Consolidation of Ni₃Ai powders by hot isostatic pressing

A series of hot isostatic pressing (HIP) consolidation experiments was performed on vacuum gas atomized powders of boron doped Ni₃A1 and Ni3A1 + Cr. The influences of time, temperature, and pressure on final densification were modeled by constructing HIP maps from reasonable estimates of input data based on available information; model predictions were found to be in good agreement with the experiments. Fine powders undergo final densification predominantly by diffusional mechanisms and densify more quickly than coarser powders for which densification is primarily controlled by power law creep. Tensile yield strengths of the consolidated alloys were comparable to values reported for fine grained aluminides produced by other means. Ductilities were somewhat lower than those determined for extrusion consolidated powders but could be improved by higher HIP temperatures or by post-consolidation heat treatment.