Copper-based rare earth high-entropy alloy cast ingot and preparation method thereof

Abstract

The invention discloses a copper-based rare earth high-entropy alloy cast ingot and a preparation method thereof, and relates to the technical field of metal material processing, and the alloy cast ingot comprises the following components in percentage by mass: 20%-50% of Cu, 5%-30% of Nd, 5%-30% of Ce, 5%-30% of Pr, 5%-30% of Y, 1.2%-2.2% of Mg and 0.05%-0.15% of Ti. According to the method, the stacking fault energy of the copper-based rare earth high-entropy alloy is reduced on the premise that a casting-crack-free high-quality microstructure is obtained by regulating and controlling the content of the rare earth element and the copper element. Therefore, on the premise that a high-quality as-cast structure is obtained, the alloy strength and hardness are greatly improved by regulating and controlling an alloy microscopic deformation mechanism, and the copper-based rare earth high-entropy alloy cast ingot which is suitable for industrial production and application and has extremely low stacking fault energy is successfully prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of metal materials, and in particular to a copper-based rare earth high-entropy alloy ingot and a preparation process thereof. Background Art

[0002] Copper alloys are widely used in the manufacture of liners and inner wall structures for liquid rocket engine thrust chambers in both civilian and military applications due to their high density, excellent plasticity, and high speed of sound, as well as excellent thermal conductivity and high-temperature strength. However, with the advancement of science and technology and the global pursuit of superior performance in advanced weapons and equipment, performance requirements for various equipment components have significantly increased. For example, the mechanical properties of copper-based liners, a key component of armor-piercing projectiles, are crucial for the stability of the resulting metal jet. To achieve a good metal jet, the service performance of the liner must be improved. Currently, research and development of liner materials primarily focuses on copper, tantalum, molybdenum, tungsten, and depleted uranium alloys. Although significant progress has been made in this research, there is still some distance to go before these new materials can be applied in engineering applications. The mechanical and physical properties of traditional metal materials may not meet the service requirements of advanced weapons and equipment, posing significant challenges to their application in related fields. Therefore, the development of a new generation of high-performance metal materials is crucial for the manufacture of advanced weapons and equipment.

[0003] Due to their strong chemical activity and affinity with elements such as O, S, and P, rare earth elements effectively purify the alloy microstructure during the smelting process. Furthermore, their strong chemical activity promotes the formation of intermetallic compounds with other elements. Optimizing subsequent deformation and heat treatment processes not only regulates the morphology, distribution, and size of the second-phase particles within the alloy, but also effectively refines the alloy grain size, thereby improving the alloy's mechanical and physical properties. Therefore, adding rare earth elements to the alloy matrix is an effective means of enhancing its overall performance.

[0004] Aiming at the urgent need for high-performance copper alloys in the manufacture of civilian and military charge liners and inner wall structures of liquid rocket engine thrust chambers, the present invention develops a high-performance copper-based rare earth high-entropy alloy with pure copper as the matrix. Summary of the Invention

[0005] This invention primarily addresses the low strength of conventional cast copper alloys. By regulating the pure copper and rare earth element contents, the stacking fault energy of the copper-based rare earth high-entropy alloy is controlled, thereby regulating the alloy's as-cast microstructure. This solves the problem of low strength in conventional cast copper alloys. The process is simple and can produce copper-based rare earth high-entropy alloy ingots with a Vickers hardness of 45 HV or higher.

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

[0007] A copper-based rare earth high-entropy alloy ingot, the alloy ingot comprising the following components by mass percentage:

[0008] Cu 20%-50%;

[0009] Nd 5%-30%;

[0010] Ce 5%-30%;

[0011] Pr 5%-30%;

[0012] Y 5%-30%;

[0013] Mg 1.2%-2.2%;

[0014] Ti 0.05%-0.15%.

