Two-phase coherent oxide coating with excellent oxidation resistance and wear resistance and preparation method of two-phase coherent oxide coating

Abstract

The invention provides a dual-phase coherent oxidation coating with excellent oxidation resistance and wear resistance and a preparation method thereof, and aims to solve the problems of complex process, high cost and negative influence on the mechanical property of an alloy in the conventional method for improving the oxidation resistance and wear resistance of a refractory multi-principal element alloy. The method mainly comprises the following steps: sequentially carrying out alloy homogenizing annealing treatment, alloy surface pretreatment and pre-oxidation treatment on the refractory multi-principal element alloy according to designed process parameters, and finally obtaining the dual-phase coherent oxide coating capable of effectively improving the oxidation resistance and wear resistance of the alloy on the surface of the refractory multi-principal element alloy in situ.

Description

Technical Field

[0001] The invention belongs to the technical field of alloy material surface treatment, and in particular relates to a two-phase coherent oxidation coating with excellent oxidation resistance and wear resistance and a preparation method thereof. Background Art

[0002] Multi-principal alloy is an emerging alloy material. Different from the traditional alloy design concept, it is usually composed of multiple alloying elements with equal or nearly equal atomic ratios. The unique properties exhibited by multi-principal alloys are summarized into four core effects, namely high entropy effect, lattice distortion effect, slow diffusion effect and cocktail effect. In particular, due to the influence of slow diffusion effect and cocktail effect, multi-principal alloys are generally considered to be potential substitutes for existing high-temperature alloys. Refractory multi-principal alloys are multi-principal alloys composed of refractory elements such as hafnium (Hf), vanadium (V), niobium (Nb), and tantalum (Ta). Compared with other multi-principal alloys, refractory multi-principal alloys exhibit extremely high melting points. The high melting point makes it have excellent high-temperature mechanical properties and stability, and is expected to break through the application temperature of existing high-temperature materials.

[0003] The potential application environment of refractory high entropy alloys puts forward more stringent requirements on the high-temperature performance of the application materials. Excellent oxidation resistance and wear resistance at high temperatures are the key factors for refractory multi-principal alloys to be able to serve stably for a long time in high-temperature environments; but unfortunately, refractory multi-principal alloys often show poor oxidation resistance and high wear rate under high temperature conditions, which limits the wide application of refractory multi-principal alloys in high-temperature fields such as aerospace. At present, in order to improve the oxidation resistance and wear resistance of refractory multi-principal alloys, alloying or coating with anti-oxidation coatings are often used. The process is complicated and costly, and it often has a negative impact on the mechanical properties of the alloy. Therefore, it is urgent to seek simple, easy-to-obtain and low-cost methods to improve the high-temperature oxidation resistance and wear resistance of refractory multi-principal alloys. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of complex process, high cost and negative impact on the mechanical properties of the existing methods for improving the oxidation resistance and wear resistance of refractory multi-principal alloys, and to provide a two-phase coherent oxidation coating and a preparation method with excellent oxidation resistance and wear resistance. This technical solution can not only improve the oxidation resistance and wear resistance of refractory multi-principal alloys under high temperature conditions, but also take into account the advantages of simplicity, ease of implementation and low cost.

[0005] To achieve the above purpose, the technical solution provided by the present invention is:

[0006] A method for improving the oxidation resistance and wear resistance of a refractory multi-principal alloy, characterized in that it comprises the following steps:

[0007] S1. Alloy homogenization annealing treatment:

[0008] The refractory multi-principal alloy is heated to a vacuum of less than 5×10 -3 Pa, 0.5Tm±50℃ environment (such as vacuum heat treatment furnace) for not less than 24h, and then cooled with the furnace to eliminate the micro segregation of elements in the cast alloy. If the vacuum is too high, the alloy will be oxidized. A short holding time or too low holding temperature will make it impossible to completely eliminate the element segregation. The composition of the refractory multi-principal alloy is (TiZrNb) x M 1-x ; Wherein, M = Mo, V, 1≥x>0.5, Tm is the melting point of the refractory multi-principal alloy;

