The depth of laser remelting layer of the plasma sprayed Al2O3 ceramic coatings

This paper deals with the calculating of depth o f laser remelting layers in the plasma sprayed Al2O3 ceramic coatings using infinite half space model and ideal contact double slabs model and the comp aring with the experimental results. The heating and cooling rates can reach 105℃/s and the temperature gradient is about 105℃/mm. The values calculated with the latter model are more approximate to the experimental results than thos e wit h the infinite half space model. The coating design has a strong effect on the remelting depth of ceramic coatings. The remelting depth of single ceramic coat ing reaches to the maximum value.The introduction of bond layer and transition l ayer will reduce the remlting depth. Furthermore, the depth will decrease as the content of doped SiO2 in the coating goes up. For the ceramic coatings with t he same design, the depth of laser remelting layer increases with the output ene rgy density of laser.