[0015] As a further improvement of the present invention, the alloy ingot comprises the following components by mass percentage:

[0016] Cu 35%-50%;

[0017] Nd 10%-20%;

[0018] Ce 10%-20%;

[0019] Pr 10%-20%;

[0020] Y 10%-20%;

[0021] Mg 1.5%-2.0%;

[0022] Ti 0.10%-0.15%.

[0023] As a further improvement of the present invention, the yield strength of the alloy ingot is greater than or equal to 320 MPa, and the resistance strength is greater than or equal to 360 Mpa.

[0024] As a further improvement of the present invention, the Vickers hardness of the alloy ingot is greater than or equal to 45 HV.

[0025] The present invention also discloses a preparation method of a copper-based rare earth high-entropy alloy ingot, the preparation method comprising the following steps:

[0026] (1) Weigh each elemental metal raw material according to the ratio, and perform impurity removal and drying treatment;

[0027] (2) Put the dried elemental metal raw materials at the bottom of the melting crucible for melting to obtain an alloy melt;

[0028] (3) Pour the alloy melt into a mold, and preheat the mold before pouring to obtain an alloy ingot;

[0029] (4) Homogenize and anneal the alloy ingot, and then perform extrusion to obtain an extruded ingot;

[0030] (5) After subjecting the extruded ingot to solution aging treatment, the copper-based rare earth high-entropy alloy ingot is obtained.

[0031] As a further improvement of the present invention, the method for impurity removal and drying treatment in step (1): ultrasonically clean the surface of the elemental metal raw material to remove impurities, and perform drying treatment through a vacuum oven. The drying temperature is 70-90 °C, the vacuum degree is less than 100 Pa, keep warm for 1-2 h, and cool with the furnace.

[0032] As a further improvement of the present invention, step (2) is specifically: put the calculated copper block ingredients at the bottom of the crucible, raise the temperature to 1280-1340 °C, and maintain at this temperature for 10-15 min. Then first add the Y raw material and stir. After melting and clearing, add the Pr raw material and continue to stir. After melting and clearing, add Nd and Ce simultaneously. After the metal in the crucible is completely melted, stop stirring. After keeping warm for 3-5 min, cool down. When the temperature drops to 750-780 °C, press Mg into the bottom of the alloy melt and react for 10-15 min. Then apply a protective gas to the alloy melt, add a refining agent, perform refining and impurity removal, add the Ti raw material to the refined alloy melt, and perform refinement treatment to obtain a refined alloy melt.

[0033] As a further improvement of the present invention, the casting temperature in step (3) is controlled at 1230-1270 °C, and the cooling rate is controlled at 5-10 °C / s.

[0034] As a further improvement of the present invention, the homogenization annealing treatment in step (4) is a two-stage homogenization annealing treatment. The temperature of the first homogenization annealing treatment is 430-450 °C, and the annealing treatment time is 10-15 h; the temperature of the second homogenization annealing treatment is 340-360 °C, and the annealing treatment time is 6-8 h.

[0035] As a further improvement of the present invention, the solution quenching temperature in the solution aging treatment in step (5) is 420-440 °C, and the artificial aging temperature is 180-190 °C.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] By regulating the contents of rare earth elements and copper elements, on the premise of obtaining a high-quality microstructure without casting cracks, the stacking fault energy of the copper-based rare earth high-entropy alloy is reduced. Thus, on the premise of obtaining a high-quality as-cast structure, the strength and hardness of the alloy are greatly improved by regulating the micro-deformation mechanism of the alloy, and a copper-based rare earth high-entropy alloy ingot with extremely low stacking fault energy suitable for industrial production and application is successfully prepared.

[0038] The present invention can solve the defect of low strength and hardness of as-cast copper alloys in the prior art. By changing the contents of alloying elements to control the stacking fault energy of the alloy and further regulating the micro-deformation mechanism of the alloy, a copper-based rare earth high-entropy alloy ingot with high strength and large hardness is obtained.

