多层复合钎料钎焊Ti(C,N)基金属陶瓷与45钢接头的组织

Microstructure of Ti(C,N)-based Cermet and 45 Steel Joint Brazed with Multi-layered Composite Filler

采用由Ag-Cu-Ti+Mo钎料、铜箔和Ag-Cu钎料组成的多层复合钎料,对Ti(C,N)基金属陶瓷和45钢在不同温度(890,920,950℃)和不同时间(10,20,30min)下进行了真空钎焊,根据接头截面形貌和剪切强度确定了最佳钎焊温度和保温时间,并分析了最佳工艺下钎焊接头的显微组织。结果表明:随钎焊温度的升高或保温时间的延长,Ag-Cu-Ti+Mo钎料与金属陶瓷间的界面反应层厚度增大,铜钛金属间化合物增多,两侧钎料区中的铜基固溶体增多,接头的剪切强度先增后降;最佳钎焊工艺为钎焊温度920℃、保温时间20min,此时接头剪切强度最大,从金属陶瓷向45钢,接头组织依次为Cu3Ti2+Ni3Ti金属间化合物,银基固溶体+铜基固溶体+钼+铜钛金属间化合物,铜,银基固溶体+铜基固溶体。

With the multi-layered composite filler composed of Ag-Cu-Ti＋Mo brazing alloy,copper foil and Ag-Cu brazing alloy,Ti（C,N）-based cermet and 45 steel was joined by vacuum brazing at different temperatures（890,920,950℃）for different times（10,20,30 min）.The optimum brazing temperature and holding time were determined on the basis of cross-section morphology and shear strength of the joint.The microstructure on crosssection of the joint brazed with the optimum process was analyzed.The results show that with the increase of brazing temperature or the holding time,the interface reaction layer between the Ag-Cu-Ti＋Mo brazing alloy and the cermet was thickened.The amount of Cu-Ti intermetallic compound in the reaction layer and that of Cu-based solid solution in brazing alloys at both sides increased.Also the shear strength of the joint increased and then decreased.The optimum brazing process was as follows：brazing temperature of 920℃and holding time of 20 min.The joint obtained with the optimum process had the largest shear strength,whose structure was composed of Cu3 Ti2＋Ni3 Ti intermetallic compounds,Ag-based solid solution＋Cu-based solid solution＋Mo＋CuTi intermetallic compound,Cu,and Ag-based solid solution＋Cu-based solid solution,in order from the cermet to 45 steel.