Joining SiAlON Ceramics Using Composite beta-SiAlON-Glass Adhesives

Abstract

Commercial β-SiAlON ceramics were joined using mixed Si3N4, Y2O3, Al2O3, and SiO2 powders. At a joining temperature of 1600°C and a hold time in excess of 10 min, the adhesive was converted to an approximate 60:40 vol% composite of β-SiAlON–glass-ceramic. The grain size of the acicular β-SiAlON grains precipitated in the joint (submicrometer diameter, average aspect ratio of 10) was significantly smaller than those in the adherend ceramic (1–5 μm diameter). Intergrowth of β-SiAlON grains at the joint interface resulted in high bond strengths. The chemistry and microstructure of the ceramic adhesives used are described.