Matches in SemOpenAlex for { <https://semopenalex.org/work/W1721666393> ?p ?o ?g. }
Showing items 1 to 81 of
81
with 100 items per page.
- W1721666393 abstract "Ceramic Thermal Barrier Coatings are widely used in different industrial applications e.g. vanes for gas blade turbines to protect hot sections in service at high temperatures, e.g. the gas inlet temperature is of 1400°C-1600°C. The in service failure of TBC coatings occurs often by delamination at the interface between metal and coating and leads further to local spallation of the TBC. The thermal and mechanical loading in service changes the microstructure and properties of the materials of the TBC system. This may reduce the resistance against initiation and propagation of delamination cracks (interfacial fracture toughness). Despite the diversity of test methods, there are still practical problems in using one or the other test method for the case of the TBC systems and in understanding the results of the tests. The aim of the present work was to use different fracture mechanics tests to evaluate the change in adherence after heat treatment of industrially used EB-PVD TBC systems and to contribute to a better understanding of the damage mechanisms in the TBC systems. The core test method was the sharp indentation with the following variations: Vickers indentation at the interface ceramic/metal and Rockwell indentation tests perpendicular to the TBC. Theoretical models for calculating interfacial fracture toughness need material properties. Therefore, they have been also experimentally determined. Young’s modulus (E) of the component materials of the TBC system has been determined by means of the Impulse Excitation Technique method. For the case of the TBC material, a general trend of increase of the Young’s modulus after heat treatment has been obtained. The measured value of the Young’s modulus of the substrate material IN625 did not change after heat treatment. The measured value of E of the BC material after heat treatment did not change significantly. Interfacial Vickers indentation tests gave reasonable results. After 24h exposure at 1000°C, a decrease of the apparent interfacial fracture toughness for all TBC thicknesses has been obtained. After 100h at 1000°C, a small increase of the interfacial fracture toughness in comparison with the values after 24h heat treatment has been observed, but the values are still smaller than the values in the as coated condition. Rockwell indentation tests on specimens with anisotropic substrates resulted in butterfly shaped delamination cracks. Measuring the crack lengths in cross section by SEM, for specimens with anisotropic substrates, it has been found that the crack length increases with the increase of the load. By means of SEM investigations, it has been observed that for a TBC system having a ceramic top coat with a thickness of about 280µm, the substrate was slightly deformed, when the TBC was substantial damaged. That means that the assumption of Vasinonta and Beuth [7], for the case of TBC system with a thickness of the top coat of 100µm, that the elasto-plastic deformations of the substrate and BC are the driving forces of the delamination is not correct for thicker TBC and the interaction TBC/indenter cannot be neglected. Instrumented Rockwell indentation test on the as coated TBC with anisotropic substrate, resulted in a butterfly shaped delamination crack of about 4mm span width that has been measured, compared to a span width of the delamination crack of about 2mm in the heat treated specimen, 500h at 1000°C in air. It implies that interfacial fracture toughness of the TBC has increased after heat treatment. A decrease of the crack length after heat treatment has been also observed after instrumented Rockwell indentation test on TBC specimens with isotropic substrate. These results are in contradiction to results obtained in [7] and [78], for EB-PVD TBC systems with a thickness of 100µm. Shorter cracks with the increase of the duration of the heat treatment implies consequently that the resistance of the TBC against crack propagation has increased." @default.
- W1721666393 created "2016-06-24" @default.
- W1721666393 creator A5041601413 @default.
- W1721666393 date "2007-06-27" @default.
- W1721666393 modified "2023-09-27" @default.
- W1721666393 title "Interfacial Fracture Toughness and Adhesion of Brittle Coatings on Ductile Substrates" @default.
- W1721666393 hasPublicationYear "2007" @default.
- W1721666393 type Work @default.
- W1721666393 sameAs 1721666393 @default.
- W1721666393 citedByCount "0" @default.
- W1721666393 crossrefType "dissertation" @default.
- W1721666393 hasAuthorship W1721666393A5041601413 @default.
- W1721666393 hasConcept C11608111 @default.
- W1721666393 hasConcept C121332964 @default.
