相图热力学计算在AM60-XGd镁合金设计中的应用

以相图热力学为基础,计算了Mg-6Al-XGd(质量分数,%,下同)镁合金的垂直截面图,200和500℃的等温截面图。根据相图设计了不同Gd含量的AM60-XGd(X为0%,0.8%,1.2%,1.6%和2.0%)镁合金。并且对不同Gd含量的AM60镁合金进行了显微组织观察、力学性能测试。结果表明,AM60合金组织随着稀土的加入得到细化。合金的抗拉强度和延伸率都得到显著提高。当合金中加入1.6%Gd时,合金表现出最好的显微组织和力学性能。

Application of Phase Diagram Thermodynamics Calculation for AM60-XGd Alloy Design

On the basis of the calculation results of Phase Diagram Thermodynamics, the phase diagrams of Mg-6Al-XGd alloy system including vertical section, isothermal section at 200 and 500 oC were calculated using Calphad software Pandat. Five kinds of AM60 alloys with different Gd additions (0wt%, 0.8wt%, 1.2wt%, 1.6wt% and 2.0wt%) were prepared and the microstructures and mechanical properties were investigated. The results show that the grain sizes of the tested alloys are greatly reduced by addition of Gd. The mechanical properties such as ultimate tensile strength (UTS) and elongation (EL) are also improved at room temperature. The alloy containing 1.6wt% Gd exhibits the finest microstructure and best mechanical properties