Intermetallic compound produced by semi-solid processing from Al/Ni powder mixture and its mechanical strength at elevated temperature

To produce Al-Ni intermetallic compound, Al-42mass%Ni powder mixture was formed by back-forward extrusion at the temperature near to melting point of aluminum. The structure of alloy extruded at 910 K consists of Al₃Ni, Al₃Ni₂ and eutectic structure. In the alloy extruded at 1010 K, it consists of the intermetallic compound Al₃Ni and Al₃Ni₂. The volume fraction of each phase in the structure changes by the heat treatment, that is, the Al₃Ni phase increases with increase of heat-treating temperature and the eutectic structure disappears. High temperature deformation behaviors of these alloys were characterized by compressive test at various temperatures. The alloy of intermetallic compound containing the eutectic structure have large ductility, the eutectic structure transforms to Al₃Ni phase during the high temperature deformation and this transformation similarly occurs by the heat treatment at eutectic temperature. It was recognized that the compressive yield stresses in Al₃Ni and Al₃Ni₂ phases became higher with rising deformation temperature, it is referred to as "anomalous strengthening behavior of intermetallic compound".