T. Kuwashima, T. Saitoh, T. Sonoda, K. Suzuki, M. Fujiwara, Iwate Industrial Research Institute, Morioka Iwate, Japan
In the thermal spraying technique, the process includes some problems such as insufficient cohesive strength between particles in the coating. It is considered that the laser treatment of thermal spray coating will be effective method to improve the coating properties. In this study, an yttrium aluminum garnet (YAG) laser treatment was carried out on the sprayed coating in order to examine the effect of laser beam on the coating properties.Several carbide powders were used as the spray material, and stainless steel (SUS304) was used as the substrate. Irradiation laser power conditions were 1.5kW, 2.0kW and 2.5kW, and defocus distance conditions were ±0mm, +30mm, +60mm, +90mm, changing the energy density and the traverse speed conditions were 100mm/s, 200mm/s, 300mm/s. The cross section of coating structure was observed by optical microscopy and was analyzed by EPMA and XRD. The hardness of the coatings was measured by micro vickers hardness tester.
The coating structure varied from the laser irradiation condition. In the conditions of defocus distance±0mm, traverses speed 100mm/s, the sprayed coatings were melted. The coating structure was different even in the identical processing condition by the place. The micro vickers hardness of melted area of coatings was lower and heat affected area of coatings was higher than no laser treatment coating.
Summary: In this study, an yttrium aluminum garnet (YAG) laser treatment was carried out on the sprayed coating in order to examine the effect of laser beam on the coating properties.Several carbide powders were used as the spray material.The cross section of coating structure was observed by optical microscopy and was analyzed by EPMA and XRD. The hardness of the coatings was measured by micro vickers hardness tester.
