Microstructure and mechanical propertites of SiC joint brazed with heat resistant active brazing alloys

SiC ceramics were bonded with a cobalt based heat resistant active brazing alloy.The effect of brazing alloy thickness and brazing temperatures on the joint microstructurs and four point bending strength was studied.Results show that the SiC/brazing alloy interface could be divided into three zones,one rich in Ni and Co,one rich in Cr and another rich in Ti.Ni and Co elements integrated at the interface,while the active Ti element distributed in the area with some distance from the interface.When the joint was brazed at 1150℃ for 10 min and the thickness of brazing alloy is 120 μm,the four point bending strength of joints reached the maximum with an average value of 160 MPa.