| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1470491 | Corrosion Science | 2011 | 6 Pages |
Isothermal oxidation tests were performed on Ir, Ir–3Hf, Ir/Pt, and Ir–3Hf/Pt in static air at 1100 °C for 200 h. The microstructural evolution and changes in the composition of the alloys were characterisation by performing scanning electron microscopy (SEM) and field-emission electron probe microanalysis (FE-EPMA). The results indicated that the specimens of all the Ir-based alloys exhibited linear mass loss due to the formation/evaporation of gaseous Ir oxide species (mainly IrO3). The oxidation behaviour, including mass change kinetics, evaporation of gaseous IrO3, and the role of Hf and Pt are discussed.
Research highlights► An interesting surface morphology with faceted structure is formed on pure Ir after oxidation. ► Above 1100 °C, Ir forms evaporative oxide species and exhibits linear mass loss. ► Hf addition is not effective to protect Ir–3Hf alloy due to the currently porous feature of HfO2. ► Pt coating alleviates the mass loss by reducing the exposed surface area or serving as a metal quilt.
