Wide-temperature-range self-adaptive anti-friction and anti-wear chromium-containing refractory high-entropy alloy material and preparation method thereof

Abstract

The invention discloses a wide-temperature-range self-adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material and a preparation method thereof, and belongs to the technical field of wear-resistant alloy materials, and the high-entropy alloy material comprises the following raw materials in percentage by mass: Ta, Mo, Ti and Cr. The preparation method comprises the steps that Ta powder, Mo powder, Ti powder and Cr powder are weighed by mass, ball milling is conducted, then sintering is conducted through a spark plasma sintering method, and the wide-temperature-range self-adaptive anti-friction and anti-wear chromium-containing refractory high-entropy alloy material is obtained. By introducing the chromium element, the alloy can adaptively form an oxide layer with lubrication and protection effects in a wide temperature range from room temperature to ultrahigh temperature, so that the alloy shows excellent tribological performance and has extremely low friction coefficient and wear rate. The material has a wide application prospect in the fields of wear-resistant lubricating materials and high-temperature wear-resistant parts.

Description

Technical Field

[0001] This invention belongs to the technical field of wear-resistant alloy materials, and particularly relates to a chromium-containing refractory high-entropy alloy material with wide temperature range adaptive friction reduction and wear resistance, and its preparation method. Background Technology

[0002] As aircraft continue to evolve towards higher thrust-to-weight ratios and higher speeds, the service environment of aero-engine systems is becoming increasingly demanding. This is manifested in significantly higher operating temperatures, a much wider temperature range, and continuously increasing operating speeds. This trend places more stringent requirements on the overall performance of key wear-resistant and lubricated components in the system. These components not only need to possess adaptive friction reduction and wear resistance, but also must simultaneously exhibit excellent high-temperature strength, thermal stability, and oxidation resistance to meet the long-term reliable operation requirements under extreme conditions.

[0003] High-entropy alloys, especially refractory high-entropy alloys, as an emerging class of multi-element alloy systems, provide a breakthrough technical approach for the innovative design of high-temperature wear-resistant materials. Their core design concept lies in the rational configuration of multiple main components, effectively suppressing the precipitation of intermetallic compounds through the high mixing entropy effect, thereby easily forming a simple and thermodynamically stable solid solution phase, completely breaking through the design limitations of traditional alloys dominated by a single or two elements. In refractory high-entropy alloys composed of high-melting-point elements such as tungsten, tantalum, molybdenum, hafnium, titanium, vanadium, and chromium as core components, they exhibit mechanical properties, thermal stability, and wear resistance far exceeding those of traditional high-temperature alloys under high-temperature conditions. With superior high-temperature structural stability and load-bearing capacity, they have become a core candidate system for a new generation of wide-temperature-range wear-resistant / lubricating materials.

[0004] However, existing refractory high-entropy alloys generally suffer from insufficient high-temperature oxidation resistance, a critical shortcoming that severely restricts their large-scale application in practical engineering scenarios such as aerospace propulsion systems. Due to their weak oxidation resistance, these alloys are prone to forming loose, easily peeling, non-protective oxides during high-temperature service, triggering the so-called "insect infestation" phenomenon, which in turn leads to powdering failure of the material surface. This process not only significantly increases the surface roughness and friction coefficient of the worn surface, but also directly damages the wear-resistant matrix structure of the alloy, severely weakening its long-term wear resistance under high-temperature conditions, becoming a core technical bottleneck restricting its engineering application. Summary of the Invention

[0005] To address this critical issue, this invention proposes a wide-temperature-range adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material and its preparation method.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] One of the objectives of this invention is to provide a wide-temperature-range adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material, which comprises the following raw materials by mass percentage: Ta: 47.6-51.4%; Mo: 25.2-27.3%; Ti: 6.4-12.8%; Cr: 13.4-14.9%, that is, the sum of the mass percentages of elemental Ta, Mo, Ti, and Cr powders is 100%.

[0008] The elemental elements Ta, Mo, Ti, and Cr used in this invention are all stable BCC (body-centered cubic) crystal structures at high temperatures, possessing similar atomic properties and high solid solubility among themselves. Therefore, their mixing and sintering readily forms a solid solution. Consequently, the chromium-containing refractory high-entropy alloy material prepared in this invention mainly consists of a BCC-structured matrix phase and a BCC-structured titanium-rich precipitate phase, with the titanium-rich precipitate phase uniformly dispersed between the matrix phases. Furthermore, the chromium element dissolved in the BCC matrix significantly enhances the alloy's oxidation resistance, enabling the formation of a protective oxide film on the alloy surface during high-temperature oxidation and friction, thereby significantly improving the high-temperature tribological properties of the refractory high-entropy alloy.

