Microstructures and phase compositions of as-cast and extruded ZK60-xBi (x = 0-1.64) alloys were investigated. Meanwhile, the tensile mechanical property and hardness were tested. With increasing the Bi content, the as-cast microstructure is first refined obviously, and then becomes coarse slightly. New small block compound which is rich in Zr, Zn, Bi and poor in Mg increases gradually, and MgZn 2 phase decreases gradually. The second phase mainly precipitates along the grain boundary. The as-cast tensile mechanical property is first enhanced obviously, where the tensile strength σ b , yield strength σ 0.2 and elongation δ can reach 265 MPa, 151 MPa and 13.5% for ZK60-0.23Bi alloy, respectively, then remains the high value for ZK60-(0.37-1.09)Bi alloys, and finally decreases obviously for ZK60-1.64Bi alloy. After hot extrusion, the obvious dynamic recrystallization occurs. Broken block compound distributes along the extrusion direction by zonal shape. The average grain size can reach only 4-6 μm. The extruded tensile mechanical property is enhanced significantly, where σ b , σ 0.2 and δ are at the range of 345-360 MPa, 285-300 MPa and 15.5-19.5%, respectively. Extruded tensile fracture exhibits a typical character of ductile fracture.
Huang, Z., Liu, W., Qi, W., Xu, J., & Zhou, N. (2015). Effects of Bi on the microstructure and mechanical property of ZK60 alloy. Journal of Magnesium and Alloys, 3(1), 29–35. https://doi.org/10.1016/j.jma.2014.12.005