UNDERSTANDING WEAR/CORROSION INTERACTIONS IN TRIBOCORROSIONOF TITANIUM AND ITS ALLOYS

摘要

Today, titanium is no longer considered to be an exotic material. Previously, it wasthought that titanium and its alloys imposed such high costs that their use was notviable. This is not the case now and there are many titanium components in service inmarine environments, such as Ti valves, impellers and heat exchanger tubes.Designers and engineers are increasingly seeing titanium and its alloys as a viablealternative to other high-grade alloys for applications in marine environments, whereerosion and corrosion resistance are important. This paper reports on studies of tribocorrosionperformance of commercially pure titanium (CP-Ti) and three alloys in twosituations (1) erosion-corrosion conditions and (2) cavitation-corrosion conditions. Astitanium relies on a passive film for its corrosion resistance, under any tribologicalapplication it may be expected that the passive film will be breached. If so, parallels towork on stainless steel under such conditions may be expected. A series ofexperiments was conducted to determine the electrochemical corrosion characteristicsand resistance to cavitation-corrosion at 1818℃ and 50 C 50℃ and erosion-corrosion at 18 C 18℃both in 3.5% NaCl. The performance of Ti and its alloys under tribo-corrosionconditions, with emphasis on the role of corrosion and cavitation/corrosion anderosion/corrosion interactions in the overall material degradation is discussed.