Effect of rare-earth additions on the microstructure and mechanical properties of die-cast mg alloys AE44-4 and AE44-2

镁合金AE 44-4设计用于高达约200°C的高温，但比钢和铝替代品更昂贵，因此竞争力较弱。这是因为AE 44-4中添加了高达4%的稀土元素，从而获得了良好的高温力学性能。一种相对较新的合金，AE44-2，是一种成本较低的配方，但其高温性能尚未得到彻底研究。通过进行实验室规模的控制铸造试验，表征微观组织，并在微观尺度上探测力学行为，我们将量化和报告凝固条件与铸态组织之间的关系，并为AE44-2和AE44-4镁合金的高温性能生成微观组织和温度相关的力学性能数据集。这些结果随后将被纳入研究团队的综合计算材料工程（ICME）模型，从而使我们的工业合作伙伴Meridian Lightweight Technologies Inc. （Strathroy， ON）能够对高压压铸AE44-2的空间变化和高温机械性能做出现实的预测，并将其与类似的压铸AE44-4和其他常见压铸镁合金进行比较。*该研究项目的成功完成将使我们的工业合作伙伴通过提高铸造优化能力和缩短AE44-2产品开发周期的能力，提高与其他Mg供应商和其他材料的竞争力。

The magnesium alloy AE 44-4 is designed for use at elevated temperature, up to about 200°C, but is more expensive, and thus less competitive, than steel and aluminum alternatives. This arises because the good high-temperature mechanical properties of AE 44-4 result from the addition of up to 4% rare earth elements. A relatively new version of the alloy, AE44-2, is a lower cost formulation but its elevated temperature performance has not been thoroughly investigated. By conducting laboratory scale controlled casting trials, characterizing microstructure, and probing mechanical behavior at the micro-scale we will quantify and report on the relationships between solidification conditions and as-cast microstructures and generate a microstructure- and temperature-dependent mechanical property dataset for the elevated temperature properties of the AE44-2 and the AE44-4 Mg alloys. These results will subsequently be incorporated into the research team's Integrated Computational Materials Engineering (ICME) models, thus enabling our industrial partner, Meridian Lightweight Technologies Inc. (Strathroy, ON) to make realistic predictions of the spatially varying, high-temperature mechanical performance of high pressure die cast AE44-2 and compare these to similarly die cast AE44-4 and other common die cast magnesium alloys.*Successful completion of this research project will give our industrial partner improved competitiveness over other Mg suppliers and other materials through improved casting optimization capability and the ability to shorten the AE44-2 product development cycle.