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| Abstract No.: |
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Scheduled at:
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Wednesday, June 04, 2008, Room 05 10:40 AM
Characterization 2
Modern characterization offers a good possibility for proofing the reliability and the performance of thermal sprayed coatings
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| Title: |
Residual stress in HVOF thermally sprayed IN718 coatings
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| Authors: |
Christophe Lyphout* / University West, Sweden
Per Nýlen/ University West, Volvo Aero Corporation affiliated, SWEDEN
Adrian Manescu/ Polytechnic University of Marche, ITALIE
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| Abstract: |
Residual stress build up in thick HVOF coatings is a limiting problem. The adherence of these coatings to the substrate is strongly influenced by the residual stress generation during the coating deposition process. In HVOF spraying process, due to lower processing temperature and higher particle velocity as compared to plasma spraying, significant peening stresses are generated during the impact of semi molten particles on substrate. The combination of these peening stresses together with quenching and cooling stresses that arise after deposition is of significant importance. In this paper both a numerical finite element analysis (FEA) method, to calculate peening, quenching and cooling residual stresses, and experimental methods, as Modified Layer Removal Method (MLRM) and Neutron Diffraction analysis, are applied. The investigation is performed for thick Inconel 718 coatings on Inconel 718 substrates. Combined, this numerical and experimental techniques yield a deeper understanding of residual stress formation and a tool for process optimisation. The relationship between the stress state and deposit/substrate thickness ratio is given particular interest.
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