Next Article in Journal
Evaluation of Mesenchymal Stem Cells and Osteoblasts’ Adhesion and Proliferation in the Presence of HA-AL Biomaterials
Next Article in Special Issue
Delayed Formation of Thermally Grown Oxide in Environmental Barrier Coatings for Non-Oxide Ceramic Matrix Composites
Previous Article in Journal
Shear Bond Strength of Nanohybrid Composite to Biodentine with Three Different Adhesives
Previous Article in Special Issue
Crack Initiation Criteria in EBC under Thermal Stress
Open AccessFeature PaperArticle

Environmental Barrier Coatings Made by Different Thermal Spray Technologies

1
Forschungszentrum Jülich GmbH, IEK-1, 52425 Jülich, Germany
2
Korea Institute of Ceramic Engineering and Technology (KICET), Engineering Ceramics Center, Shindun-myeon, Icheon-si, Gyeonggi-do 17303, Korea
3
Jülich Aachen Research Alliance: JARA-Energy, Jülich 52425, Germany
*
Author to whom correspondence should be addressed.
Coatings 2019, 9(12), 784; https://doi.org/10.3390/coatings9120784
Received: 6 October 2019 / Revised: 11 November 2019 / Accepted: 18 November 2019 / Published: 22 November 2019
(This article belongs to the Special Issue Environmental Barrier Coatings)
Environmental barrier coatings (EBCs) are essential to protect ceramic matrix composites against water vapor recession in typical gas turbine environments. Both oxide and non-oxide-based ceramic matrix composites (CMCs) need such coatings as they show only a limited stability. As the thermal expansion coefficients are quite different between the two CMCs, the suitable EBC materials for both applications are different. In the paper examples of EBCs for both types of CMCs are presented. In case of EBCs for oxide-based CMCs, the limited strength of the CMC leads to damage of the surface if standard grit-blasting techniques are used. Only in the case of oxide-based CMCs different processes as laser ablation have been used to optimize the surface topography. Another result for many EBCs for oxide-based CMC is the possibility to deposit them by standard atmospheric plasma spraying (APS) as crystalline coatings. Hence, in case of these coatings only the APS process will be described. For the EBCs for non-oxide CMCs the state-of-the-art materials are rare earth or yttrium silicates. Here the major challenge is to obtain dense and crystalline coatings. While for the Y2SiO5 a promising microstructure could be obtained by a heat-treatment of an APS coating, this was not the case for Yb2Si2O7. Here also other thermal spray processes as high velocity oxygen fuel (HVOF), suspension plasma spraying (SPS), and very low-pressure plasma spraying (VLPPS) are used and the results described mainly with respect to crystallinity and porosity. View Full-Text
Keywords: environmental barrier coatings; thermal spray methods; atmospheric plasma spraying; suspension plasma spraying; very low-pressure plasma spraying; high velocity oxygen fuel spraying environmental barrier coatings; thermal spray methods; atmospheric plasma spraying; suspension plasma spraying; very low-pressure plasma spraying; high velocity oxygen fuel spraying
Show Figures

Figure 1

MDPI and ACS Style

Vaßen, R.; Bakan, E.; Gatzen, C.; Kim, S.; Mack, D.E.; Guillon, O. Environmental Barrier Coatings Made by Different Thermal Spray Technologies. Coatings 2019, 9, 784.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop