The Effects of Graphite Filler on the Tribological Properties of Polydopamine/PTFE Coatings

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• 作者：Samuel Beckford ; Jiyu Cai ; Robert A. Fleming ; Min Zou
• 关键词：PTFE ; Polydopamine ; Graphite ; Wear ; Low ; friction coating
• 刊名：Tribology Letters
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：64
• 期：3
• 全文大小：3,341 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Tribology, Corrosion and Coatings
  Surfaces and Interfaces and Thin Films
  Theoretical and Applied Mechanics
  Physical Chemistry
  Nanotechnology
  
• 出版者：Springer Netherlands
• ISSN：1573-2711
• 卷排序：64

文摘

This investigation examines the effects of incorporating graphite as a filler in the polytetrafluoroethylene (PTFE) topcoat of a polydopamine/PTFE dual-layer coating. Polydopamine (PDA) is used to enhance the adhesion of PTFE coatings to the substrate, and graphite is used to improve the formation of a transfer film on the counterface and to take advantage of the low-friction properties of graphite. The results show that incorporating only 1.0 wt% graphite in PDA/PTFE coatings can increase their durability fivefold and reduce friction by 17 %. Examination of the wear morphology indicates that these improvements in tribological properties are in fact the result of the formation of a transfer film on the counterface that allows the coating to essentially slide against itself, creating a low shear strength interface that exhibits exceptionally low friction and low wear. Linearly increasing load scratch tests show that the improvement in durability is also the result of improved adhesion between the PTFE topcoat and the PDA basecoat, preventing large-scale delamination of the coating.