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

AE44-4镁合金设计用于高温，最高可达200°C，但与钢和铝替代品相比，价格更高，因此竞争力较差。这是因为AE44-4良好的高温机械性能源于添加了高达4%的稀土元素。该合金的一种相对较新的版本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可控铸造试验、表征微观组织和探索微观力学行为，我们将量化和报告凝固条件和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一个随组织和温度变化的力学性能数据集。这些结果随后将被纳入研究团队的集成计算材料工程(ICME)模型中，从而使我们的工业合作伙伴子午线轻量化技术公司(Strathroy，ON)能够对高压铸造AE44-2的空间变化和高温机械性能做出现实的预测，并将这些预测与类似的压铸AE44-4和其他常见的压铸镁合金进行比较。成功完成这项研究项目将通过改进铸造优化能力和缩短AE44-2产品开发周期的能力，使我们的工业合作伙伴提高相对于其他镁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.