μm) and the sintering temperature was between 1423-4473K. The microstructure of compact, however, was not consisted only of TiNi phase, but Tim4Nim2Ox (x ?? 1) and TiNim3 phases were generally formed due to the increase in the oxygen content of compact with decreaing the particle size of TiH2.