钛合金激光焊缝成形与显微组织分析
Weld formation and microstructure analysis of titanium alloy using laser welding
徐培全1，马春伟1，李永平2, 3，马丁1，张培磊1
点击：2329次 下载：0次
作者单位：1.上海工程技术大学 材料工程学院，上海 201620；2. 同济大学航空航天与力学学院 上海200092；3上海工程技术大学 航空运输学院，上海 201620
中文关键字：钛合金; 激光焊; 焊缝成形; 显微组织;
英文关键字：Titanium alloy; Laser welding; Weld formation; Microstructure;
中文摘要：为了揭示钛合金激光焊缝成形、组织分布,扩大激光焊工艺在航空工业中的应用,针对2mm厚TC4板材,利激光焊方法,在无填充材料和不开坡口条件下实现了TC4钛合金的激光焊接。利用光镜和扫描电镜分析了焊缝成形与显微组织形貌。结果表明：激光焊条件下,焊接工艺有很宽的适用窗口；激光作用下易腐蚀区表现出三种形态：梯形,双曲线和锥形；焊接过程中,分别在焊缝底部中心和近上表面发现焊缝中部气孔和熔合线气孔；显微组织主要是典型的α相+β相+针状α'马氏体的混合组织,发现明显的粗大的β相晶界；长时间腐蚀条件下,可见不同尺度的孪晶。
英文摘要：In order to disclose the titanium laser weld formation, microstructure distribution and enlarge the application of laser welding technique in aerospace industry, 2mm thickness TC4 titanium alloy weldment was obtained without groove and filler metal using laser welding. Optical microscope and Scanning Electron Microscope (SEM) were used to describe the weld formation and morphology. The results showed: welding process had a large adaptable range for titanium laser welding; three shapes were found in laser keyhole: trapezoids, hyperbola and cone. During the welding, fusion line porosity and weld central line porosity near top surface and lower surface were found. The typical microstructure consisted of α phases + β phases + needle α' martensite. Bulky β crystal boundary was also found ; different scale twins were emerged under long time corrosion.