A Study on Distribution of Ni and Ti in Brazing Sapphire to Inconel 625 Using Cu/Ni Porous Composite

In this study, a Cu/Ni porous composite was introduced when brazing sapphire to Inconel 600 using a special active filler metal of BAg-8 + 2Ti. The aim of the research is to investigate the distribution of Ni and Ti in the Cu/Ni porous composite and braze joint. The brazing was carried out in brazing temperature of 900°C for 30 minutes by a vacuum environment (10^-4 Pa). The interface of braze joint/sapphire and braze joint/Inconel 600 were observed by an electron microscope followed by elements analyzing using SEM-EDS. The observation and analysis shows that there is a black and thin reaction layer at braze joint/sapphire interface and a reaction layer was formed at braze joint/Inconel 600 interface. The formation of reaction layer is influenced by thermodynamic activity of Ti during brazing. There are also higher percentage of Ni element diffused in the braze joint in order to improve the corrosion resistance of the joining.