Heat-resistant aluminum-rare earth alloy material and preparation method thereof

Abstract

This invention belongs to the field of cast aluminum alloy technology, and more specifically, relates to a heat-resistant aluminum rare earth alloy material and its preparation method. The heat-resistant aluminum rare earth alloy material comprises: Ce 6-10 wt.%, Ni 3-5 wt.%, Si 0.6-2.0 wt.%, Mg 0.4-0.8 wt.%, and Zr 0.1-0.5 wt.%, with the balance being Al. This invention achieves a good match between room temperature strength and high temperature resistance of the alloy through a multi-element eutectic phase, preparing a medium-to-high strength heat-resistant aluminum rare earth alloy composed of multiple eutectic phases such as α-Al, eutectic Si, Al-Ce, Al-Ni, Mg-Si, and Al-Ce-Si. This heat-resistant aluminum rare earth alloy has a room temperature tensile strength of not less than 320 MPa, an elongation of not less than 3%, and a high-temperature tensile strength of not less than 190 MPa at 260℃.

Description

Technical Field

[0001] This invention belongs to the field of cast aluminum alloy technology, and more specifically relates to a heat-resistant aluminum rare earth alloy material and its preparation method. Background Technology

[0002] Cast heat-resistant aluminum rare earth alloys mainly refer to Al-Re alloys, which have advantages such as high strength, good oxidation resistance, and stable performance under high temperature environment. They are widely used in aerospace, transportation, shipbuilding and weaponry, high-voltage power transmission and other fields.

[0003] Traditional cast heat-resistant aluminum alloys are mainly Al-Si and Al-Cu based. For example, aluminum used in pistons is primarily cast Al-Si alloys, while aluminum used in engine blocks is mainly cast Al-Cu alloys. With technological advancements, the power density of heat-resistant components such as engines is increasing, placing ever higher demands on the high-temperature resistance of materials. Existing heat-resistant aluminum alloys can no longer meet these requirements. Therefore, there is an urgent need to develop heat-resistant aluminum alloys with excellent room-temperature performance, good heat resistance, and high-temperature stability to meet the needs of applications in aerospace, automotive, and marine industries. Summary of the Invention

[0004] The purpose of this invention is to provide a heat-resistant aluminum rare earth alloy material and its preparation method, which has good room temperature mechanical properties and can be stably used at 260°C, so as to solve the problem that existing heat-resistant aluminum alloys can only work below 200°C.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] One of the technical solutions of this invention: Provides a medium-to-high strength heat-resistant aluminum-rare earth alloy material, wherein, by mass percentage, the components, excluding Al, include:

[0007] Ce 6~10wt.%, Ni 3~5wt.%, Si 0.6~2.0wt.%, Mg 0.4~0.8wt.% and Zr 0.1~0.5wt.%.

[0008] Furthermore, the medium-high strength heat-resistant aluminum rare earth alloy material, by mass percentage, has the following composition:

[0009] Ce 8 wt.%, Ni 4 wt.%, Si 1.4 wt.%, Mg 0.6 wt.% and Zr 0.3 wt.%, with the balance being Al and unavoidable impurities.

[0010] The second technical solution of the present invention provides a method for preparing the above-mentioned medium-high strength heat-resistant aluminum rare earth alloy material, the steps of which include:

[0011] Prepare pure aluminum ingots, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy, aluminum-zirconium alloy, and pure magnesium ingots according to the above element ratios.

[0012] The pure aluminum ingot, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy, and aluminum-zirconium alloy are heated and melted, mixed evenly, and then heated and kept at a constant temperature. After temperature control, pure magnesium ingot is added to obtain aluminum melt.

[0013] The aluminum melt is refined, degassed, allowed to stand to remove slag, and then cast to obtain the medium-high strength heat-resistant aluminum-rare earth alloy material.

[0014] Furthermore, the heating and heat preservation involves heating to 800°C and holding for 5–10 minutes.

[0015] Furthermore, the temperature control refers to maintaining the temperature between 730 and 750°C.

[0016] Furthermore, the refining and degassing step is as follows:

[0017] After adding the refining agent to the aluminum melt, stir thoroughly and repeat the refining agent addition and stirring step at least once.

[0018] Preferably, the refining and degassing temperature is 740°C, and the refining and degassing time for each refining and degassing is 10 to 20 minutes.

[0019] Preferably, the mass ratio of the refining agent to the molten aluminum is 1 to 1.5:100.

[0020] Preferably, the refining agent is a mixture of potassium chloride and hexachloroethane in equal mass ratios.

[0021] Furthermore, the step of allowing the slag to stand and be removed is as follows:

[0022] A slag remover is added to the molten aluminum, and after standing, the surface slag is removed to obtain a pure molten aluminum.

[0023] Preferably, the settling time is 10 minutes.

