悬浮液等离子喷涂纤维掺杂Ba(Mg1/3Ta2/3)O3热障涂层的可控制备及其阻裂行为

针对新型热障涂层陶瓷层在使用过程中普遍存在的过早开裂失效的问题，本项目以Ba(Mg1/3Ta2/3)O3（BMT）材料为研究对象，提出采用悬浮液等离子喷涂制备一种具有阻裂能力的YSZ纤维掺杂BMT复合涂层。其核心是通过调控涂层微结构提升涂层应变容限，辅以纤维增韧来实现涂层阻裂能力的提升。具体通过研究悬浮液成分与制备工艺对其稳定性和雾化特性的影响，获得高稳定性、良好雾化特性的悬浮液；通过调控工艺参数，研究不同微结构涂层的组织成分特征，分析从悬浮液到涂层形成的组织成分演化，明晰涂层的沉积机理；利用热冲击实验对涂层阻裂行为进行研究，并基于涂层真实微结构的数值模拟，分析涂层的阻裂机理；最后建立工艺参数、涂层微结构及其阻裂性能间的关系。通过优化工艺参数，实现具有高阻裂性能BMT涂层的可控制备。本项目对促进BMT涂层的应用具有重要的理论意义与实际价值，同时对于其它陶瓷涂层阻裂性能的改善具有借鉴意义。

Aiming at the common problem of premature cracking failure of new ceramic coatings for thermal barrier coatings during use, this project takes Ba(Mg1/3Ta2/3)O3 (BMT) material as the research object and prepares YSZ fiber-doped BMT composite coatings with crack-resistance by using suspension plasma spraying. The core of the project is to improve the crack-resistance of the ceramic coatings by adjusting the microstructure to increase the strain tolerance, supplemented by fiber toughening. The specific contents of the study include the following aspects: the effects of composition and preparation process on the stability and atomization characteristics of the suspension liquid are studied to obtain the suspension liquid with high stability and good atomization characteristics; the microstructure and composition of different coatings prepared by adjusting the spraying parameters are characterized, and the evolution of the microstructure and composition from the suspension liquid to the coating formation is analyzed to clarify the deposition mechanism of the coatings; the crack-resistance behavior of the coatings is evaluated by thermal shock test, and the crack-resistance mechanism of the coatings is analyzed based on the numerical simulation of the actual microstructure. Finally, the relationship among the spraying parameters, the microstructure and the crack-resistance of the coatings is established. The controllable preparation of the BMT coatings with high crack-resistance is achieved by optimizing the coating preparation parameters. This project has important theoretical significance and practical value for promoting the application of BMT coatings, and also has reference significance for improving the crack-resistance of other ceramic coatings.