基于SIMA法的铝合金复杂构件触变锻造成形技术

采用半固态触变锻造技术成形铝合金构件,容易实现轻量化、低成本、短流程制造,因此在汽车、航空航天等领域应用广泛,但是对于高强铝合金复杂形状构件触变锻造存在半固态坯料制坯工序复杂、制件固液偏析严重和力学性能较弱等问题。基于SIMA制坯方法,提出了分级热处理、快速感应重熔和梯度等温处理等重熔工艺以及触变-塑变复合成形等新成形技术,优化了变形铝合金二次重熔半固态组织调控和触变锻造技术,获得了良好的半固态球晶组织并成形出合格的制件,最后提出了铝合金触变锻造成形中仍需解决的问题和发展方向。

Thixoforming Technology for Complex Aluminum Alloy Components Based on SIMA Method

Aluminum alloy components forged by semi-solid thixoforming technology have gained increasing application in the automotive and aerospace industries because of their advantages: easily achieved light-weight, low cost and short process manufacturing. However, for the thixoforming of high-strength aluminum alloy components with complex shapes, there are several disadvantages such as complex semi-solid billet fabrication, serious solid-liquid segregation and weak mechanical properties of forming parts. Based on SIMA semi-solid billet fabrication method, remelting processes were proposed such as multistep reheating regime, rapid induction heating and gradient isothermal treatment, as well as hixotropy-plastic composite forming and other new forming methods. The semi-solid structure control during remelting process and thixoforming technology of wrought aluminum alloy were optimized to obtain the fine semi-solid globular microstructure and form the qualified aluminum components. Finally, the problems and development direction of aluminum alloy thixoforming were proposed.