Abstract In this study, the effects of polytetrafluoroethylene (PTFE) thickness on the wear and friction properties of spin-coated PTFE and polydopamine (PDA)/PTFE coatings on stainless steel (SS) substrates were investigated. The PTFE coating thickness was varied by controlling the number of PTFE spin-coating deposition cycles. The PDA/PTFE coatings showed 1.4 to 4.9 times the wear life of that of the PTFE coating deposited at the same number of PTFE spin-coating cycles. The coefficients of friction and water contact angles of the PDA/PTFE coatings were found to be slightly higher than those of the PTFE coatings due to higher surface roughness. The addition of a PDA underlayer helped the PTFE to adhere more strongly to the SS substrate, which contributed to the coatings’ improved durability. The durability of the PDA/PTFE coating increased sharply when the PTFE thickness exceeded 30 μm. Notably, a 42-μm-thick PDA/PTFE coating had 105 times the wear life of that of a 3-μm-thick PTFE coating. The enhanced transfer film on the counterface and the larger contact area for supporting the load were responsible for the extended durability of the thicker coatings.

中文翻译：

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PTFE 厚度对厚 PDA/PTFE 涂层摩擦学行为的影响

摘要 本研究研究了聚四氟乙烯 (PTFE) 厚度对不锈钢 (SS) 基材上旋涂 PTFE 和聚多巴胺 (PDA)/PTFE 涂层的磨损和摩擦性能的影响。通过控制 PTFE 旋涂沉积循环的次数来改变 PTFE 涂层厚度。PDA/PTFE 涂层的磨损寿命是在相同数量的 PTFE 旋涂循环下沉积的 PTFE 涂层的磨损寿命的 1.4 到 4.9 倍。由于表面粗糙度较高，PDA/PTFE 涂层的摩擦系数和水接触角略高于 PTFE 涂层。添加 PDA 底层有助于 PTFE 更牢固地粘附在 SS 基材上，这有助于提高涂层的耐用性。当 PTFE 厚度超过 30 μm 时，PDA/PTFE 涂层的耐久性急剧增加。值得注意的是，42 微米厚的 PDA/PTFE 涂层的磨损寿命是 3 微米厚 PTFE 涂层的 105 倍。配合面上增强的转移膜和用于支撑负载的更大接触面积是较厚涂层的耐用性延长的原因。