Abstract
A fabrication of superhydrophobic Perfluoroalkoxy Alkane (PFA)coatings on stainless steel surfaces by cold-spray technique has been demonstrated in this work. The in-situ supersonic impact deposition and consolidation of finely divided 20–40 μm powder material yielded hydrophobic thin coatings of PFA which exhibited contact angles of 125° but high roll off angles of 60°. The deposition efficiencies were less than 0.5%, coating was mechanically very fragile and non-uniform. However, the cold-spray deposition efficiency was subsequently increased to almost 15% by performing simple modification of particle surface morphology by introducing organosilane coated nanoceramic layers on the PFA particles and by laser texturing the stainless steel substrate surfaces to form mountain-valley micro-structures. The nanoceramic interlayers formed bridge bonds at the particle-particle interface and laser texturing achieved efficient coating-substrate interlock. The improved coatings exhibited super-hydrophobic character with 160° contact angle and 6° roll-off angle. The superhydrophobicity was seen to be as a result of micro-/nano-structured surface consisting of papillae like structures capped by a layer of hydrophobic nanoceramic. The coating also exhibited excellent water repellency.
| Original language | English |
|---|---|
| Pages (from-to) | 17-24 |
| Number of pages | 8 |
| Journal | Surface and Coatings Technology |
| Volume | 373 |
| DOIs | |
| Publication status | Published - 2019 Sept 15 |
Keywords
- Cold spray
- PFA
- Polymer
- Superhydrophobic coating