Published October 2, 1997 | Version v1
Miscellaneous Open

Elaboration of coatings, such as WC-Co, by detonation gun

Description

Elaboration of ceramic oxide and cermet coatings by Korund detonation gun process has been developed and optimized during this study. Experimental measurements of detonation wave pressure and speed have allowed us to conclude at the representation validity of detonation with Chapman - Jouguet model and detonation product downstream flow with Taylor Zeldovich model. Composition, microhardness, roughness, porosity and adhesion optimization of different coatings including alumina, zirconia-yttria and tungsten carbide cobalt, have been obtained by spraying parameters effects studies. Coatings produced by this process are generally very dense and adherent (i.e porosity ≅ 1 at 2%; adhesion - 40 at 75 MPa). Mechanical properties have been studied by 3 or 4 point bend test which have shown that interfacial failure is combined: adhesive-cohesive. The comparison of properties, especially erosion resistance of coatings obtained by different hypersonic spray processes, has shown the very good behaviour of the coatings elaborated during this study. (author)

Abstract (French)

Lors de cette etude, nous avons mis au point et optimise les conditions d'elaboration de revetements ceramique oxyde et cermet a l'aide d'un procede de projection par canon a detonation: le Korund. Les mesures experimentales de pression et de celerite de l'onde de detonation nous permettent de conclure a la validite de la representation de la detonation se propageant a l'interieur du fut du Korund et de l'ecoulement des produits de detonation en aval de cette onde, respectivement a l'aide des modeles Chapman-Jouguet (C.J.) et Taylor Zeldovich (T.Z.). L'optimisation de la composition, de la microdurete, de la rugosite, de la porosite et de l'adherence-cohesion d'un certain nombre de revetements, dont l'alumine, la zircone-yttriee et le cermet carbure de tungstene-cobalt (WC-Co), a ete rendue possible par l'etude des parametres de l'installation Korund. Les revetements obtenus par ce procede sont generalement tres denses et tres adherents (a titre d'exemple: porosite ≅ 1 a 2%; adherence cohesion 40 a 75 Mpa). Leurs caracteristiques mecaniques ont ete etudiees par le biais d'essais de flexion 3ou 4points qui ont montre que la rupture interfaciale substrat-revetement est mixte adhesive-cohesive. La comparaison des proprietes, et notamment de la resistance a l'erosion des revetements obtenus par differents procedes de projection hypersonique, a mis en evidence le tres bon comportement des revetements optimises durant cette etude. (auteur)

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Additional details

Additional titles

Original title (French)
Elaboration de revetements, dont WC-Co, par canon a detonation

Publishing Information

Imprint Pagination
276 p.
Report number
FRCEA-TH--6999

Optional Information

Notes
283 refs.; Available from the INIS Liaison Officer for France, see the 'INIS contacts' section of the INIS website for current contact and E-mail addresses: http://www.iaea.org/inis/Contacts/