CONSOLIDATION AND COMPRESSION PROPERTY OF NANOCRYSTALLINE NIAL SYNTHESIZED BY MECHANICAL ALLOYING

The mixture of pure nickel and aluminum powders in the composition of Ni50Al50 was subjected to high energy ball milling. The high energy ba ll milling to 30 h resulted in the formation of a nanocrystalline NiAl with a grain size of about 10 nm. The as-milled NiAl powder was hot-p ressed and the compact with a density of 90% was obtained. It was show ed that heating to 900 degrees C and holding for more than 2 h failed to induce the coarsening of the fine nanocrystal in the material, the tendency of grain growth was weak. Compression testing showed that the compression ductility at room temperature reached about 7%. The ducti lity increased with the experimental temperature while the strength de creased drastically at elevated temperature.