Deformation and failure of the CrCoNi medium-entropy alloy subjected to extreme shock loading
Year: 2023
Type: article
Abstract: The extraordinary work hardening ability and fracture toughness of the face-centered cubic (fcc) high-entropy alloys render them ideal candidates for many structural applications. Here, the deformation and failure mechanisms of an equiatomic CrCoNi medium-entropyalloy (MEA) were investigated by powerful laser-driven shock experiments. Multiscale characterization demonstrates that profuse planar defects including stacking faults, nanotwins, and hexagonal nanolamella were generated during shock compression, forming a three-dimensional network. During shock release, the MEA fractured by strong tensile deformation and numerous voids was observed in the vicinity of the fracture plane. High defect populations, nanorecrystallization, and amorphization were found adjacent to these areas of localized deformation. Molecular dynamics simulations corroborate the experimental results and suggest that deformation-induced defects formed before void nucleation govern the geometry of void growth and delay their coalescence. Our results indicate that the CrCoNi-based alloys are impact resistant, damage tolerant, and potentially suitable in applications under extreme conditions.
Source: Science Advances
Institutions: Tianmushan Laboratory, Beihang University, Lawrence Berkeley National Laboratory, Chinese Academy of Sciences, Institute of Mechanics, Molecular Foundry, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto Interdisciplinario de Ciencias Básicas, IMDEA Materials, University of California, Berkeley
Language: English
Topic: High Entropy Alloys Studies
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,500
Awards: G1079818582, G1143651532, G1286236842, G1286251239, G1937294455, G30714459, G3083819904, G3137197751, G419881185, G42916606, G4314773756, G4501827968, G4504108201, G498139845, G5261056217, G6121439904, G6359522502, G650090426, G6652958823, G704498496, G7354628648, G7623115106, G843456610, G8876996369, G969889393
OpenAlex ID: W4372334599