[0039] The process of the present invention is simple, and a copper-based rare earth high-entropy alloy ingot with a Vickers hardness greater than 45 HV can be prepared, which is suitable for large-scale industrial production and application. Detailed Embodiments

[0040] The following further describes the detailed embodiments of the present invention in conjunction with embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0041] An embodiment of the present application provides a copper-based rare earth high-entropy alloy ingot, which contains the following components by mass percentage: Cu 20%-50%, Nd 5%-30%, Ce 5%-30%, Pr 5%-30%, Y 5%-30%, Mg 1.2%-2.2%, Ti 0.05%-0.15%, and the Vickers hardness of the alloy ingot is greater than or equal to 45 HV.

[0042] The copper-based rare earth high-entropy alloy ingot provided by the embodiment of the present application can be obtained by controlling the alloying elements Cu, Nd, Ce, Pr, Y, Mg and Ti within a suitable content range and combining with a specific process under the synergistic effect of the elements with specific contents, and a copper-based rare earth high-entropy alloy ingot with high strength and large hardness can be obtained.

[0043] In the embodiment of the present application, by regulating the contents of Cu, Nd, Ce, Pr, and Y, the stacking fault energy of the copper-based rare earth high-entropy alloy is controlled to further regulate the as-cast microstructure of the alloy. Moreover, there is a synergistic effect among the elements Nd, Ce, Pr, and Y, which can significantly refine the as-cast structure of the alloy, inhibit dynamic recrystallization, and thus obtain a copper-based rare earth high-entropy alloy ingot with high strength and large hardness.

[0044] In the embodiment of the present application, adding Mg can inhibit the oxidation of rare earths, thereby maximizing the activity of rare earths, achieving the regulation of the as-cast microstructure of the alloy, and Mg combines with Cu to form a composite strengthening phase, thereby further improving the strength and hardness of the copper-based rare earth high-entropy alloy ingot.

[0045] In the embodiments of the present application, the addition of Ti can improve the uniformity of the tissue composition of the alloy, and improve the fluidity, strength and plasticity of the alloy.

[0046] In the embodiments of the present application, its components are determined by comprehensively considering the contributions of various chemical elements to the comprehensive performance indicators of aluminum alloy (including yield strength, tensile strength, elongation, etc.). Through the combined action of the above-mentioned elements with specific contents, it can obtain a tissue structure with a relatively small size of strengthening phase through the process, so as to obtain a relatively high yield strength.

[0047] The embodiments of the present application will be further described below with multiple examples.

[0048] Example 1

[0049] A copper-based rare earth high-entropy alloy ingot, comprising the following components by mass percentage:

[0050]

[0051] The preparation method of the above copper-based rare earth high-entropy alloy ingot includes the following steps:

[0052] (1) Weigh each elemental metal raw material according to the ratio, and perform impurity removal and drying treatment;

[0053] (2) Put the dried elemental metal raw materials at the bottom of the melting crucible for melting to obtain an alloy melt;

[0054] (3) Pour the alloy melt into the mold, and preheat the mold before pouring to obtain an alloy ingot;

[0055] (4) Perform homogenization annealing treatment on the alloy ingot, and then perform extrusion to obtain an extruded ingot;

[0056] (5) After performing solution aging treatment on the extruded ingot, obtain the copper-based rare earth high-entropy alloy ingot.

[0057] Among them, the impurity removal and drying treatment method in the step (1): perform ultrasonic cleaning on the surface of the elemental metal raw material to remove impurities, perform drying treatment through a vacuum oven, the drying temperature is 80 °C, the vacuum degree is 70 Pa, keep warm for 1.5 h, and cool with the furnace.

