(1. 重庆理工大学 材料科学与工程学院，重庆 400050；
2. 重庆大学 材料科学与工程学院，重庆 400044；
3. 重庆科技学院 冶金与材料学院，重庆 401331；
4. 陆军勤务学院 化学与材料学院，重庆 401311)
摘 要: 为了促进镁合金大塑性变形技术的工业化，研究了一种正挤压与等通道挤压相结合的镁合金薄壁管材(Tube)挤压(Extrusion)-剪切(Shearing)-弯曲(Bending)(简写为TESB)连续塑性成形方法；采用有限元法对TESB变形过程进行计算机数值模拟。在挤压机上安装TESB成形模具，进行挤压成形试验，对挤出的管材进行微观组织观察及硬度测定，并对数据进行处理。结果表明：随着挤压速度的增大，管坯温度升高明显；随着预热温度升高及摩擦因数减小，挤压载荷会减小。TESB成形可以细化镁合金晶粒，提高TESB成形的均匀性；随着温度升高，镁合金管材硬度有所降低，但是与普通挤压相比，镁合金管材硬度明显上升，硬度最大值出现在剪切区和弯曲区交界位置。TESB成形是一种新型的镁合金管材大塑性变形方法，可以有效地细化晶粒、提高组织的均匀性。
关键字: 镁合金薄壁管材；大塑性变形；数值模拟；微观组织
（1. School of Materials Science and Engineering, Chongqing University of Technology, Chongqing 400050, China;
2. School of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
3. School of Metallurgy and Materials, Chongqing University of Science and Technology, Chongqing 401331, China;
4. School of Chemistry and Materials, Army Service College, Chongqing 401311, China）
Abstract:In order to promote the industrialization of large plastic deformation technology of magnesium alloy, an tube extrusion-shearing-bending (TESB) forming method of magnesium alloy thin-walled tube was studied by combining forward extrusion and equal channel angle extrusion. The deformation process of TESB was simulated by finite element method. The TESB forming die was installed on the extruder and TESB experiments have been done. In order to observe the microstructures of the extruded tube, the testing data were processed. The results show that the preheated temperature of tube increase with the rise of extrusion speeds obviously, and the extrusion loads decrease with the rise of preheated temperatures and the dropping of friction factors. TESB forming can refine the microstructures of magnesium alloy tube and improve the forming efficiency. TESB is a new method of large plastic deformation of magnesium alloy tube, which can effectively refine the grains and improve the uniformity of microstructures.
Key words: magnesium alloy thin-walled tube; large plastic deformation; numerical simulation; microstructure
