Effects of Ta2O5 on mechanical properties and elements diffusion of Ti/Al2O3 composites prepared via hot pressing sintering

Homogeneous Ti/Al2O3 composites with different volume percentages of Ta2O5 addition were prepared at different temperatures via hot pressing sintering. Laminated Ti/Al2O3 composites with different volume percentages of Ta2O5 added were prepared. The effects of Ta2O5 on the composition, microstructure, mechanical properties and elements diffusion of the composites were characterized and investigated. Ta2O5 inhibited the production of TiAl and Ti3Al by forming solid solution with Ti or new reaction product of Al. This solid solution melted and filled the void of Al2O3 phase to increase the density of Ti/Al2O3 composites at high temperature. Mechanical properties had also been improved by this phenomenon. Because Al element couldn't diffuse in Ta or react with it, Al couldn't diffuse through the Ta-enriched area at the interface of Ti and Al2O3.