Table nbsp Oxidation Fig nbsp xA XRD

Fig. 4. Microstructure near the interface (marked by dash curves) between the coating (upper part) and the substrate (lower part) due to the interdiffusion of elements. The P50515 is at 900 °C for 5000 hours in (a) A0 and (b) B0. “c” donates MC-type carbides rich of Ti and Ta.Figure optionsDownload full-size imageDownload high-quality image (493 K)Download as PowerPoint slide
At 1000 °C, an IBDZ forms with a β?γ transition in A0 for 1500 hours (Fig. 5a), but after a longer time (5000 hours) β?γ′ transition occurs in the IBDZ (Fig. 5b). In B0 at 1000 °C, the microstructure after 1500 hours (Fig. 5c) is similar to that at 900 °C for 5000 hours (Fig. 4b), i.e. SBP forming in the substrate and no IBDZ forming in the coating. With a longer time at 1000 °C (5000 hours), the SBP disappears and an IBDZ forms in the coating (Fig. 5d).
Fig. 5. Microstructure near the interface (marked by dash curves) between the coating (upper part) and the substrate (lower part) due to the interdiffusion of elements. The oxidation is at 1000 °C: (a) for 1500 hours in A0, (b) for 5000 hours in A0, (c) for 1500 hours in B0, and (d) for 5000 hours in B0. “c” donates MC-type carbides rich of Ti and Ta.Figure optionsDownload full-size imageDownload high-quality image (922 K)Download as PowerPoint slide