摘要
采用增材制造方法制备航空航天大尺寸构件经常会受到加工效率、设备最大加工尺寸的限制,开发增材制造和焊接相结合的复合制造技术有望解决这一问题.因此,开展了增材制造和锻造TC11钛合金激光焊试验,研究了增材制造TC11(TC11-AM)/锻造TC11(TC11-R),TC11-AM/TC11-AM和TC11-R/TC11-R 3种接头的焊接性,开展了焊接接头微观组织、硬度和拉伸试验,并观察了拉伸试样的断口形貌.结果表明,3种接头的焊缝区均未发现明显的气孔缺陷.由于熔池温度梯度大、冷却速度快,焊缝组织均为内部布满α′马氏体相的粗大柱状晶粒.3种接头抗拉强度分别约为1575,1687 MPa和1593 MPa.TC11-R/TC11-R接头和TC11-AM/TC11-AM接头横截面显微硬度呈高斯分布,硬度值分别为445 HV±31 HV和424 HV±6 HV.由于接头不同区域的组织差异明显,TC11-AM/TC11-R接头显微硬度呈台阶状分布,硬度值为432 HV±21 HV.3种接头的拉伸试样均为韧性断裂,发现断裂面均有大量韧窝.通过对比接头的抗拉强度可知,TC11-AM/TC11-R接头和TC11-AM/TC11-AM接头具有良好的焊接性.创新点:(1)对比分析了TC11-AM/TC11-R,TC11-AM/TC11-AM和TC11-R/TC11-R 3种接头的微观组织和力学性能的差异.(2)研究了不同母材状态下焊接接头维氏硬度分布特征的影响规律.
Additive manufacturing of large-size components for aerospace applications is always limited by processing efficiency and the maximum machining dimension of the equipment.Therefore,it is expected that a hybrid manufacturing technology combining additive manufacturing and welding will tackle this problem.In this paper,laser welding tests of additive and forged TC11 titanium alloy were carried out.The weldability of additive TC11 titanium alloy(TC11-AM),of"TC11-AM/forged TC11(TC11-R)"joint and of TC11-R/TC11-R joint were studied.The microstructure of welded joints,hardness and tensile tests were conducted,and the fracture morphologies of tensile specimens were observed.The results show that no obvious porosity was found in the weld zone of TC11-R/TC11-R joint,TC11-AM/TC11-R joint,or TC11-AM/TC11-AM joint.Due to the large temperature gradient and fast cooling rate of the molten pool,the microstructure of the weld was coarse columnar grain withα'martensite phase inside.The tensile strengths of the three joints mentioned above were about 1575,1687 MPa and 1593 MPa,respectively.The cross sectional microhardness of TC11-R/TC11-R and TC11-AM/TC11-AM joints shows Gaussian distribution,and the variation rangeΔHV of hardness values was about 445 HV±31 HV and 424 HV±6 HV,respectively.Due to the notable difference in the microstructures at different zones of the joint,the microhardness of TC11-AM/TC11-R joint showed a ladder-shaped distribution with higher hardness in TC11-AM side and lower hardness in TC11-R side,and the range of hardness was about 432 HV±21 HV.By comparing the tensile strength of the joints,it is found that TC11-AM/TC11-R joint and TC11-AM/TC11-AM joint are better in terms of weldability.Highlights:(1)The differences in microstructure and mechanical properties of TC11-AM/TC11-R,TC11-AM/TC11-AM and TC11-R/TC11-R joints were compared and analyzed.(2)The influence of different base metal states on Vickers hardness distribution of welded joints was analyzed.
作者
王猛
张立平
赵琳瑜
吴军
熊然
蒙永胜
李军红
WANG Meng;ZHANG Liping;ZHAO Linyu;WU Jun;XIONG Ran;MENG Yongsheng;LI Junhong(Xi'an Aerospace Power Machinery Co.,Ltd.,Xi'an,710038,China)
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2023年第10期102-110,I0008,I0009,共11页
Transactions of The China Welding Institution
关键词
增材制造TC11合金
锻造TC11合金
激光焊
微观组织
力学性能
additive manufactured TC11 titanium alloy
forged TC11 titanium alloy
laser welding
microstructure
mechanical property
