Documents disponibles écrits par cet auteur

Dendrite growth simulation during solidification in the LENS process / H. Yin in Acta materialia, Vol. 58 N° 4 (Fevrier 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 4 (Fevrier 2010) . - pp. 1455–1465 Titre : Dendrite growth simulation during solidification in the LENS process Type de document : texte imprimé Auteurs : H. Yin, Auteur ; S.D. Felicelli, Auteur Année de publication : 2011 Article en page(s) : pp. 1455–1465 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Dendrite  growth  LENS  Cellular  automaton  Solidification Résumé : A two-dimensional model combining the finite element method and the cellular automaton technique was developed to simulate dendritic growth occurring in the molten pool during the laser-engineered net shaping (LENS) process. Based on the simulation results and previously published experimental data, empirical expressions describing the relationship between the cooling rate and the dendrite arm spacing (DAS) were proposed. In addition, the influence of LENS process parameters, such as the moving speed of the laser beam, the layer thickness and the substrate size, on the DAS was also discussed. Finally, different dendrite morphologies calculated at different locations were explained based on local solidification conditions. The simulation results showed good agreement with previously published experiments. This work contributes to the understanding of microstructure formation and the resulting mechanical properties of LENS-built parts as well as providing a fundamental basis for optimization of the LENS process. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409007563 [article] Dendrite growth simulation during solidification in the LENS process [texte imprimé] / H. Yin, Auteur ; S.D. Felicelli, Auteur . - 2011 . - pp. 1455–1465. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 4 (Fevrier 2010) . - pp. 1455–1465 Mots-clés : Dendrite  growth  LENS  Cellular  automaton  Solidification Résumé : A two-dimensional model combining the finite element method and the cellular automaton technique was developed to simulate dendritic growth occurring in the molten pool during the laser-engineered net shaping (LENS) process. Based on the simulation results and previously published experimental data, empirical expressions describing the relationship between the cooling rate and the dendrite arm spacing (DAS) were proposed. In addition, the influence of LENS process parameters, such as the moving speed of the laser beam, the layer thickness and the substrate size, on the DAS was also discussed. Finally, different dendrite morphologies calculated at different locations were explained based on local solidification conditions. The simulation results showed good agreement with previously published experiments. This work contributes to the understanding of microstructure formation and the resulting mechanical properties of LENS-built parts as well as providing a fundamental basis for optimization of the LENS process. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409007563

Effects of water vapour and oxygen partial pressures on low carbon steel oxidation in N2–H2–H2O mixtures / H. Yin in Materials and corrosion, Vol. 63 N° 10 (Octobre 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 10 (Octobre 2012) . - pp. 869–877 Titre : Effects of water vapour and oxygen partial pressures on low carbon steel oxidation in N2–H2–H2O mixtures Type de document : texte imprimé Auteurs : H. Yin, Auteur ; W. Y. D. Yuen, Auteur ; D. J. Young, Auteur Année de publication : 2013 Article en page(s) : pp. 869–877 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : High  temperature  oxidation;  hydroxyl;  low  carbon  steel;  water  vapour  effect Résumé : A low carbon, low silicon steel was oxidised at temperatures of 900–1000 °C in flowing N2–H2–H2O gas mixtures in which oxygen and water vapour partial pressures were varied independently. Scales of dense, single-phase, coarse grained wüstite grew rapidly, according to parabolic kinetics. Both the scaling rate and the oxide grain growth increased with PO2 at constant PH2O and also with equation image at constant PO2. An inert marker experiment showed that significant oxygen transport but majority metal transport supported scale growth. Gas composition effects are interpreted using point defect models involving formation of hydroxyl species on anion sites as well as cation vacancies. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201206570/abstract [article] Effects of water vapour and oxygen partial pressures on low carbon steel oxidation in N2–H2–H2O mixtures [texte imprimé] / H. Yin, Auteur ; W. Y. D. Yuen, Auteur ; D. J. Young, Auteur . - 2013 . - pp. 869–877. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 10 (Octobre 2012) . - pp. 869–877 Mots-clés : High  temperature  oxidation;  hydroxyl;  low  carbon  steel;  water  vapour  effect Résumé : A low carbon, low silicon steel was oxidised at temperatures of 900–1000 °C in flowing N2–H2–H2O gas mixtures in which oxygen and water vapour partial pressures were varied independently. Scales of dense, single-phase, coarse grained wüstite grew rapidly, according to parabolic kinetics. Both the scaling rate and the oxide grain growth increased with PO2 at constant PH2O and also with equation image at constant PO2. An inert marker experiment showed that significant oxygen transport but majority metal transport supported scale growth. Gas composition effects are interpreted using point defect models involving formation of hydroxyl species on anion sites as well as cation vacancies. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201206570/abstract