Influence of Various Melt Shearing Speeds on Macrostructure, Microstructure, and Tensile Properties of A380 Aluminum Alloy

The structure and tensile properties of A380 aluminum alloy were modified by intensive melt shearing for different shearing speeds. Three different speeds, including 600, 1200, and 1800 rpm, were employed to evaluate the effect of melt shearing speed on the macrostructure, microstructure, and tensile properties of A380 aluminum alloy. It was found that the size of grains decreased with increasing the shearing speed while porosity increased, especially beyond 1200 rpm. Moreover, the grain size of the alloy became more uniform. The microstructure of the alloy was also modified so that shearing led to the change of harmful coarse eutectic Si to fibrous Si and decreased both the length and aspect ratio of the brittle β-phase. These modifications caused the alloy to be more ductile and stronger, i.e., the strength and elongation percentage of the alloy increased up to shearing at 1200 rpm.