Microstructural optimization of active element and reinforcement proportion of Si3N4/42CrMo joints

Abstract

Abstract Micron-TiN particles and Ti powder were introduced into the AgCu powder filler to design a particle-reinforced composite filler. This TiN particle (TiNp) modified brazing material was adopted to reliably braze Si3N4 ceramics onto 42CrMo steel. The ratio of active element Ti and TiNp reinforcement was optimized according to the joints’ microstructuret. The reaction layer’s thickness close to the Si3N4 increased by decreasing the TiNp content or increasing the Ti content according to the microstructural observation. In addition, higher Ti content would result in more Cu-Ti intermetallics precipitation in the joint and Ti2N could be detected instead of TiNp when 10 wt.% of Ti was used.