ZK60镁合金筒形件挤成形工艺研究

Study on Extrusion Process of ZK60 Magnesium Alloy Cylindrical Parts

摘要: 采用数值模拟和实验相结合的方式，对ZK60镁合金筒形件反挤压成形进行研究，优化工艺参数。结果表明：随着挤压温度的升高，镁合金内部晶粒细化程度越大，但温度越高动态再结晶程度愈不明显；坯料温度在290℃时最高应力可达400 MPa，零件整体应力大约在180 Mpa，380℃时最高应力为130 MPa，零件整体应力约为80 MPa；其次，随着坯料高度的减小和直径增大，成形中坯料的等效应力也随之增加，但尺寸过大或过小均会产生应力集中现象，容易产生缺陷。经过模拟分析和实验验证，坯料直径为φ70，坯料温度为350℃时，筒形件成形质量更佳。

Abstract: By means of numerical simulation and experiment, the back extrusion forming of ZK60 magnesium alloy cylinder was studied and the process parameters were optimized. The results show that with the increase of extrusion temperature, the internal grain refinement degree of magnesium alloy increases, but the dynamic recrystallization degree is less obvious with the increase of extrusion temperature. When the billet temperature is 290˚C, the maximum stress can reach 400 MPa, and the overall stress of the parts is about 180 Mpa. When the billet temperature is 380˚C, the maximum stress is 130 MPa, and the overall stress of the parts is about 80 MPa. Secondly, with the height and diameter of the billet decreasing, the equivalent stress of the billet in forming also increases, but too large or too small size will produce stress concentration phenomenon, easy to produce defects. Through simulation analysis and experimental verification, the forming quality of cylindrical parts is better when the billet diameter is φ70 and the billet temperature is 350˚C.