等离子喷涂Al_2O_3陶瓷涂层激光熔化深度的研究

The depth of laser remelting layer of the plasma sprayed Al 2O 3 ceramic coatings

采用一维半无限模型和双层板理想接触模型对等离子喷涂Al2 O3陶瓷涂层激光重熔的熔化层厚度进行了计算 ,并与实验结果进行了比较。激光加热速度和熔区自冷却速度达 10 5℃ /s以上 ,温度梯度达 10 5℃ /mm以上 ;双层板理想接触模型的计算结果比一维半无限模型的结果更接近实验值。涂层设计对熔化层厚度有显著影响 ,喷有单一陶瓷层的熔化厚度最大 ,粘结层和过渡层引入之后 ,熔化层厚度下降 ,且还随SiO2 的含量增加而进一步下降。在具有相同涂层设计时 ,熔化层厚度随激光能量密度的增大而增大。

This paper deals with the calculating of depth o f laser remelting layers in the plasma sprayed Al 2O 3 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 10 5℃/s and the temperature gradient is about 10 5℃/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 SiO 2 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.