Increasing the formability of magnesium alloy sheet

镁的主要优点是密度比铝低得多，片状镁合金是增加汽车使用量的主要途径之一。然而，使用Mg片材的问题是其低的室温可成形性，这可以通过添加合适的合金元素和/或不同的方法来制造片材和由片材制造部件来克服。该提案研究了三种提高板材可成形性的方法：（i）添加钕、稀土元素（REE）和钙;（ii）对轧制板材进行专门的热处理，以在形成部件之前适当地软化板材;以及（iii）在部件形成操作期间软化板材。稀土元素在改善轧制镁的显微组织方面的作用是众所周知的，但还没有得到很好的理解，也远远没有得到优化。因此，这项工作将包括一个原子水平的计算方法来了解稀土元素和钙的影响，以设计稀土轴承合金与贫化学。专门的热处理方法需要专门的轧制来制造板材。因此，板轧制和随后的热处理之间的相互作用将进行研究和建模，以最大限度地提高可成形性。最后，在从片材形成部件期间片材的软化以前从未被考虑过，但由于当前的成形方法使片材经受“温暖”温度（约200摄氏度）而成为可能，并且这开辟了一些真正新颖的成形方法。

The chief advantage of magnesium is a density that is much lower than aluminum and Mg alloy in sheet form is one of the main routes to increased usage in cars. However, the problem of using Mg sheet is its low room temperature formability, which could be overcome by adding suitable alloying elements and/or different approaches to making sheet and making components out of sheet. This proposal investigates three approaches to increasing sheet formability: (i) additions of neodymium, a rare earth element (REE), and calcium; (ii) specialized heat treatments of rolled sheet to appropriately soften the sheet before forming the component and (iii) softening the sheet during the component forming operation. The effect of REE in improving the microstructure of rolled Mg is well known but not well understood and far from optimised. Thus, this work will include an atomic level computational approach to understand the effects of REE and Ca, in order to design REE bearing alloys with lean chemistries. The specialized heat treatment approach needs specialized rolling to make the sheet. Therefore, the interplay between sheet rolling and subsequent heat treatment will be studied and modelled to maximise formability. Finally, softening of the sheet during the forming of a component from the sheet has never before been considered, but is made possible because the current forming approach subjects sheet to 'warm' temperatures (about 200 centigrade), and this opens up some really novel approaches to forming.