Synthesis of intermetallic compound in isochronal heating of Al/Ni powder mixture and its forming

Hot working of intermetallic compound is difficult because of its high mechanical strength at high temperature, but it seems to be possible by the forming under condition of solid-liquid state that is formed by heating at fusion temperature of lower melting metal in powder mixture. This study was done on synthesis of intermetallic compound from the solid-liquid state when Al-(40-44)mass%Ni powder mixture was heated with various heating rates. The Al-Ni solid solution forms at lower temperature than the melting point of aluminum and then the solid-liquid state forms with high exothermic heat by fusion of the solid solution. After solidification from this state, microstructures of the Al-Ni alloy are constituted with Al₃Ni₂ and Al₃Ni intermetallic phases and eutectic structure. The same microstructure in the Al-Ni alloy backward-extruded under condition of the solid-liquid state is constituted as the isochronally heated powder mixture.