Characterization of NiAl intermetallic produced by mechanical alloying and consolidated by spark plasma sintering

Bulk specimens of the NiAl intermetallic compound were produced by two different processing routes. In the first one, elemental powder mixtures were mechanically alloyed to produce powders of the intermetallic phase, which were subsequently hot consolidated by spark plasma sintering. In the second route, elemental powder mixtures were milled for times shorter than those required for the formation of the NiAl intermetallic; similarly, these mixtures were then processed by spark plasma sintering. Density, hardness and microstructure of the consolidated products resulting from both processing routes were characterized and compared. It was found that the second processing route yielded consolidated specimens having higher hardness, while with the first processing route slightly higher densification levels were achieved.