Electrochemical Study on Friction and Wear of Some Commercial Materials in Liquid Environments

研究了材料在空气、纯水和盐水中单向滑动和微动条件下的摩擦磨损特性，以阐明腐蚀环境下的摩擦磨损机理。在空气中，对严重和轻度磨损表面的三维地形进行分析，使研究从严重到轻度磨损过渡的条件成为可能。在液体环境下，研究了接触载荷、预腐蚀时间、溶液质量浓度、溶解氧含量（DO）和阴极保护对磨损模式转变的影响。研究了溶解氧对微动过程中摩擦磨损的影响。由于凸起磨损导致的平面面积增加，导致实际接触面积的平均接触压力迅速下降。这个过程导致了从严重到轻度磨损的转变。在液体环境中，从严重磨损过渡到轻度磨损的接触负荷比干燥空气中的接触负荷要高得多。在纯水中，预腐蚀时间较短时出现严重磨损，预腐蚀时间一定时出现严重到轻度磨损的过渡，轻度磨损出现的时间比预腐蚀时间长。在0.5 wt%的生理盐水中，在DO 0.05-18mg/l范围内出现轻度磨损，磨损率随着DO的降低而降低。在0.01 wt%的生理盐水中，当DO低于2mg/l.5时，磨损模式由轻度变为严重磨损。在盐水中，由于施加电位E=-0.50—0.80 V（vs）之间的腐蚀保护不完全，轻度磨损占主导地位，而不考虑DO。Ag / AgCl)。在E -0.90 V时，接触面出现了严重的磨损。纯铁在纯水和盐水中微动时，DO含量较低时摩擦力较大，随DO含量的增加而减小。另一方面，微动磨损与摩擦磨损呈相反趋势。纯铜在盐水中微动时，DO与摩擦的关系与铁微动时相同。磨损随溶解氧含量的变化对生理盐水温度的影响非常复杂。少

Friction and wear characteristics of materials under unidirectional-sliding and fretting conditions was investigated in air, in pure water, and in saline to elucidate the friction and wear mechanism in corrosive environments. In air, the analysis of three-dimensional topographies on severe and mild worn-surfaces made possible to study the condition for the transition from severe to mild wear. In liquid environments the effects of contact load, pre-corrosion time, weight-concentration of solution, dissolved-oxygen content(DO), and cathodic protection on the transition of wear mode was investigated. The effect of dissolved oxygen on the friction and wear during fretting was also studied.1. The increase in the area of flat surfaces due to the wear of asperities resulted in the rapid decrease in the mean contact pressure of real contact area. This process caused the transition from severe to mild wear.2. The contact load for the transition from severe to mild wear in liquid environments wa … More s very higher than the contact load in dry air.3. In pure water, severe wear occurred when pre-corrosion time was shorter, the transition from severe to mild wear observed at a certain pre-corrosion time, and mild wear appeared at longer time than the time.4. In 0.5 wt% saline, mild wear occurred in the range of DO 0.05-18mg/l, and the wear rate was reduced with the decrease in DO. In 0.01 wt% saline the wear mode changed from mild to severe wear at DO lower than 2mg/l.5. In saline mild wear predominated irrespective of DO due to the incomplete corrosion protection between applied potentials E=-0.50--0.80 V(vs. Ag/AgCl). At E -0.90 V severe wear appeared with the seizure of contact surfaces.6. During the fretting of pure iron in pure water and in saline, friction was higher at less DO content and decreased with the increase in the DO content. On the other hand, fretting wear presented the reverse tendency as the friction.7. During the fretting of pure copper in saline, the relationship between DO and friction was the same as observed in the fretting of iron. The variation of wear with DO content was very complicated for the temperature of saline. Less