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

摘要

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 313 K. The results obtained disclose the highly improved wear resistance of the coatings formed at the lowest temperature of 278 K. The coating formed at this temperature has lower porosity and contains higher concentration of α-Al_2O_3 phase in addition to the Al_2TiO_5 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 278 K. 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.