Increasing the formability of magnesium alloy sheet

镁的主要优点是密度比铝低得多，而片状镁合金是汽车使用量增加的主要途径之一。然而，使用镁板的问题是它的低室温成形性，这可以通过添加合适的合金元素和/或不同的方法来克服。本提案研究了三种提高板材成形性的方法：(i)添加钕，稀土元素（REE）和钙；（ii）对轧制板材进行专门热处理，使板材在成形部件前适当软化；（iii）在成形部件过程中使板材软化。稀土元素在改善轧制Mg微观结构方面的作用是众所周知的，但尚未得到很好的理解，也远未得到优化。因此，这项工作将包括原子水平的计算方法来了解稀土和钙的影响，以便设计具有低化学性质的稀土轴承合金。专门的热处理方法需要专门的轧制来制作板材。因此，板材轧制和随后的热处理之间的相互作用将被研究和建模，以最大限度地提高成形性。最后，以前从未考虑过板材在成型过程中的软化，但由于目前的成型方法使板材处于“温暖”的温度（约200摄氏度），这就开辟了一些真正新颖的成型方法。该提案包括所有将研究转化为实际应用的重要参与者，因为它是麦格纳国际公司（加拿大汽车零部件制造商），INFINIUM（新的“绿色”材料生产商，其投资组合中有镁和稀土元素），CanmetMaterials（加拿大政府实验室，拥有适当的规模设施和专业知识）以及橡树岭国家实验室之间的合作。他将从耐腐蚀的角度对优化合金的组成提出建议，这是在汽车中使用镁板的另一个主要障碍。

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.This proposal includes all the important players to make the research transfer to real applications, since it is a collaboration between Magna International, a Canadian car parts manufacturer, INFINIUM a new 'green' materials producer that has Mg and REE in it's portfolio, CanmetMaterials a Canadian government laboratory with appropriate scale-up facilities and expertise and Oak Ridge National Laboratories, who will advise on the composition of optimized alloys from the viewpoint of corrosion resistance, which is the other major obstacle to using Mg sheet in cars.