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，为汽车轻量化提供了极大的可能性。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 ** 更高的温度下，由于额外的滑移系统的激活，它们的可成形性得到改善。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。随机织构和细晶粒导致孪晶减少和可成形性增加。通常，通过添加稀土元素（RE）作为合金元素来获得更随机的 ** 织构。然而，这些元素是昂贵的，并且存在与其生产、加工和利用相关的许多环境和健康问题。最近，非对称轧制作为一种在各种金属板材中生产精细 ** 显微组织的方法进行了研究。在此过程中，顶部和 ** 底部辊之间的速度差引起剪切应力，促进再结晶，因此生产具有更细 ** 晶粒的片材。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。本计画主要研究非对称轧制镁合金板材之成形性。两种常见的 ** 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质合金（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 ** 基准镁合金板以及新合金板在室温和中等温度（高达250 °C）下冲压生产 ** 汽车零件的潜在用途。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 ** 对我们的行业来说是强制性的，以保持他们在这个竞争激烈的市场中的领导地位。

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.