TC4低熔蚀钎料设计及对接头组织和性能的影响  

The microstructure and properties of TC4 brazed with a newly designed low‑erosion Zr‑based brazing filler

作　　者：张丽霞[1] 丁彦华 孙名家 张博彧 孙湛[1] 常青[1] 张博[1] 龙伟民 ZHANG Lixia;DING Yanhua;SUN Mingjia;ZHANG Boyu;SUN Zhan;CHANG Qing;ZHANG Bo;LONG Weimin(National Key Laboratory of Precision Welding&Joining of Materials and Structures,Harbin Institute of Technology,Harbin 150001,China;State Key Laboratory of Advanced Brazing Filler Metals and Technology,Zhengzhou Research Institute of Mechanical Engineering Co.,Ltd.,Zhengzhou 450001,China)

机构地区：[1]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,黑龙江哈尔滨150001 [2]郑州机械研究所有限公司新型钎焊材料与技术国家重点实验室,河南郑州450001

出　　处：《现代交通与冶金材料》2024年第4期50-57,共8页Modern Transportation and Metallurgical Materials

基　　金：国家重点研发计划项目(2021YFB3401102)。

摘　　要：薄壁钛合金的焊接是制造高性能板翅式钛合金换热器的关键步骤,针对薄壁钛合金钎焊时母材熔蚀严重的问题,设计并制备了Zr-16Ti-9Cu-11Ni低熔点非晶箔带钎料,对TC4钛合金在840~980℃,保温时间10~120 min范围内进行钎焊,结合扫描电子显微镜(SEM)和X射线衍射(XRD)以及透射电镜(TEM)分析了接头典型组织及其演变过程。结果表明,焊缝组织主要由(Ti,Zr)_(2)(Cu,Ni)化合物、α-Ti和β-Ti组成,随钎焊温度升高和保温时间延长,接头脆性相逐渐减少直至消失,母材熔蚀程度逐渐加重。通过接头抗剪强度对其性能进行评估,结果表明,当钎焊温度在940℃、保温时间10 min时,接头强度最优,为386 MPa,但此时母材熔蚀程度较大,不适合实际生产中的焊接;综合考虑母材熔蚀程度与接头抗剪强度,880~920℃为合适的生产温度区间;通过观察接头断裂路径及断口形貌,接头的断裂模式为脆性断裂。The welding of thin-walled titanium alloy is a key step in the manufacture of highperformance plate-fin titanium alloy heat exchanger.In order to solve the problem of serious base metal erosion during brazing of thin-walled titanium alloy,Zr-16Ti-9Cu-11Ni low melting point amorphous foil strip brazing material is designed and prepared in this study.The brazing filler is used to braze TC4 in the range of 840℃~980℃and holding time of 10~120min,and the typical microstructure and evolution process of the joint are analyzed by scanning electron microscopy(SEM),X-ray diffraction(XRD)and transmission electron microscopy(TEM).(Ti,Zr)_(2)(Cu,Ni),α-Ti andβ-Ti are composed.With an increase of brazing temperature and the extension of holding time,the brittle phase of the joint gradually decreases until it disappears,and the degree of base metal erosion gradually increases.The performance of the joint is evaluated by its shear strength.The results show that when the brazing temperature is 940℃and the holding time is 10 min,the strength of the joint is optimal,which is 386 MPa,but the degree of erosion of the base metal is large at this time,which is not suitable for welding in actual production.Considering the degree of erosion of the base metal and the shear strength of the joint,880~920℃is the appropriate production temperature range.The fracture path of the joint shows that the fracture mode of the joint is brittle fracture by observing the fracture morphology of the joint.

关 键 词：钎焊 非晶钎料 薄壁钛合金 熔蚀 

分 类 号：TG454[金属学及工艺—焊接] TG407