Laser ablation behavior of nano-copper particle-filled phenolic matrix nanocomposite coatings

Laser is becoming increasing threat to materials due to its high energy that can induce thermal damage, especially high energy continuous-wave (CW) laser. In this case, laser protection has attracted more and more concerns. Nanocomposite coatings that consist of nano-copper filler with phenolic resin matrix have been designed and successfully prepared to meet the requirement of anti-laser ablation. The anti-laser ablation ability of the nanocomposite coatings is evaluated through the temperature of the back-surface substrate. Results show that the transpiration cooling effect of nano-copper particles do improve the anti-laser ablation property of the coating. The residual char with porous structure which is the pyrolysis result of phenolic resin plays a key role as a barrier to prevent laser from irradiating inside of the coating. The amorphous carbon gradually transforms to graphitic structure during CW laser irradiation. The latter has better stability at high temperature, improving anti-laser ablation. The micro-morphologies and element content analysis indicate that the evaporation of nano-copper particles occurs layer by layer until the total pyrolysis of phenolic resin located in the vertical direction of the coating. All the analyses show that this nanocomposite coating has excellent performance as a protective shield to anti-laser damage.