[0009] The appropriate addition of chromium can promote the rapid formation of continuous, dense, and firmly bonded protective oxide layers such as Cr2O3 and CrTaO4 on the alloy surface during high-temperature oxidation. This oxide layer can effectively prevent further diffusion of oxygen into the alloy interior, thereby significantly improving the alloy's resistance to high-temperature oxidation and ensuring the stable performance of its high-temperature wear resistance. Developing wide-temperature-range adaptive friction-reducing and wear-resistant materials based on chromium-containing refractory high-entropy alloys can not only effectively overcome the technical shortcomings of traditional high-temperature alloys in terms of insufficient wear resistance / lubrication performance under extreme and harsh conditions, but also provide core support for the performance upgrade of key components in aerospace equipment. This has significant engineering value and academic significance for promoting the development of aerospace propulsion systems towards higher performance and more reliable service.

[0010] Preferably, the raw materials comprise, by weight percentage: Ta: 47.6-48.1%; Mo: 25.2-25.6%; Ti: 12.4-12.8%; Cr: 13.4-14.9%.

[0011] Preferably, the raw materials comprise, by weight percentage: Ta: 51.2-51.4%; Mo: 27.1-27.3%; Ti: 6.7-6.9%; Cr: 14.7-14.9%.

[0012] Furthermore, the Ta, Mo, Ti and Cr are all elemental powders with a particle size ≤53μm and a purity ≥99.5%.

[0013] The second objective of this invention is to provide a method for preparing a wide-temperature-range adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material, comprising the following steps: weighing Ta, Mo, Ti and Cr powders by mass, ball milling, and then sintering by spark plasma sintering to obtain the wide-temperature-range adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material.

[0014] This invention utilizes high-energy ball milling to pre-alloy powder, obtaining a homogeneous refractory high-entropy alloy powder. The powder is then densified using spark plasma sintering technology, sintering it into a bulk alloy material. By introducing chromium, this alloy can adaptively form an oxide layer with lubricating and protective functions across a wide temperature range from room temperature to ultra-high temperatures, thus exhibiting excellent tribological properties, along with extremely low friction coefficients and wear rates, showing promising application prospects in the aerospace field.

[0015] Furthermore, the specific operation steps of the ball mill are as follows: set the ball-to-material ratio to 10:1, mill for 4-5 minutes, pause for 2 minutes to cool down, and this constitutes one ball milling cycle, with a total ball milling time of 1678-1798 minutes.

[0016] This invention effectively solves the technical problems of easy cold welding, adhesion, and uneven alloying of powders during the pre-alloying process by optimizing ball milling process parameters. By controlling the single ball milling time to no more than 4-5 minutes and using appropriate pause intervals, the phenomenon of powder agglomeration or adhesion to the inner wall of the ball mill jar caused by overheating during the process is effectively suppressed, while ensuring sufficient mechanical alloying effect. Excessive single ball milling time can easily lead to excessively high local temperature rise, causing powder welding or agglomeration; too short a time cannot provide sufficient energy input, making it difficult to achieve uniform alloying. In addition, a reasonable pause time helps the system to cool down sufficiently and avoid heat accumulation; the total ball milling time also needs to be precisely controlled, too short a time results in insufficient alloying degree, while too long a time introduces ineffective processing and reduces production efficiency. The powder prepared by this invention can achieve sufficient powder refinement and pre-alloying effect after the ball milling process.

[0017] Furthermore, the specific operation steps of the sintering are as follows: first, set the pressure to 50MPa and pre-press at room temperature for 5-6 minutes; then, hold at 1800℃, 50MPa, and 20-24kW for 10-12 minutes; finally, cool to room temperature with water.

