Affiliation:
1. Institut für Werkstoffe, TU Braunschweig, 38106 Braunschweig, Germany
Abstract
This study reassesses the optimum matrix composition of Co-Re-Cr-based alloys for strengthening by MC-type carbides. It is found that the composition of Co-15Re-5Cr is ideally suited for this purpose as it allows the solution of the carbide-forming elements such as Ta, Ti, Hf, and C within a matrix consisting entirely of fcc-phase (typically at 1450 °C), having a high solubility for these elements, while precipitation heat treatment (typically at 900–1100 °C) occurs in a hcp-Co matrix, displaying a much lower solubility. In the case of the monocarbides TiC and HfC, this was investigated and achieved for the first time in Co-Re-based alloys. TaC and TiC emerged as suitable particles in Co-Re-Cr alloys for creep applications due to a large population of nano-sized particle precipitation, which is not the case for the mainly coarse HfC. Both Co-15Re-5Cr-xTa-xC and Co-15Re-5Cr-xTi-xC exhibit a formerly unknown maximum solubility close to x = 1.8 at.%. Therefore, further research on the particle-strengthening effect and the governing creep mechanisms of carbide-strengthened Co-Re-Cr alloys should focus on alloys with the following compositions: Co-15Re-5Cr-1.8Ta-1.8C and Co-15Re-5Cr-1.8Ti-1.8C
Funder
Deutsche Forschungsgemeinschaft
Open-Access-Publikationsfond of University Braunschweig
Subject
General Materials Science
Reference31 articles.
1. The hotter the engine, the better;Perepezko;Science,2009
2. Thermal-barrier coatings for more efficient gas-turbine engines;Clarke;MRS Bull.,2012
3. Co-Re-based Alloys: A New Class of High Temperature Materials?;Mukherji;Adv. Eng. Mater.,2007
4. Metallic materials for structural applications beyond nickel-based superalloys;Heilmaier;JOM,2009
5. Rehman, H.U. (2016). Solid Solution Strengthening and Diffusion in Nickel- and Cobalt-Based Superalloys. [Ph.D. Thesis, Friedrich-Alexander-Universität Erlangen-Nürnberg].
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