6533b857fe1ef96bd12b4ce5

RESEARCH PRODUCT

Role of the Microstructure on the High Temperature Oxidation Properties of the Intermetallic Compound NbAl<sub>3</sub>

Jean Pierre LarpinV. GauthierEric GaffetMichel VilasiFrédéric Bernard

subject

Materials scienceAnnealing (metallurgy)Mechanical EngineeringHigh-temperature corrosionMetallurgyIntermetallicOxideAtmospheric temperature rangeCondensed Matter PhysicsMicrostructurechemistry.chemical_compoundchemistryChemical engineeringMechanics of MaterialsGeneral Materials ScienceLamellar structureCrystallite

description

The influence of the NbAl 3 microstructure on its oxidation mechanism was investigated in air under atmospheric pressure over the temperature range 500-1080°C. Different processing techniques as induction melting and mechanically-activated annealing processes (M2AP) were used to produce the intermetallic compound NbAl 3 . A protective external alumina scale grew only on Al-enriched NbAl 3 between 700 and 1080°C. Stoichiometric NbAl 3 exhibited the pesting phenomenon between 550-900°C, whereas a non protective lamellar oxide scale formed above 900°C. The proposed oxidation mechanism explains these observations which are in agreement with the oxidation study of powders with different crystallite sizes.

https://doi.org/10.4028/www.scientific.net/msf.369-372.793