scholarly journals Selected Properties of High Entropy Alloys Based on the AlFeMnNbNiTi System

2021 ◽  
Vol 60 (2) ◽  
pp. 71-80
Author(s):  
Konrad Chrzan ◽  
Kamil Cichocki ◽  
Piotr Adamczyk ◽  
Krzysztof Muszka
Keyword(s):  
Mechanical Properties ◽  
Solution Structure ◽  
Melting Process ◽  
High Entropy Alloys ◽  
X Ray ◽  
High Entropy ◽  
Protective Atmospheres ◽  
Process Heat ◽  
The Impact ◽  
Scanning Electron

The aim of this work was to study the impact of various fabrication methods used to prepare high entropy alloys based on the AlFeMnNbNiTi system. Chemical composition was customized to ensure a solid solution structure with precipitation of the Laves phase. The three manufactured alloys were prepared by melting, but with the use of various input materials and different furnaces in protective atmospheres. After the melting process, heat treatment was carried out. Structures of obtained materials were analyzed by means of a Scanning Electron Microscope (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) mapping. Mechanical properties were represented by Vickers hardness. In this paper, impact of the use of low purity input materials is shown, as well as differences in structure resulting from the utilization of different melting furnaces.

Effect of Aluminum Addition on AlxCoFeMnNiZn Multi-Component Production

2017 ◽  
Vol 751 ◽  
pp. 53-59 ◽  
Author(s):  
Amnart Suksamran ◽  
Nawarat Worauaychai ◽  
Nattaya Tosangthum ◽  
Thanyaporn Yodkaew ◽  
Rungtip Krataitong ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Melting Process ◽  
Core Shell ◽  
High Entropy Alloys ◽  
Dendritic Solidification ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Entropy ◽  
Core Shell Structure ◽  
Scanning Electron

Five multi-component alloy (MCA) formulations of CoFeMnNiZn (MCA01), Al0.5CoFeMnNiZn (MCA02), Al1.0CoFeMnNiZn (MCA03), Co5Fe5Mn30Ni20Zn40 (MCA04) and Al8.4Co4.6Fe4.6Mn27Ni18.4Zn37 (MCA05) were prepared by mechanical alloying and melting process (MAM). Five-component alloys of MCA01-MCA05 were designed using empirical formulae for high entropy alloys. Phase formation and microstructure were evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that MCA01 was partially melted by MAM process. However, MCA02-MCA05 could be melted and cast by MAM process. The microstructures of as-cast MCA02 and MCA03 showed dendritic solidification. Nevertheless, the as-cast MCA04 showed microstructure similar to that of Ni-based superalloy, i.e., the as-cast MCA04 consisted of γ matrix and γ′ phase. Moreover, egg type core shell structure was found in the interdendritic regions of the MCA05 alloy. In addition, the Al-added MCA02 and MCA03 alloys showed crystal structures of FCC1, FCC2 and BCC. MCA04 alloy demonstrated crystal structure of FCC whereas MCA05 alloy had crystal structures of FCC and Primitive Cubic.

Microstructure and Mechanical Properties of VTaTiMoAlx Refractory High Entropy Alloys

2017 ◽  
Vol 898 ◽  
pp. 638-642 ◽  
Author(s):  
Dong Xu Qiao ◽  
Hui Jiang ◽  
Xiao Xue Chang ◽  
Yi Ping Lu ◽  
Ting Ju Li
Keyword(s):  
Mechanical Properties ◽  
Vacuum Arc ◽  
High Entropy Alloys ◽  
X Ray Diffraction ◽  
Dendrite Structure ◽  
X Ray ◽  
High Entropy ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Microstructure And Mechanical Properties

A series of refractory high-entropy alloys VTaTiMoAlx with x=0,0.2,0.6,1.0 were designed and produced by vacuum arc melting. The effect of added Al elements on the microstructure and mechanical properties of refractory high-entropy alloys were investigated. The X-ray diffraction results showed that all the high-entropy alloys consist of simple BCC solid solution. SEM indicated that the microstructure of VTaTiMoAlx changes from equiaxial dendritic-like structure to typical dendrite structure with the addition of Al element. The composition of different regions in the alloys are obtained by energy dispersive spectroscopy and shows that Ta, Mo elements are enriched in the dendrite areas, and Al, Ti, V are enriched in inter-dendrite areas. The yield strength and compress strain reach maximum (σ0.2=1221MPa, ε=9.91%) at x=0, and decrease with the addition of Al element at room temperature. Vickers hardness of the alloys improves as the Al addition.

