Brazing YSZ ceramics by a novel SiO2 nanoparticles modified Ag filler

Abstract

Yttria-stabilized zirconia (YSZ) ceramics are soundly brazed in air using a novel amorphous SiO2 nanoparticles (NPs) modified Ag filler. Scanning electron microscopy, transmission electron microscopy and X-ray diffraction are employed to characterize the interfacial microstructure of YSZ joints. A uniform amorphous SiO2 layer is observed on the YSZ substrate surface. Micro-sized SiO2 clusters are dispersed in the Ag braze matrix, which forms the brazing seam. The content of SiO2 NPs and the brazing temperature exert significant effects on the formation of YSZ joints. The maximum shear strength of YSZ joints reaches 47 MPa under the optimized brazing conditions (Ag–2SiO2, 1050 °C/30 min, 2 MPa load pressure).