热能场是提高构件可成形性和尺寸精度的主要途径.针对传统热源温度波动大的问题,将可控性好的激光热源引入薄板剪切旋压成形中,通过局部加热与局部变形匹配提高构件的可旋性和成形精度.基于现有旋压机搭建激光辅助剪切旋压平台,建立激光热源刚性连接下椭球面构件激光照射点漂移模型,分析激光热场加载最优区域.理论分析表明,对于截面圆半径变化较小的构件,刚性连接的激光热源可实现旋压过程精准加热.基于此,开展铝合金椭球面薄壁件激光辅助剪切旋压试验,结果表明与室温旋压相比,激光辅助剪切旋压可以显著提高难变形材料的可旋性,并明显改善铝合金椭球面薄壁件厚度和贴模度的精度.研究结果证明了所开发试验装置和工艺设计方法的可行性.

Thermal energy field is the main way to improve the formability and dimensional precision of components in sheet forming. In order to solve the temperature fluctuation of traditional heat sources, a well-controlled laser heat source was introduced into sheet metal shear spinning to improve the spinnability and forming accuracy by matching local deformation with local heating reasonably. Laser-assisted shear spinning facility was built based on the existing spinning machine, and a model of laser irradiation point drift of ellipsoidal components under the rigid connection of laser heat source was established to analyse the optimal region of laser thermal field loading. The theoretical analysis shows that, during laser-assisted spinning, the rigid connection can be deemed as precise heating under the condition of mandrel with small variation of section circle radius. Subsequently, laser-assisted shear spinning tests on the thin-walled aluminum alloy ellipsoidal components were conducted. The results show that, compared with cold spinning, the laser assisted method extends the spinnability of difficult-to-deformation material in shear spinning and significantly improves the precision and thickness of the spun thin-walled components, which verifies the feasibility of the developed test setup and process design method.