铝合金圆锥形零件粘性介质温成形研究

Research on viscous pressure forming of aluminum alloy sheet conical part at warm temperature

采用热力耦合有限元数值模拟方法对铝合金圆锥形零件粘性介质温成形过程进行了模拟分析,研究了成形过程粘性介质和板材的温度分布、不同温度条件下成形零件壁厚分布、成形载荷等。结果表明,圆锥形零件的底部圆角区域为成形危险区域。非等温粘性介质温成形过程中,在粘性介质内部形成的非均匀温度场影响了板材的温度分布。当粘性介质温度略低于板材温度时,坯料中心区域温度较低,有利于延迟底部圆角成形时的破裂,提高了零件壁厚的均匀性。分别进行了室温和加热时铝合金圆锥形零件粘性介质压力成形试验,试验结果与数值模拟具有相同的规律。

Thermal-mechanical coupled finite element simulation was conducted for viscous pressure forming conical part made from aluminum alloy sheet at warm temperature. The temperature distributions of viscous medium and sheet metal were investigated in non-isothermal VPF. The wall-thickness distribution of sheet metal and forming load were also obtained at different forming temperatures. The bottom radius is the severely thinning area for the forming of conical part. In non-isothermal VPF, the non-uniform temperature field formed in viscous medium affects the temperature distribution of sheet metal The center region of sheet metal has lower temperature compared to the sheet near to die comer when the viscous medium temperature is lower than that of sheet metal, which is beneficial to postponing the fracture at bottom radius. The homogenization of sheet thickness distribution is improved. Finally, viscous pressure forming of conical part at room temperature and warm temperature were conducted. FE simulation results agree well with experimental observations.