A possible critical temperature mechanism for H blistering nucleation/dissociation in metals. (January 2015)

• Record Type: Journal Article
• Authors: Liu, Yue-Lin; Ma, Yuming; Dai, Zhen-Hong; Liang, Linyun
• Is Part Of: Solid state communications. Volume 201(2015)
• Page Start: 43
• Page End: 48
• Publication Date: 2015-01
• Subjects: A. W/Mo -- C. Defects -- D. Hydrogen blistering -- E. First-principles; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2014.10.010
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: We present a possible physical origin underlying the relationship between temperature and hydrogen (H) blistering nucleation/dissociation in metals according to systematic first-principles calculations in junction with statistical model and diffusion theory employing W and Mo as examples. By calculating the concentrations of total vacancies including thermal (empty) vacancy and H n -vacancy (H n V) clusters and analyzing their diffusion behaviors, we demonstrate that H and vacancy will separate from the H n V cluster to form an empty vacancy and interstitial H atoms at T =900 K in W and T =1100 K in Mo, respectively. This implies that H n V clusters cease to exist except in name (i.e., H will never stay at vacancy) when the temperature is beyond the critical upper value. More importantly, the two critical temperature values are in quantitative agreement with experiments. Our investigating could solve a long-standing puzzle on why H blistering can only nucleate when the temperature is below a certain critical value in metals. Highlights: Calculating the concentrations of vacancy and H n V clusters in W and Mo. Synergistic diffusion process between empty vacancy and H n V cluster. Revealing a critical temperature mechanism on H blistering nucleation.