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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2019-08-01
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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 °C, 1100 °C and 1200 °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 °C for 10 h. The fracture toughness was tested for different orientations on samples aged at 1200 °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 °C, 1100 °C and 1200 °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 °C for 10 h. The fracture toughness was tested for different orientations on samples aged at 1200 °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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