不同Si元素含量铝/钛激光熔钎焊界面微观结构和断裂行为  

Interface microstructure and fracture behavior of aluminum/titanium laser welding-brazing under different Si element contents

作　　者：吴佳伟 李昊岳 夏鸿博 焦俊科 WU Jiawei;LI Haoyue;XIA Hongbo;JIAO Junke(School of Mechanical Engineering,Yangzhou University,Yangzhou,225127,China;State Key Laboratory of Precision Welding&Joining of Materials and Structures,Harbin Institute of Technology,Harbin,150001,China;Zhengzhou Research Institute,Harbin Institute of Technology,Zhengzhou,450000,China)

机构地区：[1]扬州大学,机械工程学院,扬州225127 [2]哈尔滨工业大学,材料结构精密焊接与连接全国重点实验室,哈尔滨150001 [3]哈尔滨工业大学,郑州研究院,郑州450000

出　　处：《焊接学报》2025年第2期136-144,共9页Transactions of The China Welding Institution

摘　　要：采用激光熔钎焊技术,使用含有不同Si元素含量(纯铝,AlSi5和AlSi12)焊丝,成功实现了铝/钛异种金属之间的对接.分析了Si元素含量对焊缝成形、界面金属间化合物(intermetallic compound,IMC)组织、接头拉伸性能及断裂行为的影响.结果表明,随着Si元素含量的增加,界面IMC的厚度逐渐变薄,Si元素在IMC层处产生聚集现象,IMC层由Ti-Al的二元相(TiAl_(3))转变为Ti-Al-Si三元相(Ti(Al,Si)_(3));焊接接头的拉伸强度随着Si元素的含量的增加而逐渐增大,AlSi12接头抗拉强度最高,达到了197.69 MPa.当接头受到拉伸力作用时,界面上部形成的较厚且硬脆的IMC层成为接头的力学性能薄弱区域,易萌生裂纹,进而引发接头的脆性断裂,最终影响接头的抗拉强度.由于Si元素含量的增加,IMC层的厚度减少,从而降低了IMC层组织结构对接头拉伸力学性能的不利影响,使得接头的断裂路径从原来的钎焊界面转变到了铝母材的热影响区.This research successfully achieved the butt joining of aluminum/titanium dissimilar metals using laser welding-brazing technology with filler wires containing different Si content(pure Al,AlSi5,AlSi12).The study investigated the influence of Si content on weld formation,interfacial intermetallic compound(IMC),mechanical properties,and fracture behavior of joints.The results indicated that as the Si content increased,thickness of interfacial IMC gradually decreased while Si aggregation occurred along the IMC layer.The IMC layer transformed from Ti-Al binary phases(TiAl_(3))to Ti-Al-Si ternary phases(Ti(Al,Si)_(3))with the addition of Si.The tensile strength of joints gradually increased with the increment of Si content,reaching a maximum of 197.69 MPa when AlSi12 was adopted.When the joint was subjected to tensile force,thicker IMC layer formed at the upper part of interface became the weak zone of the joint's mechanical properties,prone to crack initiation,leading to brittle fracture of the joint and ultimately affecting its tensile strength.Due to the increased Si content,the reduced thickness of the IMC layer mitigated the negative effects of its microstructure on the tensile strength of the joint,shifting the fracture path from the brazing interface to the heat-affected zone of the aluminum base material.

关 键 词：铝/钛异种金属 激光熔钎焊 Si元素含量 金属间化合物 断裂行为 

分 类 号：TG456.7[金属学及工艺—焊接]