论文部分内容阅读
针对TC4钛合金电子束焊及TIG焊焊接接头的凝固组织、微观相结构及接头静载室温拉伸性能进行了对比研究。结果发现,TIG焊接头热影响区内为较粗大的等轴晶,焊缝区内凝固组织为粗大柱状晶,柱状晶粒生长方向由最初的垂直于焊缝-热影响区界面逐渐转为垂直向上生长。电子束焊接头组织形态同样是热影响区为等轴晶粒形态,而焊缝区内为柱状晶粒,等轴晶和柱状晶粒的尺寸较TIG焊均明显减小,且柱状晶生长方向始终垂直于焊缝-热影响区界面。TIG焊焊缝区原始β晶内的微观组织由魏氏α板条、针状马氏体α’以及β基体组成,而电子束焊焊缝原始β晶内的微观组织由大量细长针状马氏体α’+β基体组成。力学性能测试结果表明,电子束焊焊接接头的强度略高于TIG焊,塑性显著优于TIG焊。
Aiming at the solidification microstructure and microstructure of TC4 titanium alloy electron beam welding and TIG welding joint, the tensile properties at room temperature of the joint were studied. The results show that the coarser equiaxed grains in the heat-affected zone of TIG welding joint and the solidified microstructure in the weld zone are coarse columnar grains. The growth direction of columnar grains gradually changes from the initial perpendicular to the weld-heat affected zone interface to vertical Grow up. The electron beam welded joint morphology is also the heat affected zone equiaxed grain morphology, and the weld zone is columnar grain, equiaxed and columnar grain size is significantly reduced compared with TIG welding, and columnar crystal growth direction Always perpendicular to weld - HAZ interface. The microstructure of the original β crystal in the weld zone of TIG consists of Weisner’s α lath, acicular martensite α ’and β matrix, while the microstructure of the original β crystal in the electron beam welding seam consists of a large number of elongated acicular Martensite α ’+ β matrix composition. Mechanical properties test results show that the electron beam welded joints slightly higher than the TIG welding strength, plastic significantly better than TIG welding.