[0018] The discharge plasma sintering process defined in this invention ensures the successful preparation of uniform and dense chromium-containing refractory high-entropy alloy materials without obvious metallurgical defects such as cracks and pores, achieving excellent densification. The purpose of the room temperature pre-compression treatment is to increase the initial density of the powder, promoting the uniform distribution of pulse current during subsequent sintering, avoiding local overheating, and thus ensuring a stable and efficient sintering process. During sintering, when the pressure is lower than the set value, the material is difficult to achieve sufficient densification, resulting in high porosity and decreased mechanical properties; while excessive pressure may exceed the bearing limit of the graphite mold, causing mold damage and sintering failure. Simultaneously, when the sintering temperature is below 1800℃, the alloying reaction is insufficient, leading to inadequate densification; when the temperature exceeds 1800℃, local melting and loss of Ti elements easily occur, causing compositional deviation and structural defects.

[0019] Furthermore, the heating rate and cooling rate during the sintering process are both 100-105℃ / min.

[0020] Furthermore, both the ball milling and sintering are carried out under an argon atmosphere.

[0021] Furthermore, the discharge plasma sintering furnace is evacuated to a vacuum level of <5×10⁻⁶ within the furnace cavity. -2 mbar.

[0022] The third objective of this invention is to provide an application of a wide-temperature-range adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material in the aerospace field.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] 1. The present invention proposes a wide-temperature-range adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material. By introducing chromium into the refractory high-entropy alloy, the wear resistance and lubrication characteristics of the refractory high-entropy alloy at high temperature are improved. The powder pre-alloying is realized by high-energy ball milling, and a uniform and dense alloy material is prepared by electron discharge plasma sintering.

[0025] 2. The chromium-containing refractory high-entropy alloy material with wide temperature range adaptive friction reduction and wear resistance provided by this invention also has excellent wide temperature range wear resistance / lubrication properties, and has broad application prospects in the field of wear-resistant and lubricating materials;

[0026] 3. The raw materials of the wide-temperature-range adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material proposed in this invention are easy to obtain, the preparation method is simple and easy to operate, highly controllable and efficient, and has broad prospects for industrial application. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0028] Figure 1 Here are XRD patterns of the materials prepared in Examples 1, 2, and 1 (Comparative Example 1);

[0029] Figure 2 Here are SEM images of the microstructures of the materials prepared in Examples 1, 2, and 1 (Comparative Example 1);

[0030] Figure 3 The graph shows a comparison of the friction coefficients of the materials prepared in Example 1, Example 2 and Comparative Example 1 at test temperatures of 25°C, 300°C, 600°C, 800°C and 1000°C, respectively.

[0031] Figure 4 The chart shows a comparison of the wear rates of the materials prepared in Example 1, Example 2 and Comparative Example 1 at test temperatures of 25°C, 300°C, 600°C, 800°C and 1000°C. Detailed Implementation

[0032] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0033] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0034] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0035] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0036] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0037] High-energy ball milling was used to pre-alloy the powder, obtaining a homogeneous refractory high-entropy alloy powder. The powder was then densified using spark plasma sintering technology, sintering it into a bulk alloy material. By introducing chromium, this alloy can adaptively form an oxide layer with lubricating and protective functions over a wide temperature range from room temperature to ultra-high temperatures, thus exhibiting excellent tribological properties, with both extremely low friction coefficient and wear rate. This material has broad application prospects in wear-resistant lubricating materials and high-temperature wear-resistant components. The specific scheme is as follows:

[0038] This invention discloses a method for preparing a wide-temperature-range adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material, comprising the following steps:

[0039] S1. In a glove box protected by inert gas, the four elemental powders of Ta, Mo, Ti and Cr are uniformly mixed in a ball mill jar according to the stated mass percentages.

[0040] S2. Load the ball mill jar containing the mixed powder into the high-energy ball mill for high-energy ball milling;

[0041] S3. Take out the ball-milled powder from the glove box under inert gas protection and put it into the graphite mold;

[0042] S4. Remove the graphite mold containing the ball milled powder from the glove box and transfer it to the spark plasma sintering furnace for pre-pressing;

[0043] S5. Spark plasma sintering is performed in an inert gas environment at 1800℃. After the sintering process is completed, a chromium-containing refractory high-entropy alloy material with wide temperature range adaptive friction reduction and wear resistance is obtained.

[0044] In some preferred embodiments, the purity of each elemental powder in step S1 is ≥99.95%, and the particle size of each elemental powder is ≤53μm. The content of each elemental powder is: Ta: 47.6-51.4%; Mo: 25.2-27.3%; Ti: 6.4-12.8%; Cr: 13.4-14.9%, that is, the sum of the mass percentages of elemental Ta, Mo, Ti, and Cr powders is 100%. Preferably, the content is Ta: 47.6-48.1%; Mo: 25.2-25.6%; Ti: 12.4-12.8%; Cr: 13.4-14.9%; and even more preferably, Ta: 51.2-51.4%; Mo: 27.1-27.3%; Ti: 6.7-6.9%; Cr: 14.7-14.9%.

