AZ31+1.0Y+1.3Sr镁合金正方形截面壳体制件气胀成形工艺研究

Study on Bulging Forming Process of AZ31+1.0Y+1.3Sr Magnesium Alloy Box-shaped Parts with Square Cross Section

采用双辊连铸连轧工艺制造出了1 mm厚的AZ31+1.0Y+1.3Sr镁合金板材,使用其板材气胀成形了正方形截面盒型壳体制件,并对其工艺进行了研究。采用光学显微镜和扫描电镜对制件进行了显微组织分析,探索了镁合金变形机理和最佳成形条件。通过对制件壁厚分布和空洞组织分析,探究了正方形截面壳体制件变形过程和断裂机理。结果表明,连铸连轧的AZ31+1.0Y+1.3Sr镁合金板材在400℃、1.8 MPa气体压力下成形的零件是饱满的。

AZ31 ＋ 1.0Y＋ 1.3Sr magnesium alloy sheet with the thickness of 1 mm was manufactured by twin-roll casting （TRC）. Box-shaped shell parts with square section were formed by using the sheet and the bulging process. And the process was researched. The microstructure of the parts was analyzed with optical microscope and SEM. The deformation mechanism and optimum forming conditions of the magnesium alloy were explored. Through the analysis of the wall thickness distribution and cavity microstmcture, the deformation process and fracture mechanism of the square cross section shell parts are explored. The results show that the formed parts of AZ31 ＋1.0Y＋1.3Sr magnesium alloy sheet for continuous casting and rolling are full at 400 ℃ and the gas pressure of 1.8 MPa.