[0024] Preferably, the temperature for the static slag removal is 740°C.

[0025] Preferably, the mass ratio of the slag remover to the molten aluminum is 0.2 to 0.5: 100.

[0026] Furthermore, the casting step is as follows:

[0027] The aluminum molten material is poured into a preheated mold to obtain the medium-high strength heat-resistant aluminum rare earth alloy material.

[0028] Preferably, the preheating temperature is 300°C.

[0029] The present invention discloses the following technical effects:

[0030] This invention achieves a good match between room temperature strength and high temperature resistance of alloys through multi-element eutectic phases, and prepares a mixed eutectic heat-resistant aluminum rare earth alloy composed of multi-element eutectic phases such as α-Al, eutectic Si, Al-Ce, Al-Ni, Mg-Si, and Al-Ce-Si. The room temperature tensile strength of this medium-high strength heat-resistant aluminum rare earth alloy is not less than 320 MPa, the elongation is not less than 3%, and the high temperature tensile strength at 260℃ is not less than 190 MPa. Attached Figure Description

[0031] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0032] Figure 1 The images are SEM images of the heat-resistant aluminum rare earth alloys obtained in Example 1 and Comparative Example 6, where (a) is Example 1 and (b) is Comparative Example 6. Detailed Implementation

[0033] 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.

[0034] 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. Any stated value or intermediate value within a stated range, as well as each smaller range between 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.

[0035] 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.

[0036] 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 readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0037] 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.

[0038] In the specific embodiments of this invention, all raw materials and reagents used are commercially available products. The slagging agent is provided by Fuzhou Weishi Machinery Co., Ltd., and its main components are sodium salts, potassium salts, and fluoride salts.

[0039] Example 1

[0040] The preparation steps for medium- and high-strength heat-resistant aluminum-rare earth alloy materials are as follows:

[0041] S1. Prepare pure aluminum ingots, aluminum-cerium alloys, aluminum-nickel alloys, aluminum-silicon alloys, aluminum-zirconium alloys, and pure magnesium ingots according to the following proportions: Ce 8wt.%, Ni 4wt.%, Si 1.4wt.%, Mg 0.6wt.%, and Zr 0.3wt.%, with the balance being Al.

[0042] S2. Place pure aluminum ingots, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy, and aluminum-zirconium alloy into a furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue heating to 800°C and hold for 5 minutes. Then, control the temperature at about 740°C and add pure magnesium ingots. The pure magnesium ingots are wrapped tightly in aluminum foil and added below the liquid surface with a strainer. Stir slowly to melt the pure magnesium ingots and obtain aluminum melt.

[0043] S3. After pressing the refining agent (a mixture of potassium chloride and hexachloroethane in a mass ratio) under the aluminum melt using a bell jar, stir thoroughly to complete one refining and degassing step. Repeat the refining and degassing process twice to obtain the refined and degassed aluminum melt.

[0044] The refining and degassing temperature is maintained at around 740℃, and the refining and degassing time is 15 minutes each time. The mass ratio of refining agent to aluminum melt is 1:100.

[0045] S4. Sprinkle the slag remover evenly on the surface of the refined and degassed aluminum melt, let it stand for 10 minutes, remove the surface slag to obtain pure aluminum melt, and keep the temperature at around 740℃ during this process.

[0046] The mass ratio of slag remover to refined and degassed aluminum melt is 0.5:100;

[0047] S5. Preheat the mold to about 300℃, and then pour the pure aluminum molten material into the mold to obtain medium and high strength heat-resistant aluminum rare earth alloy material.

[0048] The medium-high strength heat-resistant aluminum rare earth alloy prepared by the above steps has a room temperature tensile strength of 328 MPa and an elongation of 3.1%; and a high temperature tensile strength of 202 MPa at 260℃.

[0049] Example 2

[0050] The preparation steps for medium- and high-strength heat-resistant aluminum-rare earth alloy materials are as follows:

[0051] S1. Prepare pure aluminum ingots, aluminum-cerium alloys, aluminum-nickel alloys, aluminum-silicon alloys, aluminum-zirconium alloys, and pure magnesium ingots according to the following proportions: Ce 10wt.%, Ni 5wt.%, Si 1.5wt.%, Mg 0.6wt.%, and Zr 0.2wt.%, with the balance being Al.

[0052] S2. Place pure aluminum ingots, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy, and aluminum-zirconium alloy into a furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue heating to 800°C and hold for 5 minutes. Then, control the temperature at about 740°C and add pure magnesium ingots. The pure magnesium ingots are wrapped tightly in aluminum foil and added below the liquid surface with a strainer. Stir slowly to melt the pure magnesium ingots and obtain aluminum melt.

[0053] S3. After pressing the refining agent (a mixture of potassium chloride and hexachloroethane in a mass ratio) under the aluminum melt using a bell jar, stir thoroughly to complete one refining and degassing step. Repeat the refining and degassing process twice to obtain the refined and degassed aluminum melt.

