Formation and characterization of wear-resistant PEO coatings formed on β-titanium alloy at different electrolyte temperatures

► Wear-resistant coatings are formed on β-titanium alloy by plasma electrolytic oxidation. ► Better coatings are formed at lower electrolyte temperatures. ► High speed video imaging was used to monitor the discharge behavior during the process. Plasma electrolytic oxidation of single β-phase Ti–15 mass% V–3 mass% Al–3 mass% Cr–3 mass% Sn (hereafter denoted as Ti–15–3) alloy has been conducted in alkaline aluminate electrolyte at different electrolyte temperatures between 278 and 313K. The results obtained disclose the highly improved wear resistance of the coatings formed at the lowest temperature of 278K. The coating formed at this temperature has lower porosity and contains higher concentration of α-Al2O3 phase in addition to the Al2TiO5 major phase. In contrast, non-uniform coatings are formed at higher temperatures and their porosity is relatively high. Thus, the highest wear resistance of the Ti–15–3 is obtained when the coating is formed at 278K. Such influence of the electrolyte temperature on the coating morphology and composition is discussed by direct imaging based on direct video imaging data during the coating process.