Deposition of PEEK coatings using a combined flame spraying-laser remelting process

Thermoplastic coatings are of great interest for industrial applications. In the present work, PEEK (poly-ether-ether-ketone) coatings were prepared on Al and stainless steel substrates using a flame spraying technique. The as-sprayed coating, however, was simply an accumulation of the PEEK powders. It presented a high porosity and, hence, bad mechanical properties. In order to obtain a dense coating, a laser treatment was chosen to remelt the polymer coating. Nd:YAG and CO₂ lasers were introduced in this work. The results show that the CO₂ laser is more suitable for densifying the PEEK coating. The PEEK coating deposited on stainless steel could be densified by the CO₂ laser. This indicates that it is feasible to obtain a dense PEEK coating by this combined flame spraying-laser remelting process. The laser-treated coating exhibits an amorphous structure. There was no obvious chemical modification observed on the PEEK after the flame spraying process and the laser treatment.