Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : December 22, 2018 - December 24, 2018
The purpose of this study is to investigate the effects of surface oxide layer on fatigue crack propagation properties of copper (Cu) nano-films. Fatigue crack propagation experiments in about 500-nm-thick Cu nano-films with native and thermal surface oxide layer were conducted under in situ field emission scanning electron microscopy (FESEM) observation. Specimens with native surface oxide layer with a thickness of about one nm, and with thermal surface oxide layer with a thickness of about six nm were fabricated. Experimental results showed that the fatigue damage area around crack in Cu nano-films with thermal surface oxide layer was narrower than in Cu nano-films with native surface oxide layer. Fatigue crack propagation rate (da/dN) is roughly the same in Cu nano-films with thermal surface oxide layer and with native surface oxide layer in lower stress intensity factor range (ΔK). However, da/dN of Cu nano-films with thermal surface oxide layer is slightly faster than that of Cu nano-films with native surface oxide layer in higher ΔK.