- W1721666393 hasConcept C127413603 @default.
- W1721666393 hasConcept C134132462 @default.
- W1721666393 hasConcept C136478896 @default.
- W1721666393 hasConcept C151730666 @default.
- W1721666393 hasConcept C152568617 @default.
- W1721666393 hasConcept C159985019 @default.
- W1721666393 hasConcept C176711861 @default.
- W1721666393 hasConcept C192562407 @default.
- W1721666393 hasConcept C2780902562 @default.
- W1721666393 hasConcept C2781448156 @default.
- W1721666393 hasConcept C30239060 @default.
- W1721666393 hasConcept C58097730 @default.
- W1721666393 hasConcept C59085676 @default.
- W1721666393 hasConcept C62520636 @default.
- W1721666393 hasConcept C77595967 @default.
- W1721666393 hasConcept C77928131 @default.
- W1721666393 hasConcept C86803240 @default.
- W1721666393 hasConcept C97549433 @default.
- W1721666393 hasConcept C99595764 @default.
- W1721666393 hasConceptScore W1721666393C11608111 @default.
- W1721666393 hasConceptScore W1721666393C121332964 @default.
- W1721666393 hasConceptScore W1721666393C127413603 @default.
- W1721666393 hasConceptScore W1721666393C134132462 @default.
- W1721666393 hasConceptScore W1721666393C136478896 @default.
- W1721666393 hasConceptScore W1721666393C151730666 @default.
- W1721666393 hasConceptScore W1721666393C152568617 @default.
- W1721666393 hasConceptScore W1721666393C159985019 @default.
- W1721666393 hasConceptScore W1721666393C176711861 @default.
- W1721666393 hasConceptScore W1721666393C192562407 @default.
- W1721666393 hasConceptScore W1721666393C2780902562 @default.
- W1721666393 hasConceptScore W1721666393C2781448156 @default.
- W1721666393 hasConceptScore W1721666393C30239060 @default.
- W1721666393 hasConceptScore W1721666393C58097730 @default.
- W1721666393 hasConceptScore W1721666393C59085676 @default.
- W1721666393 hasConceptScore W1721666393C62520636 @default.
- W1721666393 hasConceptScore W1721666393C77595967 @default.
- W1721666393 hasConceptScore W1721666393C77928131 @default.
- W1721666393 hasConceptScore W1721666393C86803240 @default.
- W1721666393 hasConceptScore W1721666393C97549433 @default.
- W1721666393 hasConceptScore W1721666393C99595764 @default.
- W1721666393 hasLocation W17216663931 @default.
- W1721666393 hasOpenAccess W1721666393 @default.
- W1721666393 hasPrimaryLocation W17216663931 @default.
- W1721666393 hasRelatedWork W1984120567 @default.
- W1721666393 hasRelatedWork W1997509617 @default.
- W1721666393 hasRelatedWork W2026686102 @default.
- W1721666393 hasRelatedWork W2071972523 @default.
- W1721666393 hasRelatedWork W2079232053 @default.
- W1721666393 hasRelatedWork W2087078521 @default.
- W1721666393 hasRelatedWork W2110525102 @default.
- W1721666393 hasRelatedWork W2148618001 @default.
- W1721666393 hasRelatedWork W2160070973 @default.
- W1721666393 hasRelatedWork W230197086 @default.
- W1721666393 hasRelatedWork W2376928386 @default.
- W1721666393 hasRelatedWork W2379990433 @default.
- W1721666393 hasRelatedWork W2802650392 @default.
- W1721666393 hasRelatedWork W2888381013 @default.
- W1721666393 hasRelatedWork W2903578385 @default.
- W1721666393 hasRelatedWork W3017965857 @default.
- W1721666393 hasRelatedWork W3176492673 @default.
- W1721666393 hasRelatedWork W832699209 @default.
- W1721666393 hasRelatedWork W896230674 @default.
- W1721666393 hasRelatedWork W1599908850 @default.
- W1721666393 isParatext "false" @default.
- W1721666393 isRetracted "false" @default.
- W1721666393 magId "1721666393" @default.
- W1721666393 workType "dissertation" @default.