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Computational & Experimental Development of Novel High Temperature Alloys
The objective of Computational and Experimental Development of Novel High Temperature Alloys is to develop alloys with enhanced high temperature oxidation resistance with robust mechanical properties. To accomplish this objective we utilize a novel multi-stage progressive “sieving process.” At this point in time, the most promising alloys are Ni-based, so the efforts will concentrate specifically on designing oxidation-resistant Ni-based alloys that can operate at temperatures close to 2500°F (~1350°C). While intermetallics, like the Mo-silicides, can withstand oxidative environments at very high temperatures, they have poor mechanical properties that preclude their implementation. On the other hand, Ni-based alloys (especially alumina formers) provide good mechanical strength and oxidation resistance. Since the melting point of Ni is 1455°C, the challenge lies in alloy compositions having significantly higher melting points, while maintaining good microstructural, thermodynamic, and chemical stability at elevated temperatures. Our approach would involve using the Miedema model for initial screening of prospective alloys, followed by more detailed thermodynamic assessments, and experiments on oxidation behavior to focus on these potential alloys.
A new material has been made to behave in two distinct ways, helping to break down a significant barrier for understanding the mechanisms of high temperature superconductivity. Known high temperature superconductors fall into two different classes — layered cuprates and iron arsenides. The undoped, parent compounds of the cuprates are insulating, while the parent compounds of iron arsenide superconductors are metallic.
Singh P.; Sharma A.; Smirnov A.V.; Diallo M.S.; Ray P.K.; Balasubramanian G.; Johnson D.D. Design of high-strength refractory complex solid-solution alloys. Npj Computational Materials 2018 4, 8. Abstract
Singh P.; Smirnov A.V.; Johnson D.D. Atomic short-range order and incipient long-range order in high-entropy alloys. Physical Review B 2015 91, 224204. Abstract
Ray P.K.; Akinc M.; Kramer M.J. Formation of multilayered scale during the oxidation of NiAl-Mo alloy. Applied Surface Science 2014 301, 107-111. Abstract