Embrittlement of Al-Ga alloys, containing upto 25wt% Ga, was investigated by the tensile tests at various temperatures, optical microscope and SEM observation methods. The results obtained are as follows.
(1) At the range of temperature from -40°C to 100°C, the fracture stress of pure Al and Al-5wt% Ga alloy decreased slowly with increasing temperature, but that of alloys containing more than 10wt% Ga, even in solid solution, rapidly decreased at the range of temperature from 0°C to 30°C.
(2) The elongation of pure Al and Al-5wt% Ga alloy increased with increasing temperature, but that of Al-10wt% Ga alloy dropped suddenly over the range of temperature from 0°C to 30°C, and the elongation of Al-17wt% Ga alloy was little at the range of all over the testing temperature.
(3) The fracture of pure Al and Al-5wt% Ga alloy was of plastic type, but that of Al-10wt% Ga alloy was an intergranular cracking.
(4) The elongation of Al-10wt% Ga alloy increased with increasing temperature above 100°C.
From the above results, it is clear that the embrittlement trough exists in the solid solution Al-Ga alloy.