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Full-Text Articles in Mechanical Engineering
Tribological Studies Of Thick Polytetrafluoroethylene Coatings Enhanced By Polydopamine And Nanoparticles, Sujan Kumar Ghosh
Tribological Studies Of Thick Polytetrafluoroethylene Coatings Enhanced By Polydopamine And Nanoparticles, Sujan Kumar Ghosh
Graduate Theses and Dissertations
Polytetrafluoroethylene (PTFE) is a popular low friction solid lubricant with high chemical and thermal stability. Thick PTFE coatings have the potential for many tribological applications, such as replacing Tin-based Babbitt materials in journal bearings. However, the weak bonding strength to the substrate and the high wear rate of PTFE coatings are current limiting factors. The lack of understanding of their tribological properties and wear mechanisms in oil-lubricated conditions and how coating thickness affects the tribological performance further hindered the use of PTFE coatings. In this dissertation, polydopamine (PDA), a bio-inspired adhesive, is used as an underlayer for or as a …
Viscoelasticity Of Ptfe-Based Face Seals, Bo Tan
Viscoelasticity Of Ptfe-Based Face Seals, Bo Tan
Theses and Dissertations--Mechanical Engineering
PTFE-based materials are widely used in areas of tribology, particularly in seal and bearing applications because of their outstanding self-lubricating properties. Often in dynamic seal applications there is a need for ultra-low mechanical friction loss between the sealing surfaces. Due to its extremely low friction coefficient, there is interest in employing Polytetrafluoroethylene (PTFE) materials in such applications. One challenging aspect of employing PTFE is that these materials are viscoelastic and plastic. This dissertation concentrates on the modeling of viscoelastic material response when used as mechanical face seals with a focus on PTFE-based materials. First, the viscoelastic characteristics are measured through …
Wear Resistant Polydopamine/Ptfe Nanoparticle Composite Coating For Dry Lubrication Applications, Samuel George Beckford
Wear Resistant Polydopamine/Ptfe Nanoparticle Composite Coating For Dry Lubrication Applications, Samuel George Beckford
Graduate Theses and Dissertations
This dissertation presents an investigation into the effect of nanoparticle fillers and a polydopamine adhesive primer on the tribological performance of thin PTFE films. The principal objective of this investigation was to reduce wear in PTFE films, an issue which precludes the use of PTFE films in tribological applications requiring high durability. The friction and wear of the composite films were evaluated using a ball-on-flat configuration in linear reciprocating motion. It was found that the use of a polydopamine adhesive primer reduces the wear of PTFE films more than 600 times. X-ray photoelectron spectroscopy (XPS) results show that a tenacious …