抄録
Sialon/SiC whisker composites with 5 and 10mass% SiC(w) were prepared by hot-isostatic-pressing. The fatigue behavior of composites at room temperature in air was investigated. Dynamic, static and cyclic fatigue tests were carried out on smooth specimens by the 3-point bending method. The microstructure, bending strength and fracture toughness of composites were similar to those of monolithic sialon. The addition of SiC(w) inhibited the slow crack growth attributable to the stress corrosion by humidity in air observed in monolithic sialon. The dynamic fatigue parameter “n” was 26 in monolithic material, 108 in composite with 5mass% SiC(w) and 90 in 10mass% SiC(w). In static fatigue tests, the observed lifetime of each sample was in agreement with that predicted from dynamic fatigue properties. The acceleration of fatigue was observed in monolithic sialon and composite with 5mass% SiC(w), but the addition of 10mass% SiC(w) reduced the accelerative effects on cyclic fatigue.
