TC4钛合金在3.5%NaCl溶液中的微动腐蚀特性

Fretting Corrosion Characteristics of TC4 Titanium Alloy in 3.5% NaCl Solution

采用SRV微动磨损试验机，对比研究了TC4钛合金在纯水介质中的微动磨损机制和3．5％NaCl（质量分数）溶液中的微动腐蚀特性，分析了钛合金在两种介质中的微动磨损机制。结果表明：振幅越小，TC4钛合金的摩擦系数曲线越稳定，磨损体积越小；钛合金在3．5％NaCI溶液中的磨损量要比纯水介质中高出一个数量级，腐蚀和磨损呈“正相关”关系；经过微动磨损／微动腐蚀的试样耐蚀性基本无差别，较钛合金基体，抗腐蚀性能明显降低一个数量级；钛合金在纯水介质中的微动磨损机制主要为粘着磨损和剥层磨损，而在3．5％NaCI溶液中的微动磨损机制主要为腐蚀磨损和磨粒磨损。

Using the SRV fretting wear tester, the fretting wear mechanism of TC4 titanium alloy in purified water and the fretting corrosion behavior in 3.5% （ mass fraction） NaCl solution were studied and compared. The fretting wear mechanism of titanium alloy in the two mediums was also analyzed. The results showed that the friction coefficient curve of TC4 titanium alloy became mote and more stable with the decrease of amplitude, and the wear volume loss also declined. The wear volume loss in 3.5% NaCl solution was an order of magnitude higher than that in purified water medium. A ＇ positive correlation＇ existed between corrosion and wear. The corrosion resistance of the sample after fretting wear/corrosion was basically no difference, but was significantly reduced by one order of magnitude compared to the TC4 substrate. The fretting wear mechanism of titanium alloy in purified water medium was mainly adhesive wear and peeling wear, while the fretting wear mechanism in 3.5% NaCl solution was mainly corrosion wear and abrasive wear.