Deposition Mechanism Analysis of Cold-Sprayed Fluoropolymer Coatings and Its Wettability Evaluation
- PDF / 2,729,170 Bytes
- 17 Pages / 595.276 x 790.866 pts Page_size
- 84 Downloads / 203 Views
PEER REVIEWED
Deposition Mechanism Analysis of Cold-Sprayed Fluoropolymer Coatings and Its Wettability Evaluation Wesley Lock Sulen1 • Kesavan Ravi1,2,4 • Chrystelle Bernard1,2,3 Yuji Ichikawa1 • Kazuhiro Ogawa1,2
•
Submitted: 27 June 2019 / in revised form: 30 April 2020 Ó ASM International 2020
Abstract Polymer coating by cold spray presents interesting features such as the possibility of protecting metallic substrates or adding functionalities to a structure. However, it is characterized by a low deposition efficiency and a weak interface between the substrate and the coating. In this study, we performed fluoropolymer coatings by the cold-spray process. Analysis of the particle deposition during cold spray highlighted the importance of the particle size, substrate temperature and inlet gas temperature and pressure on the adhesion polymer/substrate. The addition of hydrophobized fumed nano-ceramics (FNC) to the polymer feedstock enhances the deposition efficiency and polymer adhesion on the substrate. The addition of fumed nano-alumina (FNA) to the polymer feedstock tends to give better results than fumed nano-silica in terms of deposition efficiency thanks to (1) the difference in surface charge leading to the attractive force between the polymer
This article is an invited paper selected from presentations at the 2019 International Thermal Spray Conference, held May 26–29, 2019 in Yokohama, Japan and has been expanded from the original presentation. & Wesley Lock Sulen [email protected]; [email protected] 1
Fracture and Reliability Research Institute, Tohoku University, Sendai, Japan
2
ELyTMaX UMI 3757, CNRS – Universite´ de Lyon – Tohoku University, International Joint Unit, Tohoku University, Sendai, Japan
3
Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Japan
4
Present Address: Indian Institute of Technology (Indian School of Mines) Dhanbad, Dhanbad, India
and the FNA during the powder preparation stage and (2) a homogeneous repartition of the FNA on the polymer particle surface. In addition, the hydrophobization of the FNC maintains and enhances the hydrophobicity and water repellency properties of the fluoropolymer coating. Keywords Cold spray fluoropolymer hydrophobic coating nano-ceramic particles polymer powder
Introduction Fluoropolymers, like fluoroethylene propylene (FEP), polytetrafluoroethylene (PTFE) or Teflon, are known for their low-friction surface, high corrosion and chemical resistance due to their strong carbon–carbon backbone and carbon–fluorine group structure (Ref 1-3). The fluorine on a fluoropolymer repels other molecules so well that it is difficult for any material to adhere to its surface (Ref 4). FEP is a thermoplastic polymer exhibiting a semicrystalline microstructure, characterized by a degree of crystallinity lower than a PTFE (Ref 3). Due to a melting temperature in the range of 275-310 °C (Ref 5) and high inert, FEP can withstand high operating temperature and any extreme chemical abusive enviro
Data Loading...
