TC4钛合金激光焊缝成形与显微组织分析  

Weld Formation and Microstructure Analysis of TC4 Titanium Alloy Using Laser Welding

作　　者：徐培全[1] 马春伟[1] 李永平[2,3] 马丁[1] 张培磊[1] 

机构地区：[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

出　　处：《热加工工艺》2012年第11期207-209,共3页Hot Working Technology

基　　金：国家自然科学基金项目(51105240);上海市自然科学基金项目(10ZR1412900)

摘　　要：针对2mm厚的TC4钛合金板材,在无填充材料和不开坡口条件下对其进行激光焊接。利用光镜和扫描电镜分析了其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;其焊缝易腐蚀区表现出三种形态:梯形、双曲线和锥形;焊接过程中,易在接近上下表面的焊缝中部和熔合线出现气孔;焊缝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,在长时间腐蚀条件下可见不同尺度的孪晶。Aiming at TC4 titanium alloy weldment with 2 mm thickness,laser welding was carried out without groove and filler metal.Optical microscope and scanning electron microscope（SEM） were used to describe the weld formation and morphology.The results show that the welding process has 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 microstructure consists of α phases ＋β phases ＋ needle α＇ martensite.Bulky β crystal boundary is also found;Different scale twins emerge in long time corrosion.

关 键 词：钛合金 激光焊 焊缝成形 显微组织 

分 类 号：TG456.7[金属学及工艺—焊接] TG146.23[一般工业技术—材料科学与工程]