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，为车辆轻量化提供了巨大的可能性。与它们的使用相关的一个问题是它们在室温下的低成形性。在更高的温度下，由于激活了额外的滑移系统，它们的成形性得到了改善。然而，在高温下成形涉及额外的工具和能源成本，并延长了周期时间。**提高镁成形性的另一种方法是控制其织构和微观结构。随机纹理，以及细晶粒，导致孪生减少和成形性的增加。通常，通过添加稀土元素（ree）作为合金元素，可以获得更随机的织构。然而，这些元素价格昂贵，而且与它们的生产、加工和利用有关的环境和健康问题很多。近年来，非对称轧制作为一种制造各种金属薄板微结构的方法得到了广泛的研究。在这一过程中，上辊和下辊之间的速度差异会产生剪切应力，从而促进再结晶，从而生产出颗粒更细的板材。采用该工艺生产的板材具有更好的成形性能和良好的机械性能。在这个**项目中，将研究不对称轧制生产的镁板的成形性。将使用两种常见的合金（AZ31和ZEK100）作为基准，并与即将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一种具有更好的成形性和机械性能的轻型合金（合金中铝的比例增加）。在该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能够评估基线镁合金板材以及新合金板材的潜在用途，通过在室温和中等温度（高达250°C）下冲压生产**汽车零部件。随着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对于我们的行业在这个竞争激烈的市场中保持领先地位是必不可少的。

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.