TC4钛合金激光对接接头超塑变形显微组织研究
Microstructure of Ti-6Al-4V Laser Butt Welded Joint in Superplastic Deformation
程东海， 陈益平， 胡德安
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作者单位：南昌航空大学 航空制造工程学院，江西 南昌 330063
中文关键字： TC4钛合金； 激光焊接； 超塑成形
英文关键字：Ti-6Al-4V alloy; laser welding; superplastic deformation
中文摘要：通过高温拉伸试验研究TC4钛合金激光对接接头超塑性变形，用金相显微镜观察了超塑性变形前后母材及焊缝显微组织，并测量了变形前后焊缝截面的显微硬度。结果表明：激光焊接接头能够承受高温拉伸，随着变形温度的提高或应变速率的降低，母材晶粒发生一定程度的长大，β与α两相比增加。在高温超塑性变形作用下，焊缝的针状组织增厚成为片层状，并发生局部区域球化。激光焊接接头性能优良，超塑性变形后焊缝截面显微硬度约380 HV。
英文摘要：Uni-axial hot tensile tests were used to investigate the superplastic deformation of Ti-6Al-4V laser butt welded joints. The microstructures of welded joints before and after superplastic deformation were observed by optical microscope. The results show that the grains of base metal grow coarser and the phase ratio increases as temperature increasing and velocity decreasing. The microstructure of weld bead changes shorter and wider, exhibiting globing trend at higher temperature. The microhardness of the center of weld bead after deformation is 380 HV.