Chemical architecturation of high entropy alloys through powder metallurgy

JOURNAL OF ALLOYS AND COMPOUNDS

卷:835

Article

Laurent-Brocq, Mathilde¹  Mereib, Diaa¹  Garcin, Glwadys¹  Monnier, Judith¹  Perriere, Loic¹  Villeroy, Benjamin¹ 

[1] Univ Paris Est Creteil, CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, F-94320 Thiais, France

关键词: Metals and alloys;    Powder metallurgy;    Mechanical properties;    Scanning electron microscopy;    SEM;    X-ray diffraction;   

DOI  :  10.1016/j.jallcom.2020.155279

来源: Elsevier

【 摘 要 】

The chemically architectured alloys were proposed as a new concept of microstructure, with a multiscale architecturation. They are composed of a solid-solution at the atomic scale, grain boundaries and composition gradients at the micronic scale and finally a 3D network of gradients at the mesoscale. Composition gradients are between two phases with the same crystalline structure but different compositions. As a first application of this concept, powders of pure Ni and CoCrFeMnNi high entropy alloy were successfully densifled by Spark Plasma Sintering. Then the microstructure and mechanical properties were characterized by scanning electron microscope coupled with energy dispersive spectroscopy and electron backscattered diffraction, X-ray diffraction, nanoindentation and compression tests. The obtained chemically architectured alloys present a homogeneous distribution of the two phases with a 10 mu m wide chemical gradient in between. By comparison with reference non architectured materials, the chemical architecturation induces a 35% increase of the yield strength. Thus the concept of chemically architectured metallic alloys and composition gradients was proven as very promising: processing of this complex microstructure is possible and it induces a significant mechanical strengthening. (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

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