[0009] S2. Alloy surface pretreatment:

[0010] The surface of the refractory multi-principal alloy after S1 homogenization annealing was pretreated to a roughness less than Ra 1.5 to ensure that the sample surface was clean and free of impurities;

[0011] S3, pre-oxidation treatment:

[0012] The refractory multi-principal component alloy after S2 surface pretreatment is placed in an environment preheated to 1100-1200°C, oxidized at a constant temperature for 15-45 minutes, and cooled along with the furnace to obtain a refractory multi-principal component alloy with improved oxidation resistance and wear resistance. That is, a duplex coherent oxide coating is obtained in situ on the surface of the refractory multi-principal component alloy, which can effectively improve the oxidation resistance and wear resistance of the alloy.

[0013] Furthermore, S2 is specifically:

[0014] The surface of the refractory multi-principal alloy after S1 homogenization treatment was polished to 4000 mesh step by step using metallographic sandpaper to ensure that the sample roughness was less than Ra 1.5, and then the sample surface was polished to a mirror surface using silica polishing liquid.

[0015] Furthermore, in order to ensure the effect of the pre-oxidation treatment, in S3, the refractory multi-principal alloy after surface pre-treatment in S2 is placed in a muffle furnace for constant temperature oxidation, and the actual temperature deviation of the muffle furnace body is ≤10°C, and the oxidation treatment time deviation is ≤1 minute.

[0016] Furthermore, in S3, the oxidation temperature is 1100° C. and the oxidation time is 30 min. If the temperature deviates too much from this temperature, the desired oxide layer cannot be formed. Therefore, this temperature is the optimal growth temperature of the oxide layer.

[0017] Furthermore, in S1, the refractory multi-principal alloy is prepared by a vacuum arc melting method, and the specific operation is as follows:

[0018] Each elemental raw material required for the alloy component is placed in an anhydrous ethanol solution for ultrasonic cleaning, and the weight of each elemental raw material is calculated and weighed according to the atomic percentage;

[0019] The single raw materials are mixed and placed in a copper crucible of a vacuum arc melting furnace, and high-purity argon gas is introduced after vacuuming. The mixed raw materials are melted after an arc is struck on a titanium ingot, and a button-shaped ingot of a refractory high-entropy alloy is finally obtained after multiple melting processes.

[0020] In the preparation process, the melting current is 200-500 amperes, preferably 300-400 amperes, and most preferably 350 amperes. The melting is performed 4-6 times, and each melting is performed for 3 minutes.

[0021] Furthermore, the refractory multi-principal alloy is a multi-principal alloy containing equal proportions of TiZrNb, such as: TiZrNb, (TiZrNb) 0.5 V 0.5 or (TiZrNb) 0.667 Mo 0.333 .

[0022] At the same time, the present invention also provides a dual-phase coherent oxide layer with excellent oxidation resistance and wear resistance, which is special in that it is prepared in situ by the above-mentioned method for improving the oxidation resistance and wear resistance of refractory multi-principal alloy; the oxide layer has the following characteristics:

[0023] 1) The morphology shows a two-phase coupled inwardly growing oxide layer;

[0024] 2) The interface structure between the two phases of the dual-phase oxide layer is a coherent interface;

[0025] 3) In terms of composition, one phase is oxygen-rich and the other phase is oxygen-poor;

[0026] 4) The phase composition at different depths of the oxide layer is different, but the two-phase lamellar structure is always maintained; the phase changes with increasing depth. Although a clear phase cannot be given, the two-phase structure always exists.

[0027] And, a refractory multi-principal alloy with excellent oxidation resistance and wear resistance is prepared by the above method.

