Effects of Mg Enhancement and Heat Treatment on Microstructures and Tensile Properties of Al2Ca-Added ADC12 Die Casting Alloys

The effects of Mg enhancement and heat treatment on the microstructures and tensile properties of Al2Ca-added ADC12 die casting alloys were investigated. 0.3% and 0.5% Mg in the form of a master alloy including a trace amount of Al2Ca were added to conventional ADC12 (383 and AlSi10Cu2Fe) alloy with an initial Mg-content of 0.3% to increase the Mg content to 0.6% and 0.8%, respectively. To avoid heat treatment-induced surface blisters, shortened solution treatment for 15 min at 490 °C and artificial aging for 6 h at 150 °C was undertaken. The results show that a 10% improvement in the shape factor of eutectic Si particles was achieved for Al2Ca-added ADC12 with 0.8% Mg compared to the conventional ADC12 in the as-aged condition. Al2Ca-added ADC12 with 0.8% Mg exhibited a yield strength of 289 MPa, a tensile strength of 407 MPa, and an elongation of 4.22%.