Abstract
In this study NiAl coatings containing 0.6 at.% Hf have been deposited onto CMSX-4® substrates via direct current magnetron sputtering. Microstructural analysis using X-ray diffraction (XRD) and transmission electron microscopy (TEM) shows that the as deposited coatings consist of a B2 β-NiAl solid solution phase with no evidence of precipitation. However, it was found that the post-deposition annealing conditions had a great influence on the microstructure of the sputtered coatings. In monolithic coatings extracted from their substrates, nanometer-sized precipitates formed at grain boundaries and within the grain interiors during annealing in argon for 1 h at 1273 K. An increase in the annealing time to 4 h resulted in recrystallization and some grain growth. The microstructure changes of the coatings after isothermal oxidation tests were examined by scanning electron microscopy (SEM) and XRD analysis. The results showed that the heat treatment conditions and Hf concentration in these coatings had a great influence on their oxidation resistance.
Sign-in/Register to access full text options 
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.
