HIGH-PRESSURE SELF-PROPAGATING SYNTHESIS FOR PREPARATION OF NICKEL-ALUMINUM COMPOSITES

High pressure self propagating high temperature synthesis (SHS) betwee n nickel and aluminum powders (mixed in NiAl stoichiometry) is used fo r the synthesis of the intermetallic compound NiAl and NiAl-AlN compos ites. It is shown that the nature of the products is influenced by the morphology of the starting powders, the heating rate of the reaction and the nature of the pressure gas. This paper explains the effect of various material and processing parameters on the final sintered densi ty. The products of combustion were examined by using DTA analysis, X- ray diffraction, scanning electron microscopy and hardness tests.