scholarly journals Corrosion, Erosion and Wear Behavior of Complex Concentrated Alloys: A Review

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 603 ◽  
Author(s):  
Aditya Ayyagari ◽  
Vahid Hasannaeimi ◽  
Harpreet Grewal ◽  
Harpreet Arora ◽  
Sundeep Mukherjee
Keyword(s):  
Wear Behavior ◽  
Material Design ◽  
Degradation Mechanisms ◽  
New Paradigm ◽  
Alloy Development ◽  
Surface Degradation ◽  
High Entropy ◽  
New Class ◽  
Critical Knowledge ◽  
Underlying Mechanisms

There has been tremendous interest in recent years in a new class of multi-component metallic alloys that are referred to as high entropy alloys, or more generally, as complex concentrated alloys. These multi-principal element alloys represent a new paradigm in structural material design, where numerous desirable attributes are achieved simultaneously from multiple elements in equimolar (or near equimolar) proportions. While there are several review articles on alloy development, microstructure, mechanical behavior, and other bulk properties of these alloys, then there is a pressing need for an overview that is focused on their surface properties and surface degradation mechanisms. In this paper, we present a comprehensive view on corrosion, erosion and wear behavior of complex concentrated alloys. The effect of alloying elements, microstructure, and processing methods on the surface degradation behavior are analyzed and discussed in detail. We identify critical knowledge gaps in individual reports and highlight the underlying mechanisms and synergy between the different degradation routes.

scholarly journals Surface degradation mechanisms in precipitation-hardened high-entropy alloys

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Aditya V. Ayyagari ◽  
Bharat Gwalani ◽  
Saideep Muskeri ◽  
Sundeep Mukherjee ◽  
Rajarshi Banerjee
Keyword(s):  
High Entropy Alloys ◽  
Degradation Mechanisms ◽  
Surface Degradation ◽  
High Entropy

Layered High-Entropy Oxide Structures for Reversible Energy Storage

2020 ◽  
Author(s):  
Junbo Wang ◽  
Yanyan Cui ◽  
Qingsong Wang ◽  
Kai Wang ◽  
Xiaohui Wang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Cathode Material ◽  
Spray Pyrolysis ◽  
Lattice Structure ◽  
Oxide Materials ◽  
High Entropy ◽  
New Class ◽  
Nebulized Spray Pyrolysis

<p>Layered Li<i><sub>x</sub></i>MO<sub>2</sub> materials, a new class of high-entropy oxides, have been synthesized by nebulized spray pyrolysis. Specifically, the lattice structure of Li(Ni<sub>1/3</sub>Mn<sub>1/3</sub>Co<sub>1/3</sub>)O<sub>2</sub> (NCM111) cathode material has been replicated successfully while increasing the number of cations in equimolar proportions, thereby allowing transition to high-entropy oxide materials.</p>

Wear behavior of HVOF-sprayed Al0.6TiCrFeCoNi high entropy alloy coatings at different temperatures

2019 ◽  
Vol 358 ◽  
pp. 215-222 ◽  
Author(s):  
Lijia Chen ◽  
Kirsten Bobzin ◽  
Zheng Zhou ◽  
Lidong Zhao ◽  
Mehmet Öte ◽  
...  
Keyword(s):  
Wear Behavior ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Different Temperatures

Precipitation Hardenable High Entropy Alloy for Tooling Applications

MRS Advances ◽  
2019 ◽  
Vol 4 (25-26) ◽  
pp. 1427-1433
Author(s):  
O. Stryzhyboroda ◽  
U. Hecht ◽  
V. T. Witusiewicz ◽  
G. Laplanche ◽  
A. Asabre ◽  
...  
Keyword(s):  
Precipitation Hardening ◽  
High Entropy Alloy ◽  
Instrumented Indentation ◽  
Cast State ◽  
Alloy Development ◽  
High Entropy ◽  
Arc Melting ◽  
Thermodynamic Computations ◽  
Thermocalc Software ◽  
Cast Microstructure

ABSTRACTWe present a high entropy alloy (HEA) from the system Al-Co-Cr-Fe-Ni with small additions of W, Mo, Si and C which was designed to allow for precipitation hardening by annealing in the temperature range from 600 to 900 °C. The alloy development was supported by thermodynamic computations using ThermoCalc software and the specimens were produced by arc melting. The microstructure of one selected sample in as-cast and annealed conditions was analysed using SEM/EDS, SEM/EBSD and TEM. The as-cast microstructure consists of spinodally decomposed BCC dendrites enveloped by FCC+Cr23C6 eutectic. Upon annealing at 700 °C for 24 h nanoscale precipitates form within the spinodal BCC as well as from FCC. Precipitation is exquisitely uniform leading to an increase in microhardness from 415 HV0.5 in the as-cast state to 560 HV0.5 after annealing. We investigated coarsening of this microstructure using varying holding time for a constant temperature of 700 °C. The microstructure evolution during coarsening and the corresponding mechanical properties obtained from instrumented indentation experiments are presented in this work.

scholarly journals Cutting Edge of High-Entropy Alloy Superconductors from the Perspective of Materials Research

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1078
Author(s):  
Jiro Kitagawa ◽  
Shusuke Hamamoto ◽  
Naoki Ishizu
Keyword(s):  
Material Design ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
Simple Material ◽  
Σ Phase ◽  
High Entropy ◽  
Cscl Type ◽  
Materials Research ◽  
Face Centered ◽  
New Phenomena

High-entropy alloys (HEAs) are a new class of materials which are being energetically studied around the world. HEAs are characterized by a multicomponent alloy in which five or more elements randomly occupy a crystallographic site. The conventional HEA concept has developed into simple crystal structures such as face-centered-cubic (fcc), body-centered-cubic (bcc) and hexagonal-closed packing (hcp) structures. The highly atomic-disordered state produces many superior mechanical or thermal properties. Superconductivity has been one of the topics of focus in the field of HEAs since the discovery of the bcc HEA superconductor in 2014. A characteristic of superconductivity is robustness against atomic disorder or extremely high pressure. The materials research on HEA superconductors has just begun, and there are open possibilities for unexpectedly finding new phenomena. The present review updates the research status of HEA superconductors. We survey bcc and hcp HEA superconductors and discuss the simple material design. The concept of HEA is extended to materials possessing multiple crystallographic sites; thus, we also introduce multisite HEA superconductors with the CsCl-type, α-Mn-type, A15, NaCl-type, σ-phase and layered structures and discuss the materials research on multisite HEA superconductors. Finally, we present the new perspectives of eutectic HEA superconductors and gum metal HEA superconductors.

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