[0028] Concept and principle of the present invention:

[0029] In view of the fact that refractory multi-principal alloys currently exhibit poor oxidation resistance and high wear rates under high temperature conditions, the present invention intends to regulate the oxide layer structure of refractory multi-principal alloys. The regulation of the oxide layer structure can be achieved by regulating the surface mechanical properties and oxygen diffusion process, thereby improving the wear resistance and oxidation resistance of the alloy in a wide temperature range. Considering the poor mutual solubility of Zr and Nb, a single-phase solid solution alloy can be formed by stabilization with the Ti element, and the oxygen affinity of Nb and Zr is quite different. Therefore, Zr will preferentially form oxides during the oxidation process, and Nb, due to its low solid solubility in it, will diffuse outward during the growth of oxide grains to form a Nb-rich BCC solid solution phase. As the stable oxidation process begins, a two-phase coupled growth oxide layer is formed along the depth direction. This pair of components is (TiZrNb) x M 1-x Pre-oxidation treatment of a refractory multi-principal alloy (M=Mo, V, 1≥x>0.5) provides the possibility of improving the oxidation resistance and wear resistance of the refractory multi-principal alloy.

[0030] The present invention first eliminates the micro-segregation of elements in the refractory multi-principal alloy ingot by homogenization annealing; then uses surface pretreatment to remove other impurities generated during the annealing process; and finally constructs a coherent two-phase oxide coating on the surface of the refractory multi-principal alloy by pre-oxidation. This coherent two-phase oxide coating has a microstructure in which one phase is an oxide and the other phase is a metal solid solution. On the one hand, it can improve the mechanical properties of the alloy surface. On the other hand, the oxide layer with a coherent interface can reduce the inward diffusion rate of oxygen, that is, slow down the diffusion rate of oxygen into the alloy. By reducing the inward diffusion rate of oxygen and improving the mechanical properties of the surface, the oxidation weight gain rate and wear rate of the alloy can be effectively reduced, and the oxidation resistance and wear resistance of the refractory multi-principal alloy in a wide temperature range can be significantly improved, so that the alloy exhibits excellent oxidation resistance and wear resistance in a wide temperature range.

[0031] The advantages of the present invention are:

[0032] Compared with the refractory multi-principal alloy without an oxide layer, the oxidation weight gain of the refractory multi-principal alloy with the oxide layer is only one-tenth, and the wear rate is also reduced to 7% compared with the refractory multi-principal alloy without an oxide layer. This shows that by simple pre-oxidation means, constructing the oxide layer described in the present invention can greatly improve the oxidation resistance and wear resistance of the refractory multi-principal alloy. This method can become a solution to improve the application ability of refractory multi-principal alloys in high-temperature fields such as aerospace. In addition, the preparation process of the dual-phase coherent oxide layer is simple, easy to operate, low in cost, easy to realize industrialization, and will not have a negative impact on the mechanical properties of the alloy. It has excellent performance and has good application prospects in high-temperature fields such as aerospace. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a SEM image of the microstructure of a dual-phase coherent oxidation coating with excellent oxidation resistance and wear resistance constructed on the surface of a TiZrNb alloy provided by the present invention;

[0034] Among them, (a) is a cross-sectional macroscopic SEM image, (a1) and (a2) are magnified SEM images of different areas;

[0035] Figure 2 This is a TEM image of the TiZrNb oxide layer and the substrate provided by the present invention;

[0036] Among them, (a) is the HAADF-STEM and energy spectrum of the interface between the oxide layer and the substrate; (b) is a local magnified image of the interface and the corresponding SAED spot image;

[0037] Figure 3 The isothermal oxidation kinetic curves of the TiZrNb alloy with the dual-phase coherent oxidation coating having excellent oxidation resistance and wear resistance provided by the present invention (Example 1) and the TiZrNb alloy without the coating (Comparative Example 1);

[0038] Figure 4 The load-displacement graph of nanoindentation of a TiZrNb alloy having a dual-phase coherent oxide coating with excellent oxidation resistance and wear resistance provided by the present invention (Example 1) and a TiZrNb alloy without the coating (Comparative Example 1);

[0039] Figure 5 The friction and wear test results of the TiZrNb alloy with the dual-phase coherent oxidation coating having excellent oxidation resistance and wear resistance provided by the present invention and the TiZrNb alloy without the coating;

[0040] Wherein, (a) is the friction coefficient of the TiZrNb alloy without the coating, (b) is the average friction coefficient of the TiZrNb alloy with and without the coating, (c) is the friction coefficient of the TiZrNb alloy with the coating, and (d) is the wear rate of the TiZrNb alloy with and without the coating.