[0058] Among them, the specific steps of step (2) are as follows: Put the calculated copper block ingredients at the bottom of the crucible, raise the temperature to 1310 °C, and maintain it at this temperature for 13 minutes. Then first add the Y raw material and stir. After melting clear, add the Pr raw material and continue to stir. After melting clear, add Nd and Ce simultaneously. Stop stirring after the metal in the crucible is completely melted. Keep warm for 4 minutes and then cool down. When the temperature drops to 765 °C, press Mg into the bottom of the alloy melt for reaction for 13 minutes. Then apply a protective gas to the alloy melt, add a refining agent, and conduct refining to remove impurities. Add the Ti raw material to the refined alloy melt for grain refinement treatment to obtain the refined alloy melt.

[0059] Among them, the casting temperature in step (3) is controlled at 1250 °C, and the cooling rate is controlled at 7 °C / s.

[0060] Among them, the homogenization annealing treatment in step (4) is a two-stage homogenization annealing treatment. The temperature of the first homogenization annealing treatment is 440 °C, and the annealing treatment time is 13 hours; the temperature of the second homogenization annealing treatment is 350 °C, and the annealing treatment time is 7 hours.

[0061] Among them, the solution quenching temperature in the solution aging treatment in step (5) is 430 °C, and the artificial aging temperature is 185 °C.

[0062] Example 2

[0063] A copper-based rare earth high-entropy alloy ingot contains the following components by mass percentage:

[0064]

[0065] The preparation method of the above copper-based rare earth high-entropy alloy ingot includes the following steps:

[0066] (1) Weigh each elemental metal raw material according to the ratio and perform impurity removal and drying treatment;

[0067] (2) Put the dried elemental metal raw materials at the bottom of the melting crucible for melting to obtain an alloy melt;

[0068] (3) Pour the alloy melt into the mold, and preheat the mold before pouring to obtain an alloy ingot;

[0069] (4) Perform homogenization annealing treatment on the alloy ingot, and then perform extrusion to obtain an extruded ingot;

[0070] (5) After performing solution aging treatment on the extruded ingot, obtain the copper-based rare earth high-entropy alloy ingot.

[0071] Among them, the impurity removal and drying treatment method in step (1): ultrasonic cleaning is carried out on the surface of the elemental metal raw material to remove impurities, and drying treatment is carried out through a vacuum oven. The drying temperature is 70°C, the vacuum degree is 30 Pa, the heat preservation time is 1 h, and it is cooled with the furnace.

[0072] Among them, step (2) is specifically as follows: put the calculated copper block ingredients at the bottom of the crucible, raise the temperature to 1280°C, and maintain it at this temperature for 10 min. Then add the Y raw material first and stir. After melting clear, add the Pr raw material and continue to stir. After melting clear, add Nd and Ce simultaneously. After the metal in the crucible is completely melted, stop stirring. After heat preservation for 3 min, cool down. When the temperature drops to 750°C, press Mg into the bottom of the alloy melt and react for 10 min. Then apply a protective gas to the alloy melt, add a refining agent, and carry out refining to remove impurities. Add the Ti raw material to the refined alloy melt for grain refinement treatment to obtain the refined alloy melt.

[0073] Among them, the casting temperature in step (3) is controlled at 1230°C, and the cooling rate is controlled at 5°C / s.

[0074] Among them, the homogenization annealing treatment in step (4) is a two-stage homogenization annealing treatment. The temperature of the first homogenization annealing treatment is 430°C, and the annealing treatment time is 10 h; the temperature of the second homogenization annealing treatment is 340°C, and the annealing treatment time is 6 h.

[0075] Among them, the solution quenching temperature in the solution aging treatment in step (5) is 420°C, and the artificial aging temperature is 180°C.

[0076] Example 3

[0077] A copper-based rare earth high-entropy alloy ingot, comprising the following components by mass percentage:

[0078]

[0079] The preparation method of the above copper-based rare earth high-entropy alloy ingot comprises the following steps:

[0080] (1) Weigh each elemental metal raw material according to the ratio and carry out impurity removal and drying treatment;

[0081] (2) Put the dried elemental metal raw materials at the bottom of the melting crucible for melting to obtain an alloy melt;

[0082] (3) Pour the alloy melt into the mold, and preheat the mold before casting to obtain an alloy ingot;

[0083] (4) Carry out homogenization annealing treatment on the alloy ingot, and then carry out extrusion to obtain an extruded ingot;

[0084] (5) After solution aging treatment of the extruded ingot, the copper-based rare earth high-entropy alloy ingot is obtained.

