Joining of alumina ceramics with Ti and Zr interlayers by spark plasma sintering

Abstract

In this study, alumina ceramics were joined by spark plasma sintering technology using zirconium and titanium metals as interlayers. Bonding with Zr was achieved at 800 and 900 °C with an applied force of 4.2 kN, and then at 900 °C with a force of 3 kN. It was found that Ti bonded to alumina at 700, 800, and 900 °C with an applied force of 3 kN. The influence of temperature and pressure on the bonding properties was measured for both interlayers. Scanning Electron Microscope was used to examine the quality of the bonded ceramics and Energy Dispersive X-ray spectroscopy was used to gain insights into the bonding mechanism. The best joints were obtained at 900 °C for Zr and 800 °C for Ti. Oxygen diffusion via the formation of oxygen defects/vacancies and the formation of reaction products such as ZrO2 (and some Ti-Al or TiO2 reaction products) could underpin the possible bonding mechanisms.