[0041] Figure 6 The present invention provides (TiZrNb) 0.5 V 0.5 、(TiZrNb) 0.667 Mo 0.333 SEM image of the microstructure of the dual-phase coherent oxide coating with excellent oxidation resistance and wear resistance constructed on the alloy surface;

[0042] Among them, (a) is (TiZrNb) 0.5 V 0.5 Cross-sectional SEM image of (b) (TiZrNb)0.667 Mo 0.333 Cross-sectional SEM images of

[0043] Figure 7 The SEM image and macroscopic morphology comparison image of the microstructure of the dual-phase coherent oxidation coating with excellent oxidation resistance and wear resistance constructed on the surface of the TiZrNb alloy provided by the present invention at 1000°C and 1200°C;

[0044] Among them, (a) is a cross-sectional macroscopic SEM image of the coating formed at 1000°C, (a1) and (a2) are magnified SEM images of different regions; (b) is a cross-sectional macroscopic SEM image of the coating formed at 1200°C, (b1) and (b2) are magnified SEM images of different regions; (c) is a macroscopic morphology comparison image at 1000°C, 1100°C, and 1200°C;

[0045] Figure 8 The present invention provides a macroscopic morphology of the TiZrNb alloy before and after annealing and after isothermal oxidation at 1100° C. for 8 hours. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0047] Ti melting point: 1660℃; Nb melting point: 2468℃; Zr melting point: 1852℃; Mo melting point: 2620℃; V melting point: 1890℃; TiZrNb mixture rule calculated melting point: 1993.3℃; (TiZrNb) 0.5 V 0.5 Melting point calculated by mixture rule: 1941.65℃; (TiZrNb) 0.667 Mo 0.333 Melting point calculated by mixture rule: 2202.2℃.

[0048] Example 1

[0049] A method for preparing a refractory multi-principal alloy TiZrNb having a wear-resistant and oxidation-resistant dual-phase coherent oxide coating comprises the following steps:

[0050] S1. Alloy smelting:

[0051] The single raw materials required for the alloy components are ultrasonically cleaned in an anhydrous ethanol solution, and the weight of each single raw material is weighed according to the atomic percentage; the single raw materials are mixed and placed in a copper crucible of a vacuum arc melting furnace; high-purity argon gas is introduced after evacuation, and the mixed raw materials are melted after an arc is struck on a titanium ingot, and finally a button-shaped ingot of a refractory high-entropy alloy is obtained.

[0052] S2. Homogenization annealing:

[0053] The button-shaped ingot sample obtained from S1 was placed in a vacuum heat treatment furnace at 5×10 -3 After keeping the temperature at 1000℃ for 24h, the sample is cooled in the furnace and taken out after cooling.

[0054] S3. Surface pretreatment:

[0055] After the S2 homogenized annealed samples were cut as required, they were first polished to 4000 mesh using metallographic sandpaper, and then the surface of the samples was polished to a mirror surface using silica polishing liquid.

[0056] S4, pre-oxidation treatment:

[0057] The sample after S3 surface pretreatment was placed in a muffle furnace preheated to 1100°C. After constant temperature oxidation for 30 minutes, the sample was cooled with the furnace to obtain a refractory multi-principal alloy TiZrNb with a wear-resistant and oxidation-resistant dual-phase coherent oxide coating.

[0058] Example 2

[0059] A refractory multi-element alloy (TiZrNb) with a wear-resistant and oxidation-resistant dual-phase coherent oxide coating 0.5 V 0.5 The preparation method comprises the following steps:

[0060] S1. Alloy smelting:

[0061] The single raw materials required for the alloy components are ultrasonically cleaned in an anhydrous ethanol solution, and the weight of each single raw material is weighed according to the atomic percentage; the single raw materials are mixed and placed in a copper crucible of a vacuum arc melting furnace; high-purity argon gas is introduced after evacuation, and the mixed raw materials are melted after an arc is struck on a titanium ingot, and finally a button-shaped ingot of a refractory high-entropy alloy is obtained.

