Additive Manufacturing of Hierarchical Multi-Phase High-Entropy Alloys for Nuclear Component

Owing to the reduced defects, low cost, and high efficiency, the additive manufacturing (AM) technique has attracted increasingly attention and has been applied in high-entropy alloys (HEAs) in recent years. It was found that AM-processed HEAs possess an optimized microstructure and improved mechanical properties. However, no report has been proposed to review the application of the AM method in preparing bulk HEAs. Hence, it is necessary to introduce AM-processed HEAs in terms of applications, microstructures, mechanical properties, and challenges to provide readers with fundamental understanding. Specifically, we reviewed (1) the application of AM methods in the fabrication of HEAs and (2) the post-heat treatment effect on the microstructural evolution and mechanical properties. Compared with the casting counterparts, AM-HEAs were found to have a superior yield strength and ductility as a consequence of the fine microstructure formed during the rapid solidification in the fabrication process. The post-treatment, such as high isostatic pressing (HIP), can further enhance their properties by removing the existing fabrication defects and residual stress in the AM-HEAs. Furthermore, the mechanical properties can be tuned by either reducing the pre-heating temperature to hinder the phase partitioning or modifying the composition of the HEA to stabilize the solid-solution phase or ductile intermetallic phase in AM materials. Moreover, the processing parameters, fabrication orientation, and scanning method can be optimized to further improve the mechanical performance of the as-built-HEAs.

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Materials and manufacturing renaissance: Additive manufacturing of high-entropy alloys

Journal of Materials Research ◽

10.1557/jmr.2020.140 ◽

2020 ◽

Vol 35 (15) ◽

pp. 1963-1983 ◽

Cited By ~ 3

Author(s):

Jinyeon Kim ◽

Akane Wakai ◽

Atieh Moridi

Keyword(s):

Additive Manufacturing ◽

High Entropy Alloys ◽

High Entropy ◽

Image Position

Abstract

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Additive manufacturing of metals: a brief review of the characteristic microstructures and properties of steels, Ti-6Al-4V and high-entropy alloys

Science and Technology of Advanced Materials ◽

10.1080/14686996.2017.1361305 ◽

2017 ◽

Vol 18 (1) ◽

pp. 584-610 ◽

Cited By ~ 220

Author(s):

Stéphane Gorsse ◽

Christopher Hutchinson ◽

Mohamed Gouné ◽

Rajarshi Banerjee

Keyword(s):

Additive Manufacturing ◽

High Entropy Alloys ◽

High Entropy

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Low neutron cross-section FeCrVTiNi based high-entropy alloys: design, additive manufacturing and characterization

Microstructures ◽

10.20517/microstructures.2021.09 ◽

2022 ◽

Author(s):

Bosheng Dong ◽

Zhiyang Wang ◽

Hanliang Zhu ◽

Ondrej Muránsky ◽

Zhijun Qiu ◽

...

Keyword(s):

Mechanical Property ◽

Additive Manufacturing ◽

Cross Section ◽

Neutron Cross Section ◽

Nominal Composition ◽

High Entropy Alloys ◽

Contributing Factors ◽

Dendritic Microstructure ◽

High Entropy ◽

Chemical Segregation

The development of high-entropy alloys (HEAs) based on the novel alloying concept of multi-principal components presents opportunities for achieving new materials with desired properties for increasingly demanding applications. In this study, a low neutron cross-section FeCrVTiNi-based HEA was developed for potential nuclear applications. A face-centred cubic (FCC) HEA with the nominal composition of FeCr0.4V0.3Ti0.2Ni1.3 is proposed based on the empirical thermodynamic models and the CALculation of PHAse diagrams (CALPHAD) calculation. Verifications of the predictions were performed, including the additive manufacturing of the proposal material and a range of microstructural characterizations and mechanical property tests. Consistent with the prediction, the as-fabricated HEA consists of a dominant FCC phase and minor Ni3Ti precipitates. Moreover, significant chemical segregation in the alloy, as predicted by the CALPHAD modelling, was observed experimentally in the produced dendritic microstructure showing the enrichment of Ni and Ti elements in the interdendritic regions and the segregation of Cr and V elements in the dendritic cores. Heterogenous mechanical properties, including microhardness and tensile strengths, were observed along the building direction of the additively manufactured HEA. The various solid solution strengthening effects, due to the chemical segregation (in particular Cr and V elements) during solidification, are identified as significant contributing factors to the observed mechanical heterogeneity. Our study provides useful knowledge for the design and additive manufacturing of compositionally complex HEAs and their composition-microstructure-mechanical property correlation.

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