142 小球衝突によるセラミックスの表面損傷及び強度低下に関する研究(OS5-2 異物衝突損傷)(OS5 材料の衝撃強度・損傷に関する最近の知見)  [in Japanese] 142 Surface Damage and Strength Degradation in Ceramics due to Sphere Impact  [in Japanese]

In order to clarify the effect of the size of sphere and the thickness of specimen on the surface damage and residual strength, Al_2O_3 sphere impact tests and indentation tests were carried out for Al_2O_3+TiC specimen. The diameter of sphere was 1.5mm, and thicknesses of the specimen were 2.0mm, 3.6mm and 9.0mm. The residual strengths were measured by flexural test after impact tests or indentation tests. As a result, it was seen that the residual strength decreased with the increase in impact speed. Also, the residual strengths of indentation test were somewhat smaller than those of impact test. Therefore, the possibility was shown that the residual strength due to impact test would be evaluated using the method based on the elastic indentation theory.