(1. 西北工业大学 凝固技术国家重点实验室，西安 710072；
2. 中国重型机械研究院有限公司，西安 710032)
摘 要: 基于开发的AZ31镁合金薄壁管分流挤压精确、高效的DEFORM−3D有限元模型，模拟揭示分流孔轴向倾角β对挤压力、焊合压力及模口处坯料金属流速均匀性的影响规律，并对β进行优化设计。综合考虑挤压力、材料利用率、焊缝焊合质量、管材尺寸精度及其应用环境等因素，获得该规格AZ31镁合金薄壁管分流挤压模具的合理分流孔轴向倾角取值范围为−5°~1°，最优分流孔轴向倾角为β≈ −5°(即内斜5°)。
关键字: AZ31镁合金；薄壁管；分流组合模；分流孔轴向倾角；数值模拟
（1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China;
2. China National Heavy Machinery Research Institute Co., Ltd., Xi’an 710032, China）
Abstract:Based on the developed precise and efficient DEFORM−3D model of the porthole extrusion process for the thin-walled AZ31 Mg alloy thin-walled tube, the influence laws of porthole axial angle β on the extrusion load, welding pressure and the uniformity of billet flow rate at the die export were investigated and revealed by the comprehensive numerical simulations, and the value of β was optimized. In integrated consideration of the extrusion load, the material utilization rate, quality of welding area and profiles size accuracy, and taking the tube application environment into account, it is proposed that the optimum β is −5°−1°, the most suitable value of β is about −5° for the AZ31 Mg alloy thin-walled tube profile die.
Key words: AZ31 Mg alloy; thin-walled tube; porthole die; porthole axial angle; numerical simulation
