Preparation and thermal shock properties of Si3N4-WC nanocomposites

Si
₃
N
₄
-WC nanocomposites were fabricated by hot-pressing nano-sized Si
₃
N
₄
powders and sub-micrometer WC powders. The effect of WC particles on mechanical properties and thermal shock properties of silicon nitride ceramics were analyzed and discussed. The addition of proper amount of WC particles can improve the flexural strength and the fracture toughness, the optimum amount was 8wt.% and 4wt.% respectively. Si
₃
N
₄
-WC nanocomposites showed both higher critical temperature difference and better resistance to crack propagation compared to those of the monolithic silicon nitride ceramic.