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

Abstract

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-Al2O3-SiO2(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.

Keywords

• plasma spray-physical vapor deposition (ps-pvd)
• deposition mechanism
• structural regula- tion
• surface modification
• cmas corrosion