A COMPARISON BETWEEN CoNiCrAlY BOND COAT AND ZIRCONIA PLASMA SPRAYED COATINGS ON CREEP TESTS

摘要

Thermomechanical and electrical properties of zirconia-based ceramics have led to a wide range of advanced and engineering ceramic applications like solid electrolyte in oxygen sensors, fuel cells and furnace elements and its low thermal conductivity has allowed its use for thermal barrier coatings for aerospace engine components. A comparison between CoNiCrAlY bond coat and zirconia plasma sprayed coatings on creep tests of the Ti-6AI-4V alloy was studied. The material used was commercial Ti-6AI-4V alloy. Yttria (8 wt.%) stabilized zirconia (YSZ) with a CoNiCrAlY bond coat was atmospherically plasma sprayed on Ti-6AI-4V substrates by Sulzer Metco Type 9 MB. Constant load creep tests were conducted on a standard creep machine in air on coated samples, at stress levels of 520 MPa at 500℃ to evaluate the oxidation protection on creep of the Ti-6AI-4V alloy. Results indicate that the creep resistance of the ceramic coating was greater than metallic coating.