(1. 哈尔滨工业大学 材料科学与工程学院，哈尔滨 150001;
2. 哈尔滨工业大学 金属精密热加工国防重点实验室，哈尔滨 150001；
3. 南京航空航天大学 机电学院，南京 210000)
摘 要: 在一定的温度范围，以高压气体作为传力介质，通过温度、内压和补料量匹配加载使管坯贴膜的热加工技术，称为高压气胀成形技术。在800 ℃时，以不同加载路径和不同补料量对TA18管材进行胀形实验，研究加载路径和补料量对50%膨胀率TA18钛合金变径管的成形过程和壁厚分布的影响。结果表明：在补料阶段，内压过小或者过大引起材料在变径管过渡区堆积起皱；不同轴向补料量成形的TA18变径管，壁厚分布规律不同；在合适的加载路径下，分别补料20、30、36和40 mm得到的TA18变径管的最大减薄率分别为29.07%、24.01%、18.15%和13.02%。
关键字: TA18钛合金；高压气胀成形；轴向补料；变径管；壁厚分布
（1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology,
Harbin 150001, China;
3. Mechanic and Electric Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210000, China）
Abstract:At a certain temperature range, the tube blank is bulged out until it attaches to the inside of mould cavity by high pressure gas, matching with axial feeding. This plastic forming processing is called high pressure pneumatic forming (HPPF). At 800 ℃, the 50% expansion ratio tubes of TA18 titanium alloy were formed with different loading paths and different axial feedings. The results show that the wrinkles are formed in the transition zone of tube because the materials are accumulated when the inner pressure is too high or too low. The thickness of adjustable tubes with different axial feedings is changed. At the appropriate loading path, TA18 adjustable tubes without defects are formed with axial feeding of 20, 30, 36 and 40 mm, and their maximum thinning ratio are 29.02%, 18.73%, 13.41% and 10.49%.
Key words: TA18 titanium alloy; high pressure pneumatic forming; axial feeding; large expansion ratio tube; wall thickness distribution
