scholarly journals A Short Review on Welding and Joining of High Entropy Alloys

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 212 ◽  
Author(s):  
João G. Lopes ◽  
João Pedro Oliveira
Keyword(s):  
Solid State ◽  
Mechanical Performance ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Specific System ◽  
Science Field ◽  
High Entropy ◽  
Starting Point ◽  
Structural Applications ◽  
Alloy Systems

High entropy alloys are one of the most exciting developments conceived in the materials science field in the last years. These novel advanced engineering alloys exhibit a unique set of properties, which include, among others, good mechanical performance under severe conditions in a wide temperature range and high microstructural stability over long time periods. Owing to the remarkable properties of these alloys, they can become expedite solutions for multiple structural and functional applications. Nevertheless, like any other key engineering alloy, their capacity to be welded, and thus become a permanent feature of a component or structure, is a fundamental issue that needs to be addressed to further expand these alloys’ potential applications. In fact, welding of high entropy alloys has attracted some interest recently. Therefore, it is important to compile the available knowledge on the current state of the art on this topic in order to establish a starting point for the further development of these alloys. In this article, an effort is made to acquire a comprehensive knowledge on the overall progress on welding of different high entropy alloy systems through a systematic review of both fusion-based and solid-state welding techniques. From the current literature review, it can be perceived that welding of high entropy alloys is currently gaining more interest. Several high entropy alloy systems have already been successfully welded. However, most research works focus on the well-known CoCrFeMnNi. For this specific system, both fusion and solid-state welding have been used, with no significant degradation of the joints’ mechanical properties. Among the different welding techniques already employed, laser welding is predominant, potentially due to the small size of its heat source. Overall, welding of high entropy alloys is still in its infancy, though good perspectives are foreseen for the use of welded joints based on these materials in structural applications.

scholarly journals Emergence of machine learning in the development of high entropy alloy and their prospects in advanced engineering applications

2021 ◽  
Author(s):  
Nirmal Kumar Katiyar ◽  
Gaurav Goel ◽  
Saurav Goel
Keyword(s):  
Machine Learning ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Learning Approaches ◽  
Metallic Elements ◽  
Materials Synthesis ◽  
High Entropy ◽  
Structural Applications ◽  
Electromagnetic Shield ◽  
The Right

AbstractThe high entropy alloys have become the most intensely researched materials in recent times. They offer the flexibility to choose a large array of metallic elements in the periodic table, a combination of which produces distinctive desirable properties that are not possible to be obtained by the pristine metals. Over the past decade, a myriad of publications has inundated the aspects of materials synthesis concerning HEA. Hitherto, the practice of HEA development has largely relied on a trial-and-error basis, and the hassles associate with this effort can be reduced by adopting a machine learning approach. This way, the “right first time” approach can be adopted to deterministically predict the right combination and composition of metallic elements to obtain the desired functional properties. This article reviews the latest advances in adopting machine learning approaches to predict and develop newer compositions of high entropy alloys. The review concludes by highlighting the newer applications areas that this accelerated development has enabled such that the HEA coatings can now potentially be used in several areas ranging from catalytic materials, electromagnetic shield protection and many other structural applications.

scholarly journals Wear Behavior and Tribological Evolution of High Entropy Alloys

2019 ◽  
Vol 8 (2S11) ◽  
pp. 3143-3146
Keyword(s):  
Wear Behavior ◽  
Research Work ◽  
Review Article ◽  
High Entropy Alloy ◽  
Chemical Compositions ◽  
High Entropy Alloys ◽  
Multicomponent Alloys ◽  
High Entropy ◽  
Mechanical And Tribological Properties ◽  
Structural Applications

High entropy alloy are equiatomic and nonequiatomic complex concentrated/ multicomponent alloys which are recognized due to their distinctive mechanical and triboligical properties. A unique combination of excellent mechanical and tribological properties of high entropy alloys makes them promising candidate for variety of industrial and structural applications. The wear resistance needs to be examined for these complex concentrated alloys as only few numbers of reports and investigation are available in the field of new advanced HEAs materials. In the current research work, we identified the crucial achievements and breakthrough in the wear and tribological investigations of high entropy alloy and HEA based composites in recent years. This review article investigates the tribological behaviors of multicomponent alloys /high entropy alloys and HEA based composites which play an important role and draw a considerable attention in the present era. In view of recent developments on tribological and wear related mechanisms of HEAs for different type of industrial and structural applications, microstructure, chemical compositions, and mechanical properties are explained and reviewed in this review article.

