High entropy based cr-cu-mn-ni alloy system and process for preparation thereof

Abstract

The present invention relates to the technical field of the development of a novel CraCubMncNid High Entropy based Alloy (HEA) system and process for preparation thereof. More particularly, the present invention relates to CraCubMncNid high entropy alloy-based system, wherein the concentration of a in the ranges of 5-17 atomic percent (at %), b in the range of 18-35 atomic percent (at %), c in the range of 17-34 atomic percent (at %), and d in the range of 23-37 atomic percent (at %). The unique combination of these elements unlocks a new level of performance and reliability, marking a significant advancement in the field of high entropy alloys. Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) exhibiting cost effective, superior strength, hardness, tribological performance, and corrosion resistance at room temperature. Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) alloy system a robust alternative to traditional nickel-based and nickel-iron-based superalloys in a wide range of applications.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Indian Patent Application No. 202411102374, filed on Dec. 23, 2024, the subject matter of which is incorporated by reference.FIELD OF INNOVATION

[0002] The present invention relates to the technical field of the development of a novel CraCubMncNid High Entropy based Alloy (HEA) system and process for preparation thereof. More particularly, the present invention relates to CraCubMncNid high entropy alloy-based system, wherein the concentration of a in the ranges of 5-17 atomic percent (at %), b in the range of 18-35 atomic percent (at %), c in the range of 17-34 atomic percent (at %), and d in the range of 23-37 atomic percent (at %). The unique combination of these elements unlocks a new level of performance and reliability, marking a significant advancement in the field of high entropy alloys. Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) exhibiting cost effective, superior strength, hardness, tribological performance, and corrosion resistance at room temperature. Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) alloy system a robust alternative to traditional nickel-based and nickel-iron-based superalloys in a wide range of applications.BACKGROUND AND PRIOR ART OF THE INVENTION

[0003] High Entropy Alloys (HEAs) are emerging as a groundbreaking class of materials that possess a unique combination of properties due to their multi-principal element composition. Unlike conventional alloys that rely on one or two principal elements, HEAs typically consist of five or more elements in near-equiatomic proportions, resulting in a high configurational entropy. This distinctive structure leads to exceptional mechanical properties, including high strength, hardness, wear resistance, and corrosion resistance, making HEAs highly versatile for a range of engineering applications.

[0004] In industries such as automotive, aerospace, marine, and energy, there is a growing demand for materials that can provide superior performance under varying environmental conditions, including room temperature. Traditional materials, such as steels and Ni-based superalloys, often exhibit limitations at ambient conditions, particularly in applications where both mechanical durability and corrosion resistance are critical. These materials are susceptible to wear, corrosion, and phase instabilities, which can lead to premature failure or reduced efficiency. To meet these growing needs, the development of HEAs that can offer a balance of properties—high strength, excellent tribological performance, and superior corrosion resistance at room temperature—is essential. Several HEAs have been explored for different applications, but limited research has focused on optimizing HEA systems specifically for room temperature performance, where materials are subject to significant wear, friction, and environmental degradation.

[0005] The benchmark for material performance at room temperature includes maintaining structural integrity under mechanical loads, providing resistance to wear and friction in tribological systems, and exhibiting superior corrosion resistance in various environmental conditions. The current benchmarks set by conventional alloys such as stainless steel, Inconel, and Ni-based alloys are limited by factors such as surface degradation, phase instability, and susceptibility to corrosion over time.

[0006] The present invention addresses these critical challenges by developing a novel Cr—Cu—Mn—Ni based High Entropy Alloy system that exhibits significantly improved mechanical and environmental performance at room temperature. This HEA system provides enhanced strength, hardness, tribological properties, and exceptional corrosion resistance, surpassing the performance of conventional Ni-based superalloys and steels. By overcoming the limitations of traditional materials, this novel Cr—Cu—Mn—Ni HEA system meets the pressing industrial need for a versatile material that can deliver high performance in ambient conditions, making it ideal for applications such as automotive components, industrial machinery, marine structures, and other general engineering applications where room temperature performance is paramount.

[0007] Prior art search was made in patent as well as non-patent literature sources and following documents are referred because of their relevance to field of present invention.

[0008] US20020159914A1 discloses high entropy alloy major metallic elements are selected from the metallic element group consisting of aluminum, titanium, vanadium, chromium, iron, cobalt, nickel, copper, zirconium, molybdenum, palladium, silver and gold. Exceptionally high hardness: Depending on the chemical composition, their hardness in the as-cast state ranges from Hv 450 to Hv 900. The degree of hardness is on par with or greater than that of fully quenched carbon steel or alloy steel.

[0009] WO2017164602A1 discloses high entropy alloy created through computer simulation and thermodynamic calculation. An alloy composition region with the microstructure of a face-centered cubic (FCC) single phase is set up to 700° C. or higher temperatures using thermodynamic calculation. The present invention pertains specifically to a high entropy alloy based on Cr, Fe, Mn, and Ni—V that exhibits excellent low-temperature tensile strength and elongation. This alloy is capable of achieving a single-phase microstructure at room temperature and cryogenic temperature after undergoing rapid heat treatment at 700° C. or higher temperatures.

[0010] KR101831056B1 discloses high entropy alloy contrast to the easily produced intermetallic compounds found in most multicomponent alloys, these compounds have a high mixed entropy, and the multicomponent elements form a simple solid solution that gives them excellent mechanical properties and strength through solid solution strengthening.

[0011] EP3660178B1 discloses medium-entropy alloy (MEA) with excellent cryogenic mechanical properties. It also exhibits high price competitiveness due to the inexpensive Fe content, which can be added in amounts between 55 and 62.5 at %. Furthermore, the alloying elements can be controlled to cause deformation-induced phase transformation during cryogenic deformation, resulting in the adjustment of face-centered cubic (FCC) and body-centered cubic (BCC) phase stability.

[0012] JP4885530B2 discloses Ni-based superalloy that exhibits exceptional strength and ductility at high temperatures. Specifically, it concerns a Ni-base superalloy that possesses high strength and excellent ductility, regardless of whether it is a unidirectionally solidified material or a regular cast material. The current invention also relates to a moving blade or a stationary blade of an axial flow gas turbine, a centrifugal wheel for a turbocharger, a microturbine made from a casting of a Ni-base superalloy, or any of these.

[0013] JP2002173732A discloses high entropy that is highly resistant to heat, acid, and heat. The multicomponent alloy with high entropy is made up of several different types of elements. There are five to eleven primary metallic element types in the alloy. Each type of metal element has a molar number that ranges from 5% to 30% of the alloy's total mol number. High hardness, high heat resistance, and high acid resistance are features of the alloy.

[0014] CN114350989A discloses a refractory Al—Cr—Ti—V—Nb light high-entropy alloy and a method of preparation for it. The elements that make up the refractory light high-entropy alloy are primarily Al, Cr, Ti, V, and Nb. The atomic percentages of the components are as follows: 22-25% of Al, 22-25% of Cr, 22-25% of Ti, 22-25% of V, and 0-12% of Nb. and using direct casting and vacuum arc melting to produce an alloy ingot. The alloy has a single BCC phase structure, uniform components, no segregation, no precipitated phase generation, and high hardness more than 540HV as well as a density of roughly 5.24 g / cm3 to 5.52g / cm3. In contrast to traditional refractory alloy. The density of the high entropy alloy is lower.

[0015] WO2019039743A1 discloses Fe—Ni—V—Cr new entropy alloy with nickel (Ni), iron (Fe), chromium (Cr), and vanadium (V) as the primary constituents. In contrast to alloy, which is one of the primary constituent elements of alloys like steel, aluminium alloy, and titanium alloy, high-entropy alloy (HEA) is a multi-element alloy that is produced by alloying five or more constituent elements at a similar rate. With a high entropy of mixing, the alloy forms a single-phase structure, such as a face-centered cubic (FCC) or body-centered cubic (BCC), rather than an intermetallic compound or intermediate phase.

[0016] Wang et al., Journal of materials science & technology, 34(10), 1791-1798, 2018 discloses studying the sluggish diffusion of high-entropy alloys, three different face centered cubic Co—Cr—Cu—Fe—Ni high-entropy alloys, and assembled into three groups of sandwich-type diffusion multiple annealed at 1273, 1323, and 1373 K respectively. By means of the electron probe microanalyzer technique and recently developed numerical inverse method, the composition-dependent inter diffusivities at different temperatures were effectively evaluated by minimizing the residual between the model-predicted compositions / interdiffusion fluxes and the respectively experimental ones.

[0017] Ge et al., Adv. Powder Technol., 28, 2556-2563, 2017 discloses CuZrAlTiNi High entropy alloy (HEA) coating was synthesized on T10 substrate using mechanical alloying (MA) and vacuum hot-pressing sintering (VHPS) technique. The MA results show that the final product of as-milled powders is amorphous phase. The obtained coating sintered at 950° C. is compact and about 0.9 mm in thickness. It is composed of a couple of face-centered cubic (FCC), one body-centered cubic (BCC) solid solutions and AlNi2Zr phase. The interface strength between coating and substrate is 355.5 MPa measured by three point bending test.

[0018] Liu et al., Intermetallics 72, 44-52, 2016 discloses fluxing and cyclic superheating technique to investigate the rapid solidification behavior of CoCrCuFexNi (x=1.0, 1.5, 2.0, molar concentration) high-entropy alloys. The microstructures of CoCrCuFexNi (x=1.0, 1.5, 2.0) high-entropy alloys solidified at different undercoolings (ΔT) were investigated. Liquid-phase separation leading to Cu-rich and Cu-depleted regions, were obtained in the solidified microstructure from highly undercooled melt. This occurs when the melt undercooling exceeds a critical undercooling (ΔTcrit) of 160 K for CoCrCuFeNi, 190 K for CoCrCuFe1.5Ni and 293 K for CoCrCuFe2Ni alloy. However, typical dendrites and interdendritic regions were observed in rapid-solidified CoCrCuFexNi alloys prepared from melts with a small undercooling (ΔT<ΔTcrit).

[0019] Curiotto et al., Fluid Phase Equilibr. 256, 132-136, 2007 discloses Cu-based alloys, like Cu—Co, Cu—Fe and Cu—Co—Fe, display a liquid metastable miscibility gap. When the melt is undercooled below a certain temperature depending on the alloy composition, they present a separation in two liquid phases, followed by coagulation before dendritic solidification. In order to predict the phase equilibria and the mechanisms of microstructure formation, a determination of the metastable monotectics in the phase diagrams is essential. This paper focuses on the up-to-date findings on the Cu—Co, Cu—Fe and Cu—Co—Fe metastable miscibility gap in the liquid phase. Furthermore, the knowledge on the phase equilibria in the three systems is extended by presenting new results obtained by differential scanning calorimetry (DSC) and comparing them with the calculated phase diagrams.

[0020] Hsu et al., Mater. Sci. Eng. A, 460-461, 403-408, 2007 discloses preparation of AlCoCrCuNi, AlCoCrCuFeNi, AgAlCoCrCuNi and AlAuCoCrCuNi, by the arc melting and casting method. The alloy specimens were polished and etched with aqua regia for observation with an optical microscope and scanning electron microscope (SEM, JEOL JSM-5410). The chemical compositions of the different phases were analyzed by SEM energy dispersive spectrometry (EDS).

[0021] Derimow et al., Mater. Today Commun., 15, 1-10, 2018 discloses observations of the as-cast microstructures of equiatomic quaternary and quinary multiprincipal element alloys (MPEAs) containing equiatomic ternary CoCrCu—X with X being Fe, Mn, Ni, V, FeMn, FeNi, FeV, MnNi, MnV, and NiV. Out of the 11 MPEA combinations studied, CoCrCuNi, CoCrCuFeNi, and CoCrCuMnNi displayed FCC solid solution dendritic microstructures while the remaining 8 displayed a liquid phase separation into Cu-lean and Cu-rich liquids which solidified into highly phase separated regions. Calculations for enthalpy of mixing (ΔHmix) were carried out on the possible equiatomic combinations of these alloys using Miedema's scheme for sub-regular solutions.

[0022] Munitz et al., J. Mater. Sci., 44, 64-73, 2008 discloses Electromagnetic levitation to determine Cu—Nb phase diagram and to study supercooling effects on solidification characteristics of the alloys containing 5-70 wt % Nb. The Cu—Nb stable phase diagram was found to exhibit near-flat liquidus with a peritectic reaction at 1093° C. Melt separation was found only for specimens containing approximately 20 wt % Nb. The results indicate that melt separation in the alloy requires supercooling exceeding 230K combined with high cooling rates during solidification. Some specimens quenched from the solid+liquid zone on a copper chill also show evidence of melt separation which is attributed to minor oxygen impurities. Nb-rich liquid which nucleates below the T 0 curve solidifies as a metastable Nb-bcc lattice containing only 67 wt % Nb as compared to 96 wt % of the regular Nb dendrites.

[0023] Lourengo, J. C., Corros. Sci., 193, 2021 discloses Inconel 625 based alloys with different iron contents were prepared by arc-melting. Alloys with up to 5 wt. % iron are composed of the y matrix, metal monocarbides (MC) and Laves precipitates. Alloys with 10-15 wt. % iron comprise the y matrix and y / Laves eutectic-like constituent. MC precipitates are cathodic and the Laves phase anodic with respect to the matrix. In 3.5 wt. % NaCl, alloys with 10-15 wt. %, iron showed improved corrosion behaviour compared to 5 wt. % iron due to absence of MC phase formation. The results are important as they potentially allow faster and more economical welding processes to be employed.

[0024] The above information disclosed is only for the enhancement of understanding of the background of the invention.

[0025] The limitations of existing nickel-based and nickel-iron-based superalloys, especially concerning room temperature applications, can be elaborated as follows:

[0026] High Cost Due to Precious Elements: Nickel-based superalloys often require the addition of expensive elements such as molybdenum (Mo), tantalum (Ta), tungsten (W), rhenium (Re), or ruthenium (Ru) to enhance their mechanical properties, such as creep strength and fatigue resistance. While these elements improve high-temperature performance, they significantly increase the manufacturing cost, making these alloys less cost-effective and limiting their widespread use in various industrial applications.

[0027] Formation of Intermetallic Phases in Nickel-Iron Superalloys: Nickel-iron-based superalloys were introduced as a cost-effective alternative to nickel-based ones, but they also exhibit limitations. When trace elements such as aluminium (Al) are added to enhance the material's strength, they can form detrimental intermetallic phases such as Ni2AlTi if the aluminium content exceeds 5 wt %. These intermetallic reduce the high-temperature mechanical properties and creep strength of the alloy, particularly in the presence of high iron (Fe) content, further limiting their performance.

[0028] Low Quality-Price Ratio: The overall quality-price ratio of conventional nickel-based and nickel-iron-based superalloys is low. These alloys often do not deliver sufficient performance benefits to justify their high cost, particularly in applications requiring both high strength and affordability. As a result, industries are seeking more efficient materials with improved cost-performance trade-offs.

[0029] Tribological Performance: Both nickel-based and nickel-iron-based superalloys show limited tribological properties. Wear and friction are critical in applications like aerospace and automotive components, and the current alloys do not provide the necessary wear resistance and friction control for these demanding applications.

[0030] Inferior Corrosion Resistance at Room Temperature: Nickel-iron-based alloys, in particular, tend to have inferior corrosion resistance compared to other materials such as stainless steels or titanium alloys, especially in environments that contain moisture, chlorides, or other corrosive agents commonly encountered in industrial settings. This corrosion susceptibility can limit the use of these alloys in applications where components are exposed to harsh environments at room temperature, such as chemical processing, marine, and general industrial applications. The corrosion degradation over time can lead to material failure, reducing the operational lifespan of components and increasing replacement costs. Thus, industries require materials with improved corrosion resistance under ambient conditions.

[0031] Thus, keeping in view the drawbacks of the hitherto reported prior arts, present invention relates to the technical field of the development of a novel High Entropy Cr—Cu—Mn—Ni-based Alloy (HEA) system and process for preparation thereof which obviates the drawbacks of the hitherto known prior art as detailed above. More particularly, the present invention relates to a high entropy CraCubMncNid alloy-based system, wherein the concentration of “a” in the ranges of 5-17%, b in the range of 18-35%, c in the range of 17-34%, and d in the range of 23-37%. The unique combination of these elements unlocks a new level of performance and reliability, marking a significant advancement in the field of high entropy alloys.Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) exhibiting cost effective, superior strength, hardness, tribological performance, and corrosion resistance at room temperature. Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) alloy system a robust alternative to traditional nickel-based and nickel-iron-based superalloys in a wide range of applicationsOBJECTIVE OF THE INVENTION

[0032] The main objective of the invention is to provide a High Entropy Cr—Cu—Mn—Ni-based Alloy (HEA) system with optimized atomic ratios of CraCubMncNid alloy-based system, wherein the concentration of “a” in the ranges of 5-17 atomic percent (at %), b in the range of 18-35 atomic percent (at %), c in the range of 17-34 atomic percent (at %), and d in the range of 23-37 atomic percent (at %). The unique combination of these elements unlocks a new level of performance and reliability, marking a significant advancement in the field of high entropy alloys.

[0033] Another object of the present invention is to provide CraCubMncNid High Entropy alloy-based system having enhancement in hardness ranging from 161.20-164.78 HV0.1 / 20s, when compared to a super alloy predominantly based on nickel

[0034] Another object of the present invention is to provide CraCubMncNid High Entropy alloy-based system having COF (Coefficient of Friction) in the range of 0.38-0.45.

[0035] Another object of the present invention is to provide CraCubMncNid High Entropy alloy-based system exceptional tensile strength, ductility, and toughness at room temperature, outperforming conventional nickel-based and nickel-iron-based alloys. This makes the alloy ideal for structural and engineering applications that operate under ambient conditions, such as automotive components, industrial machinery, and general-purpose equipment.

[0036] Another object of the present invention is to provide CraCubMncNid High Entropy alloy-based system that avoids the formation of brittle intermetallic phases that are common in nickel-iron superalloys when trace elements like aluminum (Al) are added. The CraCubMncNid High Entropy alloy-based system exhibits greater phase stability, ensuring consistent mechanical properties without the risk of embrittlement or premature failure at room temperature, even under long-term mechanical stress or environmental exposure.

[0037] Another object of the present invention is to provide CraCubMncNid High Entropy alloy-based system that having enhanced resistance to corrosion at room temperature in environments commonly industrial chemicals. Corrosion resistance surpasses that of many nickel-based and nickel-iron-based superalloys, making the alloy a more durable choice for industrial applications where exposure to corrosive media is a concern.

[0038] These objectives of the present invention, as well as other objectives related thereto, will be readily apparent post consideration of the description of the invention, together with reference to the contents of the Figures of the drawings. Additional objects, advantages and other novel features of the invention will appear as the description proceeds and in part will become apparent to those skilled in the art upon examination of the following.

[0039] The disclosure highlights the objectives of the invention, its distinctive features, and various innovations. To gain a better grasp of the invention, its operational benefits, and the specific goals it achieves, referring to the accompanying drawings and descriptive content, which showcase preferred embodiments of the invention, would be beneficial.SUMMARY OF THE INVENTION

[0040] Additional features and embodiments of the present disclosure will be better understood through the techniques and other aspects of the disclosure. Other embodiments of the invention are described in detail herein and are considered a part of the claimed disclosure.

[0041] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description section. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0042] The following is a condensed description of the disclosure to give the reader with a basic understanding. Its main goal is to present some of the principles described in this document in a simpler version as a prologue to the more extensive exposition that follows.

[0043] The present invention, and in accordance with main aspect of the present invention provide High Entropy Cr—Cu—Mn—Ni-based Alloy (HEA) system with optimized atomic ratios of CraCubMncNid alloy-based system, wherein the concentration of “a” in the ranges of 5-17 atomic percent (at %), b in the range of 18-35 atomic percent (at %), c in the range of 17-34 atomic percent (at %), and d in the range of 23-37 atomic percent (at %). The unique combination of these elements unlocks a new level of performance and reliability, marking a significant advancement in the field of high entropy alloys.

[0044] Another aspect of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, comprising:

[0045] i. Chromium (Cr) in the range of 5 to 17 atomic percent (at %);

[0046] ii. Copper (Cu) in the range of 18 to 35 atomic percent (at %);

[0047] iii. Manganese (Mn) in the range of 17 to 34 atomic percent (at %);

[0048] iv. Nickel (Ni) in the range of 23 to 37 atomic percent (at %);

[0049] v. The remainder consisting of inevitable impurities, wherein the sum of the atomic percentages of Cr, Cu, Mn, and Ni is equal to 100%.

[0050] Another aspect of the present invention is to provide a CraCubMncNid High Entropy Alloy (HEA) composition, wherein the atomic percentages of each element are in the range of 10 to 30 at %.

[0051] Another aspect of the present invention is to provide a CraCubMncNid High Entropy Alloy (HEA) composition, wherein the atomic percentages of each element are in the range of 15 to 25 at %.

[0052] Another aspect of the present invention is to provide a CraCubMncNid High Entropy Alloy (HEA) composition, wherein process for preparing the High Entropy Alloy (HEA) composition of claim 1, comprising:

[0053] a. Gathering high-purity solid forms of Chromium (Cr), Copper (Cu), Manganese (Mn), and Nickel (Ni), each with a purity level of at least 99.9% and converting the atomic percentages of Cr, Cu, Mn, and Ni into corresponding weight percentages based on their respective atomic masses;

[0054] b. Weighing the high-purity solid forms according to their respective weight percentages to achieve a combined total weight of 25 grams;

[0055] c. Introducing the weighed elements as obtained in step (b) into a vacuum arc melting furnace capable of inducing material melting through an arc generated between a tungsten electrode and the workpiece, under an inert atmosphere;

[0056] d. Establishing a vacuum of at least 10{circumflex over ( )}-6 millibars within the furnace;

[0057] e. Displacing the vacuum with an inert gas, wherein Argon gas is introduced to create an inert atmosphere within the furnace during the melting process;

[0058] f. Repeating the melting process at least four times to ensure thorough mixing and homogeneity of the alloy to obtained Cr—Cu—Mn—Ni-based High Entropy Alloy.

[0059] Another aspect of the present invention is to provide a preparation of CraCubMncNid High Entropy Alloy (HEA) composition, wherein melting procedure in step (c) is repeated more than four times to ensure optimal homogeneity of the alloy.

[0060] Another aspect of the present invention is to provide a preparation of CraCubMncNid High Entropy Alloy (HEA) composition, wherein final High Entropy Alloy is cooled and solidified after the completion of the melting steps (c).

[0061] Another aspect of the present invention is to provide CraCubMncNid High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein composition comprises Chromium, Copper, Manganese, and Nickel in atomic percentages.

[0062] Yet another aspect of the present invention is to provide a preparation of CraCubMncNidHigh Entropy Alloy (HEA) composition, wherein analyzing the final alloy to confirm that the atomic percentages of Chromium, Copper, Manganese, and Nickel fall within the defined ranges.

[0063] Yet another aspect of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein the alloy exhibits enhanced properties, including improved mechanical strength, corrosion resistance, or thermal stability, due to the specific combination of Cr, Cu, Mn, and Ni.

[0064] Yet another aspect of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein CraCubMncNid High Entropy Alloy composition having enhancement in hardness ranging from 161.20-164.78 HV0.1 / 20s, when compared to a super alloy predominantly based on nickel.

[0065] Yet another aspect of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein composition having COF (Coefficient of Friction) in the range of 0.38-0.45.BRIEF DESCRIPTION OF THE DRAWINGS

[0066] To complete the description and in order to provide for a better understanding of the present invention, a set of drawings is provided. The drawings form an integral part of the description and illustrate an embodiment of the present invention, which should not be interpreted as restricting the scope of the invention, but just as an example of how the invention can be carried out. The drawings comprise the following figures: The present invention is illustrated in FIGS. 1 to 9 of the drawings accompanying this specification.

[0067] FIG. 1 illustrate Casted Cr—Cu—Mn—Ni CCMN-1 HEA in Bottom-Shaped Mold

[0068] FIG. 2 illustrate Microstructure and XRD Analysis of the Developed Cr—Cu—Mn—Ni CCMN-1 HEA

[0069] FIG. 3 illustrate SEM Analysis of the As-Cast Cr—Cu—Mn—Ni CCMN-1 HEA.

[0070] FIG. 4 illustrate Phase fraction diagram predicted through Themro-Calc software for the developed HEA with varying atomic fraction of Cr (X=1, 0.7, 0.5 and 0.25).

[0071] FIG. 5 illustrate Microhardness Measurements at Various Locations in the Cr—Cu—Mn-NiCCMN-1 HEA Matrix

[0072] FIG. 6 illustrate Stress-Strain Curve of the Developed Cr—Cu—Mn—NiCCMN-1 HEA at Room Temperature

[0073] FIG. 7 illustrate Corrosion Behavior of the Developed Cr—Cu—Mn—Ni HEA CCMN-1in 3.5 wt. % NaCl Aqueous Solution compared to Inconel 625 with and without Iron addition.

[0074] FIG. 8 illustrate Wear Rate Comparison Between Inconel 625 and the Developed Cr—Cu—Mn—NiCCMN-1 HEA Under Different Load and Frequency Conditions

[0075] FIG. 9 illustrate Coefficient of Friction (COF) Comparison Between Inconel 625 and the Developed Cr—Cu—Mn—Ni CCMN-1 HEA Under Different Load and Frequency ConditionsABBREVIATIONSCALPHAD: Calculation of Phase Diagram

[0077] HEA: High Entropy Alloy

[0078] FCC: Face Centered Cubic

[0079] BCC: Body Centered Cubic

[0080] LPS: Liquid Phase Separation

[0081] SEM: Scanning Electron Microscope

[0082] XRD: X-ray Diffraction

[0083] COF: Co-efficient of FrictionDETAILED DESCRIPTION OF THE INVENTION

[0084] The following description is not to be taken in a limiting sense but is given solely for the purpose of describing the broad principles of the invention. Embodiments of the invention will be described by way of example, with reference to the above-mentioned drawings showing elements and results according to the present invention.

[0085] The foregoing detailed description of the disclosure is elaborated to provide a clear understanding to the person who is skilled in the art. Additional features, embodiments and advantages of the invention will be described hereinafter which form the subject of the claims of the disclosure, However, the set forth disclosure provide in the specification will best be understood in conjunction with the appended claims and figures as provide heretofore. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent processes do not depart from the spirit and scope of the disclosure as set forth in the appended claims. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in various configurations, all of which are explicitly contemplated and make part of this disclosure.

[0086] While the invention has been disclosed with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the invention without departing from its scope.

[0087] Throughout the specification and claims, the following terms take the meanings explicitly associated herein unless the context clearly dictates otherwise. The meaning of “a”, “an”, and “the” include plural references. The meaning of “in” includes “in” and “on.” Referring to the figures, like numbers indicate like parts throughout the views. Additionally, a reference to the singular includes a reference to the plural unless otherwise stated or inconsistent with the disclosure herein.

[0088] Accordingly, present invention provides an provide a High Entropy Cr—Cu—Mn—Ni-based Alloy (HEA) system and process for preparation thereof. More particularly, the present invention relates to a high entropy CraCubMncNid alloy based system, wherein the concentration of a” in the ranges of 5-15 atomic percent (at %), b in the range of 5-35 atomic percent (at %), c in the range of 16-32 atomic percent (at %), and d in the range of 25-37 atomic percent (at %). The unique combination of these elements unlocks a new level of performance and reliability, marking a significant advancement in the field of high entropy alloys.Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) exhibiting cost effective, superior strength, hardness, tribological performance, and corrosion resistance at room temperature. Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) alloy system a robust alternative to traditional nickel-based and nickel-iron-based superalloys in a wide range of applications.

[0089] In embodiment of the present invention is to provide High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, comprising:

[0090] i. Chromium (Cr) in the range of 5 to 17 atomic percent (at %);

[0091] ii. Copper (Cu) in the range of 18 to 35 atomic percent (at %);

[0092] iii. Manganese (Mn) in the range of 17 to 34 atomic percent (at %);

[0093] iv. Nickel (Ni) in the range of 23 to 37 atomic percent (at %);

[0094] v. The remainder consisting of inevitable impurities, wherein the sum of the atomic percentages of Cr, Cu, Mn, and Ni is equal to 100%.

[0095] In embodiment of the present invention is to provide CraCubMncNid High Entropy Alloy (HEA) composition, wherein the atomic percentages of each element are in the range of 10 to 30 at %.

[0096] In embodiment of the present invention is to provide CraCubMncNid High Entropy Alloy (HEA) composition, wherein the atomic percentages of each element are in the range of 15 to 25 at %.

[0097] In embodiment of the present invention is to provide CraCubMncNid High Entropy Alloy (HEA) composition, wherein process for preparing the High Entropy Alloy (HEA) composition of claim 1, comprising:

[0098] a. Gathering high-purity solid forms of Chromium (Cr), Copper (Cu), Manganese (Mn), and Nickel (Ni), each with a purity level of at least 99.9% and converting the atomic percentages of Cr, Cu, Mn, and Ni into corresponding weight percentages based on their respective atomic masses;

[0099] b. Weighing the high-purity solid forms according to their respective weight percentages to achieve a combined total weight of 25 grams;

[0100] c. Introducing the weighed elements as obtained in step (b) into a vacuum arc melting furnace capable of inducing material melting through an arc generated between a tungsten electrode and the workpiece, under an inert atmosphere;

[0101] d. Establishing a vacuum of at least 10{circumflex over ( )}-6 millibars within the furnace;

[0102] e. Displacing the vacuum with an inert gas, wherein Argon gas is introduced to create an inert atmosphere within the furnace during the melting process;

[0103] f. Repeating the melting process at least four times to ensure thorough mixing and homogeneity of the alloy to obtained Cr—Cu—Mn—Ni-based High Entropy Alloy.

[0104] In embodiment of the present invention is to provide a preparation of CraCubMncNid High Entropy Alloy (HEA) composition, wherein melting procedure in step (c) is repeated more than four times to ensure optimal homogeneity of the alloy.

[0105] In embodiment of the present invention is to provide a preparation of CraCubMncNid High Entropy Alloy (HEA) composition, wherein final High Entropy Alloy is cooled and solidified after the completion of the melting steps (c).

[0106] In embodiment of the present invention is to provide High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein composition comprises Chromium, Copper, Manganese, and Nickel in atomic percentages.

[0107] In embodiment of the present invention is to provide a preparation of High Entropy Alloy (HEA) CraCubMncNid composition, wherein analyzing the final alloy to confirm that the atomic percentages of Chromium, Copper, Manganese, and Nickel fall within the defined ranges.

[0108] In embodiment of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein the alloy exhibits enhanced properties, including improved mechanical strength, corrosion resistance, or thermal stability, due to the specific combination of Cr, Cu, Mn, and Ni.

[0109] In embodiment of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein High Entropy Alloy composition having enhancement in hardness ranging from 161.20-164.78 HV0.1 / 20s, when compared to a super alloy predominantly based on nickel.

[0110] In embodiment of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein composition having COF (Coefficient of Friction) in the range of 0.38-0.45.

[0111] Phase Composition and Stability Analysis: The CraCubMncNid High Entropy Alloy (HEA) outlined in this invention is distinguished by its composition encompassing 5 to 35 atomic percent (at %) of Chromium (Cr), 5 to 35 at % of Copper (Cu), 5 to 35 at % of Manganese (Mn), 5 to 35 at % of Nickel (Ni), with the remainder comprising inevitable impurities. The composition is shown in Table 1. The initial idea of alloy development is based upon the prediction of superior mechanical property through a well-stablished machine learning model

[21] . A four-component alloy system with varying composition as mentioned above is predicted to have superior strengths.TABLE 1Elemental Composition of the Developed CraCubMncNidHigh Entropy Alloy CCMN-1 (HEA) and the range in whichelement composition can be varied for optimized resultsCr (a,Cu (b,Mn (c,Ni (d,a + b +at. %)at. %)at. %)at. %)c + dGeneral5-1718-3517-3423-37100rangeCCMN-111263033100CCMN-273327.532.5100*a + b + c + d = 100

[0112] To understand the expected microstructure in the developed CraCubMncNid HEA, the phase fraction diagrams generated through Thermo-Calc software with varying Cr content (i.e. X as atomic fraction) is shown in FIG. 1. The CrCuMnNi system shows a dual-phase equilibrium microstructure at room temperature with matrix (i.e., primary phase) as FCC_L12 and BCC_B2 as secondary phase. With a decrease in Cr content, FCC phase fraction was predicted to be increasing whereas BCC phase fraction was decreasing. At lower Cr content, two type of BCC phases (i.e., BCC_B2 and BCC_B2 #2) becomes stable at higher temperature in this system.High Entropy Alloy Development Process:

[0113] Synthesis of CraCubMncNid High Entropy Alloy: In the initial phase, high-purity solid forms of the constituent elements—Chromium (Cr), Copper (Cu), Manganese (Mn), and Nickel (Ni)—with a purity level of 99.9% were gathered. To achieve the desired composition, the atomic percentages of each element were converted into weight percentages. Specific quantities of each element were then meticulously measured to yield a total combined weight of 50 grams. For instance, in the case of creating an equiatomic high entropy alloy of CrCuMnNi, 25% atomic composition of each element (Cr, Cu, Mn, and Ni) was converted into weight percentages to ensure the desired composition. Individual solid pellets of each element were weighed according to their respective weight ratios, culminating in the creation of a 50-gram mixture. Subsequently, a vacuum arc melting (VAM) furnace, capable of inducing material melting through an arc generated between a tungsten electrode and the workpiece in an inert atmosphere, was employed. A vacuum of 10-6 millibars was established within the chamber. Following this, the vacuum was displaced by the introduction of inert Argon gas. This inert atmosphere was maintained during the melting process to prevent oxidation. To ensure thorough mixing and homogeneity, this melting procedure was repeated five times. Ultimately, a rod-shaped solid ingot weighing 50 grams was successfully fabricated shown in FIG. 2.

[0114] FIG. 3 represents the optical microscopy and X-ray diffraction (XRD) of the CraCubMncNid High Entropy Alloy. The optical micrograph (FIG. 3(a)) of the as-cast HEA exhibits a microstructure comprises of irregular broken dendrites with light contrast and fine interdenritic region with dark contrast. The XRD (FIG. 3(b)) indicates that the matrix is having Face centered cubic (FCC) crystal structure completely which can be due to rapid cooling from FCC phase region provided by the cooling system attached to the Cu mould in VAM setup.

[0115] FIG. 4 displays the outcomes of Scanning electron microscopy (SEM) analysis conducted at room temperature for the as-cast HEA. The elemental mapping acquired during the SEM investigation of the as-cast alloy reveals the uniform distribution of each of the elemental component uniformly throughout the dendritic region with a slight degree of Copper (Cu) segregation observed in the interdendritic region. The microstructural investigation indicates that the developed HEA is single phase FCC based solid solution.

[0116] Mechanical behaviour of the developed CraCubMncNid High Entropy Alloy:

[0117] FIG. 5 depicts the microhardness measurement of the developed CraCubMncNid High Entropy Alloy. The microhardness measurement has been performed at eight different locations in the HEA and an average value of 377±11 HV was obtained. FIG. 6 depicts the stress-strain curve of the developed HEA for as-cast condition. With Yield strength (YS) at 776 MPa and Ultimate tensile strength (UTS) at 862 MPa, the developed HEA demonstrates superior YS and UTS in comparison to as-cast nickel-based superalloys.

[0118] FIG. 7 depicts the corrosion characteristics of the developed CraCubMncNid High Entropy Alloy in a 3.5 wt. % NaCl aqueous solution. The potentiodynamic polarization curve obtained during electrochemical corrosion of the HEA is shown in FIG. 6(a). The Corrosion potential (Ecorr) of −0.184 V and the Corrosion current density (Icorr) value of 5.02×10-7 A was determined for the HEA depicting a high corrosion resistance associated with the developed alloy which is also superior to stainless steel [25-27] and different class of HEA.Tribological Behaviour of HEA:

[0119] FIG. 8 and FIG. 9 shows tribological performance of CraCubMncNid High Entropy Alloy, where a tribo-testing experiment was conducted with different load (50-200N) and frequency level (1-4 Hz) to evaluate wear rate and the coefficient of friction (COF) generated during the experiment. To compared the results similar type of experiment was conducted with Inconel 625.

[0120] We found that the wear rate and coefficient of friction values were comparatively lower than that of the Inconel 625, which is a standard material in tribo-testing comparison. This experiment indicates that developed high entropy alloy shows superior tribological performance compared to Inconel 625.

[0121] The developed CraCubMncNid High Entropy Alloy showcases a unique combination of excellent mechanical properties, superior corrosion resistance, and enhanced tribological performance. These characteristics make it a strong candidate for a wide range of applications, including marine environments, structural components, and tribological systems that require materials to perform under harsh conditions at room temperature. Through precise alloying techniques and advanced characterization methods, this novel HEA has demonstrated its potential to surpass conventional materials like stainless steel and nickel-based superalloys in both strength and wear resistance, offering new possibilities for advanced engineering solutions.Inventive Step of the Invention

[0122] The comparative analysis of the newly developed CraCubMncNid High Entropy Alloy reveals significant advancements in material properties, particularly in the context of room temperature applications. A systematic series of hardness tests conducted on the HEA demonstrated a marked improvement in hardness when compared to traditional nickel-based superalloys, as illustrated in FIG. 4. This improvement indicates the HEA's potential to excel in a range of applications requiring enhanced mechanical performance at room temperature.

[0123] CraCubMncNid High Entropy Alloy for room temperature applications include:

[0124] Superior Mechanical Properties at Room Temperature: The Cr—Cu—Mn—Ni HEA system offers exceptional tensile strength, ductility, and toughness at room temperature, outperforming conventional nickel-based and nickel-iron-based alloys. This makes the alloy ideal for structural and engineering applications that operate under ambient conditions, such as automotive components, industrial machinery, and general-purpose equipment.

[0125] Cost-Effectiveness by Reducing Precious Element Dependency: Unlike traditional nickel-based superalloys that rely on expensive elements such as molybdenum (Mo), tantalum (Ta), rhenium (Re), and ruthenium (Ru), the CraCubMncNid High Entropy Alloy uses more abundant and cost-effective elements. This significantly lowers material costs while maintaining excellent mechanical and corrosion resistance properties at room temperature, making the alloy more economically viable for widespread industrial use.

[0126] Improved Phase Stability without Detrimental Intermetallic Phases: The alloy design avoids the formation of brittle intermetallic phases that are common in nickel-iron superalloys when trace elements like aluminum (Al) are added. The CraCubMncNid High Entropy Alloy system exhibits greater phase stability, ensuring consistent mechanical properties without the risk of embrittlement or premature failure at room temperature, even under long-term mechanical stress or environmental exposure.

[0127] Enhanced Tribological Properties for Room Temperature Applications: The CraCubMncNid High Entropy Alloy demonstrates superior wear resistance and friction control compared to traditional superalloys, making it highly suitable for applications requiring high wear performance at ambient conditions. This is particularly advantageous in sectors such as automotive, aerospace, and industrial machinery, where wear and friction at room temperature can significantly affect component longevity and performance.

[0128] Excellent Corrosion Resistance in Room Temperature Environments: The CraCubMncNid High Entropy Alloy system provides enhanced resistance to corrosion in environments commonly industrial chemicals. This corrosion resistance surpasses that of many nickel-based and nickel-iron-based superalloys, making the alloy a more durable choice for industrial applications where exposure to corrosive media is a concern.

[0129] Improved Quality-Price Ratio for Room Temperature Applications: The CraCubMncNid High Entropy Alloy system delivers a better balance of performance and cost, especially in applications that do not demand the extreme high-temperature capabilities of traditional superalloys. This alloy offers high strength, durability, and corrosion resistance at a more affordable price, making it an ideal choice for industries that require a high-performing yet cost-effective material for room temperature operations.

[0130] In summary, the CraCubMncNid High Entropy Alloy developed in this invention provides an optimal solution for industries seeking superior mechanical performance, enhanced wear resistance, and excellent corrosion protection at room temperature, all while maintaining cost-efficiency by reducing reliance on precious alloying elements. This makes the alloy system a robust alternative to traditional nickel-based and nickel-iron-based superalloys in a wide range of applications.Enhanced Hardness and Its Implications for Room Temperature Applications

[0131] Aerospace Sector: In aerospace applications, components such as brackets, supports, and other structural elements are often required to perform reliably under various loading conditions at room temperature. The HEA's superior hardness offers a significant advantage, potentially enhancing the performance of these components by improving their resistance to deformation and fatigue. This is particularly critical in ensuring safety and reliability in aircraft operations.

[0132] Automotive Industry: The automotive industry continuously seeks materials that can improve vehicle performance, efficiency, and safety. The enhanced hardness of the HEA makes it a strong candidate for use in engine components, chassis, and other critical parts operating at room temperature. The ability to withstand wear and tear while maintaining structural integrity can lead to improved fuel efficiency, reduced maintenance, and extended lifespan of automotive parts.

[0133] Energy Sector: Within the energy sector, room temperature applications such as structural supports for power generation equipment, piping, and various components in renewable energy systems could greatly benefit from the HEA's improved hardness. The increased wear resistance and strength of the HEA can help reduce maintenance intervals and extend the life of these components, contributing to overall efficiency and reliability in energy systems.

[0134] Electronics Industry: The electronics industry demands materials that can perform reliably in compact and mechanically stressed environments. The HEA's elevated hardness can lead to the development of more robust electronic housings and components, enhancing their resistance to mechanical shock and wear. This could be particularly beneficial in applications such as smartphones, laptops, and other consumer electronics that are subject to frequent handling and environmental stresses.

[0135] Manufacturing and Tooling: In manufacturing applications, particularly for tooling and dies, the hardness of the HEA positions it as an excellent candidate for tools that must withstand high stress and wear during machining operations. Enhanced tool life and performance at room temperature can lead to improved efficiency in production processes, reducing costs and increasing productivity.

[0136] In summary, the newly developed CraCubMncNid High Entropy Alloy pronounced increase in hardness compared to traditional nickel-based superalloys presents a wealth of opportunities for room temperature applications across various industries. The exceptional mechanical properties of the HEA make it a viable material for critical applications in aerospace, automotive, energy, electronics, and manufacturing sectors. Ongoing research and optimization efforts aim to further enhance the HEA's performance, ensuring that it meets the evolving demands of contemporary technology and industry standards.EXAMPLES

[0137] The following examples are given by way of illustration of the working of the invention in actual practice and therefore should not be construed to limit the scope of the present invention.

[0138] Working concept of shaping tool in combination with heat treatment method that can manufacture variety of memory alloy stent-graft rings has been demonstrated in examples.Experimental Procedure:

[0139] The development of the novel CraCubMncNid High Entropy Alloy system involved several carefully planned experimental steps to ensure precise composition and desired microstructure. The objective was to design an alloy system exhibiting superior mechanical properties, such as strength, hardness, tribological performance, and corrosion resistance, under room temperature conditions.Material Preparation and Alloy Synthesis:

[0140] In the first stage of synthesis, high-purity solid forms of the constituent elements—Chromium (Cr), Copper (Cu), Manganese (Mn), and Nickel (Ni)—were sourced. Each element had a purity level of 99.9%, ensuring minimal contamination and superior quality in the final alloy. To achieve the desired atomic composition, the atomic percentages of each element were converted into corresponding weight percentages, facilitating precise control over the alloy's overall composition.

[0141] For example, in the case of developing an equiatomic CrCuMnNi High Entropy Alloy, each element was allotted a 25% atomic composition. These atomic percentages were then converted into their weight equivalents, ensuring that the mixture reflected the targeted composition. Specific amounts of each element were meticulously measured to yield a total combined weight of 50 grams for the alloy. Table 1 presents the elemental composition used in the alloying process.

[0142] Example 1: The composition of the elements in CCMN-1 High Entropy Alloy is Chromium 11%, Copper 26%, Manganese 30% and Nickel 33% by atomic percentage. This is converted to the weight percentage as Chromium 10%, Copper 28%, Manganese 28% and Nickel 34%. To produce 50 gm of sample the corresponding weight of each element is Chromium 5 gm, Copper 14 gm, Manganese 14 gm and Nickel 17 gm. The following steps are performed in preparation of High Entropy Alloy:

[0143] 1. The exact weights of the elements in pallets form are feed in the vacuum arc melting furnace.

[0144] 2. A vacuum of 10−3 mbar is achieved in the furnace initially and then inert gas Argon is purged in the furnace. The process is repeated two more time to evacuate the air from the furnace chamber and to increase the purity of inert gas argon in chamber.

[0145] 3. A higher vacuum of 10−6 m bar is achieved with the help of turbo pump.

[0146] 4. The chamber is again purged with the Argon gas to the vacuum of 10−3 m bar for melting the pallets with arc melting. As it is difficult to maintain the arc at high vacuum of 10−6 mbar.

[0147] 5. The arc is produced and by striking the electrodes and melting is done smoothly.

[0148] 6. The melting process is repeated 5 times to get the homogeneity.

[0149] Example 2: The composition of the elements in CCMN-2HEA is Chromium 7%, Copper 33%, Manganese 27.5% and Nickel 32.5% by atomic percentage. This is converted to the weight percentage as Chromium 6%, Copper 36%, Manganese 26% and Nickel 32%. To produce 50 gm of sample the corresponding weight of each element is Chromium 3 gm, Copper 18 gm, Manganese 13 gm and Nickel 16 gm. the synthesis process is same as discussed in example 1. To achieve the desired properties, we can tailor the different compositions CCMN High Entropy Alloy using these elements in the given range of Alloy Melting and Solidification:

[0150] Once the elements were accurately weighed and combined, the synthesis process began. The mixture was placed into a vacuum arc melting furnace, a sophisticated apparatus designed to melt metals by generating an arc between a tungsten electrode and the alloy mixture. This arc heats the materials to their melting point under an inert atmosphere, preventing oxidation and contamination during the process. To prepare the furnace, a high vacuum of 10−6 millibars was established within the chamber, effectively removing all air. Subsequently, the vacuum was replaced with inert Argon gas to create a stable, non-reactive environment for melting. This inert atmosphere was critical for preventing oxidation and ensuring the chemical integrity of the elements during melting.

[0151] The alloy mixture was then subjected to the arc melting process. To guarantee homogeneity and thorough mixing, the melting procedure was repeated five times, with the material being remelted and solidified after each iteration. This repetitive melting cycle ensured that the alloy's microstructure was uniform and free from segregation. The molten alloy was allowed to solidify into a bottom-shaped ingot, weighing 50 grams, as shown in FIG. 1.Microstructure Characterization:

[0152] Following casting, the microstructure of the CrCuMnNiCCMN-1 High Entropy Alloy was examined using optical microscopy and X-ray diffraction (XRD). FIG. 2 presents the optical micrograph of the as-cast HEA, which reveals a microstructure consisting of irregular broken dendrites (light contrast) and a fine interdendritic region (dark contrast). XRD analysis confirmed that the matrix phase of the alloy exhibits a face-centered cubic (FCC) crystal structure, typical of high entropy alloys with a balanced elemental composition. This combination of dendritic morphology and FCC phase structure is essential for the alloy's mechanical performance.SEM and Elemental Mapping:

[0153] FIG. 3 shows the results from Scanning Electron Microscopy (SEM) and elemental mapping of the as-cast High Entropy Alloy. The SEM images reveal a uniform distribution of all constituent elements (Cr, Cu, Mn, and Ni) throughout the alloy. The elemental mapping highlights a slight segregation of Copper (Cu) in the interdendritic regions, while the overall microstructure is dominated by a single-phase FCC-based solid solution. This uniform elemental distribution indicates the effectiveness of the melting and mixing process in producing a homogenous alloy.Microstructure Prediction:

[0154] The expected microstructure of the developed High Entropy Alloy was predicted using phase fraction diagrams generated through Thermo-Calc software, with varying Chromium (Cr) content (X represents atomic fraction). FIG. 4 illustrates how the CrCuMnNiCCMN-1 High Entropy Alloy system exhibits a dual-phase equilibrium microstructure at room temperature, with the matrix phase identified as FCC_L12 and the secondary phase as BCC_B2. As the Cr content decreases, the fraction of the FCC phase increases, while the BCC phase fraction diminishes. Notably, at lower Cr concentrations, two distinct BCC phases-BCC_B2 and BCC_B2 #2become stable at elevated temperatures within this system. This prediction provides valuable insight into the alloy's phase stability and microstructural evolution, particularly as it relates to the influence of Cr on phase behaviour.Mechanical Properties:

[0155] To evaluate the mechanical properties, the microhardness of the as-cast High Entropy Alloy was measured at eight different locations across the alloy, as shown in FIG. 5. The average microhardness value was 377±11 HV, demonstrating the alloy's superior hardness compared to many traditional materials. This high hardness is attributed to the fine microstructure and solid solution strengthening effects provided by the multi-element composition.

[0156] The tensile properties of the alloy were also measured, and the stress-strain curve is presented in FIG. 6. The CrCuMnNiCCMN-1 High Entropy Alloy exhibited a yield strength (YS) of 776 MPa and an ultimate tensile strength (UTS) of 862 MPa. These values are significantly higher than those of standard as-cast nickel-based superalloys, indicating that the developed HEA offers superior strength without sacrificing ductility. The superior mechanical performance makes this alloy highly suitable for structural applications at room temperature where strength and toughness are critical.Corrosion Resistance

[0157] The corrosion resistance of the developed High Entropy Alloy (HEA) was evaluated through potentiodynamic polarization tests conducted in a 3.5 wt. % NaCl aqueous solution. FIG. 7 illustrates the corrosion polarization curves of the developed CrCuMnNiCCMN-1 High Entropy Alloy, benchmarked against Inconel 625 with and without iron addition.

[0158] The CrCuMnNiCCMN-1HEA displayed exceptional corrosion resistance, characterized by a corrosion potential (Ecorr) of −0.184 V and a corrosion current density (Icorr) of 5.02×10−7 A. These values underscore the superior corrosion resistance of the HEA, with a more noble Ecorr and significantly lower Icorr compared to both variants of Inconel 625.

[0159] This performance indicates the CrCuMnNiCCMN-1HEA's robust ability to withstand corrosive conditions, making it a highly attractive candidate for marine applications and other environments prone to aggressive corrosion. Its excellent resistance not only enhances durability but also reduces maintenance and operational costs, contributing to its potential for long-term application in critical industries.Tribological Performance

[0160] The wear and friction characteristics of the CrCuMnNiCCMN-1 High Entropy Alloy were assessed through tribological testing, conducted under different load (50-200N) and frequency (1-4 Hz) conditions. FIG. 8 illustrates the wear rate comparison between the CrCuMnNiCCMN-1 High Entropy Alloy and Inconel 625, a standard material in tribological applications. The CrCuMnNiCCMN-1HEA showed significantly lower wear rates across all tested conditions, demonstrating its superior resistance to material loss under frictional forces.

[0161] Similarly, FIG. 9 compares the coefficient of friction (COF) of the CrCuMnNiCCMN-1 High Entropy Alloy with that of Inconel 625 under varying load and frequency conditions. The developed High Entropy Alloy exhibited a lower COF, indicating smoother sliding and better wear resistance. This improved tribological performance is a key advantage for applications involving high wear and friction, such as in bearings, gears, and other mechanical components.Advantages of the Invention1. Cr—Cu—Mn—Ni High Entropy Alloy offers superior Mechanical Properties at Room Temperature;

[0163] 2. Cr—Cu—Mn—Ni High Entropy Alloy offers exceptional tensile strength, ductility, and toughness at room temperature, outperforming conventional nickel-based and nickel-iron-based alloys;

[0164] 3. Cr—Cu—Mn—Ni High Entropy Alloy offers Cost-Effectiveness by Reducing Precious Element Dependency;

[0165] 4. Improved Phase Stability without Detrimental Intermetallic Phases;

[0166] 5. Enhanced Tribological Properties for Room Temperature Applications;

[0167] 6. Excellent Corrosion Resistance in Room Temperature Environments;

[0168] 7. Improved Quality-Price Ratio for Room Temperature Applications;

[0169] 8. Cr—Cu—Mn—Ni High Entropy Alloy provides an optimal solution for industries seeking superior mechanical performance, enhanced wear resistance, and excellent corrosion protection at room temperature, all while maintaining cost-efficiency by reducing reliance on precious alloying elements.

Examples

example 1

[0142] The composition of the elements in CCMN-1 High Entropy Alloy is Chromium 11%, Copper 26%, Manganese 30% and Nickel 33% by atomic percentage. This is converted to the weight percentage as Chromium 10%, Copper 28%, Manganese 28% and Nickel 34%. To produce 50 gm of sample the corresponding weight of each element is Chromium 5 gm, Copper 14 gm, Manganese 14 gm and Nickel 17 gm. The following steps are performed in preparation of High Entropy Alloy:[0143]1. The exact weights of the elements in pallets form are feed in the vacuum arc melting furnace.[0144]2. A vacuum of 10−3 mbar is achieved in the furnace initially and then inert gas Argon is purged in the furnace. The process is repeated two more time to evacuate the air from the furnace chamber and to increase the purity of inert gas argon in chamber.[0145]3. A higher vacuum of 10−6 m bar is achieved with the help of turbo pump.[0146]4. The chamber is again purged with the Argon gas to the vacuum of 10−3 m bar for melting the pa...

example 2

[0149] The composition of the elements in CCMN-2HEA is Chromium 7%, Copper 33%, Manganese 27.5% and Nickel 32.5% by atomic percentage. This is converted to the weight percentage as Chromium 6%, Copper 36%, Manganese 26% and Nickel 32%. To produce 50 gm of sample the corresponding weight of each element is Chromium 3 gm, Copper 18 gm, Manganese 13 gm and Nickel 16 gm. the synthesis process is same as discussed in example 1. To achieve the desired properties, we can tailor the different compositions CCMN High Entropy Alloy using these elements in the given range of Alloy Melting and Solidification:

[0150]Once the elements were accurately weighed and combined, the synthesis process began. The mixture was placed into a vacuum arc melting furnace, a sophisticated apparatus designed to melt metals by generating an arc between a tungsten electrode and the alloy mixture. This arc heats the materials to their melting point under an inert atmosphere, preventing oxidation and contamination duri...

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Indian Patent Application No. 202411102374, filed on Dec. 23, 2024, the subject matter of which is incorporated by reference.FIELD OF INNOVATION

[0002] The present invention relates to the technical field of the development of a novel CraCubMncNid High Entropy based Alloy (HEA) system and process for preparation thereof. More particularly, the present invention relates to CraCubMncNid high entropy alloy-based system, wherein the concentration of a in the ranges of 5-17 atomic percent (at %), b in the range of 18-35 atomic percent (at %), c in the range of 17-34 atomic percent (at %), and d in the range of 23-37 atomic percent (at %). The unique combination of these elements unlocks a new level of performance and reliability, marking a significant advancement in the field of high entropy alloys. Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) exhibiting cost effective, superior strength, hardness, tribological performance, and corrosion resistance at room temperature. Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) alloy system a robust alternative to traditional nickel-based and nickel-iron-based superalloys in a wide range of applications.BACKGROUND AND PRIOR ART OF THE INVENTION

[0003] High Entropy Alloys (HEAs) are emerging as a groundbreaking class of materials that possess a unique combination of properties due to their multi-principal element composition. Unlike conventional alloys that rely on one or two principal elements, HEAs typically consist of five or more elements in near-equiatomic proportions, resulting in a high configurational entropy. This distinctive structure leads to exceptional mechanical properties, including high strength, hardness, wear resistance, and corrosion resistance, making HEAs highly versatile for a range of engineering applications.

[0004] In industries such as automotive, aerospace, marine, and energy, there is a growing demand for materials that can provide superior performance under varying environmental conditions, including room temperature. Traditional materials, such as steels and Ni-based superalloys, often exhibit limitations at ambient conditions, particularly in applications where both mechanical durability and corrosion resistance are critical. These materials are susceptible to wear, corrosion, and phase instabilities, which can lead to premature failure or reduced efficiency. To meet these growing needs, the development of HEAs that can offer a balance of properties—high strength, excellent tribological performance, and superior corrosion resistance at room temperature—is essential. Several HEAs have been explored for different applications, but limited research has focused on optimizing HEA systems specifically for room temperature performance, where materials are subject to significant wear, friction, and environmental degradation.

[0005] The benchmark for material performance at room temperature includes maintaining structural integrity under mechanical loads, providing resistance to wear and friction in tribological systems, and exhibiting superior corrosion resistance in various environmental conditions. The current benchmarks set by conventional alloys such as stainless steel, Inconel, and Ni-based alloys are limited by factors such as surface degradation, phase instability, and susceptibility to corrosion over time.

[0006] The present invention addresses these critical challenges by developing a novel Cr—Cu—Mn—Ni based High Entropy Alloy system that exhibits significantly improved mechanical and environmental performance at room temperature. This HEA system provides enhanced strength, hardness, tribological properties, and exceptional corrosion resistance, surpassing the performance of conventional Ni-based superalloys and steels. By overcoming the limitations of traditional materials, this novel Cr—Cu—Mn—Ni HEA system meets the pressing industrial need for a versatile material that can deliver high performance in ambient conditions, making it ideal for applications such as automotive components, industrial machinery, marine structures, and other general engineering applications where room temperature performance is paramount.

[0007] Prior art search was made in patent as well as non-patent literature sources and following documents are referred because of their relevance to field of present invention.

[0008] US20020159914A1 discloses high entropy alloy major metallic elements are selected from the metallic element group consisting of aluminum, titanium, vanadium, chromium, iron, cobalt, nickel, copper, zirconium, molybdenum, palladium, silver and gold. Exceptionally high hardness: Depending on the chemical composition, their hardness in the as-cast state ranges from Hv 450 to Hv 900. The degree of hardness is on par with or greater than that of fully quenched carbon steel or alloy steel.

[0009] WO2017164602A1 discloses high entropy alloy created through computer simulation and thermodynamic calculation. An alloy composition region with the microstructure of a face-centered cubic (FCC) single phase is set up to 700° C. or higher temperatures using thermodynamic calculation. The present invention pertains specifically to a high entropy alloy based on Cr, Fe, Mn, and Ni—V that exhibits excellent low-temperature tensile strength and elongation. This alloy is capable of achieving a single-phase microstructure at room temperature and cryogenic temperature after undergoing rapid heat treatment at 700° C. or higher temperatures.

[0010] KR101831056B1 discloses high entropy alloy contrast to the easily produced intermetallic compounds found in most multicomponent alloys, these compounds have a high mixed entropy, and the multicomponent elements form a simple solid solution that gives them excellent mechanical properties and strength through solid solution strengthening.

[0011] EP3660178B1 discloses medium-entropy alloy (MEA) with excellent cryogenic mechanical properties. It also exhibits high price competitiveness due to the inexpensive Fe content, which can be added in amounts between 55 and 62.5 at %. Furthermore, the alloying elements can be controlled to cause deformation-induced phase transformation during cryogenic deformation, resulting in the adjustment of face-centered cubic (FCC) and body-centered cubic (BCC) phase stability.

[0012] JP4885530B2 discloses Ni-based superalloy that exhibits exceptional strength and ductility at high temperatures. Specifically, it concerns a Ni-base superalloy that possesses high strength and excellent ductility, regardless of whether it is a unidirectionally solidified material or a regular cast material. The current invention also relates to a moving blade or a stationary blade of an axial flow gas turbine, a centrifugal wheel for a turbocharger, a microturbine made from a casting of a Ni-base superalloy, or any of these.

[0013] JP2002173732A discloses high entropy that is highly resistant to heat, acid, and heat. The multicomponent alloy with high entropy is made up of several different types of elements. There are five to eleven primary metallic element types in the alloy. Each type of metal element has a molar number that ranges from 5% to 30% of the alloy's total mol number. High hardness, high heat resistance, and high acid resistance are features of the alloy.

[0014] CN114350989A discloses a refractory Al—Cr—Ti—V—Nb light high-entropy alloy and a method of preparation for it. The elements that make up the refractory light high-entropy alloy are primarily Al, Cr, Ti, V, and Nb. The atomic percentages of the components are as follows: 22-25% of Al, 22-25% of Cr, 22-25% of Ti, 22-25% of V, and 0-12% of Nb. and using direct casting and vacuum arc melting to produce an alloy ingot. The alloy has a single BCC phase structure, uniform components, no segregation, no precipitated phase generation, and high hardness more than 540HV as well as a density of roughly 5.24 g / cm3 to 5.52g / cm3. In contrast to traditional refractory alloy. The density of the high entropy alloy is lower.

[0015] WO2019039743A1 discloses Fe—Ni—V—Cr new entropy alloy with nickel (Ni), iron (Fe), chromium (Cr), and vanadium (V) as the primary constituents. In contrast to alloy, which is one of the primary constituent elements of alloys like steel, aluminium alloy, and titanium alloy, high-entropy alloy (HEA) is a multi-element alloy that is produced by alloying five or more constituent elements at a similar rate. With a high entropy of mixing, the alloy forms a single-phase structure, such as a face-centered cubic (FCC) or body-centered cubic (BCC), rather than an intermetallic compound or intermediate phase.

[0016] Wang et al., Journal of materials science & technology, 34(10), 1791-1798, 2018 discloses studying the sluggish diffusion of high-entropy alloys, three different face centered cubic Co—Cr—Cu—Fe—Ni high-entropy alloys, and assembled into three groups of sandwich-type diffusion multiple annealed at 1273, 1323, and 1373 K respectively. By means of the electron probe microanalyzer technique and recently developed numerical inverse method, the composition-dependent inter diffusivities at different temperatures were effectively evaluated by minimizing the residual between the model-predicted compositions / interdiffusion fluxes and the respectively experimental ones.

[0017] Ge et al., Adv. Powder Technol., 28, 2556-2563, 2017 discloses CuZrAlTiNi High entropy alloy (HEA) coating was synthesized on T10 substrate using mechanical alloying (MA) and vacuum hot-pressing sintering (VHPS) technique. The MA results show that the final product of as-milled powders is amorphous phase. The obtained coating sintered at 950° C. is compact and about 0.9 mm in thickness. It is composed of a couple of face-centered cubic (FCC), one body-centered cubic (BCC) solid solutions and AlNi2Zr phase. The interface strength between coating and substrate is 355.5 MPa measured by three point bending test.

[0018] Liu et al., Intermetallics 72, 44-52, 2016 discloses fluxing and cyclic superheating technique to investigate the rapid solidification behavior of CoCrCuFexNi (x=1.0, 1.5, 2.0, molar concentration) high-entropy alloys. The microstructures of CoCrCuFexNi (x=1.0, 1.5, 2.0) high-entropy alloys solidified at different undercoolings (ΔT) were investigated. Liquid-phase separation leading to Cu-rich and Cu-depleted regions, were obtained in the solidified microstructure from highly undercooled melt. This occurs when the melt undercooling exceeds a critical undercooling (ΔTcrit) of 160 K for CoCrCuFeNi, 190 K for CoCrCuFe1.5Ni and 293 K for CoCrCuFe2Ni alloy. However, typical dendrites and interdendritic regions were observed in rapid-solidified CoCrCuFexNi alloys prepared from melts with a small undercooling (ΔT<ΔTcrit).

[0019] Curiotto et al., Fluid Phase Equilibr. 256, 132-136, 2007 discloses Cu-based alloys, like Cu—Co, Cu—Fe and Cu—Co—Fe, display a liquid metastable miscibility gap. When the melt is undercooled below a certain temperature depending on the alloy composition, they present a separation in two liquid phases, followed by coagulation before dendritic solidification. In order to predict the phase equilibria and the mechanisms of microstructure formation, a determination of the metastable monotectics in the phase diagrams is essential. This paper focuses on the up-to-date findings on the Cu—Co, Cu—Fe and Cu—Co—Fe metastable miscibility gap in the liquid phase. Furthermore, the knowledge on the phase equilibria in the three systems is extended by presenting new results obtained by differential scanning calorimetry (DSC) and comparing them with the calculated phase diagrams.

[0020] Hsu et al., Mater. Sci. Eng. A, 460-461, 403-408, 2007 discloses preparation of AlCoCrCuNi, AlCoCrCuFeNi, AgAlCoCrCuNi and AlAuCoCrCuNi, by the arc melting and casting method. The alloy specimens were polished and etched with aqua regia for observation with an optical microscope and scanning electron microscope (SEM, JEOL JSM-5410). The chemical compositions of the different phases were analyzed by SEM energy dispersive spectrometry (EDS).

[0021] Derimow et al., Mater. Today Commun., 15, 1-10, 2018 discloses observations of the as-cast microstructures of equiatomic quaternary and quinary multiprincipal element alloys (MPEAs) containing equiatomic ternary CoCrCu—X with X being Fe, Mn, Ni, V, FeMn, FeNi, FeV, MnNi, MnV, and NiV. Out of the 11 MPEA combinations studied, CoCrCuNi, CoCrCuFeNi, and CoCrCuMnNi displayed FCC solid solution dendritic microstructures while the remaining 8 displayed a liquid phase separation into Cu-lean and Cu-rich liquids which solidified into highly phase separated regions. Calculations for enthalpy of mixing (ΔHmix) were carried out on the possible equiatomic combinations of these alloys using Miedema's scheme for sub-regular solutions.

[0022] Munitz et al., J. Mater. Sci., 44, 64-73, 2008 discloses Electromagnetic levitation to determine Cu—Nb phase diagram and to study supercooling effects on solidification characteristics of the alloys containing 5-70 wt % Nb. The Cu—Nb stable phase diagram was found to exhibit near-flat liquidus with a peritectic reaction at 1093° C. Melt separation was found only for specimens containing approximately 20 wt % Nb. The results indicate that melt separation in the alloy requires supercooling exceeding 230K combined with high cooling rates during solidification. Some specimens quenched from the solid+liquid zone on a copper chill also show evidence of melt separation which is attributed to minor oxygen impurities. Nb-rich liquid which nucleates below the T 0 curve solidifies as a metastable Nb-bcc lattice containing only 67 wt % Nb as compared to 96 wt % of the regular Nb dendrites.

[0023] Lourengo, J. C., Corros. Sci., 193, 2021 discloses Inconel 625 based alloys with different iron contents were prepared by arc-melting. Alloys with up to 5 wt. % iron are composed of the y matrix, metal monocarbides (MC) and Laves precipitates. Alloys with 10-15 wt. % iron comprise the y matrix and y / Laves eutectic-like constituent. MC precipitates are cathodic and the Laves phase anodic with respect to the matrix. In 3.5 wt. % NaCl, alloys with 10-15 wt. %, iron showed improved corrosion behaviour compared to 5 wt. % iron due to absence of MC phase formation. The results are important as they potentially allow faster and more economical welding processes to be employed.

[0024] The above information disclosed is only for the enhancement of understanding of the background of the invention.

[0025] The limitations of existing nickel-based and nickel-iron-based superalloys, especially concerning room temperature applications, can be elaborated as follows:

[0026] High Cost Due to Precious Elements: Nickel-based superalloys often require the addition of expensive elements such as molybdenum (Mo), tantalum (Ta), tungsten (W), rhenium (Re), or ruthenium (Ru) to enhance their mechanical properties, such as creep strength and fatigue resistance. While these elements improve high-temperature performance, they significantly increase the manufacturing cost, making these alloys less cost-effective and limiting their widespread use in various industrial applications.

[0027] Formation of Intermetallic Phases in Nickel-Iron Superalloys: Nickel-iron-based superalloys were introduced as a cost-effective alternative to nickel-based ones, but they also exhibit limitations. When trace elements such as aluminium (Al) are added to enhance the material's strength, they can form detrimental intermetallic phases such as Ni2AlTi if the aluminium content exceeds 5 wt %. These intermetallic reduce the high-temperature mechanical properties and creep strength of the alloy, particularly in the presence of high iron (Fe) content, further limiting their performance.

[0028] Low Quality-Price Ratio: The overall quality-price ratio of conventional nickel-based and nickel-iron-based superalloys is low. These alloys often do not deliver sufficient performance benefits to justify their high cost, particularly in applications requiring both high strength and affordability. As a result, industries are seeking more efficient materials with improved cost-performance trade-offs.

[0029] Tribological Performance: Both nickel-based and nickel-iron-based superalloys show limited tribological properties. Wear and friction are critical in applications like aerospace and automotive components, and the current alloys do not provide the necessary wear resistance and friction control for these demanding applications.

[0030] Inferior Corrosion Resistance at Room Temperature: Nickel-iron-based alloys, in particular, tend to have inferior corrosion resistance compared to other materials such as stainless steels or titanium alloys, especially in environments that contain moisture, chlorides, or other corrosive agents commonly encountered in industrial settings. This corrosion susceptibility can limit the use of these alloys in applications where components are exposed to harsh environments at room temperature, such as chemical processing, marine, and general industrial applications. The corrosion degradation over time can lead to material failure, reducing the operational lifespan of components and increasing replacement costs. Thus, industries require materials with improved corrosion resistance under ambient conditions.

