The optimized tensile and fatigue properties of electromagnetically stirred and thermally transformed semi-solid 357 and modified 319 aluminum alloys

Abstract

The mechanical properties of 357 and modified 319 semi-solid formed (SSM) aluminum alloys are reported. Some alloys were electromagnetically stirred (EM) while other alloys were formed from ingot which was not stirred during solidification but had undergone a semi-solid thermal transformation (SSTT) during heating to produce a spherical microstructure suitable for semi-solid forming. The T4, T5 and T6 tensile properties were also optimized for both SSTT alloys using various aging studies of formed parts. The T6 fatigue properties of both SSTT alloys were also investigated. The SSM tensile and fatigue properties were superior to conventionally cast alloys and the properties of SSTT appear at least comparable to SSM prepared by EM.