ELECTRODEPOSITION OF PLATINUM-IRIDIUM ALLOY ON NICKEL-BASE SINGLE-CRYSTAL SUPERALLOY TMS-75

摘要

Electrodeposition of Pt-Ir alloy coatings from amidosulfuric acid baths was successfully achieved on Ni-base single crystal superalloys. Pt-Ir alloy coatings of the expected compositions can be fabricated according to the relationship between the mole concentration ratios of Ir~(3+)/(PtClf_6~(2-) + Ir~(3+)) in the electrolyte and the compositions of the coatings. X-ray diffraction confirmed that platinum and iridium form a continuous solid solution system in the coatings, in which the measured lattice parameter decreases linearly with the increase of the iridium content. Thus this relation follows the Vegard's law.