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Measurements of fluorine depth-profiles on TiAl turbine blades using ion beam analytical techniques / S. Neve in Materials and corrosion, Vol. 62 N° 7 (Juillet 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 7 (Juillet 2011) . - pp. 713–716 Titre : Measurements of fluorine depth-profiles on TiAl turbine blades using ion beam analytical techniques Type de document : texte imprimé Auteurs : S. Neve, Auteur ; P. J. Masset, Auteur ; H.-E. Zschau, Auteur Année de publication : 2011 Article en page(s) : pp. 713–716 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Halogen-effect  PIGE  RBS  TiAl  Titanium  aluminides  Turbine  blade Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Intermetallic TiAl alloys are foreseen to substitute Ni-based alloys in several high-temperature applications such as turbine blades for aeronautics. Because of their low density the mass of these components could be reduced by half. However, a mixed oxide scale of TiO2 and Al2O3 which provides no oxidation protection is growing at temperatures above 700 °C. By means of the halogen-effect the high-temperature oxidation resistance of TiAl alloys can be improved by orders of magnitude. Therefore fluorine was introduced into turbine blades using two different chemical fluorination methods. The application of a fluorine treatment promotes the growth of a pure and dense alumina scale which prevents the alloy from increased oxidation. In previous work it has been shown that an appropriate fluorine content after oxidation and its location beneath the surface are indicators of a successful fluorine effect. In the present work, the fluorine content was measured before and after oxidation of TNB alloy as a function of depth by using proton induced gamma-ray emission (PIGE) in a specially designed vacuum chamber at the 2.5 MV van-de-Graaff accelerator at the IKF. Additionally, composition and thickness of the oxide scale was determined by Rutherford backscattering spectrometry (RBS). The ion beam techniques are non-destructive and thus offer a method for quality assurance of the halogen treatment. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005886/abstract [article] Measurements of fluorine depth-profiles on TiAl turbine blades using ion beam analytical techniques [texte imprimé] / S. Neve, Auteur ; P. J. Masset, Auteur ; H.-E. Zschau, Auteur . - 2011 . - pp. 713–716. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 7 (Juillet 2011) . - pp. 713–716 Mots-clés : Halogen-effect  PIGE  RBS  TiAl  Titanium  aluminides  Turbine  blade Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Intermetallic TiAl alloys are foreseen to substitute Ni-based alloys in several high-temperature applications such as turbine blades for aeronautics. Because of their low density the mass of these components could be reduced by half. However, a mixed oxide scale of TiO2 and Al2O3 which provides no oxidation protection is growing at temperatures above 700 °C. By means of the halogen-effect the high-temperature oxidation resistance of TiAl alloys can be improved by orders of magnitude. Therefore fluorine was introduced into turbine blades using two different chemical fluorination methods. The application of a fluorine treatment promotes the growth of a pure and dense alumina scale which prevents the alloy from increased oxidation. In previous work it has been shown that an appropriate fluorine content after oxidation and its location beneath the surface are indicators of a successful fluorine effect. In the present work, the fluorine content was measured before and after oxidation of TNB alloy as a function of depth by using proton induced gamma-ray emission (PIGE) in a specially designed vacuum chamber at the 2.5 MV van-de-Graaff accelerator at the IKF. Additionally, composition and thickness of the oxide scale was determined by Rutherford backscattering spectrometry (RBS). The ion beam techniques are non-destructive and thus offer a method for quality assurance of the halogen treatment. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005886/abstract

Oxidation protection of Ni-base superalloys by halogen treatment / H.-E. Zschau in Materials and corrosion, Vol. 62 N° 7 (Juillet 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 7 (Juillet 2011) . - pp. 687–694 Titre : Oxidation protection of Ni-base superalloys by halogen treatment Type de document : texte imprimé Auteurs : H.-E. Zschau, Auteur ; P. J. Masset, Auteur ; M. Schutze, Auteur Année de publication : 2011 Article en page(s) : pp. 687–694 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Borderline  materials  Halogen  effect  Ion  implantation  Ni-base  superalloys  Protective  alumina  scale Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A new concept of oxidation protection is proposed for Ni-base alloys with Al-amounts of 2–5 wt%. Following Wagner's theory of oxidation the formation of a dense protective alumina scale is possible if the Al-activity is sufficiently high. This condition can be fulfilled by using the halogen effect. Thermodynamical calculations reveal the existence of regions for a positive effect of F and Cl for the alloys IN738 and IN939. In the case of fluorine these results are transformed into F concentrations in a screening by using ion implantation. By the F-effect the oxidation mechanism at 1050 °C/air was changed from internal oxidation of Al to an external formation of an Al2O3 – scale. Optimal implantation parameters were defined. The formation and stability of the protective alumina scale was proved within 1000 h/1050 °C. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005879/abstract [article] Oxidation protection of Ni-base superalloys by halogen treatment [texte imprimé] / H.-E. Zschau, Auteur ; P. J. Masset, Auteur ; M. Schutze, Auteur . - 2011 . - pp. 687–694. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 7 (Juillet 2011) . - pp. 687–694 Mots-clés : Borderline  materials  Halogen  effect  Ion  implantation  Ni-base  superalloys  Protective  alumina  scale Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A new concept of oxidation protection is proposed for Ni-base alloys with Al-amounts of 2–5 wt%. Following Wagner's theory of oxidation the formation of a dense protective alumina scale is possible if the Al-activity is sufficiently high. This condition can be fulfilled by using the halogen effect. Thermodynamical calculations reveal the existence of regions for a positive effect of F and Cl for the alloys IN738 and IN939. In the case of fluorine these results are transformed into F concentrations in a screening by using ion implantation. By the F-effect the oxidation mechanism at 1050 °C/air was changed from internal oxidation of Al to an external formation of an Al2O3 – scale. Optimal implantation parameters were defined. The formation and stability of the protective alumina scale was proved within 1000 h/1050 °C. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005879/abstract