铝合金局部热处理技术及其在板材成形中的应用发展现状

铝合金因具有密度低、比强度高、耐蚀性好、回收再生性好等诸多优点,在航空航天、汽车等领域获得广泛的应用。然而铝合金的室温成形性较差,常依靠加热辅助其成形,不仅增加制造成本,降低生产效率,而且严重降低产品表面质量,从而限制其在复杂结构零部件以及高端制造领域中的应用。而局部热处理技术能够有效制备具有梯度性能分布的铝合金差性板,可以改善板材的变形行为和与模具之间的接触摩擦作用,实现调控成形过程中材料的流动时序,从而提高铝合金的室温成形能力。本文系统论述铝合金局部热处理技术的工艺原理及特点,对材料微观组织和力学性能的影响规律,快速加热的实现方式及优缺点,热处理路径的选取、加热温度和保温时间等关键技术,以及在实际板材成形中的应用。详细介绍局部热处理软化和硬化对铝合金板材强韧化的作用和调控机制,对比分析局部热处理提高铝合金板材成形能力的实际效果,从而加快推进该技术在我国高端铝制品加工行业中的实践和应用。

Development Status of Tailored Heat Treatment Technology and Its Application on Sheet Metal Forming of Aluminum Alloys

Aluminum alloys have gained much attention in aerospace,military and automobile applica-tions because of their outstanding properties such as low density,high specific strength,and good damage tolerance compared with the other commercial alloys.However,the formability of aluminum alloy is poor at room temperature,thus a further heating process is necessary to improve its formabili-ty and manufacture complex shaped products.On the other hand,this leads to the increase of manu-facturing costs and the reduction of production efficiency and poorer surface quality of the product,re-stricts its application in complex structural components and high-end manufacturing fields.Therefore, the tailored heat treatment technology is used to address the above mentioned issues and significantly improve the formability of aluminum alloys at room temperature.In this paper,the characteristics and technical principles of tailored heat treatment technology for aluminum alloys were discussed.In addi-tion,the influence of the tailored heat on the microstructural evolution and mechanical properties of aluminum alloys,as well as,the means to achieve tailored heat treatment,besides the heat treatment layout and the application in the actual sheet metal forming were systematically reviewed.Further-more,the main microstructural mechanisms of tailored heat treatment on the softening and hardening behavior of aluminum alloys were introduced.Finally,the real effect of the tailored heat treatment on improving the formability of aluminum alloys sheets was analyzed and compared,in order to promote this novel technology to manufacture high-performance aluminum products in China.