Grain Structure Formation in Ni 3 Al Intermetallic Compound Synthesized Under High-Temperature and Pressure Conditions

The paper presents theoretical and experimental results of studying the grain structure formation of the Ni 3 Al intermetallic compound produced by self-propagating high-temperature synthesis (SHS) under the pressure and volume exothermic reaction conditions, in a stoichiometric powder mixture. It is shown that the grain size in the SHS-produced intermetallic compound depends on both the preliminary load on the powder mixture and the SHS product deformation during its crystallization. It is found that the increased pressure on the initial powder mixture reduces the grain size in the bulk of the SHS-produced intermetallic compound, whereas its deformation provides a manifold decrease of the grain size at a simultaneous averaging of its distribution in the bulk of the SHS product obtained under pressure.