ZL205A真空调压铸造有效应力控制与性能研究

Study on Effective Stress Control and Properties of Vacuum Pressure Regulating Casting ZL205A

为控制铸件在真空调压铸造凝固成形过程中平均应力大小,避免热裂发生,利用有限元分析软件ProCAST对ZL205A铝合金进行了温度场与应力场模拟,并针对浇注温度、模具预热温度、换热系数和模具壁厚等铸造应力影响因素展开研究,得到合理的铸造工艺,并进行试验验证,测试铸件性能。结果表明:模具预热温度、金属型换热系数、模具厚度和金属液浇注温度对铸件的影响程度由高到低依次减小,在试验条件下得到最佳工艺参数:浇注温度为700℃,模具预热温度为350℃,模具壁厚150 mm,换热系数为1000 W/m^2·K。通过试验验证,该工艺所得铸件组织均匀,表面光洁,抗拉强度可达525 MPa,屈服强度达462 MPa。

In order to control the average stress of the casting during vacuum pressure regulating casting solidification to avoid hot tearing,the temperature field and stress field of ZL205 A aluminum alloy were simulated by using the finite element analysis software ProCAST.The study was carried out on the factors affecting the casting stress,such as casting temperature,pre-heat temperature of metal mold,heat transfer coefficient as well as the thickness of metal mold.A reasonable casting process was obtained.The results show that:the influence degree of mold preheating temperature,heat transfer coefficient of metal mold,mold thickness and metal liquid pouring temperature on the casting decreases successively from high to low,and the best technological parameters under experimental conditions were obtained as follows:pouring temperature is 700℃,mold preheating temperature is 350℃,mold wall thickness is 150 mm,and heat transfer coefficient is 1000 W/(m2·K).The experiment verifies that the castings obtained by this process have uniform structure,smooth surface,and the tensile strength is up to 525 MPa and yield strength is up to 462 MPa.