TC4钛合金曲母线回转体蒙皮成形工艺

Forming process of rotary skin with curved generatrix for TC4 titanium alloy

以航天某型号薄壁曲母线回转体蒙皮为研究对象,通过对蒙皮结构分析,制定了分瓣热成形后再热校形的工艺方案,选择热成形及热校形温度为700℃,并基于材料线膨胀系数分析计算,得出热成形模具及热校形模具的设计尺寸,并通过热成形试验和热校形试验优化了成形工艺参数。结果表明:热成形保温保压时间为1000 s,成形后的零件弧度与样板间隙小于0.3 mm,满足后续焊接需要。不同预紧力和保温时间的对比试验结果显示,热校形的过程中使模具对产品施加一定预紧力,通过30 min的热校形,制造的蒙皮产品尺寸精度达±0.3 mm,证明了该工艺方法的可行性。

For the rotary skin with curved generatrix in aerospace,the technological scheme of first split thermoforming and then thermal sizing was developed by analyzing the skin structure,and the temperatures of thermoforming and thermal sizing were selected as 700℃.Then,based on the analysis and calculation of the linear expansion coefficient of material,the design dimensions of the thermoforming and thermal sizing dies were obtained respectively,and the forming process parameters were optimized by the thermoforming and thermal sizing experiments.The results show that when the heat and pressure holding time during the thermoforming is 1000 s,the gap between the arc of formed part and the template is less than 0.3 mm,which meets the subsequent welding needs.Furthermore,the comparison test results of different preloads and heat holding times show that the die applies a certain preload to the product during the thermal sizing process,and after thermal sizing of 30 min,the dimensional accuracy of the manufactured skin product reaches±0.3 mm,which proves the feasibility of this process.