航空发动机TC4机匣加工变形控制研究

航空发动机机匣零件的设计采用整体化、轻量化设计思想,使得结构复杂、规格尺寸大、薄壁特征多,而设计精度要求却在逐渐提高,机匣件加工后产生的变形问题尤显突出。探讨了薄壁结构机匣零件加工变形产生机理,提出分区去除余量控制加工变形的方法。使用Prism电子斑纹干涉钻孔残余应力仪测量了钛合金TC4机匣毛坯表层深度残余应力,通过有限元仿真结果预测出机匣毛坯内部残余应力分布规律。建立了机匣切削加工的有限元仿真模型并进行数值仿真,对两种工艺路线下的变形进行对比分析。最后,通过机匣的切削加工试验验证了仿真结果的正确性。

Study on Controlling Machining Distortion of Aeroengine TC4 Casing

Owing to such features as lightweight, integrity, the aeroengine casing evolves into complex structure, large dimension, thin walls. Associated with increasing requirement for accuracy, casing is prone to severe distortion after machining. This research investigated the mechanism of casing distortion and proposed a strategy of deformation control based on the allowance division. The surface residual stress of TC4 forging casing blank was measured by the ESPI (Elec-tronic Speckle Pattern Interferometry) technologies. Then, the inner residual stress distribution of TC4 casing was deduced from the ifnite element simulation. Machining process of TC4 casing was modelled and simulated. Two simulation strate-gies were proposed and optimized by comparing the deformation. Finally, the simulation result was veriifed by experiment for machining a casing under optimized plan in the workshop.