Abstract
The chemical composition of NiCoCrAlHfYSi with a suitable particle size, deposited using an activated combustion-high velocity air fuel (AC-HVAF) spray, is a potentially promising process because dense, continuous and pure alumina can be formed on the surface of the MCrAlY metallic coatings after isothermal oxidation exposure. The NiCoCrAlHfYSi (Amdry386) and NiCoCrAlTaY (Amdry997) coatings were produced using AC-HVAF and APS, respectively. Isothermal oxidation was subsequently conducted at 1050 °C in air for 200 h. This paper compares the characteristics of four coated samples, including the surface roughness, elastic modulus, hardness, oxide content, microstructural characteristics and phase evolution of thermally grown oxides (TGO). The growth of both the TGO and alumina scales in the TGO of the HVAF386 coating was relatively rapid. The θ- to α-alumina phase transformation was strongly determined by the Hf and Si dopants in the HVAF386 coating. Finally, the extent of grain refinement and deformation storage energy in the HVAF997 coatings were determined to be significantly crucial for the θ- to α-alumina phase transformation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
