Brazing SiO2f/SiO2 with TC4 alloy with the help of coating graphene

The joining of SiO2f/SiO2 to TC4 alloys suffers from the problems of poor wettability with AgCuTi, excessive Ti dissolving from TC4 and emergence of high residual stress among the joint. To solve these problems, an effective method by coating graphene on the SiO2f/SiO2 is developed. Wetting experiments confirm that contact angle notably reduces from 131° to 42.8° after coating rGO. Further, rGO react with Ti element from the brazing alloy and TC4 alloy, inhibiting the formation of excessive brittle reaction layer and in situ forming TiC reinforcement. The highest shear strength of SiO2f/SiO2-TC4 brazed joints was up to 39.2 MPa.