10.3390/polym8030084

Vollständiger Abstract

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This work explores V-alloyed Al 0.4 Co 0.5 V 0.2 FeNi high-entropy alloys that are solution-treated at 1000-1200 °C for five hours and water-quenched. Solidification of this high-entropy alloy follows the sequence face-centered cubic (FCC) → ordered L1 2 → body-centered cubic (BCC) → ordered B2. All treated alloys maintain dual FCC-BCC-B2 microstructures, with temperature altering only morphological features. At 1000 and 1100 °C, coherent spinodal decomposition takes place in FCC matrices to form rodlike precipitates with 20.3% lattice misfit; meanwhile, Ostwald ripening lengthens the precipitates from 1.41 to 2.11 μm. Spinodal decomposition is inhibited at 1200 °C, which is accompanied by coarsening and granulation of B2-ordered BCC grains. Slow atomic diffusion prevents recrystallization even above 0.4<i>T</i> m . Solution heat treatment dissolves the B2 phases to generate supersaturated solutions stronger than the as-cast counterparts. Elevated solution temperatures reduce hardness (243-190 MPa) and tensile strength (919-839 MPa) but boost elongation (26-35%). Fractures display mixed dimple-cleavage features. Overall, a five-hour solution treatment at 1100 °C plus water quenching delivers balanced strength (851 MPa) and ductility (33%), serving as the optimal heat treatment for this alloy.

Abstract: PubMed · Datensatz