Heat Flux Controls by In Situ Laser Treatment for Thermal Spraying

In this study, Ni-Al powder is plasma sprayed on various substrates prepared by in-situ laser ablation and preheating. Surface topography and splat shape are examined in order to assess how laser induced heat flux affects surface modifications and variations in splat shape. The causes of laser induced surface modifications are identified for Al, Ti, and stainless steel substrates and it is shown that laser preheating improves surface absorptivity, which effectively subjects more defects to the effects of the laser.