PS-PVD热障涂层柱状结构沉积调控及表面改性

Columnar structure deposition regulation and surface modification of PS-PVD thermal barrier coatings

等离子-物理气相沉积(PS-PVD)具有涂层多结构调控的特性,为高隔热、长寿命热障涂层的制备提供可能,是实现未来高性能航空发动机发展的关键技术之一。PS-PVD柱状结构涂层独特的微观结构使其兼具高隔热和热循环寿命长的双重优势,在航空发动机热障涂层领域有着广阔的应用前景。但PS-PVD柱状结构涂层工艺调控是在大量的实验基础上实现的,缺少相关的理论研究,而且高孔隙率的柱状结构涂层面临的CaO-MgO-Al 2O 3-SiO 2(CMAS)腐蚀失效问题仍然限制着涂层的使用。本文从涂层结构特征入手,阐述了沉积单元相态对涂层结构的影响规律,揭示了柱状结构涂层的气相沉积机理。在此基础上分析了涂层结构的工艺影响,并基于涂层材料在射流内的相态转变,从理论层面阐明了工艺参数调控的本质。此外,分析了PS-PVD柱状结构涂层CMAS腐蚀失效机理,阐述了表面镀铝改性对涂层抗CMAS腐蚀性能的影响机制,并对PS-PVD涂层结构调控和性能提升以及PS-PVD技术在环境障涂层和功能薄膜等领域的应用进行了展望。

Plasma spray-physical vapor deposition(PS-PVD)technology which has many characteristics of the multi-structure regulation,provides the possibility for the preparation of thermal barrier coatings with high thermal insulation and long life.It is one of the key technology to realize the development of high performance aero-engine.The unique microstructure of PS-PVD columnar structure coatings has dual advantages of high thermal insulation and long thermal cycle life,and has broad application prospects in the field of thermal barrier coatings for aircraft engines.However,the process control of PS-PVD columnar structure coating is achieved on the basis of a large number of experiments,and there is a lack of relevant theoretical research.Moreover,the CaO-MgO-Al 2O 3-SiO 2(CMAS)corrosion failure problem faced by the columnar structure coating with high porosity restricts the use of the coating.The influence of deposition unit phase states on the coating structure was described from the structural characteristics of the coating,and the vapor deposition mechanism of columnar coating was revealed.Based on the phase transition of coating material in the jet,the essence of process parameters regulation was clarified.In addition,the corrosion mechanism of CMAS and the corrosion resistance mechanism of Al-modified coating were investigated.Finally,the structure control and performance improvement of PS-PVD coating and the application of PS-PVD technology in environmental barrier coatings and functional films were prospected.