Review of alloys developed using the entropy approach

2021 ◽  
Vol 23 (2) ◽  
pp. 116-146
Author(s):  
Zinaida Bataeva ◽  
◽  
Alexey Ruktuev ◽  
Ivan Ivanov ◽  
Aleksandr Yurgin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Melt Spinning ◽  
Solution Structure ◽  
Russian Language ◽  
High Wear Resistance ◽  
Diffusion Welding ◽  
High Entropy Alloys ◽  
Multicomponent Alloys ◽  
High Entropy

This paper provides a review of studies on the development and characterization of high-entropy alloys (HEAs). It is structured in the following way. Alloys’ design strategy based on entropy approach. Expectations and modern perceptions. This section describes the initial principles of multicomponent alloys design which provide stable structure and mechanical properties. It is noted that the role of high mixing entropy in the formation of disordered solid solutions and the suppression of the brittle intermetallic phases formation have been significantly reconsidered over time. Currently, obtaining a single-phase solid solution structure is not the main requirement for HEAs. The composition of HEAs. This section describes some typical multicomponent alloys having different elemental compositions. It is shown, that at present time the most studied alloys are based on 3-d transition elements. Using alloys of this group the possibility of providing both high and low values of strength and ductility is shown. Fabrication methods of HEAs. This section describes the methods for the fabrication of high-entropy alloys. It is noted that the most commonly used methods are based on the melting of the initial materials and its subsequent crystallization. Such methods of HEAs fabrication as powder metallurgy, magnetron sputtering, self-propagating high-temperature synthesis, melt spinning, and diffusion welding are also discussed. Structure of HEAs. This section provides the data on HEAs possessing multiphase structure and containing fine nanosized precipitates. Besides, the studies in which HEAs have been obtained in the form of metallic glasses, carbides, oxides, and borides are reviewed. The factors that can affect the structural state of the multicomponent alloys are discussed. The ambiguity of opinions of different research groups is noted. Properties of HEAs. This section mainly concentrates on the mechanical properties of HEAs. However, some other promising properties of HEAs like high wear resistance and reduced diffusivity are also discussed. Plastic deformation of HEAs. This section describes the evolution of the structure and properties of HEAs caused by thermal and mechanical processing. Characterization methods of HEAs. This section lists the characterization techniques, which are most frequently used to study HEAs. The structure of these alloys is mainly studied by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and optical microscopy. The methods for properties measurements are also briefly reviewed. Application of HEAs. This section describes the promising fields of HEAs application. It can be utilized in the aerospace, aircraft, and nuclear industries as well as for car manufacturing, austoelectronics, and in the design of microwave devices. Russian-language publications on HEAs. This section lists the studies, published in the Russian language as well as the thesis, done in Russian universities.

scholarly journals Effect of Mo Addition on The Microstructure and Mechanical Properties of CoCuFeNi High Entropy Alloy

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1017
Author(s):  
Yang Shao ◽  
Huan Ma ◽  
Yibing Wang
Keyword(s):  
Mechanical Properties ◽  
Solution Structure ◽  
Tensile Tests ◽  
Atomic Ratio ◽  
Vacuum Arc ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Microstructure And Mechanical Properties ◽  
Mo Content

In order to reveal the effect of Mo addition on the microstructure and mechanical properties, (CoCuFeNi)100-xMox (x = 0, 10, 15, 19, and 25, x values in atomic ratio) high entropy alloys were prepared by vacuum arc-melting. The results showed that with Mo addition, the μ phase formed and serious separation occurred in the high entropy alloys. The content of μ phase increased with the increase in Mo content. The microstructure of the alloys changed from an initial single-phase face-center-cubic (FCC) solid solution structure (x = 0) to a hypoeutectic microstructure (x = 15), then to a full eutectic microstructure (x = 19), and finally to a hypereutectic microstructure (x = 25). Coherent interface between μ phase and FCC phase was observed. The (CoCuFeNi)81Mo19 alloy with fully eutectic microstructures exhibited the highest yield strength of 557 MPa and fracture strength of 767 MPa in tensile tests at room temperature. The fracture surface revealed that the formation of great amounts of the μ phase resulted in the loss of ductility of (CoCuFeNi)100-xMox alloys.

