Bonding and Thermal Fracture of Silicon Nitride / Stainless Steal (SUS316)

Abstract

Diffusion bonding and thermal fracture between Si 3 N 4 ceramic and stainless steel (SUS316) were investigated. Sintered Si 3 N 4 ceramics were fabricated by hot-pressing of a-Si3N 4 powder with 5wt% Yz03 and 5 -1 Owt% Ah0 3 . Bonding between SUS316 plate with 1 mm thick and Si 3 N 4 specimens was carried out at 8 -24 MPa and at 1000° -1300°C for 1 h in vacuum. Thermal decomposition of the bonded specimen in air was followed by acoustic emission and high-temperature microscope. Bonding between SUS and ShN 4 was achieved by heating at 1150 and 1200°C in vacuum. When the bonded sample was heated in air, small cracking was formed at 700°C at the interface between SUS and Si3N 4 , followed by decomposition of the bonded sample at 900°C.