Roughening improves hydrogen embrittlement resistance of Ti-6Al-4V. (November 2021)

• Record Type: Journal Article
• Authors: Kim, Jinwoo; Hall, Dylan; Yan, Haoxue; Shi, Yitong; Joseph, Sudha; Fearn, Sarah; Chater, Richard J.; Dye, David; Tasan, C. Cem
• Is Part Of: Acta materialia. Volume 220(2021)
• Publication Date: 2021-11
• Subjects: Titanium -- Hydrogen -- Surface -- Hydrogen uptake -- Hydrogen embrittlement; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2021.117304
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Polished surfaces of Ti-6Al-4V, the most commonly used titanium alloy, were observed to suffer from hydride growth and associated embrittlement during hydrogen charging, whereas rough surfaces suffered no such susceptibility. Direct microscopic analyses of recombined hydrogen bubbles and thermal desorption spectroscopy (TDS) revealed that the surface roughening promotes recombination of atomic hydrogen to molecular hydrogen, in turn, reducing the relative amount of atomic hydrogen uptake. Subsurface time-of-flight secondary-ion mass spectrometry (ToF-SIMS) further revealed that the high defect density underneath the roughened surface impedes hydrogen diffusion into the bulk. These combined effects mean that, unexpectedly, roughening significantly reduces hydrogen uptake into Ti-6Al-4V and enhances its resistance against hydrogen embrittlement – all resulting from a simple surface treatment. Graphical abstract: Image, graphical abstract