多軸鍛造した工業用純TI薄板の大気中および生理食塩水中における疲労挙動

抄録

Fatigue tests of ultrafine-grained pure Ti plates fabricated by multi-directional forging (MDFing) were conducted in laboratory air and physiological saline. The plate with 1 mm in thickness was developed aiming at dental implant application. The fatigue strengths of MDFed pure Ti plates in laboratory air were higher than those of rolled pure Ti plates. It could be attributed to the much finer grains evolved by MDFing. In the very high cycle fatigue (VHCF) regime, sub-surface crack initiation was observed in the MDFed pure Ti, and the sub-surface crack initiation mechanism was related to the inhomogeneity of microstructure. The corrosion fatigue strengths in physiological saline were comparable to those in laboratory air, indicating high corrosion resistance of MDFed pure Ti.