Cu-Pd-V钎料真空钎焊Cf/SiBCN复合材料的界面组织与性能

Microstructure and mechanical property of C_f/SiBCN composite joint brazed with Cu-Pd-V filler alloy

利用Cu-Pd-V钎料对新型四元陶瓷基复合材料C_f/SiBCN进行了真空钎焊连接.利用座滴法研究了CuPd-V钎料对C_f/SiBCN复合材料的动态润湿性.利用SEM和XRD对钎焊接头微观组织及断口物相进行了分析表征.结果表明,经1 170℃保温30 min后钎料在复合材料上的润湿角为57°.在1 170℃-10 min钎焊规范下,CuPd-V钎料在C_f/SiBCN复合材料表面形成厚度约为1μm的V(C,N)反应层,主要包括VC和VN化合物,钎缝中央为Cu_3Pd和CuPd两种固溶体相.接头的室温三点弯曲强度为58.1 MPa,当测试温度提高至600℃时接头强度上升至90.2 MPa,在700和800℃测试温度下钎焊接头强度呈下降趋势,但仍然可以维持在室温强度水平,分别为66.9和64.6 MPa.

Cu-Pd-V filler alloy was used to join Cf/SiBCN composite.Its dynamic wettability on the composite was studied with the sessile drop method.After heating at 1 170°C for 30 min,the filler alloy showed a contact angle of 57°.The microstructure and phase confirmation of the joint were analyzed by SEM and XRD,respectively.When brazed at 1 170°C for holding time of 10 min,the interfacial reactions resulted in resulted in the formation of V(C,N)reaction band with the thickness of 1μm at the surface of Cf/SiBCN composite,and the microstructure in the central part of the joint is composed of Cu3Pd and CuPd solid solutions.The average three-point bend strength of Cf/SiBCN-Cf/SiBCN joints at room temperature is 58.1 MPa.When the test temperature was increased to 600°C,the average joint strength was even elevated to 90.2 MPa.Eventhough the strength of brazed joints decreased at 700°C and 800°C,which was 66.9 MPa and 64.6 MPa respectively,it still maintained at room temperature strength value.