Abstract:

The tribological behavior and corrosion resistance of poly tetrafluoroethene (PTFE)composites filled with various amount of potassium titanate whiskers (PTW) and carbon fibers (CF) in sulfuric acid solution and under dry conditions were investigated respectively.The related mechanisms were discussed based on the SEM examinations of worn surfaces and optical micrographs of transfer behavior.The results indicated that the wear resistance of pure PTFE in acid increased by two orders of magnitude than that sliding in dry condition, and the friction coefficient was only 15.3% of that in dry condition.Compared with CF/PTFE composites, PTW/PTFE composites showed higher wear and corrosion resistance in acid.The wear rate and friction coefficient of PTFE in acid can be further decreased by PTW.At 15%(mass) PTW filler content, the wear rate of PTW/PTFE composites reached the lowest value, which increased the wear resistance of PTFE in acid by 13.8 times, and also 3.2 times higher than that of CF/PTFE composites.Owing to the cooling and lubricating effects of acid solution, the friction coefficient of PTFE composites decreased obviously than that in dry condition.However, the transfers onto the counterpart rings were significantly hindered when they were sliding in acid.When filler content was above 15%（mass）, furrow and abrasive wear were the main mechanisms for PTFE composites whether sliding in dry condition or in acid.

摘要：

分别研究了不同含量钛酸钾晶须(PTW)、碳纤(CF)填充聚四氟乙烯(PTFE)复合材料在硫酸溶液中和干摩擦条件下摩擦学性能以及酸中的耐蚀性能，借助SEM等分析探讨了相关机理。结果表明，酸中纯PTFE耐磨性较干摩擦条件下提高了2个数量级，摩擦系数也只有干摩擦的15.3%。与CF/PTFE相比，PTW/PTFE复合材料在酸中显示更好的耐蚀和耐磨性能。PTW可以进一步提高PTFE酸中耐磨性能、降低摩擦系数。含15%（质量）PTW时复合材料具有最低的磨损率，此时比纯PTFE酸中耐磨性提高13.8倍，是相同含量CF/PTFE耐磨性的3.2倍。由于酸溶液的冷却和润滑作用，复合材料的摩擦系数与干条件相比明显降低。然而，酸溶液阻止了转移膜的形成。不管是干摩擦还是在酸性溶液中，当填料含量超过15%（质量）时，犁削和磨粒磨损是PTFE复合材料的主要磨损机理。