EFFECT OF Yb ADDITION ON THE MICROSTRUCTURE AND TENSILE PROPERTIES OF Mg-5Al ALLOY

In the present study, the effect of ytterbium (Yb) addition on the microstructure and tensile properties of Mg-5Al alloys was investigated. Experimental results showed that the microstructure of the Mg-5Al alloy consisted mainly of α-Mg and Mg₁₇Al₁₂ phases. In addition, an Al₂Yb phase was newly formed on the grain boundaries and its volume percent was increased with increasing Yb content. The tensile strength, yield strength and elongation were decreased at ambient temperature with increasing Yb content. At elevated temperature, however, the tensile strength and yield strength were significantly improved while the elongation was decreased.