(哈尔滨工业大学(威海) 材料科学与工程学院，威海 264209)
摘 要: 通过气压胀形实验研究AZ31/AA5083双金属筒形件气压胀形-冷缩结合工艺的基本成形规律。结果表明：双金属筒形件的适宜成形温度为450 ℃左右，双金属筒形件因两种金属热膨胀系数不同而收缩不同，在筒间形成过盈配合，筒间残余接触应力取决于双金属收缩量的差异，计算出筒间残余接触应力为2.96 MPa，接触应力过大会导致底部失稳凸起；同时，给出筒底凸起失稳发生的判据。降低成形温度、增大筒底圆角半径和保压冷却等能够防止内层筒筒底失稳；内外层筒形件壁厚不均匀，底部圆角处减薄率达到80%，最易发生破裂；加载路径对壁厚分布几乎没有影响。
关键字: 双金属筒形件；气压胀形；冷缩结合；残余接触应力
（School of Materials Science and Engineering, Harbin Institute of Technology at Weihai, Weihai 264209, China）
Abstract:The forming behavior of gas blow forming-cooling contraction bonding of AZ31/AA5083 bimetal cylinder was researched by gas blow forming tests. The experimental results show that the optimum temperature is about 450 ℃. The residual contact stress between bimetallic cylindrical components results from interference fit and is about 2.96 MPa. The excessive contact stress can lead to instability at the bottom of inner cylindrical component and the corresponding instability criterion is proposed. Decreasing forming temperature, increasing the round corner radius of bottom and cooling with the gas pressure can avoid the instability. The wall thickness distribution of internal and external cylinders is non-uniform and the thickness thinning rate of corners on the bottom reaches up to 80% and thus this location is the most vulnerable to rupture. With the same initial pressure and the maximum pressure, the loading path has no effect on the wall thickness distribution.
Key words: bimetal cylinder; gas blow gagforming; cooling contraction bonding; residual contact stress
