一种新型钛基钎料钎焊TiAl合金接头的界面组织及性能  

Microstructure and Properties of TiAl Alloy Joints Brazed with a Novel Ti-based Filler

作　　者：冷斌[1,2,3] 袁雷昕 王一轩 陈昱橦 罗芬 李力 LENG Bin;YUAN Leixin;WANG Yixuan;CHEN Yutong;LUO Fen;LI Li(School of Mechanical Electrical and Architectural Engineering,Jiangxi Tourism&Commerce professional College,Nanchang 330100,China;School of Materials Science and Engineering,East China Jiaotong University,Nanchang 330013,China;State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure,East China Jiaotong University,Nanchang 330013,China)

机构地区：[1]江西旅游商贸职业学院机电与建筑工程学院,江西南昌330100 [2]华东交通大学材料科学与工程学院,江西南昌330013 [3]华东交通大学轨道交通基础设施性能监测与保障国家重点实验室,江西南昌330013

出　　处：《热加工工艺》2024年第23期26-31,38,共7页Hot Working Technology

基　　金：国家自然科学基金资助项目(51865012);江西省自然科学基金资助项目(20202BABL204040);江西省教育厅科学技术研究项目(GJJ170372);国家金属材料近净成形工程技术研究中心开放基金项目(2016005);GF基础科研计划资助项目(JCKY2016603C003);民口配套规划研制项目(JPPT125GH038)。

摘　　要：采用机械球磨制备的Ti H_(2)-65Ni和Ti B_(2)复合粉末钎料对Ti-47Al-2Nb-2Cr-0.15B(at%)合金进行钎焊连接,钎焊温度1190~1250℃、钎焊时间10 min。研究了Ti Al合金钎焊接头界面组织及钎焊温度对接头组织与室温抗剪强度的影响。结果表明,Ti Al钎焊接头由3个界面反应层组成,主要物相为α_(2)-Ti_(3)Al、τi_(3)-Ali_(3)Ni Ti_(2)、Ti B。随着钎焊温度的升高,形成的连续α_(2)-Ti_(3)Al层壁垒被打破,钎料元素向母材的扩散量及母材的溶解量增加,导致钎缝厚度增加。Ti Al钎焊接头抗剪强度随钎焊温度的升高先增加后减小。当钎焊温度为1230℃时,与钎缝基体具有相似的热膨胀系数的Ti B晶须尺寸细化,数量增加,层Ⅲ中组织更细化、物相分布更均匀,获得的接头抗剪强度最大,为332.87 MPa。钎焊接头以准解理断裂方式脆断于以τi_(3)-Ali_(3)Ni Ti_(2)为主要物相的层Ⅱ中。TiH_(2)-65Ni and TiB_(2) composite powder filler prepared by mechanical milling was employed to vacuum braze Ti-47Al-2Nb-2Cr-0.15B(at%)alloy under the brazing temperature of 1190-1250℃for 10 min.The interfacial microstructure of the TiAl alloy brazed joints and the effect of the brazing temperature on the microstructure and the room temperature shear strength of the joint were investigated.It is found that the TiAl brazed joint is divided into three layers and it mainly consists ofα_(2)-Ti_(3)Al,τi_(3)-Ali_(3)NiTi_(2) and TiB phases.With the increase of the brazing temperature,the formed continuousα_(2)-Ti_(3)Al layer barrier layer is broken,the dissolution of the filler element into the TiAl substrate and the the dissolution of the TiAl substrate are increased,which results in an increase of brazing seam thickness.With the brazing temperature increasing,the shear strength of the joint increases firstly and then decreases.When the brazing temperature is 1230℃,the aspect ratio and quantity of the TiB whiskers with good thermodynamic compatibility to the brazing seam matrix increase significantly,the microstructure of the layerⅢis refined and the phase distribution is uniformly distributed.The joint presents the maximum shear strength of 332.87 MPa and it brittlely fractures in layerⅡwhich mainly consists ofτi_(3)-Ali_(3)NiTi_(2) in quasi-cleavage mode.

关 键 词：钛基粉末钎料 TIAL合金 钎焊温度 界面组织 抗剪强度 

分 类 号：TG454[金属学及工艺—焊接]