SiC陶瓷与316L不锈钢真空活性钎焊

Vacuum Brazing of SiC Ceramic and 316L Stainless Steel

采用Ag-Cu-Ti活性钎料,通过真空钎焊方法进行了SiC陶瓷与316L不锈钢的连接,研究了接头的界面组织、特征点成分和物相,并探讨了钎焊温度(800～930℃)、保温时间(0～30 min)对接头界面组织和连接强度的影响。结果表明,SiC陶瓷与316L不锈钢钎焊抗剪断口均发生在SiC陶瓷与钎料连接界面处,由于活性元素Ti的作用,在陶瓷与钎料的界面处形成了连续的反应层,反应生成了Ti C和Ti5Si3;在316L不锈钢与钎料的界面处,生成了Fe-Ti化合物和Cu-Ti化合物。随着钎焊温度升高及保温时间延长,接头强度均呈现出一个峰值,在温度为900℃,保温20 min的工艺条件下可获得最大接头抗剪强度。

The SiC rod（ Ф15 mm × 15 mm） and 316 L stainless steel disc（ Ф15 mm × 5 mm） were firmly jointed by vacuum brazing with AgCuTi alloy filler. The influence of the brazing temperature,holding time and interface properties on the phase-structures and bonding strength at the joints was investigated with X-ray diffraction,energy dispersive spectroscopy,scanning electron microscopy and mechanical tools. The results show that the brazing temperature,holding time and interface properties all had a major impact. For example,the shear fractures often occurred at the SiC/alloy-filler interface,where highly active Ti induced formation of a continuous reaction layer,mainly comprising Ti C and Ti5 Si3 phases; in contrast,at the interface of stainless steel and alloy-filler,the intermetallics of Fe-Ti and Cu-Ti formed. Brazed at 900℃ for a holding time of 20 min,the joints displayed the strongest shear strength.