|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Magnesium Alloy Development: An LMD Symposium in Honor of Karl Kainer
||Development of Magnesium-Rare Earth Die-casting Alloys
||Mark Easton, Mark Gibson, Suming Zhu, Trevor Abbott, Jian-Feng Nie, Colleen Bettles, Gary Savage
|On-Site Speaker (Planned)
An overview of the development of a high performance Mg-RE based alloy, HP2+, is presented, which has a good combination of die castability and mechanical properties at ambient and elevated temperatures. The original alloy, HP2, was a die-casing version of the sand-cast alloy SC1 developed for powertrain applications. However, HP2 tended to crack substantially, leading to unusable castings. It was found that the solidification path of Mg-RE alloys can be engineered to reduce the propensity to hot tearing by changing the mixture of rare earth elements towards La-rich, which led to an increase in the amount of eutectic and a reduction of the solidification range. Precipitate-forming REs, such as Nd or Y, were optimized for HP2+ to meet the requirement for high temperature creep resistance. Whilst some challenges remain with the commercial application of HP2+, the learnings from the alloy design process can be applied to other alloy development programs.