Abstract
In this study, the tensile properties and crystal structure by the addition of Ca with subsequent cast of AZX311 magnesium alloy which subjected to a multi-axis forging (MAF) process and rolled process were investigated. The yield stress and ultimate tensile strength of the cast of AZX311 magnesium alloy were 65 MPa and 119 MPa respectively, and elongation was 5%. The result of observation of the crystal structure, the average grain size of 480 μm in the coarse grains, dendrite structure had spread to network shape. The forged of AZX311 magnesium alloy which has been subjected to forging into cast material, the yield stress and ultimate tensile strength were 214 MPa similar, and elongation was 2.6%. Cause of the decrease in ductility is due to the insufficient broken and dispersion of the intermetallic (Al_2Ca) compounds by the MAF. The rolled of AZX311 magnesium alloy which has been subjected to rolling into forged material, the yield stress and ultimate tensile strength were 340 MPa and 351 MPa respectively, and elongation was 6%. The result of observation of the crystal structure, Al_2Ca compound was fine-dispersed in a lamellae shape by plastic flow. Therefore, strength and ductility is improved. From these, the found that as a strengthening mechanism of AZX311 magnesium alloy, Al_2Ca compound is an important factor.
