Superplastic aluminium alloys contg. gallium - where superplasticity can be subsequently removed by diffusion heat treatment

摘要

Novel aluminium alloys having high ductility or superplastic properties at room temp. have a microstructure consisting of small grains surrounded by a thin layer of phase enriched with gallium. This phase pref. contains 15-20% Ga and the alloy grain size is 100 mu. The alloy is prepared by impregnating molten Ga into the alloy in an intergranular manner at is not 100 degrees C, and heating the alloy at 50-200 degrees C to eliminate the Al-Ga eutectic. The original properties of the alloy can be restored by heating at 100-300 degrees C to diffuse Ga into the grains.