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FeCrAl alloys are under development as possible candidate materials of accident-tolerant fuel cladding in light water reactors. In this study, the cracking resistance of FeCrAl alloys was evaluated using half-size Charpy impact tests at temperatures ranging from room temperature to 600 °C. Ingot-metallurgy wrought FeCrAl alloys with base alloy compositions of Fe-(10–13)Cr-6Al-2Mo, in weight percent, and commercial powder-metallurgy FeCrAl alloys (Kanthal APMT) were investigated. All studied alloys showed almost zero absorbed impact energy at room temperature with brittle fracture behavior. The as-received APMT alloys exhibited poor impact toughness even at 600 °C. The ductile-brittle transition temperatures of the wrought FeCrAl alloys varied from 119 to 318 °C. The possible effects of microstructures, residual strain, materials preparation methods, process conditions, and chemical composition on the impact toughness of FeCrAl alloys were investigated by examining the Charpy impact data in combination with microstructural details of the alloys. [ABSTRACT FROM AUTHOR]

The stability of coherent L12-ordered Ni3(Al,Ti) intermetallic precipitates was studied in Fe–14Cr–32Ni–3Nb–(3–4)Al–(1–3)Ti (wt.%) based alumina-forming austenitic stainless alloys. Computational thermodynamics predicted the formation of multi-intermetallic phases, including L12 and β-NiAl (B2), in an austenite matrix below ∼900°C. Microstructure characterization revealed a significant stabilization of the L12 phase by Zr addition, with the amount of L12 increasing with increasing Ti addition. However, the Ti addition also degraded the oxidation resistance. Further additions of C and B successfully improved both creep and oxidation properties. [ABSTRACT FROM AUTHOR]

The microstructures and mechanical properties of deformed and annealed Nb-containing FeCrAl alloys were investigated. Fine dispersion of Fe 2 Nb-type Laves phase particles was observed in the bcc-Fe matrix after applying a thermomechanical treatment, especially along grain/subgrain boundaries, which effectively stabilized the recovered and recrystallized microstructures compared with the Nb-free FeCrAl alloy. The stability of recovered areas increased with Nb content up to 1 wt%. The recrystallized grain structure in Nb-containing FeCrAl alloys consisted of elongated grains along the rolling direction with a weak texture when annealed below 1100 °C. An abnormal relationship between recrystallized grain size and annealing temperature was found. Microstructural inhomogeneity in the deformed and annealed states was explained based on the Taylor factor. Annealed Nb-containing FeCrAl alloys showed a good combination of strength and ductility, which is desirable for their application as fuel cladding in light-water reactors. [ABSTRACT FROM AUTHOR]

A recent investigation has confirmed that solute atoms segregated to the interfaces between aluminum and θ ′-Al 2 Cu can extend the stability of metastable θ ′ to higher temperatures. Herein, we present an extensive first-principles database of the segregation energies of 34 elements to the Al/ θ ′ interface and identify key descriptors that can guide the design of higher temperature Al-Cu alloys. We find that the segregation energies are strongly correlated with the size and volume of solute atoms and their solubilities within θ ′. We provide a physical/chemical basis to the experimentally observed elemental hierarchy in terms of the ability of individual elements to stabilize the Al/ θ ′ interface. Finally, we suggest a new microalloying strategy that offers opportunities to further increase the critical temperature limit of Al-Cu alloys. [ABSTRACT FROM AUTHOR]