scholarly journals CrMnFeCoNi high entropy alloys with carbon and nitrogen: mechanical properties, wear and corrosion resistance

2021 ◽  
Vol 3 (11) ◽  
Author(s):  
L. Chmielak ◽  
L. Mujica Roncery ◽  
P. Niederhofer ◽  
S. Weber ◽  
W. Theisen
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Austenitic Steels ◽  
High Entropy Alloys ◽  
Interstitial Free ◽  
High Entropy ◽  
Carbon And Nitrogen ◽  
Wear And Corrosion ◽  
Wear And Corrosion Resistance ◽  
The Impact

AbstractThe use of interstitial elements has been a key factor for the development of different kinds of steels. However, this aspect has been little explored in the field of high entropy alloys (HEAs). In this investigation, the effect of carbon and nitrogen in a near-equiatomic CrMnFeCoNi HEA is studied, analyzing their impact on the microstructure, and mechanical properties from 77K to 673K, as well as wear, and corrosion resistance. Carbon and nitrogen are part of the FCC solid solution and contribute to the formation of precipitates. An increase in the yield and ultimate tensile strength accompanied with a decrease in the ductility are the main effects of C and N. The impact toughness of the interstitial-free material is higher than that of C and C+N alloyed systems. Compared to CrNi and CrMn austenitic steels, the wear resistance of the alloys at room temperature is rather low. The surface corrosion resistance of HEAs is comparable to austenitic steels; nevertheless HEAs are more susceptible to pitting in chloride containing solutions.

scholarly journals Microstructure and Room Temperature Mechanical Properties of Different 3 and 4 Element Medium Entropy Alloys from HfNbTaTiZr System

Entropy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 114 ◽  
Author(s):  
Jiří Zýka ◽  
Jaroslav Málek ◽  
Jaroslav Veselý ◽  
František Lukáč ◽  
Jakub Čížek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Testing ◽  
Room Temperature ◽  
High Entropy Alloys ◽  
Lower Strength ◽  
X Ray ◽  
High Entropy ◽  
Elongation To Failure ◽  
Zero Values ◽  
Bcc Phase

Refractory high entropy alloys (HEA) are promising materials for high temperature applications. This work presents investigations of the room temperature tensile mechanical properties of selected 3 and 4 elements medium entropy alloys (MEA) derived from the HfNbTaTiZr system. Tensile testing was combined with fractographic and microstructure analysis, using scanning electron microscope (SEM), wavelength dispersive spectroscope (WDS) and X-Ray powder diffraction (XRD). The 5 element HEA alloy HfNbTaTiZr exhibits the best combination of strength and elongation while 4 and 3 element MEAs have lower strength. Some of them are ductile, some of them brittle, depending on microstructure. Simultaneous presence of Ta and Zr in the alloy resulted in a significant reduction of ductility caused by reduction of the BCC phase content. Precipitation of Ta rich particles on grain boundaries reduces further the maximum elongation to failure down to zero values.

Studies on Mechanical Properties and Structure of LLDPE/Nano-Montmorillonite Composites

2012 ◽  
Vol 510 ◽  
pp. 579-584
Author(s):  
Yu Xin Liu ◽  
Qi Yang ◽  
Fang Yang ◽  
Yong Fei Zhu ◽  
Xian Zhong Mo
Keyword(s):  
Mechanical Properties ◽  
Mechanical Test ◽  
Linear Low Density Polyethylene ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Melting Method ◽  
X Ray ◽  
Small Angle Light Scattering ◽  
The Impact ◽  
Scanning Electron

Linear low-density polyethylene (LLDPE)/nano-montmorillonite (nano-MMT) composites were prepared by melting method. Mechanical test, scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and small angle light scattering (SALS) measurements were used to characterize the mechanical properties and structure of the LLDPE composite. The results indicated that the impact strength of LLDPE decreased with the increase of nano-MMT content. However, the tensile strength firstly increased and then decreased. The aggregation of nano-MMT in LLDPE happened at larger content. The spherulite size and crystallinity of LLDPE reduced with the addition of nano-MMT. Furthermore, it was found that the structure of the spherulite was destroyed by the nano-MMT. The microcrystal size of LLDPE also decreased with the increase of nano-MMT content.

