Interactions, joining and microstructure of Sn-Ti/ZrO2 system

Brazing and soldering following pre-metallization were employed to obtain reliable ZrO2/Sn-Ti/ZrO2 joints. Both the metallization and brazing depend on the wettability of ZrO2 by Sn-Ti alloys. The interfacial microstructure of joints was analyzed by SEM, XRD and TEM, and the shear strength of joints was evaluated. Good brazed joints and fully covered metallization layers, leading to good soldered joints, were obtained by the Sn-4Ti and Sn-8Ti alloys, while unsatisfactory results were obtained with Sn-1Ti and Sn-2Ti alloys owing to their limited wettability on ZrO2. Both kinds of ZrO2/Sn-Ti/ZrO2 joints possessed a beta-Sn matrix with Ti6Sn5 and Ti2O3 interfacial layers. A higher Ti concentration per unit area induced the formation of a Ti11.31Sn3O10 layer along with the reduction of the Ti2O3 layer thickness at the interface in the soldered joints. All the joints exhibited a similar shear strength of 22 similar to 28 MPa and fractured through the beta-Sn matrix.