[0031] Thus, keeping in view the drawbacks of the hitherto reported prior arts, present invention relates to the technical field of the development of a novel High Entropy Cr—Cu—Mn—Ni-based Alloy (HEA) system and process for preparation thereof which obviates the drawbacks of the hitherto known prior art as detailed above. More particularly, the present invention relates to a high entropy CraCubMncNid alloy-based system, wherein the concentration of “a” in the ranges of 5-17%, b in the range of 18-35%, c in the range of 17-34%, and d in the range of 23-37%. The unique combination of these elements unlocks a new level of performance and reliability, marking a significant advancement in the field of high entropy alloys.Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) exhibiting cost effective, superior strength, hardness, tribological performance, and corrosion resistance at room temperature. Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) alloy system a robust alternative to traditional nickel-based and nickel-iron-based superalloys in a wide range of applicationsOBJECTIVE OF THE INVENTION

[0032] The main objective of the invention is to provide a High Entropy Cr—Cu—Mn—Ni-based Alloy (HEA) system with optimized atomic ratios of CraCubMncNid alloy-based system, wherein the concentration of “a” in the ranges of 5-17 atomic percent (at %), b in the range of 18-35 atomic percent (at %), c in the range of 17-34 atomic percent (at %), and d in the range of 23-37 atomic percent (at %). The unique combination of these elements unlocks a new level of performance and reliability, marking a significant advancement in the field of high entropy alloys.

[0033] Another object of the present invention is to provide CraCubMncNid High Entropy alloy-based system having enhancement in hardness ranging from 161.20-164.78 HV0.1 / 20s, when compared to a super alloy predominantly based on nickel

[0034] Another object of the present invention is to provide CraCubMncNid High Entropy alloy-based system having COF (Coefficient of Friction) in the range of 0.38-0.45.

[0035] Another object of the present invention is to provide CraCubMncNid High Entropy alloy-based system exceptional tensile strength, ductility, and toughness at room temperature, outperforming conventional nickel-based and nickel-iron-based alloys. This makes the alloy ideal for structural and engineering applications that operate under ambient conditions, such as automotive components, industrial machinery, and general-purpose equipment.

[0036] Another object of the present invention is to provide CraCubMncNid High Entropy alloy-based system that avoids the formation of brittle intermetallic phases that are common in nickel-iron superalloys when trace elements like aluminum (Al) are added. The CraCubMncNid High Entropy alloy-based system exhibits greater phase stability, ensuring consistent mechanical properties without the risk of embrittlement or premature failure at room temperature, even under long-term mechanical stress or environmental exposure.

[0037] Another object of the present invention is to provide CraCubMncNid High Entropy alloy-based system that having enhanced resistance to corrosion at room temperature in environments commonly industrial chemicals. Corrosion resistance surpasses that of many nickel-based and nickel-iron-based superalloys, making the alloy a more durable choice for industrial applications where exposure to corrosive media is a concern.

[0038] These objectives of the present invention, as well as other objectives related thereto, will be readily apparent post consideration of the description of the invention, together with reference to the contents of the Figures of the drawings. Additional objects, advantages and other novel features of the invention will appear as the description proceeds and in part will become apparent to those skilled in the art upon examination of the following.

[0039] The disclosure highlights the objectives of the invention, its distinctive features, and various innovations. To gain a better grasp of the invention, its operational benefits, and the specific goals it achieves, referring to the accompanying drawings and descriptive content, which showcase preferred embodiments of the invention, would be beneficial.SUMMARY OF THE INVENTION

[0040] Additional features and embodiments of the present disclosure will be better understood through the techniques and other aspects of the disclosure. Other embodiments of the invention are described in detail herein and are considered a part of the claimed disclosure.

[0041] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description section. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0042] The following is a condensed description of the disclosure to give the reader with a basic understanding. Its main goal is to present some of the principles described in this document in a simpler version as a prologue to the more extensive exposition that follows.

[0043] The present invention, and in accordance with main aspect of the present invention provide High Entropy Cr—Cu—Mn—Ni-based Alloy (HEA) system with optimized atomic ratios of CraCubMncNid alloy-based system, wherein the concentration of “a” in the ranges of 5-17 atomic percent (at %), b in the range of 18-35 atomic percent (at %), c in the range of 17-34 atomic percent (at %), and d in the range of 23-37 atomic percent (at %). The unique combination of these elements unlocks a new level of performance and reliability, marking a significant advancement in the field of high entropy alloys.

[0044] Another aspect of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, comprising:

[0045] i. Chromium (Cr) in the range of 5 to 17 atomic percent (at %);

[0046] ii. Copper (Cu) in the range of 18 to 35 atomic percent (at %);

[0047] iii. Manganese (Mn) in the range of 17 to 34 atomic percent (at %);

[0048] iv. Nickel (Ni) in the range of 23 to 37 atomic percent (at %);

[0049] v. The remainder consisting of inevitable impurities, wherein the sum of the atomic percentages of Cr, Cu, Mn, and Ni is equal to 100%.

[0050] Another aspect of the present invention is to provide a CraCubMncNid High Entropy Alloy (HEA) composition, wherein the atomic percentages of each element are in the range of 10 to 30 at %.

[0051] Another aspect of the present invention is to provide a CraCubMncNid High Entropy Alloy (HEA) composition, wherein the atomic percentages of each element are in the range of 15 to 25 at %.

[0052] Another aspect of the present invention is to provide a CraCubMncNid High Entropy Alloy (HEA) composition, wherein process for preparing the High Entropy Alloy (HEA) composition of claim 1, comprising:

[0053] a. Gathering high-purity solid forms of Chromium (Cr), Copper (Cu), Manganese (Mn), and Nickel (Ni), each with a purity level of at least 99.9% and converting the atomic percentages of Cr, Cu, Mn, and Ni into corresponding weight percentages based on their respective atomic masses;

[0054] b. Weighing the high-purity solid forms according to their respective weight percentages to achieve a combined total weight of 25 grams;

[0055] c. Introducing the weighed elements as obtained in step (b) into a vacuum arc melting furnace capable of inducing material melting through an arc generated between a tungsten electrode and the workpiece, under an inert atmosphere;

[0056] d. Establishing a vacuum of at least 10{circumflex over ( )}-6 millibars within the furnace;

[0057] e. Displacing the vacuum with an inert gas, wherein Argon gas is introduced to create an inert atmosphere within the furnace during the melting process;

[0058] f. Repeating the melting process at least four times to ensure thorough mixing and homogeneity of the alloy to obtained Cr—Cu—Mn—Ni-based High Entropy Alloy.

[0059] Another aspect of the present invention is to provide a preparation of CraCubMncNid High Entropy Alloy (HEA) composition, wherein melting procedure in step (c) is repeated more than four times to ensure optimal homogeneity of the alloy.

[0060] Another aspect of the present invention is to provide a preparation of CraCubMncNid High Entropy Alloy (HEA) composition, wherein final High Entropy Alloy is cooled and solidified after the completion of the melting steps (c).

[0061] Another aspect of the present invention is to provide CraCubMncNid High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein composition comprises Chromium, Copper, Manganese, and Nickel in atomic percentages.

[0062] Yet another aspect of the present invention is to provide a preparation of CraCubMncNidHigh Entropy Alloy (HEA) composition, wherein analyzing the final alloy to confirm that the atomic percentages of Chromium, Copper, Manganese, and Nickel fall within the defined ranges.

[0063] Yet another aspect of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein the alloy exhibits enhanced properties, including improved mechanical strength, corrosion resistance, or thermal stability, due to the specific combination of Cr, Cu, Mn, and Ni.

[0064] Yet another aspect of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein CraCubMncNid High Entropy Alloy composition having enhancement in hardness ranging from 161.20-164.78 HV0.1 / 20s, when compared to a super alloy predominantly based on nickel.

[0065] Yet another aspect of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein composition having COF (Coefficient of Friction) in the range of 0.38-0.45.BRIEF DESCRIPTION OF THE DRAWINGS

[0066] To complete the description and in order to provide for a better understanding of the present invention, a set of drawings is provided. The drawings form an integral part of the description and illustrate an embodiment of the present invention, which should not be interpreted as restricting the scope of the invention, but just as an example of how the invention can be carried out. The drawings comprise the following figures: The present invention is illustrated in FIGS. 1 to 9 of the drawings accompanying this specification.

[0067] FIG. 1 illustrate Casted Cr—Cu—Mn—Ni CCMN-1 HEA in Bottom-Shaped Mold

[0068] FIG. 2 illustrate Microstructure and XRD Analysis of the Developed Cr—Cu—Mn—Ni CCMN-1 HEA

[0069] FIG. 3 illustrate SEM Analysis of the As-Cast Cr—Cu—Mn—Ni CCMN-1 HEA.

[0070] FIG. 4 illustrate Phase fraction diagram predicted through Themro-Calc software for the developed HEA with varying atomic fraction of Cr (X=1, 0.7, 0.5 and 0.25).

[0071] FIG. 5 illustrate Microhardness Measurements at Various Locations in the Cr—Cu—Mn-NiCCMN-1 HEA Matrix

[0072] FIG. 6 illustrate Stress-Strain Curve of the Developed Cr—Cu—Mn—NiCCMN-1 HEA at Room Temperature

[0073] FIG. 7 illustrate Corrosion Behavior of the Developed Cr—Cu—Mn—Ni HEA CCMN-1in 3.5 wt. % NaCl Aqueous Solution compared to Inconel 625 with and without Iron addition.

[0074] FIG. 8 illustrate Wear Rate Comparison Between Inconel 625 and the Developed Cr—Cu—Mn—NiCCMN-1 HEA Under Different Load and Frequency Conditions

[0075] FIG. 9 illustrate Coefficient of Friction (COF) Comparison Between Inconel 625 and the Developed Cr—Cu—Mn—Ni CCMN-1 HEA Under Different Load and Frequency ConditionsABBREVIATIONSCALPHAD: Calculation of Phase Diagram

[0077] HEA: High Entropy Alloy

[0078] FCC: Face Centered Cubic

[0079] BCC: Body Centered Cubic

[0080] LPS: Liquid Phase Separation

[0081] SEM: Scanning Electron Microscope

[0082] XRD: X-ray Diffraction

[0083] COF: Co-efficient of FrictionDETAILED DESCRIPTION OF THE INVENTION

[0084] The following description is not to be taken in a limiting sense but is given solely for the purpose of describing the broad principles of the invention. Embodiments of the invention will be described by way of example, with reference to the above-mentioned drawings showing elements and results according to the present invention.

[0085] The foregoing detailed description of the disclosure is elaborated to provide a clear understanding to the person who is skilled in the art. Additional features, embodiments and advantages of the invention will be described hereinafter which form the subject of the claims of the disclosure, However, the set forth disclosure provide in the specification will best be understood in conjunction with the appended claims and figures as provide heretofore. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent processes do not depart from the spirit and scope of the disclosure as set forth in the appended claims. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in various configurations, all of which are explicitly contemplated and make part of this disclosure.

[0086] While the invention has been disclosed with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the invention without departing from its scope.

[0087] Throughout the specification and claims, the following terms take the meanings explicitly associated herein unless the context clearly dictates otherwise. The meaning of “a”, “an”, and “the” include plural references. The meaning of “in” includes “in” and “on.” Referring to the figures, like numbers indicate like parts throughout the views. Additionally, a reference to the singular includes a reference to the plural unless otherwise stated or inconsistent with the disclosure herein.

[0088] Accordingly, present invention provides an provide a High Entropy Cr—Cu—Mn—Ni-based Alloy (HEA) system and process for preparation thereof. More particularly, the present invention relates to a high entropy CraCubMncNid alloy based system, wherein the concentration of a” in the ranges of 5-15 atomic percent (at %), b in the range of 5-35 atomic percent (at %), c in the range of 16-32 atomic percent (at %), and d in the range of 25-37 atomic percent (at %). The unique combination of these elements unlocks a new level of performance and reliability, marking a significant advancement in the field of high entropy alloys.Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) exhibiting cost effective, superior strength, hardness, tribological performance, and corrosion resistance at room temperature. Cr—Cu—Mn—Ni-based High Entropy Alloys (HEAs) alloy system a robust alternative to traditional nickel-based and nickel-iron-based superalloys in a wide range of applications.

[0089] In embodiment of the present invention is to provide High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, comprising:

[0090] i. Chromium (Cr) in the range of 5 to 17 atomic percent (at %);

[0091] ii. Copper (Cu) in the range of 18 to 35 atomic percent (at %);

[0092] iii. Manganese (Mn) in the range of 17 to 34 atomic percent (at %);

[0093] iv. Nickel (Ni) in the range of 23 to 37 atomic percent (at %);

[0094] v. The remainder consisting of inevitable impurities, wherein the sum of the atomic percentages of Cr, Cu, Mn, and Ni is equal to 100%.

[0095] In embodiment of the present invention is to provide CraCubMncNid High Entropy Alloy (HEA) composition, wherein the atomic percentages of each element are in the range of 10 to 30 at %.

[0096] In embodiment of the present invention is to provide CraCubMncNid High Entropy Alloy (HEA) composition, wherein the atomic percentages of each element are in the range of 15 to 25 at %.

[0097] In embodiment of the present invention is to provide CraCubMncNid High Entropy Alloy (HEA) composition, wherein process for preparing the High Entropy Alloy (HEA) composition of claim 1, comprising:

[0098] a. Gathering high-purity solid forms of Chromium (Cr), Copper (Cu), Manganese (Mn), and Nickel (Ni), each with a purity level of at least 99.9% and converting the atomic percentages of Cr, Cu, Mn, and Ni into corresponding weight percentages based on their respective atomic masses;

[0099] b. Weighing the high-purity solid forms according to their respective weight percentages to achieve a combined total weight of 25 grams;

[0100] c. Introducing the weighed elements as obtained in step (b) into a vacuum arc melting furnace capable of inducing material melting through an arc generated between a tungsten electrode and the workpiece, under an inert atmosphere;

[0101] d. Establishing a vacuum of at least 10{circumflex over ( )}-6 millibars within the furnace;

[0102] e. Displacing the vacuum with an inert gas, wherein Argon gas is introduced to create an inert atmosphere within the furnace during the melting process;

[0103] f. Repeating the melting process at least four times to ensure thorough mixing and homogeneity of the alloy to obtained Cr—Cu—Mn—Ni-based High Entropy Alloy.

