Influence of the surface condition on the biaxial strength of a commercial silicon carbide

In order to heal surface defects and to find the best healing conditions 5 samples of specimens were heat treated under different conditions and then tested with the B3B-test. For a better comparison of the obtained results all heat treated samples had the same surface finishing (ground with a grit size of 46 μm). Microscopic investigations showed that defects are healed by the formation of a glassy layer. The layer fills cracks and pores (at least partially) and causes a significant increase of strength.