Tracking the role of nitrogen in the improvement of the high temperature oxidation resistance of titanium by mechanical treatments

• Published in: Corrosion science Vol. 197; p. 110080
• Main Authors: Lavisse, L., Berger, P., Kanjer, A., Optasanu, V., Gorny, C., Peyre, P., François, M., Montesin, T., Marco de Lucas, M.C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01-04-2022; Elsevier BV; Elsevier
• Subjects: A. Titanium; Analytical techniques; B. Nuclear reaction analysis; C. High temperature corrosion; C. Interfaces; C. Mechanical surface treatments; C. Oxidation; Chemical Sciences; Diffusion barriers; Diffusion layers; High temperature; Ion beams; Laser shock processing; Material chemistry; Nitrogen; Oxidation; Oxidation resistance; Titanium; C. High temperature corrosion; C. Interfaces; C. Oxidation; C. Mechanical surface treatments; B. Nuclear reaction analysis; A. Titanium
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2021.110080

We report the role of ultrasonic shot-peening (SP) and laser-shock peening (LSP) on the insertion of atmospheric nitrogen during high temperature oxidation of pure titanium and the improvement of its oxidation resistance. Ion Beam analysis showed that for short oxidation durations, a layer of Ti2N is formed at the oxide-metal interface. However, only the LSP treatment leads to the formation of a long-term stable nitrogen-rich layer which acts as a barrier for the diffusion of oxygen. This explains the efficiency of the LSP treatment to reduce the oxidation of Ti and prevent embrittlement.
•A N-rich layer was detected at the oxyde-metal interface by Ion Beam Analysis from early oxidation hours.•At short exposure times, shot-peening promotes the formation of interfacial Ti2N and reduces oxidation.•Long-term oxidation of shot-peened Ti is hindered by the disappearance of the interfacial Ti2N layer.•Laser-shock peening induces a long-term stable N-rich layer which acts as a diffusion barrier for oxygen.•Laser-shock peening prevents embrittlement by reducing long-term oxygen diffusion in the metal.