Anisotropy of destruction viscosity of hot-pressed silicon nitride

The paper discusses the study of destruction viscosity and hardness of silicon nitride samples produced by hot pressing from powder and rolled ribbons. Anisotropy of crack resistance and a crystallographic texture are identified in both types of samples. The studies establish that the destruction viscosity in the direction parallel to the hot pressing force is higher than in the perpendicular direction. Acomparative analysis of anisotropy reveals its weak dependence on preliminary rolling.