Effect of mechanical alloying on the structure and property of Ni3Al fabricated by hot pressing

Ni3Al intermetallics has been successfully made with mechanically alloyed powders with nominal compositions Ni–22.89 at.% Al–0.5 at.% B by hot pressing. The effect of mechanical alloying (MA) on the structure of elemental powders and the properties of hot pressing alloy has been investigated by X-ray diffraction, scan electronic microscopy, and bending test, etc. The results showed that the intermetallics prepared from milled powders exhibits high strength though low density in comparison with one prepared from elemental powders. The high density of defects brought during mechanical alloying and deficiently eliminated by following hot pressing led to the low hardness and density. Fine grains and dispersion of fine precipitation caused by mechanical alloying are related to the improvement of strength of alloy.