Research on Electromagnetic Properties of High Entropy Alloys

2013 ◽  
Vol 837 ◽  
pp. 277-282 ◽  
Author(s):  
Iulia Florea ◽  
Raluca Maria Florea ◽  
Oana Bălţătescu ◽  
Vasile Soare ◽  
Costel Roman ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Hardness ◽  
Electromagnetic Properties ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
Metallic Elements ◽  
High Entropy ◽  
Good Thermal Stability ◽  
Structural Applications

In 1995, Yeh suggested the formation of an alloy made up of at least five metallic elements which have large mixing entropy solutions with many elements forming solide alloys. This alloy appeared because traditional alloys are characteised by high fragility and are difficult to process. High entropy alloys are alloys which have approximately equal concentrations, formed by a group of 5 to 11 elements majority in composition, mole fraction of each major metallic element in the alloy is between 5% and 30%. During the research it has been proved that this alloy has a high hardness and it is also corrosion proof and also resistance and good thermal stability It should be mentioned that High Entropy Alloys are characterized as alloys consisting of roughly equal concentrations of at least five metallic elements and are claimed to favor close-packed, disordered structures due to high configurational entropy. Such crystal structures, e.g. face-centered cubic (FCC), are advantageous in that they should offer multiple active slip systems usually observed in ductile metals and alloys. This opens the door to a large number of rich chemistries which would otherwise contain unacceptable volume fractions of intermetallic compounds to be useful in structural applications That way in this paper will carry out research to one specific high entropy alloy, we analyze the physical, chemical, electrical, magnetic, corrosion resistance of these materials, heat treatments corresponding and plastic deformation. This paper is divided into several chapters which will present application domains, and also a number of conclusions. Key words : high entropy alloys, properties of alloys, application domains, corrosion proof, thermal stability

scholarly journals Tribological and Mechanical Properties of Multicomponent CrVTiNbZr(N) Coatings

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 41
Author(s):  
Yin-Yu Chang ◽  
Cheng-Hsi Chung
Keyword(s):  
Mechanical Properties ◽  
Nitrogen Content ◽  
Adhesion Strength ◽  
Mechanical Performance ◽  
Bulk Material ◽  
High Entropy Alloy ◽  
Composition Gradient ◽  
Multilayered Structures ◽  
High Entropy ◽  
Alloy Target

Multi-element material coating systems have received much attention for improving the mechanical performance in industry. However, they are still focused on ternary systems and seldom beyond quaternary ones. High entropy alloy (HEA) bulk material and thin films are systems that are each comprised of at least five principal metal elements in equally matched proportions, and some of them are found possessing much higher strength than traditional alloys. In this study, CrVTiNbZr high entropy alloy and nitrogen contained CrVTiNbZr(N) nitride coatings were synthesized using high ionization cathodic-arc deposition. A chromium-vanadium alloy target, a titanium-niobium alloy target and a pure zirconium target were used for the deposition. By controlling the nitrogen content and cathode current, the CrNbTiVZr(N) coating with gradient or multilayered composition control possessed different microstructures and mechanical properties. The effect of the nitrogen content on the chemical composition, microstructure and mechanical properties of the CrVTiNbZr(N) coatings was investigated. Compact columnar microstructure was obtained for the synthesized CrVTiNbZr(N) coatings. The CrVTiNbZrN coating (HEAN-N165), which was deposited with nitrogen flow rate of 165 standard cubic centimeters per minute (sccm), exhibited slightly blurred columnar and multilayered structures containing CrVN, TiNbN and ZrN. The design of multilayered CrVTiNbZrN coatings showed good adhesion strength. Improvement of adhesion strength was obtained with composition-gradient interlayers. The CrVTiNbZrN coating with nitrogen content higher than 50 at.% possessed the highest hardness (25.2 GPa) and the resistance to plastic deformation H3/E*2 (0.2 GPa) value, and therefore the lowest wear rate was obtained because of high abrasion wear resistance.

scholarly journals Effect of Copper Addition on the AlCoCrFeNi High Entropy Alloys Properties via the Electroless Plating and Powder Metallurgy Technique

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 540
Author(s):  
Mohamed Ali Hassan ◽  
Hossam M. Yehia ◽  
Ahmed S. A. Mohamed ◽  
Ahmed Essa El-Nikhaily ◽  
Omayma A. Elkady
Keyword(s):  
Compressive Strength ◽  
Powder Metallurgy ◽  
Atomic Radius ◽  
The Other ◽  
High Entropy Alloy ◽  
Coating Process ◽  
High Entropy Alloys ◽  
Powder Metallurgy Technique ◽  
Copper Metal ◽  
High Entropy

