Grain-anisotropied high-strength Ni6Cr4WFe9Ti high entropy alloys with outstanding tensile ductility

The focus of this study is the evaluation of the influence of Ti concentration on the tensile properties of powder metallurgy high entropy alloys. Three Ni1.5Co1.5CrFeTiX alloys with X = 0.3; 0.5 and 0.7 were produced by mechanical alloying and spark plasma sintering. Additional annealing heat treatment at 1100 °C was utilized to obtain homogenous single-phase face centered cubic (FCC) microstructures, with minor oxide inclusions. The results show that Ti increases the strength of the alloys by increasing the average atomic size misfit i.e., solid solution strengthening. An excellent combination of mechanical properties can be obtained by the proposed method. For instance, annealed Ni1,5Co1,5CrFeTi0.7 alloy possessed the ultimate tensile strength as high as ~1600 MPa at a tensile ductility of ~9%, despite the oxide contamination. The presented results may serve as a guideline for future alloy design of novel, inclusion-tolerant materials for sustainable metallurgy.

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Additive manufacturing of high-strength CrMnFeCoNi-based High Entropy Alloys with TiC addition

Intermetallics ◽

10.1016/j.intermet.2019.04.005 ◽

2019 ◽

Vol 109 ◽

pp. 162-166 ◽

Cited By ~ 20

Author(s):

Abdukadir Amar ◽

Jinfeng Li ◽

Shuo Xiang ◽

Xue Liu ◽

Yuzhao Zhou ◽

...

Keyword(s):

Additive Manufacturing ◽

High Strength ◽

High Entropy Alloys ◽

High Entropy

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Microstructure and Mechanical Properties of FeNiCrCuAl High Entropy Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1036.101 ◽

2014 ◽

Vol 1036 ◽

pp. 101-105

Author(s):

Gheorghe Buluc ◽

Iulia Florea ◽

Oana Bălţătescu ◽

Costel Roman ◽

Ioan Carcea

Keyword(s):

Mechanical Properties ◽

Solid Solution ◽

High Hardness ◽

High Strength ◽

High Entropy Alloys ◽

Engineering Applications ◽

High Entropy ◽

Good Thermal Stability ◽

Microstructure And Mechanical Properties ◽

Wide Range

This paper presents the microstructure and the mechanical properties of FeNiCrCuAl high entropy alloys. The microstructure and mechanical properties of the annealed FeNiCrCuAl high entropy alloys were investigated using scanning electron microscopy, and X-ray diffraction. High entropy alloys have been known as a new type of materials and have been defined as having five or more principal elements, each one having a concentration between 5 and 35 at.%. Previous researches show that HEAs can be processed to form simple solid solution structures instead of intermetallics and other complicated compounds. This phenomenon is commonly attributed to the high configurational entropy in the solid solution state of HEAs. Furthermore, HEAs have also exhibited interesting properties such as high hardness and high strength, good thermal stability outstanding wear and oxidation resistance which offer great potential for engineering applications. The HEA systems explored in the past decade show that metallic elements are the most commonly used, e.g. Al, Cr, Fe, Co, Ni, Cu,Ti, etc. A wide range of HEAs exhibit high hardness, high strength, distinctive electrical and magnetic properties, high-temperature softening resistance, as well as favorable combination of compression strength and ductility. This combination of properties and the particular structures of HEAs are attractive for a number of potential engineering applications.

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Strength can be controlled by edge dislocations in refractory high-entropy alloys

Nature Communications ◽

10.1038/s41467-021-25807-w ◽

2021 ◽

Vol 12 (1) ◽

Cited By ~ 1

Author(s):

Chanho Lee ◽

Francesco Maresca ◽

Rui Feng ◽

Yi Chou ◽

T. Ungar ◽

...

Keyword(s):

High Strength ◽

Recent Theory ◽

High Entropy Alloys ◽

High Entropy ◽

Refractory Elements ◽

Transmission Electron ◽

In Situ Neutron Diffraction ◽

Edge Dislocations ◽

Strength Retention

AbstractEnergy efficiency is motivating the search for new high-temperature (high-T) metals. Some new body-centered-cubic (BCC) random multicomponent “high-entropy alloys (HEAs)” based on refractory elements (Cr-Mo-Nb-Ta-V-W-Hf-Ti-Zr) possess exceptional strengths at high temperatures but the physical origins of this outstanding behavior are not known. Here we show, using integrated in-situ neutron-diffraction (ND), high-resolution transmission electron microscopy (HRTEM), and recent theory, that the high strength and strength retention of a NbTaTiV alloy and a high-strength/low-density CrMoNbV alloy are attributable to edge dislocations. This finding is surprising because plastic flows in BCC elemental metals and dilute alloys are generally controlled by screw dislocations. We use the insight and theory to perform a computationally-guided search over 107 BCC HEAs and identify over 106 possible ultra-strong high-T alloy compositions for future exploration.

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Phase transformation and strengthening mechanisms of nanostructured high-entropy alloys

Nanotechnology Reviews ◽

10.1515/ntrev-2021-0071 ◽

2021 ◽

Vol 10 (1) ◽

pp. 1116-1139

Author(s):

Jinmei Chen ◽

Xiaosong Jiang ◽

Hongliang Sun ◽

Zhenyi Shao ◽

Yongjian Fang ◽

...

Keyword(s):

Phase Transformation ◽

Performance Optimization ◽

High Performance ◽

High Strength ◽

Easy Access ◽

High Entropy Alloys ◽

Strengthening Mechanisms ◽

Toughening Mechanisms ◽

High Entropy ◽

Transition Mechanism

Abstract High-entropy alloys (HEAs) have become a research focus because of their easy access to nanostructures and the characteristics of high strength, hardness, wear resistance, and oxidation resistance, and have been applied in aerospace lightweight materials, ultrahigh temperature materials, high-performance materials, and biomimetic materials. At present, the study of HEAs mainly focuses on the microstructure and mechanical properties. HEAs of Mo, Ti, V, Nb, Hf, Ta, Cr, and W series have high strength, while HEAs of Fe, Co, Ni, Cr, Cu, and Mn series have good toughness. However, the emergence of medium-entropy alloys, metastable HEAs, dual-phase HEAs, and multiphase HEAs increased the complexity of the HEA system, and the phase transition mechanism and strengthening and toughening mechanisms were not fully established. In this article, the preparation, phase formation, phase transformation as well as strengthening and toughening mechanisms of the HEAs are reviewed. The inductive effects of alloying elements, temperature, magnetism, and pressure on the phase transformation were systematically analyzed. The strengthening mechanisms of HEAs are discussed, which provides a reference for the design and performance optimization of HEAs.

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Preparing bulk ultrafine-microstructure high-entropy alloys via direct solidification

Nanoscale ◽

10.1039/c7nr07281c ◽

2018 ◽

Vol 10 (4) ◽

pp. 1912-1919 ◽

Cited By ~ 28

Author(s):

Yiping Lu ◽

Xiaoxia Gao ◽

Yong Dong ◽

Tongmin Wang ◽

Hai-Lin Chen ◽

...

Keyword(s):

Mechanical Properties ◽

High Strength ◽

High Entropy Alloys ◽

High Entropy ◽

The Past

In the past three decades, nanostructured (NS) and ultrafine-microstructure (UFM) materials have received extensive attention due to their excellent mechanical properties such as high strength.

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