The effective connection of Si C ceramics can be achieved through the brazing with Ag-Cu-Ti filler. A large residual stress is caused in the cooling process of brazing due to a big difference of thermal expansion coefficient between the filler and Si C ceramic. In this article,the thermal expansion coefficient of Ag-26.7 Cu-4.5 Ti filler is adjusted by adding W particles with different volume fraction to make it closer to Si C ceramics. The influence of brazing parameters on microstructure and mechanical properties of weld is studied by changing brazing temperature and holding time. The results show that W particles are uniformly distributed in the matrix and do not react with other elements. When adding a suitable volume fraction of W particles,a composite joint with uniform microstructure and good connection is formed under an appropriate brazing temperature and holding time. When the adding volume fraction of W is 10%,the maximum shear strength of 95.05 MPa is obtained at 807 ℃ for 10 min.
SiC ceramicsbrazingAg-Cu-Ti +W composite fillershear strength