[0045] In some preferred embodiments, the ball milling process in step S2 is carried out at a ball-to-material ratio of 10:1, with each ball milling lasting 4-5 minutes (exemplary, 5 minutes), followed by a 2-minute pause to cool down, and a total ball milling time of 1678-1798 minutes (exemplary, 1678 minutes).

[0046] In some preferred embodiments, the pre-compression time in step S4 is 5-6 minutes (exemplary, the pre-compression time is 6 minutes), and the pressure is 50 MPa.

[0047] In some preferred embodiments, in step S5, the discharge plasma sintering furnace is evacuated until the vacuum level inside the furnace cavity is less than 5 × 10⁻⁶. -2 After repeated purging three times, the furnace cavity is ensured to be filled with an argon protective atmosphere with a mass concentration of 99.9% or higher.

[0048] In some preferred embodiments, the sintering process in step S5 is first held at 1800°C for 10-12 min at a pressure of 50 MPa and a power of 20-24 kW (exemplary, such as 24 kW), and then water-cooled to room temperature. The heating rate and cooling rate of the entire process are both 100-105°C / min (exemplary, such as 100°C / min).

[0049] Using the above preparation method, a wide-temperature-range adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material can be prepared. By mass percentage, it includes the following raw materials: 47.6-51.4%; Mo: 25.2-27.3%; Ti: 6.4-12.8%; Cr: 13.4-14.9%, that is, the sum of the mass percentages of elemental Ta, Mo, Ti, and Cr powders is 100%.

[0050] The aforementioned wide-temperature-range adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material can be used in the aerospace field.

[0051] Unless otherwise specified, "room temperature" in this invention refers to 25±2℃.

[0052] Unless otherwise specified, the term "parts" in this invention refers to parts by weight.

[0053] All raw materials used in this invention were purchased from the market.

[0054] The technical solution of the present invention will be further illustrated by the following embodiments.

[0055] Example 1

[0056] A method for preparing a wide-temperature-range adaptive friction-reducing and wear-resistant chromium-containing refractory high-entropy alloy material includes the following steps:

[0057] S1. In a glove box under inert gas protection, powders of Ta, Mo, Ti, and Cr are uniformly mixed in a ball mill jar according to their mass percentages; wherein the purity of each elemental powder is ≥99.95%, and the particle size of each elemental powder is ≤53μm; the mass percentages are: Ta: 47.6%; Mo: 25.4%; Ti: 12.5%; Cr: 14.5%;

[0058] S2. The ball mill jar containing the mixed powder is loaded into a high-energy ball mill for high-energy ball milling. The ball milling process is carried out at a ball-to-material ratio of 10:1. After each ball milling for 5 minutes, the process is paused for 2 minutes to cool down. This cycle is repeated, and the total ball milling time is 1678 minutes.

[0059] S3. Take out the ball-milled powder from the glove box under inert gas protection and put it into the graphite mold;

[0060] S4. Remove the graphite mold containing the ball milled powder from the glove box and transfer it to the spark plasma sintering furnace, where it is cold-pressed for 6 minutes at a pressure of 50 MPa.

[0061] S5. Evacuate the spark plasma sintering furnace until the vacuum level inside the furnace cavity is less than 5×10⁻⁶. -2 After repeated purging three times to ensure an argon protective atmosphere with a mass concentration of over 99.9% within the furnace cavity, spark plasma sintering was performed at 1800℃ under this atmosphere. The specific spark plasma sintering process was as follows: first, the furnace was held at 1800℃ for 12 minutes at a pressure of 50 MPa and a power of 24 kW; then, it was cooled to room temperature, ending the sintering process and yielding a chromium-containing refractory high-entropy alloy material. The heating and cooling rates throughout the entire process were both 100℃ / min.