To improve the AlCoCrFeNi high entropy alloys’ (HEAs’) toughness, it was coated with different amounts of Cu then fabricated by the powder metallurgy technique. Mechanical alloying of equiatomic AlCoCrFeNi HEAs for 25 h preceded the coating process. The established powder samples were sintered at different temperatures in a vacuum furnace. The HEAs samples sintered at 950˚C exhibit the highest relative density. The AlCoCrFeNi HEAs model sample was not successfully produced by the applied method due to the low melting point of aluminum. The Al element’s problem disappeared due to encapsulating it with a copper layer during the coating process. Because the atomic radius of the copper metal (0.1278 nm) is less than the atomic radius of the aluminum metal (0.1431 nm) and nearly equal to the rest of the other elements (Co, Cr, Fe, and Ni), the crystal size powder and fabricated samples decreased by increasing the content of the Cu wt%. On the other hand, the lattice strain increased. The microstructure revealed that the complete diffusion between the different elements to form high entropy alloy material was not achieved. A dramatic decrease in the produced samples’ hardness was observed where it decreased from 403 HV at 5 wt% Cu to 191 HV at 20 wt% Cu. On the contrary, the compressive strength increased from 400.034 MPa at 5 wt% Cu to 599.527 MPa at 15 wt% Cu with a 49.86% increment. This increment in the compressive strength may be due to precipitating the copper metal on the particles’ surface in the nano-size, reducing the dislocations’ motion, increasing the stiffness of produced materials. The formability and toughness of the fabricated materials improved by increasing the copper’s content. The thermal expansion has increased gradually by increasing the Cu wt%.

A review on phase prediction in high entropy alloys

2021 ◽  
pp. 095440622110089
Author(s):  
Vinay Kumar Soni ◽  
S Sanyal ◽  
K Raja Rao ◽  
Sudip K Sinha
Keyword(s):  
Solid Solution ◽  
Phase Formation ◽  
Single Phase ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Modeling Tools ◽  
High Entropy ◽  
Recent Developments ◽  
Phase Prediction ◽  
The Stability

The formation of single phase solid solution in High Entropy Alloys (HEAs) is essential for the properties of the alloys therefore, numerous approach were proposed by many researchers to predict the stability of single phase solid solution in High Entropy Alloy. The present review examines some of the recent developments while using computational intelligence techniques such as parametric approach, CALPHAD, Machine Learning etc. for prediction of various phase formation in multicomponent high entropy alloys. A detail study of this data-driven approaches pertaining to the understanding of structural and phase formation behaviour of a new class of compositionally complex alloys is done in the present investigation. The advantages and drawbacks of the various computational are also discussed. Finally, this review aims at understanding several computational modeling tools complying the thermodynamic criteria for phase formation of novel HEAs which could possibly deliver superior mechanical properties keeping an aim at advanced engineering applications.

Mechanical performance of FeCrCoMnAl high-entropy alloys from first-principle

2018 ◽  
Vol 210 ◽  
pp. 37-42 ◽  
Author(s):  
Shuo Huang ◽  
Xiaoqing Li ◽  
He Huang ◽  
Erik Holmström ◽  
Levente Vitos
Keyword(s):  
Mechanical Performance ◽  
High Entropy Alloys ◽  
First Principle ◽  
High Entropy

scholarly journals Synthesis of high-entropy alloy thin films via grain boundary diffusion–assisted solid-state alloying

2022 ◽  
Vol 207 ◽  
pp. 114302
Author(s):  
Seungjin Nam ◽  
Sang Jun Kim ◽  
Moon J. Kim ◽  
Manuel Quevedo-Lopez ◽  
Jun Yeon Hwang ◽  
...  
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Grain Boundary ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
High Entropy Alloy ◽  
High Entropy

Microstructure development and mechanical performance of Al2CrFeMnTi light-weight high entropy alloy

2021 ◽  
Vol 139 ◽  
pp. 107376
Author(s):  
Hadi Jahangiri ◽  
Samira Mohagheghi ◽  
Armin Asghari Alamdari ◽  
Rifat Yilmaz ◽  
Kübra Gürcan Bayrak ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
High Entropy Alloy ◽  
Light Weight ◽  
Microstructure Development ◽  
High Entropy
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