Effect of nickel particle size on the compaction behavior of rotator mixed and mechanically alloyed nickel and aluminum powders

Elemental powder mixing prior to processes such as self-propagating high temperature synthesis (SHS) is a vital processing step that needs careful consideration. This is particularly true for powders with submicron particle sizes. The present paper investigates the effect of mechanical alloying of mixtures of aluminum and nickel (with different nickel particle sizes) on the dispersion and cold compaction behavior of the composite powders. The concepts of the theory of plasticity of porous bodies are also employed to assess the influence of mechanical alloying (MA) on the theoretical yield stress of the composite powder compact. It was found that after mechanical alloying, the yield stress increased only for nickel powder sizes equal to and greater than 5 μm.