Pawel Rokicki

Abstract:

Environments that contain volcanic ashes can lead to serious damage of static and rotating elements of the jet engine. The mechanism standing behind the issue are complex, and concern not only erosion processes but also chemical interactions in elevated temperature reaching up to 1500°C [1]. Volcanic ash melts inside the engine, and in such a form hits the surface of the blade/vane. Nowadays, the most commonly used thermal and environmental barrier coatings (TBC/EBC) for turbine blades is yttrium stabilized zirconia dioxide (YSZ) [2,3]. It is a part of a whole coating consisting of two interacting layers, namely bond coat and top coat. The main role of the bond coat is to provide proper adhesion to sustain all the other surface parameters responsible for the efficiency of the whole blade. As the YSZ is characterized by proper thermal properties, it does not provide sufficient chemical resistance to the volcanic ash environment [3,4]. Thus, the research presented in the paper aims to develop a technology for manufacturing a coating that would be resistant to not only erosion, but also to chemical meaning in complex environments. This paper presents a step-by-step technology of EB-PVD, thermal, and plasma spraying processes leading to the manufacture of environmental barrier coatings based on YSZ and gadolinium zirconate (GZO). The coating obtained in the research were analysed by means of optical and electron microscopy, which allows a full description of their structure.