Ti(C,N)基金属陶瓷与低碳钢真空钎焊的界面结构及接头强度

Interface Structure and Joint Strength of Ti(C,N)-based Cermet and Low-carbon Steel by Vacuum Brazing

本文采用CuMnNiCrSi钎料实现了对Ti(C,N)基金属陶瓷与低碳钢的真空钎焊连接。研究了钎焊温度和保温时间对钎焊接头剪切强度的影响,通过XRD、SEM和EDS对接头的物相、显微组织、元素分布及断口形貌进行分析。研究表明:在钎焊温度为1030℃,保温时间为20 min的工艺条件下,钎焊接头的结合强度达到最大,其剪切强度为301.5 MPa。Ti(C,N)基金属陶瓷/低碳钢焊缝由α-Ti基固溶体和Cr基固溶体构成。在金属陶瓷一侧的界面处形成Cu基固溶体,在钢一侧形成(Cu,Ni)固溶体和(Fe,Ni)固溶体。Ti(C,N)基金属陶瓷/低碳钢接头断裂发生在Cu基钎料处,其断裂方式为韧性断裂。

Vacuum brazing of Ti（C,N）-based cermet and low-carbon steel was performed by using CuMnNiCrSi alloy filler. The effects of brazing temperature and holding time on the shear strength of the Ti（C,N）-based cermet/low-carbon steel joint were investigated. The phase, microstructure, areal distribution of elements and fracture morphology of the joint were examined by XRD, SEM and EDS. The results show that the shear strength of the joint achieves the maximum value of 301.5MPa after brazed at 1 030 ℃ for 20 min. The phases in the welding clearance consist of α-Ti solid solution and Cr solid solution. Cu solid solution is formed on the interface close to the Ti（C,N）-based cermet, while（Cu,Ni） and（Fe,Ni） solid solutions are occurred on the interface close to the steel. The fracture of the joint locates in the Cu-based alloy and belongs to a toughness fracture.