| Popis: |
In this article, high temperature oxidation behaviour of plasma sprayed carbides and oxides reinforced composite CoCrAlY coatings were investigated at 700°C. CoCrAlY was reinforced with Al2O3+YSZ, CeO2, WC-Co, Cr3C2-NiCr individually to produce four different coatings. SEM, EDS and XRD are used to analyze the oxide scales formed during oxidation process on the coatings surface. From the results it is found that, all these coatings exhibited parabolic weight gain nature, indicating presence of protective oxide scale on coating surface, whereas changes in total weight gain is observed. CoCrAlY+Al2O3+YSZ coatings exhibited higher oxidation resistance than other coatings. The distribution of thermodynamically stable á- Al2O3 in the coating is shown slow-scale growth kinetics during the oxidation. |