[0062] Figure 1 This is an XRD pattern of the material prepared in Example 1; from Figure 1As can be seen from the data, the material prepared in Example 1 consists of the BCC phase, and no other impurity phases are precipitated. Figure 2 This is a SEM image of the microstructure of the chromium-containing refractory high-entropy alloy material prepared in Example 1; from Figure 2 As can be seen from the data, the material prepared in Example 1 has a uniform and dense structure, with the Ti-rich phase evenly distributed in the BCC phase matrix. Figure 1 and Figure 2 The results show that Example 1 successfully prepared a chromium-containing refractory high-entropy alloy material with wide temperature range adaptive friction reduction and wear resistance.

[0063] The material prepared in Example 1 was machined into long strip-shaped friction samples, which were then polished using metallographic sandpaper ranging from 240 to 3000 grit, from smallest to largest. The friction and wear properties of the samples were tested using a high-temperature friction and wear testing machine, and the tests were repeated at least three times.

[0064] Figure 3 This is a comparison chart of the friction coefficients of the material prepared in Example 1 at test temperatures of room temperature, 300°C, 600°C, 800°C, and 1000°C; from... Figure 3 As can be seen, the friction coefficient of the chromium-containing refractory high-entropy alloy material prepared in Example 1 is lower than 0.48 at all temperatures, and is between 0.27 and 0.48. Figure 4 This is a comparison chart of the wear rate of the material prepared in Example 1 at test temperatures of room temperature, 300°C, 600°C, 800°C, and 1000°C; from Figure 4 As can be seen from the data, the wear rates of the chromium-containing refractory high-entropy alloy material prepared in Example 1 at room temperature, 300℃, 600℃, 800℃, and 1000℃ are 1.6×10⁻⁶. -5 mm 3 / Nm, 7.41×10 -5 mm 3 / Nm, 7.48×10 -7 mm 3 / Nm, 2.81×10 -7 mm 3 / Nm and 3.17×10 - 7 mm 3 / Nm. Figure 3 and Figure 4 The results show that the chromium-containing refractory high-entropy alloy material prepared in Example 1 exhibits excellent tribological properties over a wide temperature range.

[0065] Example 2

[0066] Same as Example 1, except that the amount of elemental powder is different, specifically: Ta: 51.3%; Mo: 27.2%; Ti: 6.8%; Cr: 14.7%.

[0067] Figure 1 This is an XRD pattern of the material prepared in Example 2; Figure 2 This is a SEM image of the microstructure of the chromium-containing refractory high-entropy alloy material prepared in Example 2; from Figure 1 and Figure 2 As can be seen, the material prepared in Example 2 is similar to that in Example 1. This indicates that Example 2 successfully prepared a chromium-containing refractory high-entropy alloy material with wide-temperature-range adaptive friction reduction and wear resistance.

[0068] The material prepared in Example 2 was machined into long strip-shaped friction samples, which were then polished using metallographic sandpaper ranging from 240 to 3000 grit, from smallest to largest. The friction and wear properties of the samples were tested using a high-temperature friction and wear testing machine, and the tests were repeated at least three times.

[0069] Figure 3 This is a comparison chart of the friction coefficients of the material prepared in Example 2 at test temperatures of room temperature, 300°C, 600°C, 800°C, and 1000°C; from... Figure 3 As can be seen from the data, the friction coefficient of the chromium-containing refractory high-entropy alloy material prepared in Example 2 is also lower than 0.48 at 25-1000℃, and is between 0.3-0.48. Figure 4 This is a comparison chart of the wear rate of the material prepared in Example 2 at test temperatures of room temperature, 300°C, 600°C, 800°C, and 1000°C; from Figure 4 As can be seen from the data, the wear rates of the chromium-containing refractory high-entropy alloy material prepared in Example 2 at room temperature, 300℃, 600℃, 800℃, and 1000℃ were 9.53 × 10⁻⁶ and 9.53 × 10⁻⁶, respectively. -5 mm 3 / Nm, 1.58×10 -4 mm 3 / Nm, 1.03×10 -6 mm 3 / Nm, 2.81×10 -7 mm 3 / Nm and 8.52×10 - 7 mm 3 / Nm. Figure 3 and Figure 4 The results show that the chromium-containing refractory high-entropy alloy material prepared in Example 2 exhibits excellent tribological properties over a wide temperature range.

[0070] Comparative Example 1

[0071] Same as Example 1, except that Ti element is not added, i.e., Ta: 55%; Mo: 29.2%; Cr: 15.8%, to obtain TaMoCr ternary medium-entropy alloy.

