窒素イオン注入した純チタン材の疲労き裂発生と初期疲労き裂成長挙動に及ぼす切欠深さの影響

概要

論文の詳細を見る
The aim of this work is to investigate the effects of notch depth on crack initiation, early crack growth behavior and fatigue life of pure titanium implanted the nitrogen ions by the dynamic mixing. Three point bending fatigue tests were carried out using an electro hydraulic fatigue testing machine with a frequency of 20Hz and a stress ratio of R=0 at room temperature. The fatigue crack initiation and the early crack growth were observed by using an optical microscope adopting and a plastic replica method. The main results obtained are summarized as follows. (1)The fatigue life of N-ion-implanted pure titanium decreased with increasing notch depth, which depended on magnitude of stress concentration factor. (2)For N-ion-implanted pure titanium, there were few slip bands on the surface of the notch root. Several intergranular or transgranular micro cracks at the notch root surface coalesced into each other at the early fatigue stage. The crack initiation life of which the fatigue crack grew to 0.1mm was well represented by K_tΔσ regardless of the notch depth. (3)At early fatigue crack growth process, there were two types of fatigue crack growth. It was a tendency to appear the second type of crack growth as the cyclic stress increased. (4)The two types of crack growth were affected by the microstructure. The crack length at which the early fatigue crack started to propagate successively agreed well with the distance from the notch root at a constant value of σ/Δσ=1.5 which was estimated from nondimensional elastic stress distribution, σ/Δσ.
一般社団法人日本機械学会の論文
1996-10-25

窒素イオン注入した純チタン材の疲労き裂発生と初期疲労き裂成長挙動に及ぼす切欠深さの影響

スポンサーリンク

概要

著者

関連論文

スポンサーリンク