Abstract
Oxide-dispersion-strengthened (ODS) Fe-Al-Y2O3-based alloys (denoted as FeAlOY) containing 5 vol. % of nano-oxides have a potential to become top oxidation and creep-resistant alloys for applications at temperatures of 1100–1300 °C. Oxide dispersoids cause nearly perfect strengthening of grains; thus, grain boundaries with limited cohesive strength become the weak link in FeAlOY in this temperature range. One of the possibilities for significantly improving the strength of FeAlOY is alloying with appropriate elements and increasing the cohesive strength of grain boundaries. Nearly 20 metallic elements have been tested with the aim to increase cohesive strength in the frame of preliminary tests. A positive influence is revealed for Al, Cr, and Y, whereby the influence of Y is enormous (addition of 1% of metallic Y increases strength by a factor of 2), as it is presented in this paper.
Highlights
The application of advanced materials with excellent oxidation and high-temperature creep resistance enables an increase in operating temperature of heat engines and, an increase in efficiency with a positive impact on the environment
The present study clearly revealed that achieving an excellent tensile and creep strength at 1100 ◦ C and higher temperatures is conditioned by complete secondary recrystallization resulting in very coarse grains
The conclusions can be summarized in the following items:
Summary
The application of advanced materials with excellent oxidation and high-temperature creep resistance enables an increase in operating temperature of heat engines and, an increase in efficiency with a positive impact on the environment. Top-level metallic materials with the best creep performance are represented by Ni-based superalloy single crystals [1] that are applicable up to 1100 ◦ C and by oxide-dispersion-strengthened (ODS) ferritic alloys [2,3] applicable up to 1300 ◦ C. In both cases, excellent creep resistance is achieved by the Orowan mechanism due to the dispersion of particles effectively prohibiting dislocation motion at high temperatures. A homogeneous powder consisting of a matrix with dispersed nano-sized Y2 O3 is produced by mechanical alloying (MA). The powder is consolidated via hot extrusion, hot isostatic pressing, spark plasma sintering, or via their combinations [5,6,7,8,9,10,11]
Sign-in/Register to view highlights & summary 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.
