YSZ粉末致密度对涂层性能的影响

The Influence of Densification of YSZ Powder on Coating Properties

为了研究YSZ粉末特性对热障涂层性能的影响,选择三种通过造粒烧结工艺制备的商用YSZ粉末,测试对比了粉末颗粒的各项性能,发现三种粉末仅致密度存在显著差异。在两种不同功率条件下采用等离子喷涂工艺利用三种YSZ粉末制备了热障涂层,观察了涂层的金相组织和断口形貌,测试了涂层孔隙率和结合强度,并采用电弧风洞考核了涂层的服役性能。研究结果表明,粉末致密度对涂层性能有显著影响,致密度高的YSZ粉末喷涂过程中熔融状态更好,涂层的孔隙率更低,结合强度更高;针对致密度低的粉末,增大喷涂功率可改善粉末的熔融状态,从而改善涂层的性能。经工艺调控制备的孔隙率和结合强度相近的涂层具有相当的隔热防护效果。

In order to study the influence of the characteristics of YSZ powder on the performance of thermal barrier coating,three kinds of commercial YSZ powder prepared by granulation and sintering process were selected.The properties of powder particles are tested and compared.Only the powder density was significantly different.The thermal barrier coating was prepared by plasma spraying process with three kinds of YSZ powder under two power conditions.The microstructure and fracture morphology of the coatings were observed,the porosity and tensile bonding strength of the coatings were tested,and the service performance of the coating was evaluated by arc wind tunnel.The results show that the powder density has a significant effect on the properties of the coating.The coating prepared with high density powder has lower porosity and higher tensile bonding strength,because of the better melting state;increasing the plasma power can improve the melting state of the low density powder,and improve the properties of the coating.The coatings with similar porosity and tensile bonding strength,which prepared by process adjustment,have considerable heat insulation and protection effect.