Crack Growth Tests in Air Plasma-Sprayed Yttria Coatings for Alumina Ceramic Matrix Composites

Yttria coatings for all-oxide combustor walls were tested for their crack-growth behavior. These environmental and thermal barrier Y<sub>2</sub>O<sub>3</sub>-coatings were processed by atmospheric plasma spraying (APS). The stiffness and strength were measured for as-received...

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Bibliographic Details
Main Authors: Stefan Hackemann, Marion Bartsch
Format: Article
Language:English
Published: MDPI AG 2019-08-01
Series:Ceramics
Subjects:
EBC
CMC
Online Access:https://www.mdpi.com/2571-6131/2/3/39
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spelling doaj-2b5d5059dc6f4812b2fffb72ea59111f2020-11-25T01:15:29ZengMDPI AGCeramics2571-61312019-08-012351452410.3390/ceramics2030039ceramics2030039Crack Growth Tests in Air Plasma-Sprayed Yttria Coatings for Alumina Ceramic Matrix CompositesStefan Hackemann0Marion Bartsch1German Aerospace Center (DLR), Institute of Materials Research, D-51170 Cologne, GermanyGerman Aerospace Center (DLR), Institute of Materials Research, D-51170 Cologne, GermanyYttria coatings for all-oxide combustor walls were tested for their crack-growth behavior. These environmental and thermal barrier Y<sub>2</sub>O<sub>3</sub>-coatings were processed by atmospheric plasma spraying (APS). The stiffness and strength were measured for as-received and aged samples that were heat treated at 1000 &#176;C, 1100 &#176;C and 1200 &#176;C for a 10 h dwell time. The results show a clear development with respect to the aging conditions. The changes of the modulus and the bending strength indicate that the microstructural changes are not completed, even after aging at 1200 &#176;C for 10 h. The fracture toughness was tested for different orientations on samples aged at 1200 &#176;C. Bending tests as well as indentation experiments were conducted. Furthermore, a bending device was designed to observe the crack-growth in situ. The device had to be rigid and is driven by a piezo stack. The crack growth resistance shows differences in the rise of the R-curves for different orientations of the crack propagation. This is in agreement with the microstructure that results from the plasma spray process.https://www.mdpi.com/2571-6131/2/3/39yttriaplasma sprayingEBCCMCmechanical testingcrack growth resistance
collection DOAJ
language English
format Article
sources DOAJ
author Stefan Hackemann
Marion Bartsch
spellingShingle Stefan Hackemann
Marion Bartsch
Crack Growth Tests in Air Plasma-Sprayed Yttria Coatings for Alumina Ceramic Matrix Composites
Ceramics
yttria
plasma spraying
EBC
CMC
mechanical testing
crack growth resistance
author_facet Stefan Hackemann
Marion Bartsch
author_sort Stefan Hackemann
title Crack Growth Tests in Air Plasma-Sprayed Yttria Coatings for Alumina Ceramic Matrix Composites
title_short Crack Growth Tests in Air Plasma-Sprayed Yttria Coatings for Alumina Ceramic Matrix Composites
title_full Crack Growth Tests in Air Plasma-Sprayed Yttria Coatings for Alumina Ceramic Matrix Composites
title_fullStr Crack Growth Tests in Air Plasma-Sprayed Yttria Coatings for Alumina Ceramic Matrix Composites
title_full_unstemmed Crack Growth Tests in Air Plasma-Sprayed Yttria Coatings for Alumina Ceramic Matrix Composites
title_sort crack growth tests in air plasma-sprayed yttria coatings for alumina ceramic matrix composites
publisher MDPI AG
series Ceramics
issn 2571-6131
publishDate 2019-08-01
description Yttria coatings for all-oxide combustor walls were tested for their crack-growth behavior. These environmental and thermal barrier Y<sub>2</sub>O<sub>3</sub>-coatings were processed by atmospheric plasma spraying (APS). The stiffness and strength were measured for as-received and aged samples that were heat treated at 1000 &#176;C, 1100 &#176;C and 1200 &#176;C for a 10 h dwell time. The results show a clear development with respect to the aging conditions. The changes of the modulus and the bending strength indicate that the microstructural changes are not completed, even after aging at 1200 &#176;C for 10 h. The fracture toughness was tested for different orientations on samples aged at 1200 &#176;C. Bending tests as well as indentation experiments were conducted. Furthermore, a bending device was designed to observe the crack-growth in situ. The device had to be rigid and is driven by a piezo stack. The crack growth resistance shows differences in the rise of the R-curves for different orientations of the crack propagation. This is in agreement with the microstructure that results from the plasma spray process.
topic yttria
plasma spraying
EBC
CMC
mechanical testing
crack growth resistance
url https://www.mdpi.com/2571-6131/2/3/39
work_keys_str_mv AT stefanhackemann crackgrowthtestsinairplasmasprayedyttriacoatingsforaluminaceramicmatrixcomposites
AT marionbartsch crackgrowthtestsinairplasmasprayedyttriacoatingsforaluminaceramicmatrixcomposites
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