Development of a magnesium alloy sheet with enhanced formability for vehicle lightweighting

镁合金具有低密度和高比刚度的特点，为汽车制造提供了极大的可能性 轻量化。与它们的使用相关的问题之一是它们在室温下的低成形性。在 在更高的温度下，由于附加的滑移系统的活化，它们的可成形性得到改善。然而，在这方面， 在高温下成形涉及额外的加工和能量成本，并延长了循环时间。 改善镁可成形性的另一种方法是控制其织构和微观结构。一种随机纹理， 以及细晶粒，导致孪晶减少和可成形性增加。通常情况下， 通过添加稀土元素（RE）作为合金元素获得织构。但这些 元件是昂贵的并且存在许多与其生产相关的环境和健康问题， 加工和利用。近年来，非对称轧制作为一种生产精细轧制的方法得到了研究， 各种金属板中的微观结构。在这个过程中，顶部和顶部之间的速度差 下辊引起剪切应力，促进再结晶，因此生产具有更细的 晶粒使用该方法生产的片材显示出改进的可成形性和良好的机械性能。在这 项目，研究非对称轧制镁合金板材的成形性能。两种常见 合金（AZ31和ZEK100）将被用作基准，并与将要开发的新合金进行比较。 这种新型合金由德国合作伙伴开发，旨在为汽车行业提供 具有改进的可成形性和机械性能的轻合金（其中铝的比例增加）， 合金）。在这个项目中进行的成形性研究将使我们的加拿大工业合作伙伴评估 基准镁合金板以及新合金板的潜在用途， 在室温和中等温度（高达250 °C）下冲压汽车零件。与 对轻量化汽车零部件的需求不断增长，新材料和新技术的研究项目 我们的工业必须在这个竞争激烈的市场中保持领导地位。

With their low density and high specific stiffness, magnesium alloys offer great possibilities for vehicle lightweighting. One of the issues associated with their use is their low formability at room temperature. At higher temperatures, their formability is improved due to the activation of additional slip systems. However, forming at high temperatures involves additional tooling and energy costs and lengthens the cycle time. Another way to improve magnesium formability is to control its texture and microstructure. A random texture, as well as fine grains, lead to a reduction of twinning and an increase in formabilty. Typically, more random textures are obtained by the addition of rare earths elements (REEs) as alloying elements. However, these elements are costly and there are many environmental and health issues associated to their production, processing, and utilization. Recently, asymmetric rolling has been studied as a way to produce fine microstructures in various metal sheets. During this process, the difference in speed between the top and bottom rollers induces shear stresses that promote recrystallization, therefore producing sheets with finer grains. Sheets produced using this process show improved formability and good mechanical properties. In this project, the formability of magnesium sheets produced by asymmetric rolling will be studied. Two common alloys (AZ31 and ZEK100) will be used as a baseline, and compared with a new alloy that will be developed. This new alloy is being developed by German partners with the aim of offering, to the automotive sector, a light alloy with improved formability and mechanical properties (with an increased proportion of aluminium in the alloy). The formability studies performed in this project will allow our Canadian industrial partner to assess the potential uses of the baseline magnesium alloy sheets, as well as the new alloy sheets, for the production of automotive parts by stamping at room temperature and moderate temperatures (up to 250°C). With the growing demand for lightweight automotive components, research projects on new materials and technology are mandatory for our industries to maintain their leadership in this highly competitive market.