[0085] Among them, the impurity removal and drying treatment method in the step (1): Ultrasonic cleaning is carried out on the surface of the elemental metal raw material to remove impurities and dirt, and drying treatment is carried out through a vacuum oven. The drying temperature is 90 °C, the vacuum degree is 90 Pa, the heat preservation time is 2 h, and it is cooled with the furnace.

[0086] Among them, the step (2) is specifically as follows: Put the calculated copper block ingredients at the bottom of the crucible, raise the temperature to 1340 °C, and maintain at this temperature for 15 min. Then add the Y raw material first and stir. After melting and clearing, add the Pr raw material and continue to stir. After melting and clearing, add Nd and Ce at the same time. Stop stirring after the metal in the crucible is completely melted. After heat preservation for 5 min, cool down. When the temperature drops to 780 °C, press Mg into the bottom of the alloy melt for reaction for 15 min. Then apply a protective gas to the alloy melt, add a refining agent, and carry out refining and impurity removal. Add the Ti raw material to the refined alloy melt for grain refinement treatment to obtain the refined alloy melt.

[0087] Among them, the casting temperature in the step (3) is controlled at 1270 °C, and the cooling rate is controlled at 10 °C / s.

[0088] Among them, the homogenization annealing treatment in the step (4) is a two-stage homogenization annealing treatment. The temperature of the first homogenization annealing treatment is 450 °C, and the annealing treatment time is 15 h; the temperature of the second homogenization annealing treatment is 360 °C, and the annealing treatment time is 8 h.

[0089] Among them, the solution quenching temperature in the solution aging treatment in the step (5) is 440 °C, and the artificial aging temperature is 190 °C.

[0090] Test example

[0091] The mechanical properties (yield strength, tensile strength and elongation) and hardness of the copper-based rare earth high-entropy alloy ingots prepared in Examples 1-3 were tested. The mechanical properties of the products were tested in accordance with GB / T 228.1-2010 "Metallic materials-Tensile testing-Part 1: Method of test at room temperature"; a 50 mm gauge extensometer was used, and the tensile speed was 5 mm / min. The Vickers hardness was tested in accordance with GB / T4340.1-2009 "Metallic materials-Vickers hardness test-Part 1: Test method". The test force: 300 gf (0.3 Kgf), and the pressure holding time was 10 s. The test results are shown in Table 1.

[0092] Table 1

[0093] Yield strength (MPa) Tensile strength (MPa) Elongation rate (%) Vickers hardness (HV) Example 1 328 366 8 55 Example 2 323 367 10 49 Example 3 326 361 9 52

[0094] As can be analyzed in combination with Table 1, for the copper-based rare earth high-entropy alloy ingots of Examples 1-3 of the present application, by regulating the contents of Cu, Nd, Ce, Pr, and Y, the stacking fault energy of the copper-based rare earth high-entropy alloy is controlled, and then the as-cast microstructure of the alloy is regulated. Moreover, there is a synergistic effect among the elements Nd, Ce, Pr, and Y, which can significantly refine the as-cast structure of the alloy, inhibit dynamic recrystallization, and through improving the conventional preparation and processing technology, the yield strength and tensile strength of the obtained alloy ingots are significantly improved, and it has a relatively high elongation and a relatively high hardness.

[0095] The present invention can solve the defect of low strength and hardness of the as-cast copper alloy in the prior art. By changing the contents of alloying elements to control the stacking fault energy of the alloy and then regulating the micro-deformation mechanism of the alloy, a copper-based rare earth high-entropy alloy ingot with high strength and high hardness is obtained.

[0096] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent substitution on some of the technical features. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A copper-based rare earth high-entropy alloy ingot, characterized in that, The alloy ingot contains the following components by mass percentage: Cu 20%-50%; Nd 5%-30%; Ce 5%-30%; Pr 5％-30％； Y 5％-30％； Mg 1.2%-2.2%; Ti 0.05%-0.15%.

2. The copper-based rare earth high-entropy alloy ingot according to claim 1, characterized in that, The alloy ingot contains the following components by mass percentage: Cu 35%-50%; Nd 10%-20%; Ce 10%-20%; Pr 10％-20％； Y 10％-20％； Mg 1.5%-2.0%; Ti 0.10%-0.15%.

3. The copper-based rare earth high-entropy alloy ingot according to claim 1, wherein, The yield strength of the alloy ingot is greater than or equal to 320 MPa, and the tensile strength is greater than or equal to 360 MPa.

4. The copper-based rare earth high-entropy alloy ingot according to claim 1, wherein The Vickers hardness of the alloy ingot is greater than or equal to 45 HV.

5. The preparation method of the copper-based rare earth high-entropy alloy ingot according to any one of claims 1-4, characterized in that It includes the following steps: (1) Weigh each elemental metal raw material according to the ratio, and perform impurity removal and drying treatment; (2) Put the dried elemental metal raw materials at the bottom of the melting crucible for melting to obtain an alloy melt; (3) Pour the alloy melt into a mold, and preheat the mold before pouring to obtain an alloy ingot; (4) Perform homogenization annealing treatment on the alloy ingot, and then perform extrusion to obtain an extruded ingot; (5) After performing solution aging treatment on the extruded ingot, obtain the copper-based rare earth high-entropy alloy ingot.

6. The preparation method of the copper-based rare earth high-entropy alloy ingot according to claim 5, characterized in that, The impurity removal and drying treatment method in step (1): Perform ultrasonic cleaning on the surface of the elemental metal raw material to remove impurities, and perform drying treatment through a vacuum oven. The drying temperature is 70-90 °C, the vacuum degree is less than 100 Pa, keep warm for 1-2 h, and cool with the furnace.

7. The preparation method of the copper-based rare earth high-entropy alloy ingot according to claim 5, characterized in that, Step (2) is specifically as follows: Put the calculated copper block ingredients at the bottom of the crucible, raise the temperature to 1280-1340 °C, and maintain the temperature at this temperature for 10-15 min. Then first add the Y raw material and stir. After melting and clearing, add the Pr raw material and continue to stir. After melting and clearing, add Nd and Ce at the same time. Stop stirring after the metal in the crucible is completely melted. After keeping warm for 3-5 min, lower the temperature. When the temperature drops to 750-780 °C, press Mg into the bottom of the alloy melt for reaction for 10-15 min. Then apply a protective gas to the alloy melt, add a refining agent, perform refining to remove impurities, add the Ti raw material to the refined alloy melt, perform grain refinement treatment to obtain a refined alloy melt.

8. The preparation method of the copper-based rare earth high-entropy alloy ingot according to claim 5, characterized in that, The casting temperature in step (3) is controlled at 1230-1270 °C, and the cooling rate is controlled at 5-10 °C / s.

9. The preparation method of the copper-based rare earth high-entropy alloy ingot according to claim 5, wherein, The homogenization annealing treatment in step (4) is a two-stage homogenization annealing treatment. The temperature of the first homogenization annealing treatment is 430-450 °C, and the annealing treatment time is 10-15 h; the temperature of the second homogenization annealing treatment is 340-360 °C, and the annealing treatment time is 6-8 h.

10. The preparation method of the copper-based rare earth high-entropy alloy ingot according to claim 5, characterized in that, The solution quenching temperature in the solution aging treatment in step (5) is 420-440 °C, and the artificial aging temperature is 180-190 °C.

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