Influence of Ca Element on Microstructure and Mechanical Properties of AZ61-1.2Y

The effects of Ca element on the microstructure and mechanical properties of AZ61-1. 2Y alloy were investigated by microstructure observation, tensile tests and fracture analysis. The results show that, with the addition of Ca element, the microstructure of AZ61-1.2Y was obviously refined, high melting point Al2Ca intermetallic compound formed, and/3-Mg17 Al12 phase disappeared. With 1. 0% Ca addition, the values of tensile strength at 25, 150 and 175 ℃ reached their maxima simultaneously, 225, 182, and 175 MPa, respectively. Meanwhile, the values of elongation at room temperature and elevated temperature were also up to their peaks. The enhancement of the mechanical properties of AZ61-1.2Y with Ca can be attributed to the functions of grain refmement strengthening and dispersion strengthening.