Effect of Nanoscale SiC Particles on Strength Distribution of Joined Si3N4 to Inconel Alloy

Abstract

Two-layered Si3N4/SiC nano-composites with 50vol.% SiC have been fabricated by two-step sintering of a powder mixture of a-Si3N4 and carbon powder with a mean size of 13nm, and 5wt.% Y2O3. Nano-sized SiC particles were formed through reactions: carbon and surface SiO2 on the Si3N4 particles, and carbon and Si3N4 particles. To combine the specific advantages of nanoscale ceramics with that of metals, they are often used together within one composite component. In this study, the fabrication and mechanical properties of a nanoscale SiC layer brazed with an Inconel alloy were investigated. It was shown that, with a variation of strain rate, the joints have a bending strength of 330-380MPa, and the deflection of the interlayer increases with increasing strain rate. The fracture types are classified into three groups; cracks grow into the metal-brazing filler layer, the ceramicbrazing filler layer or inside the ceramic.