Ni元素扩散行为对硬质合金/钢钎焊接头微观组织及力学性能的影响  

Effect of Element Ni Diffusion on Microstructure and Mechanical Properties of Brazed Joints of Cemented Carbide and Steel

作　　者：李远星[1] 张晓山[1] 朱宗涛[1] 何永攀 韩灯泉 陈辉[1] 

机构地区：[1]西南交通大学,四川成都610031

出　　处：《稀有金属材料与工程》2017年第4期1120-1125,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51505392);中央高校基本科研业务费专项资金(2682015CX002)

摘　　要：采用不同质量分数的Ni元素的钎料对YG15硬质合金与35Cr Mo钢进行了钎焊,分别研究了Ni元素含量、钎焊温度以及超声作用等因素对钎焊接头微观组织与力学性能的影响。研究表明:钎焊温度为800℃时,随钎料中Ni元素的增加,界面处可获得连续的α-Cu固溶体层;当钎料中Ni元素质量分数为4.7%时,其接头剪切强度最高,为295 MPa;钎焊温度影响Ni元素的扩散行为,从而影响界面处贫Co区的宽度,在温度为730℃时,贫Co区宽度最小,接头剪切强度值最高,为350 MPa;施加超声可以增加贫Co区宽度,降低共晶组织含量,并使WC颗粒迁移进入钎缝金属。当超声时间为30 s时,贫Co区宽度为17.5μm,接头剪切强度为371 MPa,比无超声时接头强度提高6%。YG15 cemented carbides and 35CrMo steel were brazed by Ag-based filler metal with different contents of element Ni. The effect of the Ni content, brazing temperature and ultrasonic vibration on the microstructure and mechanical properties of the joints was investigated. Results show that continuous a-Cu solution layers can be obtained by increasing the Ni content, and the shear strength peak is 295 MPa with the 4.7 wt% Ni filler metal at the brazing temperature of 800 ℃. The brazing temperature influences the depleted zone width of element Co of joints through the impact on the diffusion of element Ni. The minimum of the depleted zone width of element Co is observed in the joints at the brazing temperature of 730 ℃, and the shear strength of the joint reaches maximum 350 MPa. The brazing process with ultrasonic vibration can enlarge the width of the depleted zone of element Co of the joints, decrease the content of eutectic structure, and drive the migration of WC particles into bonds. The maximum shear strength 371 MPa of the joints with 17.5 μm wide depleted zone of element Co is obtained with ultrasonic brazing for 30 s, which is increased by 6% compared with that without ultrasound.

关 键 词：钎焊 硬质合金 Ag-Cu-Zn-Mn-Ni钎料 扩散 超声波 

分 类 号：TG454[金属学及工艺—焊接]