Effect of platinum on the growth rate of the oxide scale formed on cast nickel aluminide intermetallic alloys

Yannick Cadoret (1) , Daniel Monceau (2) , Marie-Pierre Bacos , Pierre Josso , Vincent Maurice (2) , Philippe Marcus (2)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
2 LPCS - Laboratoire de Physico-Chimie des Surfaces

Thermo-Gravimetric Analysis ( TGA) and Scanning Electron M icroscopy ( SEM ) data of the initial stages of oxidation of Ni50Al50 and Ni40Pt10Al50 alloys of low and high sulfur content at 900◦ C and 1100◦ C are reported. The results show that the addition of Pt promotes the growth of the transient θ- Al2O3 oxide scale. This effect is particularly sensitive in the initial stages of oxidation at 1100◦ C where Pt considerably increases the total mass gain. It is attenuated in the presence of a high sulfur content in the alloy, indicating a competitive effect of Pt and S on the segregation of Al. The slower θ-to- α transition observed in the presence of Pt leads to an extended lifetime of the θ phase layer, which is proposed to be benecial to the relaxation of the stresses created by the growth of α-Al2O3.

Mots clés: Nickel aluminide; Platinum sulfur effect; High temperatureoxidation; Transition alumina

Domaines: Matériaux

Yannick Cadoret, Daniel Monceau, Marie-Pierre Bacos, Pierre Josso, Vincent Maurice, et al.. Effect of platinum on the growth rate of the oxide scale formed on cast nickel aluminide intermetallic alloys. Oxidation of Metals, 2005, 64 (3-4), pp.185-205. ⟨10.1007/s11085-005-6558-4⟩. ⟨hal-03601070⟩