[0062] S2. Homogenization annealing:

[0063] The button-shaped ingot sample obtained from S1 was placed in a vacuum heat treatment furnace at 5×10 -3 After keeping the temperature at 1000℃ for 24h, the sample is cooled in the furnace and taken out after cooling.

[0064] S3. Surface pretreatment:

[0065] After the S2 homogenized annealed samples were cut as required, they were first polished to 4000 mesh using metallographic sandpaper, and then the surface of the samples was polished to a mirror surface using silica polishing liquid.

[0066] S4, pre-oxidation treatment:

[0067] The sample after S3 surface pretreatment was placed in a muffle furnace preheated to 1100°C and oxidized at constant temperature for 30 minutes. The sample was cooled with the furnace to obtain a refractory multi-principal alloy (TiZrNb) with a wear-resistant and oxidation-resistant dual-phase coherent oxide coating. 0.5 V 0.5 .

[0068] Example 3

[0069] A refractory multi-element alloy (TiZrNb) with a wear-resistant and oxidation-resistant dual-phase coherent oxide coating 0.667 Mo 0.333 The preparation method comprises the following steps:

[0070] S1. Alloy smelting:

[0071] The single raw materials required for the alloy components are ultrasonically cleaned in an anhydrous ethanol solution, and the weight of each single raw material is weighed according to the atomic percentage; the single raw materials are mixed and placed in a copper crucible of a vacuum arc melting furnace; high-purity argon gas is introduced after evacuation, and the mixed raw materials are melted after an arc is struck on a titanium ingot, and finally a button-shaped ingot of a refractory high-entropy alloy is obtained.

[0072] S2. Homogenization annealing:

[0073] The button-shaped ingot sample obtained from S1 was placed in a vacuum heat treatment furnace at 5×10 -3 After keeping the temperature at 1100℃ for 24h, the sample is cooled in the furnace and taken out after cooling.

[0074] S3. Surface pretreatment:

[0075] After the S2 homogenized annealed samples were cut as required, they were first polished to 4000 mesh using metallographic sandpaper, and then the surface of the samples was polished to a mirror surface using silica polishing liquid.

[0076] S4, pre-oxidation treatment:

[0077] The sample after S3 surface pretreatment was placed in a muffle furnace preheated to 1100°C and oxidized at constant temperature for 30 minutes. The sample was cooled with the furnace to obtain a refractory multi-principal alloy (TiZrNb) with a wear-resistant and oxidation-resistant dual-phase coherent oxide coating. 0.667 Mo 0.333 .

[0078] Example 4

[0079] The difference from Example 1 is that in S4, the sample after surface pretreatment in S3 is placed in a muffle furnace preheated to 1200°C.

[0080] Comparative Example 1

[0081] A method for preparing a refractory multi-principal alloy TiZrNb comprises the following steps:

[0082] S1. Alloy smelting:

[0083] The single raw materials required for the alloy components are ultrasonically cleaned in anhydrous ethanol solution, and the weight of each single raw material is calculated according to the atomic percentage. The single raw materials are mixed and placed in a copper crucible of a vacuum arc melting furnace. After evacuation, high-purity argon gas is introduced, and the mixed raw materials are melted after an arc is struck on the titanium ingot, and finally a button-shaped ingot of a refractory high-entropy alloy is obtained.

[0084] S2. Homogenization annealing:

[0085] The button-shaped ingot sample obtained from S1 was placed in a vacuum heat treatment furnace at 5×10 -3 After keeping the temperature below 1000°C for 24 hours, cool it in the furnace and take out the sample after cooling.

