Microstructure and thermal property of AZ91 magnesium alloy prepared by powder metallurgy

AZ91 magnesium alloy was fabricated by powder metallurgy. The effects of sintering temperature on the relative density and thermal conductivity were investigated. The microstructure of the material was observed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The result shows that the best sintering temperature is 610 12. At this sintering temperature the relative density can reach 97.4% and the highest thermal conductivity can be up to 63.1 W·m^-1·K^-1. The sintering microstructure of the alloy is composed of α-Mg solid solution matrix and β-Mg₁₇Al₁₂. The β phase exhibits two main forms, i.e., divorced eutectic 13 phase and discontinuous precipitated β phase.