INDENTATION, EROSION, AND STRENGTH DEGRADATION OF SILICON-ALLOYED PYROLYTIC CARBON

The effect of sharp particle erosion on the strength and wear of silic on-alloyed pyrolytic carbon was studied. Contact damage at Vickers and Knoop indentations was also examined for comparison with damage at si ngle-particle impact sites. It was found that pyrolytic carbon behaves much differently from most other brittle materials in that even at in dentation loads up to 445 N, radial and lateral cracks were not produc ed. Single-particle impact sites showed a similar lack of radial and l ateral crack formation, but did exhibit surface pit formation due to m icrofracture within, and spalling of, the contact zone. The steady-sta te erosion rate was similar to that of other polycrystalline ceramic m aterials. Post-erosion strength and strength variability decreased wit h increasing particle kinetic energy.