[0086] S3. Surface pretreatment:

[0087] After the S2 homogenized annealed samples were cut as required, they were first polished to 4000 mesh using metallographic sandpaper, and then the surface of the samples was polished to a mirror surface using silica polishing liquid.

[0088] Comparative Example 2

[0089] A method for preparing a refractory multi-principal alloy TiZrNb comprises the following steps:

[0090] S1. Alloy smelting:

[0091] The single raw materials required for the alloy components are ultrasonically cleaned in anhydrous ethanol solution, and the weight of each single raw material is calculated according to the atomic percentage. The single raw materials are mixed and placed in a copper crucible of a vacuum arc melting furnace. After evacuation, high-purity argon gas is introduced, and the mixed raw materials are melted after an arc is struck on the titanium ingot, and finally a button-shaped ingot of a refractory high-entropy alloy is obtained.

[0092] S2. Surface pretreatment:

[0093] After the button-shaped ingot obtained from S1 was cut as required, it was first polished to 4000 mesh using metallographic sandpaper step by step, and then the surface of the sample was polished to a mirror surface using silica polishing liquid.

[0094] Comparative Example 3

[0095] The difference from Example 1 is that in S4, the two samples after surface pretreatment in S3 are respectively placed in a muffle furnace preheated to 1000°C.

[0096] In order to verify the feasibility of the method of the present invention, the sample prepared in Example 1 was analyzed. Figure 1This is a SEM image of the microstructure of the dual-phase coherent oxidation coating with excellent oxidation resistance and wear resistance prepared in Example 1. Figure 1 Analysis shows that in the oxide layer, the two-phase lamellar coherent oxide coating grows along the depth direction and is evenly distributed.

[0097] Figure 2 Further analysis of the oxide layer structure of Example 1 shows that the oxide layer is composed of Nb sheets of BCC structure and Ti2ZrO sheets of HCP structure, respectively, with obvious segregation in composition; and, combined with SAED spots, it can be found that the two-phase interface is a coherent interface.

[0098] Figure 3 1 is an oxidation kinetics curve of the TiZrNb alloy obtained in Example 1 and Comparative Example 1 under constant temperature oxidation at 800°C and 900°C. Figure 3 It can be seen that the TiZrNb alloy with the oxidation coating exhibits better oxidation resistance than the TiZrNb alloy without the coating. Under the same time, the oxidation weight gain is reduced by one order of magnitude.

[0099] Figure 4 Figure 1 is a load-displacement graph of the TiZrNb alloy nanoindentation obtained in Example 1 and Comparative Example 1. Figure 4 It can be seen that the TiZrNb alloy with oxide layer exhibits higher hardness than the TiZrNb alloy without oxide layer.

[0100] Figure 5 The friction and wear test results of the TiZrNb alloy with the dual-phase coherent oxide coating having excellent oxidation resistance and wear resistance in Example 1 and the TiZrNb alloy without the coating in Comparative Example 1 were rubbed for 30 minutes under the conditions of 10N load and 5Hz frequency. It can be seen that under the conditions of room temperature to 800°C, the wear rate of the TiZrNb alloy with the oxide coating is reduced by 1 to 2 orders of magnitude compared with the wear rate of the TiZrNb alloy without the coating.

[0101] Similarly, in order to verify the universality of the method of the present invention, the samples prepared in Example 2 and Example 3 were analyzed. Figure 6 The following is a SEM image of the microstructure of the dual-phase coherent oxidation coating with excellent oxidation resistance and wear resistance prepared in Example 2 and Example 3. Figure 6 Analysis shows that in the oxide layer, the two-phase lamellar coherent oxide coating grows along the depth direction and is evenly distributed.

[0102] In order to verify that the homogenization annealing is a necessary process in the method of the present invention, the samples prepared in Example 1 and Comparative Example 2 were subjected to constant temperature oxidation at 1100°C. Figure 8 As shown, it can be found that without homogenization annealing, the alloy will crack severely, while after annealing, the sample will not crack. Therefore, the annealing process is a necessary process in the method of the present invention.

