TC4钛合金钎焊界面组织及力学性能研究  

Study on the interface structure and mechanical properties of TC4 titanium alloy brazing

作　　者：张丽霞[1] 丁彦华 朱鑫鑫 张博彧 孙湛[1] 常青[1] 张博[1] 钟素娟 龙伟民 ZHANG Lixia;DING Yanhua;ZHU Xinxin;ZHANG Boyu;SUN Zhan;CHANG Qing;ZHANG Bo;ZHONG Sujuan;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》2025年第2期91-97,共7页Modern Transportation and Metallurgical Materials

基　　金：国家重点研发计划项目(2021YFB3401102)。

摘　　要：为了保证钛合金板翅式换热器中接头的高温强度要求,本文设计并制备了Ti_(23.75)Zr_(23.75)Ni_(23.75)Cu_(23.75)Sn_(5)高熵非晶钎料,并利用所制备钎料对TC4钛合金进行真空钎焊,对不同工艺参数下接头的显微组织和力学性能进行了研究。结果表明,930℃/10 min的工艺条件下接头的组织主要由(Ti,Zr)_(2)(Ni,Cu)和少量的Zr_(5)Sn_(3)金属间化合物、α-Ti+(Ti,Zr)_(2)(Ni,Cu)共析组织及针状α-Ti组成;随着钎焊温度的升高,元素扩散更加充分,焊缝内部的脆性化合物相逐渐消失,形成以针状α-Ti为主的焊缝组织。随着保温时间延长,接头组织内部的针状α-Ti逐渐生长,保温时间过长会造成α-Ti组织粗大,对接头强度有害,970℃/30 min工艺条件下,最高室温抗剪强度与450℃高温抗剪强度分别为494 MPa与408 MPa;(Ti,Zr)_(2)(Ni,Cu)脆性相是接头的薄弱环节,接头断裂形式为脆性断裂。To ensure the high-temperature strength of the joints in the Ti alloy plate-fin heat ex-changer,Ti_(23.75)Zr_(23.75)Ni_(23.75)Cu_(23.75)Sn_(5) high-entropy amorphous solder is designed and prepared.The TC4 is brazed by the high-entropy amorphous solder.The microstructure and mechanical properties of the joints with different parameters are studied.The results show that the weld microstructure is mainly composed of(Ti,Zr)_(2)(Ni,Cu),Zr_(5)Sn_(3),α-Ti+(Ti,Zr)_(2)(Ni,Cu)eutectoid structure and needle-α-Ti with the condition of 930℃/10 min.As the brazing temperature increases,the element diffusion is more sufficient,and the brittle phase in the weld center gradually disappears.Needle-likeα-Ti be-comes the main tissue.With the extension of the holding time,the needle-likeα-Ti gradually grows,and theα-Ti tissue will be coarse due to the long holding time,which is harmful to the joint strength.The maximum shear strength at room temperature and 450℃ are respectively 494 MPa and 408 MPa with the parameter of 970℃/30 min.(Ti,Zr)2(Ni,Cu)is the weak link of the joint.The fracture form of the joint is brittle fracture.

关 键 词：TC4钛合金 高熵非晶钎料 显微组织 力学性能 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TG115.21[金属学及工艺—金属材料]