[0104] In embodiment of the present invention is to provide a preparation of CraCubMncNid High Entropy Alloy (HEA) composition, wherein melting procedure in step (c) is repeated more than four times to ensure optimal homogeneity of the alloy.

[0105] In embodiment of the present invention is to provide a preparation of CraCubMncNid High Entropy Alloy (HEA) composition, wherein final High Entropy Alloy is cooled and solidified after the completion of the melting steps (c).

[0106] In embodiment of the present invention is to provide High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein composition comprises Chromium, Copper, Manganese, and Nickel in atomic percentages.

[0107] In embodiment of the present invention is to provide a preparation of High Entropy Alloy (HEA) CraCubMncNid composition, wherein analyzing the final alloy to confirm that the atomic percentages of Chromium, Copper, Manganese, and Nickel fall within the defined ranges.

[0108] In embodiment of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein the alloy exhibits enhanced properties, including improved mechanical strength, corrosion resistance, or thermal stability, due to the specific combination of Cr, Cu, Mn, and Ni.

[0109] In embodiment of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein High Entropy Alloy composition having enhancement in hardness ranging from 161.20-164.78 HV0.1 / 20s, when compared to a super alloy predominantly based on nickel.

[0110] In embodiment of the present invention is to provide a High Entropy Alloy (HEA) composition having general formula of CraCubMncNid, wherein composition having COF (Coefficient of Friction) in the range of 0.38-0.45.

[0111] Phase Composition and Stability Analysis: The CraCubMncNid High Entropy Alloy (HEA) outlined in this invention is distinguished by its composition encompassing 5 to 35 atomic percent (at %) of Chromium (Cr), 5 to 35 at % of Copper (Cu), 5 to 35 at % of Manganese (Mn), 5 to 35 at % of Nickel (Ni), with the remainder comprising inevitable impurities. The composition is shown in Table 1. The initial idea of alloy development is based upon the prediction of superior mechanical property through a well-stablished machine learning model

[21] . A four-component alloy system with varying composition as mentioned above is predicted to have superior strengths.TABLE 1Elemental Composition of the Developed CraCubMncNidHigh Entropy Alloy CCMN-1 (HEA) and the range in whichelement composition can be varied for optimized resultsCr (a,Cu (b,Mn (c,Ni (d,a + b +at. %)at. %)at. %)at. %)c + dGeneral5-1718-3517-3423-37100rangeCCMN-111263033100CCMN-273327.532.5100*a + b + c + d = 100

[0112] To understand the expected microstructure in the developed CraCubMncNid HEA, the phase fraction diagrams generated through Thermo-Calc software with varying Cr content (i.e. X as atomic fraction) is shown in FIG. 1. The CrCuMnNi system shows a dual-phase equilibrium microstructure at room temperature with matrix (i.e., primary phase) as FCC_L12 and BCC_B2 as secondary phase. With a decrease in Cr content, FCC phase fraction was predicted to be increasing whereas BCC phase fraction was decreasing. At lower Cr content, two type of BCC phases (i.e., BCC_B2 and BCC_B2 #2) becomes stable at higher temperature in this system.High Entropy Alloy Development Process:

[0113] Synthesis of CraCubMncNid High Entropy Alloy: In the initial phase, high-purity solid forms of the constituent elements—Chromium (Cr), Copper (Cu), Manganese (Mn), and Nickel (Ni)—with a purity level of 99.9% were gathered. To achieve the desired composition, the atomic percentages of each element were converted into weight percentages. Specific quantities of each element were then meticulously measured to yield a total combined weight of 50 grams. For instance, in the case of creating an equiatomic high entropy alloy of CrCuMnNi, 25% atomic composition of each element (Cr, Cu, Mn, and Ni) was converted into weight percentages to ensure the desired composition. Individual solid pellets of each element were weighed according to their respective weight ratios, culminating in the creation of a 50-gram mixture. Subsequently, a vacuum arc melting (VAM) furnace, capable of inducing material melting through an arc generated between a tungsten electrode and the workpiece in an inert atmosphere, was employed. A vacuum of 10-6 millibars was established within the chamber. Following this, the vacuum was displaced by the introduction of inert Argon gas. This inert atmosphere was maintained during the melting process to prevent oxidation. To ensure thorough mixing and homogeneity, this melting procedure was repeated five times. Ultimately, a rod-shaped solid ingot weighing 50 grams was successfully fabricated shown in FIG. 2.

[0114] FIG. 3 represents the optical microscopy and X-ray diffraction (XRD) of the CraCubMncNid High Entropy Alloy. The optical micrograph (FIG. 3(a)) of the as-cast HEA exhibits a microstructure comprises of irregular broken dendrites with light contrast and fine interdenritic region with dark contrast. The XRD (FIG. 3(b)) indicates that the matrix is having Face centered cubic (FCC) crystal structure completely which can be due to rapid cooling from FCC phase region provided by the cooling system attached to the Cu mould in VAM setup.

[0115] FIG. 4 displays the outcomes of Scanning electron microscopy (SEM) analysis conducted at room temperature for the as-cast HEA. The elemental mapping acquired during the SEM investigation of the as-cast alloy reveals the uniform distribution of each of the elemental component uniformly throughout the dendritic region with a slight degree of Copper (Cu) segregation observed in the interdendritic region. The microstructural investigation indicates that the developed HEA is single phase FCC based solid solution.

[0116] Mechanical behaviour of the developed CraCubMncNid High Entropy Alloy:

[0117] FIG. 5 depicts the microhardness measurement of the developed CraCubMncNid High Entropy Alloy. The microhardness measurement has been performed at eight different locations in the HEA and an average value of 377±11 HV was obtained. FIG. 6 depicts the stress-strain curve of the developed HEA for as-cast condition. With Yield strength (YS) at 776 MPa and Ultimate tensile strength (UTS) at 862 MPa, the developed HEA demonstrates superior YS and UTS in comparison to as-cast nickel-based superalloys.

[0118] FIG. 7 depicts the corrosion characteristics of the developed CraCubMncNid High Entropy Alloy in a 3.5 wt. % NaCl aqueous solution. The potentiodynamic polarization curve obtained during electrochemical corrosion of the HEA is shown in FIG. 6(a). The Corrosion potential (Ecorr) of −0.184 V and the Corrosion current density (Icorr) value of 5.02×10-7 A was determined for the HEA depicting a high corrosion resistance associated with the developed alloy which is also superior to stainless steel [25-27] and different class of HEA.Tribological Behaviour of HEA:

[0119] FIG. 8 and FIG. 9 shows tribological performance of CraCubMncNid High Entropy Alloy, where a tribo-testing experiment was conducted with different load (50-200N) and frequency level (1-4 Hz) to evaluate wear rate and the coefficient of friction (COF) generated during the experiment. To compared the results similar type of experiment was conducted with Inconel 625.

[0120] We found that the wear rate and coefficient of friction values were comparatively lower than that of the Inconel 625, which is a standard material in tribo-testing comparison. This experiment indicates that developed high entropy alloy shows superior tribological performance compared to Inconel 625.

[0121] The developed CraCubMncNid High Entropy Alloy showcases a unique combination of excellent mechanical properties, superior corrosion resistance, and enhanced tribological performance. These characteristics make it a strong candidate for a wide range of applications, including marine environments, structural components, and tribological systems that require materials to perform under harsh conditions at room temperature. Through precise alloying techniques and advanced characterization methods, this novel HEA has demonstrated its potential to surpass conventional materials like stainless steel and nickel-based superalloys in both strength and wear resistance, offering new possibilities for advanced engineering solutions.Inventive Step of the Invention

[0122] The comparative analysis of the newly developed CraCubMncNid High Entropy Alloy reveals significant advancements in material properties, particularly in the context of room temperature applications. A systematic series of hardness tests conducted on the HEA demonstrated a marked improvement in hardness when compared to traditional nickel-based superalloys, as illustrated in FIG. 4. This improvement indicates the HEA's potential to excel in a range of applications requiring enhanced mechanical performance at room temperature.

[0123] CraCubMncNid High Entropy Alloy for room temperature applications include:

[0124] Superior Mechanical Properties at Room Temperature: The Cr—Cu—Mn—Ni HEA system offers exceptional tensile strength, ductility, and toughness at room temperature, outperforming conventional nickel-based and nickel-iron-based alloys. This makes the alloy ideal for structural and engineering applications that operate under ambient conditions, such as automotive components, industrial machinery, and general-purpose equipment.

[0125] Cost-Effectiveness by Reducing Precious Element Dependency: Unlike traditional nickel-based superalloys that rely on expensive elements such as molybdenum (Mo), tantalum (Ta), rhenium (Re), and ruthenium (Ru), the CraCubMncNid High Entropy Alloy uses more abundant and cost-effective elements. This significantly lowers material costs while maintaining excellent mechanical and corrosion resistance properties at room temperature, making the alloy more economically viable for widespread industrial use.

[0126] Improved Phase Stability without Detrimental Intermetallic Phases: The alloy design avoids the formation of brittle intermetallic phases that are common in nickel-iron superalloys when trace elements like aluminum (Al) are added. The CraCubMncNid High Entropy Alloy system exhibits greater phase stability, ensuring consistent mechanical properties without the risk of embrittlement or premature failure at room temperature, even under long-term mechanical stress or environmental exposure.

[0127] Enhanced Tribological Properties for Room Temperature Applications: The CraCubMncNid High Entropy Alloy demonstrates superior wear resistance and friction control compared to traditional superalloys, making it highly suitable for applications requiring high wear performance at ambient conditions. This is particularly advantageous in sectors such as automotive, aerospace, and industrial machinery, where wear and friction at room temperature can significantly affect component longevity and performance.

[0128] Excellent Corrosion Resistance in Room Temperature Environments: The CraCubMncNid High Entropy Alloy system provides enhanced resistance to corrosion in environments commonly industrial chemicals. This corrosion resistance surpasses that of many nickel-based and nickel-iron-based superalloys, making the alloy a more durable choice for industrial applications where exposure to corrosive media is a concern.

[0129] Improved Quality-Price Ratio for Room Temperature Applications: The CraCubMncNid High Entropy Alloy system delivers a better balance of performance and cost, especially in applications that do not demand the extreme high-temperature capabilities of traditional superalloys. This alloy offers high strength, durability, and corrosion resistance at a more affordable price, making it an ideal choice for industries that require a high-performing yet cost-effective material for room temperature operations.

[0130] In summary, the CraCubMncNid High Entropy Alloy developed in this invention provides an optimal solution for industries seeking superior mechanical performance, enhanced wear resistance, and excellent corrosion protection at room temperature, all while maintaining cost-efficiency by reducing reliance on precious alloying elements. This makes the alloy system a robust alternative to traditional nickel-based and nickel-iron-based superalloys in a wide range of applications.Enhanced Hardness and Its Implications for Room Temperature Applications

[0131] Aerospace Sector: In aerospace applications, components such as brackets, supports, and other structural elements are often required to perform reliably under various loading conditions at room temperature. The HEA's superior hardness offers a significant advantage, potentially enhancing the performance of these components by improving their resistance to deformation and fatigue. This is particularly critical in ensuring safety and reliability in aircraft operations.

[0132] Automotive Industry: The automotive industry continuously seeks materials that can improve vehicle performance, efficiency, and safety. The enhanced hardness of the HEA makes it a strong candidate for use in engine components, chassis, and other critical parts operating at room temperature. The ability to withstand wear and tear while maintaining structural integrity can lead to improved fuel efficiency, reduced maintenance, and extended lifespan of automotive parts.

[0133] Energy Sector: Within the energy sector, room temperature applications such as structural supports for power generation equipment, piping, and various components in renewable energy systems could greatly benefit from the HEA's improved hardness. The increased wear resistance and strength of the HEA can help reduce maintenance intervals and extend the life of these components, contributing to overall efficiency and reliability in energy systems.

[0134] Electronics Industry: The electronics industry demands materials that can perform reliably in compact and mechanically stressed environments. The HEA's elevated hardness can lead to the development of more robust electronic housings and components, enhancing their resistance to mechanical shock and wear. This could be particularly beneficial in applications such as smartphones, laptops, and other consumer electronics that are subject to frequent handling and environmental stresses.

[0135] Manufacturing and Tooling: In manufacturing applications, particularly for tooling and dies, the hardness of the HEA positions it as an excellent candidate for tools that must withstand high stress and wear during machining operations. Enhanced tool life and performance at room temperature can lead to improved efficiency in production processes, reducing costs and increasing productivity.

[0136] In summary, the newly developed CraCubMncNid High Entropy Alloy pronounced increase in hardness compared to traditional nickel-based superalloys presents a wealth of opportunities for room temperature applications across various industries. The exceptional mechanical properties of the HEA make it a viable material for critical applications in aerospace, automotive, energy, electronics, and manufacturing sectors. Ongoing research and optimization efforts aim to further enhance the HEA's performance, ensuring that it meets the evolving demands of contemporary technology and industry standards.EXAMPLES

[0137] The following examples are given by way of illustration of the working of the invention in actual practice and therefore should not be construed to limit the scope of the present invention.

[0138] Working concept of shaping tool in combination with heat treatment method that can manufacture variety of memory alloy stent-graft rings has been demonstrated in examples.Experimental Procedure:

[0139] The development of the novel CraCubMncNid High Entropy Alloy system involved several carefully planned experimental steps to ensure precise composition and desired microstructure. The objective was to design an alloy system exhibiting superior mechanical properties, such as strength, hardness, tribological performance, and corrosion resistance, under room temperature conditions.Material Preparation and Alloy Synthesis:

[0140] In the first stage of synthesis, high-purity solid forms of the constituent elements—Chromium (Cr), Copper (Cu), Manganese (Mn), and Nickel (Ni)—were sourced. Each element had a purity level of 99.9%, ensuring minimal contamination and superior quality in the final alloy. To achieve the desired atomic composition, the atomic percentages of each element were converted into corresponding weight percentages, facilitating precise control over the alloy's overall composition.

