Microstructures and Mechanical Properties of Mg-8Al-1Nd-0.5Zn-xSr Alloys
The influence of trace strontium (Sr) addition on the microstructure and mechanical properties of Mg-8Al-1Nd-0.5Zn was investigated with OM, SEM, and XRD etc. The results show that the lamellar eutectics and divorced β-Mg17Al12 were reduced or refined with trace Sr addition. Among the as-cast Mg-8Al-1Nd-0.5Zn-xSr alloys, the Mg-8Al-1Nd-0.5Zn-0.05Sr alloy exhibited the best mechanical properties in which the tensile strength, the yield strength reached to 244.9 MPa and 111.7 MPa respectively. In addition, with the increase of Sr addition, the ductility was improved and it was observed that the number of cleavage steps and secondary cracks decreased on the fracture surfaces of tensile samples. It was also observed that the fractures occurred in the coarse β-Mg17Al12 phase instead of the Mg/Mg17Al12 interface or Al11Nd3 phase.
Yafang Han, Junpin Lin, Chengbo Xiao and Xiaoqin Zeng
B. L. Shi et al., "Microstructures and Mechanical Properties of Mg-8Al-1Nd-0.5Zn-xSr Alloys", Materials Science Forum, Vols. 747-748, pp. 282-288, 2013