航空铝锂合金热成形研究进展

与传统铝合金相比,铝锂合金拥有更低的密度、更高的比强度、更好的耐腐蚀性,在航空、航天和航海领域得到了广泛应用。铝锂合金的优异性能归因于在铝基体中添加元素锂。但铝锂合金存在常温延伸率低、回弹大和各向异性强等问题,这些问题严重限制了铝锂合金的应用。为解决铝锂合金常温成形性差的问题,国内外学者针对铝锂合金热成形工艺开展了大量研究。本文首先介绍铝锂合金的发展,随后基于基础实验、失稳理论以及损伤理论三个方面介绍铝锂合金热成形研究进展,了解铝锂合金高温宏微观变形机理以及损伤演化规律,从而实现铝锂合金零件在高温条件下成形成性一体化控制；最后对航空铝锂合金热成形的发展趋势进行了展望。本文可为航空铝锂合金材料热成形生产工艺的制定提供一定的理论参考。

Research Process on Thermal Formability of Al?Li Alloys for Aeronautic Industry

The aluminum-lithium (Al-Li) alloys, which are characterized with lower density, higher specific strength and better corrosion resistance as compared with conventional aluminum alloys, had been widely applied in the fields of aviation, aerospace and navigation. A1-Li alloys exceptional properties are attributed to the addition of Li into the Al matrix. However, A1-Li alloys have problems such as poor formability, large rebound, and anisotropy at room temperature, which severely limit their applications. While the formability of Al-Li alloys could be effectively improved by heating. Schlors had made a lot of research on the hot forming process of Al Li alloys. This paper firstly, introduced the development of Al Li alloys and the research process on thermal formability of Al?Li Alloys based on experiments, instablity criterion and damage theory; aiming at obtained the macro and micro deformation mechanism and damage evolution law of Al Li alloys at high temperature. Additionally, thermal forming and ageing hardening of the Al-Li alloys would be integrated together to approach the target of shape forming and properties improvement of the parts. Finally, the development direction of thermal formability of Al?Li Alloys for aeronautic industry was prospected. This paper can provide a theoretical guidance for the application of the Al-Li alloys thermal forming process.