Effects of rare earth element Y on the microstructure and mechanical properties of 2A12 aluminum alloy prepared by powder metallurgy method

The 2A12 aluminum alloys were prepared by powder metallurgy technology with the addition of rare earth element Y in the mass fraction of 0, 0.2%, 0.4%, and 0.6% in this study. The effects of Y addition on the microstructure and mechanical properties of 2A12 aluminum alloy were investigated by the metallographic analysis, X-ray diffraction, scanning electron microscopy, energy spectrum analysis, and mechanical properties tests, and the distribution characteristics of Y in aluminum alloy were studied. The results show that, when the mass fraction of rare earth element Y is 0.2%, the 2A12 alloys achieve the highest tensile strength and the best plasticity. The Y addition can inhibit the grain growth of aluminum alloy during sintering. In addition, most of Y is distributed in the grain boundary of aluminium matrix as YAl, Cu₂Y, and YAl₂, and a small part of Y is dissolved into the aluminum matrix.