Experimental Study on Impact Mechanical Properties of Waste Printed Circuit Boards

2010 ◽  
Vol 113-116 ◽  
pp. 1123-1127
Author(s):  
Nian Xin Zhou ◽  
Ya Qun He ◽  
Chen Long Duan ◽  
Shu Ai Wang
Keyword(s):  
Mechanical Properties ◽  
Printed Circuit Boards ◽  
Impact Load ◽  
Circuit Board ◽  
Circuit Boards ◽  
X Ray ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
The Impact ◽  
Scanning Electron

Comminution is a key part of the reutilization of discarded circuit board. In order to find out the most appropriate method of crushing, the characteristics of the materials and the mechanical properties of resistance impact of discarded circuit boards were studied. The substrate of circuit boards, slots of ISA and PCI were adopted as the specimen. The scanning electron microscope (SEM) and energy disperse X-ray spectroscopy (EDX) were used to characterize and analyze the combined state of the fracturing materials on the specimen surfaces after comminution. Results showed that the metals and nonmetals in the slots were crushed and dissociated easily.At the same time, the metal and nonmetal combined interfaces in the substrate have a trend to be broken and separated under the impact effect, which means the crushing circuit board has a favorable break effect under impact load.

scholarly journals Impact of Chemical Fluctuations on Stacking Fault Energies of CrCoNi and CrMnFeCoNi High Entropy Alloys from First Principles

Entropy ◽  
2018 ◽  
Vol 20 (9) ◽  
pp. 655 ◽  
Author(s):  
Yuji Ikeda ◽  
Fritz Körmann ◽  
Isao Tanaka ◽  
Jörg Neugebauer
Keyword(s):  
Mechanical Properties ◽  
First Principles ◽  
Mechanical Performance ◽  
Stacking Faults ◽  
Stacking Fault ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Linear Behavior ◽  
The Impact

Medium and high entropy alloys (MEAs and HEAs) based on 3d transition metals, such as face-centered cubic (fcc) CrCoNi and CrMnFeCoNi alloys, reveal remarkable mechanical properties. The stacking fault energy (SFE) is one of the key ingredients that controls the underlying deformation mechanism and hence the mechanical performance of materials. Previous experiments and simulations have therefore been devoted to determining the SFEs of various MEAs and HEAs. The impact of local chemical environment in the vicinity of the stacking faults is, however, still not fully understood. In this work, we investigate the impact of the compositional fluctuations in the vicinity of stacking faults for two prototype fcc MEAs and HEAs, namely CrCoNi and CrMnFeCoNi by employing first-principles calculations. Depending on the chemical composition close to the stacking fault, the intrinsic SFEs vary in the range of more than 150 mJ/m 2 for both the alloys, which indicates the presence of a strong driving force to promote particular types of chemical segregations towards the intrinsic stacking faults in MEAs and HEAs. Furthermore, the dependence of the intrinsic SFEs on local chemical fluctuations reveals a highly non-linear behavior, resulting in a non-trivial interplay of local chemical fluctuations and SFEs. This sheds new light on the importance of controlling chemical fluctuations via tuning, e.g., the annealing condition to obtain the desired mechanical properties for MEAs and HEAs.

Effect of the structure of vacuum condensates of high entropy alloys of Cr–Fe–Co–Ni–Cu system on their mechanical properties

2020 ◽  
Vol 2020 (4) ◽  
pp. 16-22
Author(s):  
A.I. Ustinov ◽  
◽  
V.S. Skorodzievskii ◽  
S.A. Demchenkov ◽  
S.S. Polishchuk ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Vacuum Condensates
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