Effect of the pre-homogenization on the precipitation behaviors, mechanical and corrosion properties of as-extruded Mg Y binary alloys

Abstract

The effect and its mechanism of pre-homogenization of as-extruded MgY alloys on mechanical and corrosion properties are investigated by the tensile and compressive tests, immersion, and electrochemical tests. The pre-homogenized temperature would improve the mechanical properties of as-extruded alloys by influencing fine grain strengthening, precipitation strengthening, and solid solution strengthening. The higher Y content would accelerate the micro-galvanic effect of the second phases and the impurities to worse the corrosion resistance of the matrix. In contrast, the higher pre-homogenization reduces the micro-galvanic effect by decreasing the volume fraction. The as-extruded alloys (wt%) with pre-homogenization of 500 °C exhibit relatively excellent corrosion resistance due to the weaker micro-galvanic effect, the lower interface energy, and the strong {0002} 〈10−10〉 basal texture. Furthermore, the as-extruded Mg11Y pre-homogenizing at 500 °C performs superior mechanical properties attributing to the bimodal microstructure and the solid solution strengthening of Y