TY - JOUR
T1 - Effect of Ta on microstructure and phase distribution in cyclic oxidized Ir-Ta modified aluminide coatings on nickel base single crystal superalloy
AU - Kuppusami, P.
AU - Murakami, H.
PY - 2007/4/15
Y1 - 2007/4/15
N2 - The effect of Ir-Ta coating (with varying amounts of Ta) on microstructure, composition variation and phase distribution in the modified aluminides on Ni-base single crystal superalloy, TMS-75 subjected to cyclic oxidation has been investigated. Ir-Ta coatings with Ta = 14.1, 23.1, 40.7 and 82.9 at.% deposited on 〈1 0 0〉 oriented nickel base single crystal superalloy, TMS-75 were aluminized and subjected to cyclic oxidation at 1373 K, for 600 h. The mass gain as a function of number of cycles data demonstrates an improved oxidation resistance with decreasing Ta content. In contrary to Ta-rich aluminides, Ir-rich aluminides show a large volume fraction of the β-phase, a less amount of γ′-Ni3Al phase near the surface of the coatings. Rapid decrease in the concentration of Al in the diffusion zone and formation of interconnected γ′-Ni3Al has been found to be responsible for the lower oxidation resistance of Ta-rich aluminides.
AB - The effect of Ir-Ta coating (with varying amounts of Ta) on microstructure, composition variation and phase distribution in the modified aluminides on Ni-base single crystal superalloy, TMS-75 subjected to cyclic oxidation has been investigated. Ir-Ta coatings with Ta = 14.1, 23.1, 40.7 and 82.9 at.% deposited on 〈1 0 0〉 oriented nickel base single crystal superalloy, TMS-75 were aluminized and subjected to cyclic oxidation at 1373 K, for 600 h. The mass gain as a function of number of cycles data demonstrates an improved oxidation resistance with decreasing Ta content. In contrary to Ta-rich aluminides, Ir-rich aluminides show a large volume fraction of the β-phase, a less amount of γ′-Ni3Al phase near the surface of the coatings. Rapid decrease in the concentration of Al in the diffusion zone and formation of interconnected γ′-Ni3Al has been found to be responsible for the lower oxidation resistance of Ta-rich aluminides.
KW - Aluminide
KW - Diffusion
KW - Iridium
KW - Microstructure
KW - Oxidation
KW - Tantalum
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U2 - 10.1016/j.msea.2006.10.162
DO - 10.1016/j.msea.2006.10.162
M3 - Article
AN - SCOPUS:33847311300
VL - 452-453
SP - 254
EP - 261
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
SN - 0921-5093
ER -