Densification behavior of mechanically alloyed NiAl powder compact during spark-plasma sintering and its mechanical property

Mechanically-alloyed NiAl powder was sintered by spark-plasma sintering (SPS) process. Densification behaviour and mechanical property were determined from the experimental results and analysis such as changes in linear shrinkage, shrinkage rate, microstructure, and phase during sintering process, Vicker´s hardness, and transverse-rupture-strength (TRS). Above 97% relative density was obtained after sintering at 1150 /spl deg/C for 5 min. Crystallite size determined by the Scherrer method was approximately 80 nm. From the X-ray diffraction analysis it was confirmed that the sintered bodies were composed mainly of NiAl phase together with Ni/sub 3/Al phase. Measured Vicker´s hardness and TRS value were 555/spl plusmn/10 H/sub v/ and 1393/spl plusmn/75 MPa , respectively.