[0072] Figure 1 This is a schematic diagram of the XRD pattern of the material prepared in Comparative Example 1; from Figure 1 As can be seen from the data, in addition to the BCC phase, Comparative Example 1 also contains intermetallic compound phases and oxide phases. Figure 2 This is a SEM image of the microstructure of the material prepared in Comparative Example 1, which further demonstrates... Figure 1 The conclusion.

[0073] The material prepared in Comparative Example 1 was machined into long strip-shaped friction samples, which were then polished using metallographic sandpaper ranging from 240 grit to 3000 grit, from smallest to largest. The friction and wear properties of the samples were tested using a high-temperature friction and wear testing machine, and the tests were repeated at least three times.

[0074] Figure 3 The graph shows a comparison of the friction coefficients of the material prepared in Comparative Example 1 at test temperatures of room temperature, 300℃, 600℃, 800℃, and 1000℃. Figure 3 As can be seen, the material prepared in Comparative Example 1 has a high coefficient of friction at all temperatures, with the coefficient of friction ranging from 0.28 to 0.65. Figure 4 This is a comparison chart of the wear rates of the material prepared in Comparative Example 1 at test temperatures of room temperature, 300℃, 600℃, 800℃, and 1000℃; from... Figure 4 As can be seen from the data, the wear rates of the TaMoCr ternary medium-entropy alloy at 600℃, 800℃, and 1000℃ are 3.10×10⁻⁶. -5 mm 3 / Nm, 3.17×10 -6 mm 3 / Nm and 8.94×10 -6 mm 3 / Nm.

[0075] In summary, it can be seen that the wear rate of Comparative Example 1 under high temperature test conditions is higher than that of Examples 1-2. Although it has a lower wear rate under room temperature and 300°C test conditions, its intrinsic brittleness leads to sample fracture failure.

[0076] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A chromium-containing refractory high-entropy alloy material with wide-temperature-range adaptive friction reduction and wear resistance, characterized in that, The following raw materials are included by weight percentage: Ta: 47.6-51.4%; Mo: 25.2-27.3%; Ti: 6.4-12.8%; Cr: 13.4-14.9%.

2. The chromium-containing refractory high-entropy alloy material with wide temperature range adaptive friction reduction and wear resistance according to claim 1, characterized in that, The following raw materials are included by weight percentage: Ta: 47.6-48.1%; Mo: 25.2-25.6%; Ti: 12.4-12.8%; Cr: 13.4-14.9%.

3. The chromium-containing refractory high-entropy alloy material with wide temperature range adaptive friction reduction and wear resistance according to claim 1, characterized in that, The following raw materials are included by weight percentage: Ta: 51.2-51.4%; Mo: 27.1-27.3%; Ti: 6.7-6.9%; Cr: 14.7-14.9%.

4. The chromium-containing refractory high-entropy alloy material with wide temperature range adaptive friction reduction and wear resistance according to claim 1, characterized in that, The particle size of Ta, Mo, Ti and Cr is ≤53μm and the purity is ≥99.5%.

5. A method for preparing a chromium-containing refractory high-entropy alloy material with wide temperature range adaptive friction reduction and wear resistance as described in any one of claims 1-4, characterized in that, The process includes the following steps: weighing Ta, Mo, Ti and Cr powders by mass percentage, ball milling, and then sintering using spark plasma sintering to obtain a chromium-containing refractory high-entropy alloy material with wide temperature range adaptive friction reduction and wear resistance.

6. The preparation method according to claim 5, characterized in that, The specific operation steps of the ball mill are as follows: set the ball-to-material ratio to 10:1, mill for 4-5 minutes, pause for 2 minutes to cool down, and this is one ball milling cycle. The total ball milling time is 1678-1798 minutes.

7. The preparation method according to claim 5, characterized in that, The specific sintering operation steps are as follows: First, set the pressure to 50MPa and pre-press at room temperature for 5-6 minutes; then, hold at 1800℃, 50MPa, and 20-24kW for 10-12 minutes; finally, cool to room temperature with water.

8. The preparation method according to claim 5, characterized in that, The heating and cooling rates during the sintering process are both 100-105℃ / min.

9. The preparation method according to claim 5, characterized in that, Both ball milling and sintering were performed under an argon atmosphere.

10. The application of a chromium-containing refractory high-entropy alloy material with wide temperature range adaptive friction reduction and wear resistance as described in any one of claims 1-4 in the aerospace field.

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