[0141] For example, in the case of developing an equiatomic CrCuMnNi High Entropy Alloy, each element was allotted a 25% atomic composition. These atomic percentages were then converted into their weight equivalents, ensuring that the mixture reflected the targeted composition. Specific amounts of each element were meticulously measured to yield a total combined weight of 50 grams for the alloy. Table 1 presents the elemental composition used in the alloying process.

[0142] Example 1: The composition of the elements in CCMN-1 High Entropy Alloy is Chromium 11%, Copper 26%, Manganese 30% and Nickel 33% by atomic percentage. This is converted to the weight percentage as Chromium 10%, Copper 28%, Manganese 28% and Nickel 34%. To produce 50 gm of sample the corresponding weight of each element is Chromium 5 gm, Copper 14 gm, Manganese 14 gm and Nickel 17 gm. The following steps are performed in preparation of High Entropy Alloy:

[0143] 1. The exact weights of the elements in pallets form are feed in the vacuum arc melting furnace.

[0144] 2. A vacuum of 10−3 mbar is achieved in the furnace initially and then inert gas Argon is purged in the furnace. The process is repeated two more time to evacuate the air from the furnace chamber and to increase the purity of inert gas argon in chamber.

[0145] 3. A higher vacuum of 10−6 m bar is achieved with the help of turbo pump.

[0146] 4. The chamber is again purged with the Argon gas to the vacuum of 10−3 m bar for melting the pallets with arc melting. As it is difficult to maintain the arc at high vacuum of 10−6 mbar.

[0147] 5. The arc is produced and by striking the electrodes and melting is done smoothly.

[0148] 6. The melting process is repeated 5 times to get the homogeneity.

[0149] Example 2: The composition of the elements in CCMN-2HEA is Chromium 7%, Copper 33%, Manganese 27.5% and Nickel 32.5% by atomic percentage. This is converted to the weight percentage as Chromium 6%, Copper 36%, Manganese 26% and Nickel 32%. To produce 50 gm of sample the corresponding weight of each element is Chromium 3 gm, Copper 18 gm, Manganese 13 gm and Nickel 16 gm. the synthesis process is same as discussed in example 1. To achieve the desired properties, we can tailor the different compositions CCMN High Entropy Alloy using these elements in the given range of Alloy Melting and Solidification:

[0150] Once the elements were accurately weighed and combined, the synthesis process began. The mixture was placed into a vacuum arc melting furnace, a sophisticated apparatus designed to melt metals by generating an arc between a tungsten electrode and the alloy mixture. This arc heats the materials to their melting point under an inert atmosphere, preventing oxidation and contamination during the process. To prepare the furnace, a high vacuum of 10−6 millibars was established within the chamber, effectively removing all air. Subsequently, the vacuum was replaced with inert Argon gas to create a stable, non-reactive environment for melting. This inert atmosphere was critical for preventing oxidation and ensuring the chemical integrity of the elements during melting.

[0151] The alloy mixture was then subjected to the arc melting process. To guarantee homogeneity and thorough mixing, the melting procedure was repeated five times, with the material being remelted and solidified after each iteration. This repetitive melting cycle ensured that the alloy's microstructure was uniform and free from segregation. The molten alloy was allowed to solidify into a bottom-shaped ingot, weighing 50 grams, as shown in FIG. 1.Microstructure Characterization:

[0152] Following casting, the microstructure of the CrCuMnNiCCMN-1 High Entropy Alloy was examined using optical microscopy and X-ray diffraction (XRD). FIG. 2 presents the optical micrograph of the as-cast HEA, which reveals a microstructure consisting of irregular broken dendrites (light contrast) and a fine interdendritic region (dark contrast). XRD analysis confirmed that the matrix phase of the alloy exhibits a face-centered cubic (FCC) crystal structure, typical of high entropy alloys with a balanced elemental composition. This combination of dendritic morphology and FCC phase structure is essential for the alloy's mechanical performance.SEM and Elemental Mapping:

[0153] FIG. 3 shows the results from Scanning Electron Microscopy (SEM) and elemental mapping of the as-cast High Entropy Alloy. The SEM images reveal a uniform distribution of all constituent elements (Cr, Cu, Mn, and Ni) throughout the alloy. The elemental mapping highlights a slight segregation of Copper (Cu) in the interdendritic regions, while the overall microstructure is dominated by a single-phase FCC-based solid solution. This uniform elemental distribution indicates the effectiveness of the melting and mixing process in producing a homogenous alloy.Microstructure Prediction:

[0154] The expected microstructure of the developed High Entropy Alloy was predicted using phase fraction diagrams generated through Thermo-Calc software, with varying Chromium (Cr) content (X represents atomic fraction). FIG. 4 illustrates how the CrCuMnNiCCMN-1 High Entropy Alloy system exhibits a dual-phase equilibrium microstructure at room temperature, with the matrix phase identified as FCC_L12 and the secondary phase as BCC_B2. As the Cr content decreases, the fraction of the FCC phase increases, while the BCC phase fraction diminishes. Notably, at lower Cr concentrations, two distinct BCC phases-BCC_B2 and BCC_B2 #2become stable at elevated temperatures within this system. This prediction provides valuable insight into the alloy's phase stability and microstructural evolution, particularly as it relates to the influence of Cr on phase behaviour.Mechanical Properties:

[0155] To evaluate the mechanical properties, the microhardness of the as-cast High Entropy Alloy was measured at eight different locations across the alloy, as shown in FIG. 5. The average microhardness value was 377±11 HV, demonstrating the alloy's superior hardness compared to many traditional materials. This high hardness is attributed to the fine microstructure and solid solution strengthening effects provided by the multi-element composition.

[0156] The tensile properties of the alloy were also measured, and the stress-strain curve is presented in FIG. 6. The CrCuMnNiCCMN-1 High Entropy Alloy exhibited a yield strength (YS) of 776 MPa and an ultimate tensile strength (UTS) of 862 MPa. These values are significantly higher than those of standard as-cast nickel-based superalloys, indicating that the developed HEA offers superior strength without sacrificing ductility. The superior mechanical performance makes this alloy highly suitable for structural applications at room temperature where strength and toughness are critical.Corrosion Resistance

[0157] The corrosion resistance of the developed High Entropy Alloy (HEA) was evaluated through potentiodynamic polarization tests conducted in a 3.5 wt. % NaCl aqueous solution. FIG. 7 illustrates the corrosion polarization curves of the developed CrCuMnNiCCMN-1 High Entropy Alloy, benchmarked against Inconel 625 with and without iron addition.

[0158] The CrCuMnNiCCMN-1HEA displayed exceptional corrosion resistance, characterized by a corrosion potential (Ecorr) of −0.184 V and a corrosion current density (Icorr) of 5.02×10−7 A. These values underscore the superior corrosion resistance of the HEA, with a more noble Ecorr and significantly lower Icorr compared to both variants of Inconel 625.

[0159] This performance indicates the CrCuMnNiCCMN-1HEA's robust ability to withstand corrosive conditions, making it a highly attractive candidate for marine applications and other environments prone to aggressive corrosion. Its excellent resistance not only enhances durability but also reduces maintenance and operational costs, contributing to its potential for long-term application in critical industries.Tribological Performance

[0160] The wear and friction characteristics of the CrCuMnNiCCMN-1 High Entropy Alloy were assessed through tribological testing, conducted under different load (50-200N) and frequency (1-4 Hz) conditions. FIG. 8 illustrates the wear rate comparison between the CrCuMnNiCCMN-1 High Entropy Alloy and Inconel 625, a standard material in tribological applications. The CrCuMnNiCCMN-1HEA showed significantly lower wear rates across all tested conditions, demonstrating its superior resistance to material loss under frictional forces.

[0161] Similarly, FIG. 9 compares the coefficient of friction (COF) of the CrCuMnNiCCMN-1 High Entropy Alloy with that of Inconel 625 under varying load and frequency conditions. The developed High Entropy Alloy exhibited a lower COF, indicating smoother sliding and better wear resistance. This improved tribological performance is a key advantage for applications involving high wear and friction, such as in bearings, gears, and other mechanical components.Advantages of the Invention1. Cr—Cu—Mn—Ni High Entropy Alloy offers superior Mechanical Properties at Room Temperature;

[0163] 2. Cr—Cu—Mn—Ni High Entropy Alloy offers exceptional tensile strength, ductility, and toughness at room temperature, outperforming conventional nickel-based and nickel-iron-based alloys;

[0164] 3. Cr—Cu—Mn—Ni High Entropy Alloy offers Cost-Effectiveness by Reducing Precious Element Dependency;

[0165] 4. Improved Phase Stability without Detrimental Intermetallic Phases;

[0166] 5. Enhanced Tribological Properties for Room Temperature Applications;

[0167] 6. Excellent Corrosion Resistance in Room Temperature Environments;

[0168] 7. Improved Quality-Price Ratio for Room Temperature Applications;

[0169] 8. Cr—Cu—Mn—Ni High Entropy Alloy provides an optimal solution for industries seeking superior mechanical performance, enhanced wear resistance, and excellent corrosion protection at room temperature, all while maintaining cost-efficiency by reducing reliance on precious alloying elements.

Examples

example 1

[0142] The composition of the elements in CCMN-1 High Entropy Alloy is Chromium 11%, Copper 26%, Manganese 30% and Nickel 33% by atomic percentage. This is converted to the weight percentage as Chromium 10%, Copper 28%, Manganese 28% and Nickel 34%. To produce 50 gm of sample the corresponding weight of each element is Chromium 5 gm, Copper 14 gm, Manganese 14 gm and Nickel 17 gm. The following steps are performed in preparation of High Entropy Alloy:[0143]1. The exact weights of the elements in pallets form are feed in the vacuum arc melting furnace.[0144]2. A vacuum of 10−3 mbar is achieved in the furnace initially and then inert gas Argon is purged in the furnace. The process is repeated two more time to evacuate the air from the furnace chamber and to increase the purity of inert gas argon in chamber.[0145]3. A higher vacuum of 10−6 m bar is achieved with the help of turbo pump.[0146]4. The chamber is again purged with the Argon gas to the vacuum of 10−3 m bar for melting the pa...

example 2

[0149] The composition of the elements in CCMN-2HEA is Chromium 7%, Copper 33%, Manganese 27.5% and Nickel 32.5% by atomic percentage. This is converted to the weight percentage as Chromium 6%, Copper 36%, Manganese 26% and Nickel 32%. To produce 50 gm of sample the corresponding weight of each element is Chromium 3 gm, Copper 18 gm, Manganese 13 gm and Nickel 16 gm. the synthesis process is same as discussed in example 1. To achieve the desired properties, we can tailor the different compositions CCMN High Entropy Alloy using these elements in the given range of Alloy Melting and Solidification:

[0150]Once the elements were accurately weighed and combined, the synthesis process began. The mixture was placed into a vacuum arc melting furnace, a sophisticated apparatus designed to melt metals by generating an arc between a tungsten electrode and the alloy mixture. This arc heats the materials to their melting point under an inert atmosphere, preventing oxidation and contamination duri...

Claims

1. A novel high entropy multielement alloy consisting essentially of four major metallic elements having of general formula CraCubMncNid, to ensures a balanced and diverse elemental composition conducive to enhanced mechanical properties and performance, comprising:i. Chromium (Cr) in the range of 5 to 17 atomic percent (at %);ii. Copper (Cu) in the range of 18 to 35 atomic percent (at %);iii. Manganese (Mn) in the range of 17 to 34 atomic percent (at %);iv. Nickel (Ni) in the range of 23 to 37 atomic percent (at %);v. the remainder consisting of inevitable impurities, wherein the sum of the atomic percentages of Cr, Cu, Mn, and Ni is equal to 100%;wherein atomic percentages of each element in CraCubMncNid are in the range of 5 to 37 at %; andwherein CraCubMncNid composition comprises Chromium, Copper, Manganese, and Nickel in atomic percentages(at %).

2. A process for preparing the CraCubMncNid High Entropy Alloy (HEA) composition of claim 1, comprising the step of:a. gathering high-purity solid forms of Chromium (Cr), Copper (Cu), Manganese (Mn), and Nickel (Ni), each with a purity level of at least 99.9% and converting the atomic percentages of Cr, Cu, Mn, and Ni into corresponding weight percentages based on their respective atomic masses;b. weighing the high-purity solid forms according to their respective weight percentages to achieve a combined total weight of 25 grams;c. introducing the weighed elements as obtained in step (b) into a vacuum arc melting furnace capable of inducing material melting through an arc generated between a tungsten electrode and the workpiece, under an inert atmosphere;d. establishing a vacuum of at least 10{circumflex over ( )}-6 millibars within the furnace;e. displacing the vacuum with an inert gas, wherein Argon gas is introduced to create an inert atmosphere within the furnace during the melting process;f. repeating the melting process at least four times to ensure thorough mixing and homogeneity of the alloy to obtained Cr—Cu—Mn—Ni-based High Entropy Alloy.

3. The process for preparation of CraCubMncNid High Entropy Alloy (HEA) of claim 2, wherein melting procedure in step (c) is repeated more than four times to ensure optimal homogeneity of the alloy.

4. The process for preparation of CraCubMncNid High Entropy Alloy (HEA) of claim 2, wherein final High Entropy Alloy is cooled and solidified after the completion of the melting steps (c).

5. The process for preparation of CraCubMncNid High Entropy Alloy (HEA) of claim 2, wherein analyzing the final alloy to confirm that the atomic percentages of Chromium, Copper, Manganese, and Nickel fall within the defined ranges.

6. The High Entropy Alloy (HEA) composition having general formula of CraCubMncNid of claim 1, wherein the alloy exhibits enhanced properties, including improved mechanical strength, corrosion resistance, or thermal stability, due to the specific combination of Cr, Cu, Mn, and Ni.

7. The High Entropy Alloy (HEA) composition having general formula of CraCubMncNid of claim 1, wherein High Entropy Alloy composition having enhancement in hardness ranging from 161.20-164.78 HV0.1 / 20s, when compared to a super alloy predominantly based on nickel.

8. The High Entropy Alloy (HEA) composition having general formula of CraCubMncNid of claim 1, wherein composition having COF (Coefficient of Friction) in the range of 0.38-0.45.

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