Joining of alumina to Tetragonal Zirconia Polycrystal (TZP) using a Bi2O3-Y2O3 filler

In this study, joining of alumina to zirconia was conducted using a Bi2O3-Y2O3 filler under a normal atmosphere. In order to prevent the possible diffusion of yttrium from zirconia substrate into the interface, yttria was added to the filler. The wettability of 97Bi(2)O(3)-3Y(2)O(3) (wt%) filler was examined, and it was found that this filler has good wettability on alumina and zirconia. The bonded samples that were brazed at 975 degrees C for 10, 15, and 20 min were determined to be acceptable, while the samples that underwent various process temperatures showed defects such as voids, incomplete fusion, and cracks. Three new phases were observed formed at the interface using SEM images, and the content of these phases increased with increasing holding time. The effectiveness of adding yttria to the filler was confirmed by EDS analysis, as the yttrium of the zirconia substrate did not diffuse into the interface. The fracture surfaces were studied, and XRD analysis was taken from them. Brittle fracture has occurred in all samples, and BiAlO3, Y3Al5O12, and (Bi1.85Zr0.15) O-3.75 phases were identified at the interface. According to measurements of the shear strength of the joints, the sample brazed for 15 min at a temperature of 975 degrees C had the maximum strength of 31 MPa.