激光重熔对等离子喷涂ZrO_2-20%Y_2O_3热障涂层隔热性能的影响

采用大气等离子喷涂(APS)技术在铝基体表面制备氧化锆(ZrO2-20%Y2O3,质量分数)热障涂层,并用脉冲激光对其进行重熔处理,研究了激光重熔对涂层组织形貌、物相转变和隔热性能的影响。研究结果表明激光的比能量对涂层的成型及性能有重要影响,过高的比能量会使涂层表面粗糙度增加,涂层成型变差。在选用合适的低比能量激光重熔条件下,扫描电镜观察结果表明经激光重熔可消除喷涂态涂层的孔隙和层状结构。对粉末和重熔前后的涂层进行了X射线衍射分析,结果表明喷涂及重熔过程中都没有发生相变;隔热试验结果表明重熔后涂层的隔热温度有所下降。

Effect of laser remelting on heat insulation performance of plasma sprayed ZrO2-20%Y2O3 thermal barrier coatings

The influence of laser remelting on properties of ZrO2-20%Y2O3 thermal barrier coatings deposited by APS method on aluminum substrate, such as the microstructure, phase transition and heat insulation performance is investigated. Pulse laser was used for laser remelting of coating surface. The results show that different specific energy of the laser has an obvious impact on the shaping and performance of the coating. The surface roughness increases and the shaping get worse while the specific energy increases. Under suitable low specific energy laser remelting conditions, the surface and section morphology investigated by SEM indicates that laser remelting can eliminate the layer stacking structure and porosity of coating layer. XRD analysis shows that no phase transition occurred during plasma spraying and laser remelting process. The heat insulation test indicates that the heat insulation performance of APS coatings decreased after laser remelting.