[0103] In order to verify that the pre-oxidation temperature selected in the method of the present invention is the most preferred, the samples prepared in Example 1, Example 4 and Comparative Example 3 were analyzed. Figure 7 The following are SEM images and macroscopic morphologies of the microstructure of the dual-phase coherent oxidation coatings with excellent oxidation resistance and wear resistance prepared in Example 1, Example 4 and Comparative Example 3. Figure 7 It is obvious from the analysis that 1000℃ will cause the alloy to crack, which will directly affect the subsequent further use. Although an additional oxide coating will grow on the outer surface of the alloy at 1200℃, it can still meet the material's requirements for oxidation resistance and wear resistance. It is just that the additional oxide coating needs to be processed during application. Therefore, 1100℃ is the most preferred temperature.

[0104] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A method for improving the oxidation resistance and wear resistance of a refractory multi-principal alloy, characterized in that: The following steps are involved: S1. Alloy homogenization annealing: The refractory multi-principal alloy is heated to a vacuum of less than 5×10 -3 After keeping in an environment of Pa, 0.5Tm±50℃ for not less than 24h, cool down with the furnace; The composition of the refractory multi-principal alloy is (TiZrNb) x M 1-x ; Wherein, M = Mo, V, 1≥x>0.5, Tm is the melting point of the refractory multi-principal alloy; S2. Alloy surface pretreatment: Pre-treating the surface of the refractory multi-principal alloy after S1 homogenization annealing to a roughness less than Ra 1.5; S3, pre-oxidation treatment: The refractory multi-principal alloy after S2 surface pretreatment is placed in an environment preheated to 1100-1200°C, oxidized at a constant temperature for 15-45 minutes, and cooled along with the furnace to obtain a refractory multi-principal alloy with improved oxidation resistance and wear resistance.

2. The method for improving the oxidation resistance and wear resistance of a refractory multi-principal alloy according to claim 1, characterized in that: S2 is specifically: The surface of the refractory multi-principal alloy after S1 homogenization treatment was polished step by step to 4000 mesh using metallographic sandpaper, and then the surface of the sample was polished to a mirror surface using silica polishing liquid.

3. The method for improving the oxidation resistance and wear resistance of a refractory multi-principal alloy according to claim 1 or 2, characterized in that: In S3, the refractory multi-principal alloy after surface pretreatment in S2 is placed in a muffle furnace for constant temperature oxidation, and the actual temperature deviation of the muffle furnace body is ≤10°C, and the oxidation treatment time deviation is ≤1 minute.

4. The method for improving the oxidation resistance and wear resistance of a refractory multi-principal alloy according to claim 3, characterized in that: In S3, the oxidation temperature is 1100°C and the oxidation time is 30 minutes.

5. The method for improving the oxidation resistance and wear resistance of a refractory multi-principal alloy according to claim 1, characterized in that: In S1, the refractory multi-principal alloy is prepared by a vacuum arc melting method.

6. The method for improving the oxidation resistance and wear resistance of a refractory multi-principal alloy according to claim 5, characterized in that: The refractory multi-principal alloy is TiZrNb, (TiZrNb) 0.5 V 0.5 or (TiZrNb) 0.667 Mo 0.333 .

7. A two-phase coherent oxide layer with excellent oxidation resistance and wear resistance, characterized in that: The alloy is prepared in situ by the method for improving the oxidation resistance and wear resistance of refractory multi-principal alloys as claimed in any one of claims 1 to 6; 1) The morphology shows a two-phase coupled inwardly growing oxide layer; 2) The interface structure between the two phases of the dual-phase oxide layer is a coherent interface; 3) In terms of composition, one phase is oxygen-rich and the other phase is oxygen-poor; 4) The phase composition of the oxide layer varies at different depths, but the two-phase lamellar structure is always maintained.

8. A refractory multi-principal alloy having excellent oxidation resistance and wear resistance, characterized in that: The alloy is prepared by the method for improving the oxidation resistance and wear resistance of a refractory multi-principal alloy as described in any one of claims 1 to 6.

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