TB18高强韧钛合金电子束焊接头的显微组织和力学性能研究  

Study on Microstructure and Mechanical Properties of Electron Beam Welded Joint of TB18 High-Strength and Toughness Titanium Alloy

作　　者：王浩军 张颖云 李波 王维贤 张乐 韩珂欣 WANG Haojun;ZHANG Yingyun;LI Bo;WANG Weixian;ZHANG Le;HAN Kexin(AVIC Xi'an Aircraft Industry Group Company Ltd.,Xi'an 710089,China)

机构地区：[1]中航西安飞机工业集团股份有限公司,陕西西安710089

出　　处：《热加工工艺》2023年第23期75-78,共4页Hot Working Technology

摘　　要：对20 mm厚TB18钛合金板材进行了电子束焊接试验,比较了TB18母材和电子束焊接头的显微组织和力学性能。结果表明:母材和接头的平均抗拉强度分别为1330 MPa和1344 MPa,接头的抗拉强度略高于母材;母材和接头的断后伸长率分别为8.8%和8.4%,接头的塑性较母材差。母材拉伸试样断口存在大量韧窝,为韧性断裂,而接头拉伸试样断口形貌主要由韧窝和解理面组成,为准解理断裂。焊缝区的平均显微硬度最高,为378 HV;母材和热影响区的显微硬度值接近,为364~368 HV。这3个区域的β晶粒内都发现了大量的针状次生α相,但焊缝区的次生α相的长度和宽度较母材要小。The electron beam welding test of 20 mm thick TB18 titanium alloy plate was carried out,and the microstructure and mechanical properties of the TB18 base metal and the welded joint were compared.The results show that the average tensile strength of the base metal and the joint is 1330 MPa and 1344 MPa,respectively.The tensile strength of the joint is slightly higher than that of the base metal.The elongation of the base metal and the joint after fracture is 8.8%and 8.4%,respectively,and the plasticity of the joint is worse than that of the base metal.The tensile fracture of the base metal is composed of a lot of dimples,which is characterized by ductile fracture,while the tensile fracture morphology of the joint is mainly composed of dimples and cleavage planes,indicating that it is quasi-cleavage fracture.The average microhardness of the weld zone is highest,reaching 378 HV.And the microhardness of the base metal and heat affected zone is close,which is 364-368 HV.A large number of acicular secondaryαphases are observed in theβgrains of the three regions,but the length and width of the secondaryαphase in the weld zone are smaller than that in the base metal.

关 键 词：TB18钛合金 电子束焊接 断口 显微组织 

分 类 号：TG456.3[金属学及工艺—焊接]