Mechanism of high-pressure torsion-induced shear banding and lamellar thickness saturation in Co–Cr–Fe–Ni–Nb high-entropy composites

Abstract

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Fabrication, Microstructure, and Physico-Mechanical Properties of Fe–Cr–Ni–Mo–W High-Entropy Alloys from Elemental Powders

“…The FCC, BCC, and sigma phases were fixed in the structure. Moreover, the Cr-rich sigma phase was found to be very common in Cr-containing HEAs in sintered powder bulks [47,48], as well as in heat-treated cast alloys [49]. The presence of the sigma phase in the structure of the specimens determines the high values of strength, hardness, and low strain before fracture.…”

Effect of energy density on the microstructure and properties of the CrFeCoNiNb high-entropy cladded layer

“…Maity et al found that due to the addition of Nb element, the lamellar eutectic morphology fragments of CrCoNb generated would be embedded into the FeCoNiCr single-phase solid solution. The regular lamellar morphology was conducive to improving the structural stability and significantly improving the strength and toughness [5]. Another eutectic point of Co-Cr-Fe-Ni-M (M = Hf, Ta, Nb) system was successfully obtained by Xie et al, and the eutectic composition of the coating was thus changed.…”

Powder metallurgy of Al0.1CoCrFeNi high-entropy alloy

“…Strengthening of alloys with the fcc phase can be achieved by either grain refinement [31,32,33,34,35,36] or by dispersion strengthening (adding hard particles in the matrix) [37,38,39,40,41]. Grain refinement is one of the effective strengthening strategies that can be achieved in two ways: (i) Changing the processing technique (employ processes with a high cooling rate like additive manufacturing or copper mold casting or melt spinning) [42,43,44,45] or using non-equilibrium processing like the mechanical alloying (MA) [46,47,48] or (ii) Employing thermomechanical processes [25,36,49,50,51]. Mainly, A-HEA-based alloys were strengthened by thermomechanical processing like severe plastic deformation (processing with friction stir processing [25], highpressure torsion [49], etc.).…”

“…Grain refinement is one of the effective strengthening strategies that can be achieved in two ways: (i) Changing the processing technique (employ processes with a high cooling rate like additive manufacturing or copper mold casting or melt spinning) [42,43,44,45] or using non-equilibrium processing like the mechanical alloying (MA) [46,47,48] or (ii) Employing thermomechanical processes [25,36,49,50,51]. Mainly, A-HEA-based alloys were strengthened by thermomechanical processing like severe plastic deformation (processing with friction stir processing [25], highpressure torsion [49], etc.). Kumar et al have achieved a yield strength improvement of about 315 MPa by grain refinement (reduction from millimeter to micrometer-range sized grains) [25].…”