Oxidation behavior of TiCr and TiMo alloys formed by low-energy pulsed electron beam impact

• Published in: Surface & coatings technology 2022-03, Vol.434, p.128227, Article 128227
• Main Authors: Shymanski, V.I., Esipenko, D.V., Uglov, V.V., Koval, N.N., Ivanov, Y.F., Teresov, A.D.
• Format: Article
• Language: English
• Subjects: Alloys; Anatase; Chromium; Diffusion layers; Electron beams; Intermetallic compounds; Molybdenum; Oxidation; Oxidation resistance; Oxygen; Penetration depth; Phase composition; Pulsed electron beams; Rutile; Solid solutions; Stoichiometry; Surface modification; Titanium; Titanium base alloys; Titanium dioxide; Titanium oxide; Titanium-chromium alloy; Titanium-molybdenum alloy
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2022.128227

The titanium-based alloys with 2–3 at.% of chromium (TiCr) and molybdenum (TiMo) were produced on the top of titanium samples by means of the high-intense pulsed electron beam impact on the titanium with preliminary deposited Cr and Mo coatings. The TiCr and TiMo alloys were subjected to oxidation in open air atmosphere at temperature 600 °C. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and energy-disperse X-ray microanalysis (EDX) were used for structure and elemental composition determination in the samples. The analysis of oxygen depth profiles showed the increase in oxygen penetration depth in the case of TiCr alloy in comparable to pure titanium. The oxygen concentration corresponding to stoichiometry of the oxide phase TiO2 was found on the depth equaled to the thickness of the TiCr alloy that shows the enhancement of the diffusion of oxygen in the modified layer. The diffusion of oxygen at the temperature of 600 °C is enhanced by decomposition of the solid solutions based on bcc β-Ti phase with free chromium and molybdenum atoms releasing. The free molybdenum atoms take part in the stabilization of TiO2 anatase phase while the free chromium atoms form intermetallic compound TiCr2 preventing the sample from oxidation. •Oxidation resistance of TiCr and TiMo alloys under the open-air heating was investigated.•The free Cr atoms released from solid solution β-Ti(Cr) during heating form intermetallic phase TiCr2 preventing the surface from oxygen penetration.•The volume fraction of both modifications of TiO2 phase, rutile and anatase, is higher in TiMo alloy.