Nanophase metallic alloys consolidated from powders prepared by mechanical alloying

Nanocrystalline metals and intermetallic compounds (Fe, Fe₃Al, Ni₃Al) have been prepared by mechanical alloying of elemental powders. This simple and inexpensive route yielded sufficient quantity of powders for consolidation experiments to produce bulk nanophase samples. By employing high pressure, relatively low temperature, and protective Ar atmosphere during hot pressing/forging, mechanically-alloyed nanophase metallic alloy powders have been consolidated to near full density (≥91% of theoretical density) with average grain sizes maintained to below about 20 nm. Contamination of oxygen and carbon in consolidated samples was below about 2 at.% in iron and about 1 at.% in intermetallics. Further improvement of processing steps to achieve full density and reduce contamination is discussed.