318 極薄板金属材料の疲労特性に及ぼすTiNコーティングの影響(OS1-3 表面改質処理と疲労強度)(OS1 高強度材・表面改質材の疲労と破壊)  [in Japanese] 318 Effect of TiN coating on fatigue characteristic of ultra thin sheet of SUS304 stainless steel  [in Japanese]

The object of this study is to investigate the effect of coating of ceramic film on the fatigue characteristic of the ultra thin sheet material. Smooth specimens of austenite stainless steel SUS304 (0.05mm thick) were fatigue tested under constant tension-tension loading condition after the surface of the specimen was coated with sputtered TiN film of thickness from 0.5 to 2.5 μm. The influences of coating on the S-N curves were examined. The micro hardness of TiN film and the residual stress of the surface of SUS304 were also measured. The following results were obtained, (1) the fatigue strength of coated specimens increased at about 30 % in the high cycle region and were little influenced in the low cycle region, (2) the fatigue strength in the high cycle region somewhat depended on the film thickness, (3) the increase in fatigue strength is explained by the hardness rather than the residual stress.