[0054] The refining and degassing temperature is maintained at around 740℃, and the refining and degassing time is 15 minutes each time. The mass ratio of refining agent to aluminum melt is 1:100.

[0055] S4. Sprinkle the slag remover evenly on the surface of the refined and degassed aluminum melt, let it stand for 10 minutes, remove the surface slag to obtain pure aluminum melt, and keep the temperature at around 740℃ during this process.

[0056] The mass ratio of slag remover to refined and degassed aluminum melt is 0.5:100;

[0057] S5. Preheat the mold to about 300℃, and then pour the pure aluminum molten material into the mold to obtain medium and high strength heat-resistant aluminum rare earth alloy material.

[0058] The medium-high strength heat-resistant aluminum rare earth alloy prepared by the above steps has a room temperature tensile strength of 324 MPa and an elongation of 3.9%; and a high temperature tensile strength of 197 MPa at 260℃.

[0059] Example 3

[0060] The preparation steps for medium- and high-strength heat-resistant aluminum-rare earth alloy materials are as follows:

[0061] S1. Prepare pure aluminum ingots, aluminum-cerium alloys, aluminum-nickel alloys, aluminum-silicon alloys, aluminum-zirconium alloys, and pure magnesium ingots according to the following proportions: Ce 7wt.%, Ni 4wt.%, Si 2wt.%, Mg 0.8wt.%, and Zr 0.4wt.%, with the balance being Al.

[0062] S2. Place pure aluminum ingots, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy, and aluminum-zirconium alloy into a furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue heating to 800°C and hold for 5 minutes. Then, control the temperature at about 740°C and add pure magnesium ingots. The pure magnesium ingots are wrapped tightly in aluminum foil and added below the liquid surface with a strainer. Stir slowly to melt the pure magnesium ingots and obtain aluminum melt.

[0063] S3. After pressing the refining agent (a 1:1 mixture of potassium chloride and hexachloroethane) under the aluminum melt using a bell jar, stir thoroughly to complete one refining and degassing cycle. Repeat the refining and degassing cycle twice to obtain the refined and degassed aluminum melt.

[0064] The refining and degassing temperature is maintained at around 740℃, and the refining and degassing time is 15 minutes each time. The mass ratio of refining agent to aluminum melt is 1:100.

[0065] S4. Sprinkle the slag remover evenly on the surface of the refined and degassed aluminum melt, let it stand for 10 minutes, remove the surface slag to obtain pure aluminum melt, and keep the temperature at around 740℃ during this process.

[0066] The mass ratio of slag remover to refined and degassed aluminum melt is 0.3:100;

[0067] S5. Preheat the mold to about 300℃, and then pour the pure aluminum molten material into the mold to obtain medium and high strength heat-resistant aluminum rare earth alloy material.

[0068] The medium-high strength heat-resistant aluminum rare earth alloy prepared by the above steps has a room temperature tensile strength of 326 MPa and an elongation of 3.4%; and a high temperature tensile strength of 190 MPa at 260℃.

[0069] Comparative Example 1

[0070] Al-Ce binary heat-resistant alloy using Al-Ti-B as a refining agent:

[0071] S1. Prepare pure aluminum ingots, aluminum-cerium alloy and grain refiner Al-Ti-B according to the following proportions: Ce 12wt.%, Ti 0.12wt.%, B < 0.05wt.%, with the balance being Al.

[0072] S2. Place pure aluminum ingots and aluminum-cerium alloy into a furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue heating to 800°C and hold for 5 minutes. Then control the temperature at around 740°C.

[0073] S3. After pressing the refining agent (a mixture of potassium chloride and hexachloroethane in a mass ratio) under the aluminum melt using a bell jar, stir thoroughly to complete one refining and degassing cycle. Repeat the refining and degassing cycle once to obtain the refined and degassed aluminum melt.

[0074] The refining and degassing temperature is maintained at around 740℃, and the refining and degassing time is 15 minutes each time. The mass ratio of refining agent to aluminum melt is 1:100.

[0075] S4. Sprinkle the slag remover evenly on the surface of the refined and degassed aluminum melt, let it stand for 10 minutes, remove the surface slag to obtain pure aluminum melt, and keep the temperature at around 740℃ during this process.

[0076] The mass ratio of slag remover to refined and degassed aluminum melt is 0.5:100;

[0077] S5. Add the Al-Ti-B wire to the furnace and stir thoroughly for 5 minutes, keeping the temperature at around 720℃.

[0078] S6. Preheat the mold to about 280°C, and then pour the pure aluminum molten material into the mold to obtain the Al-Ce alloy material.

[0079] The Al-Ce alloy prepared by the above steps has a room temperature tensile strength of 183 MPa and an elongation of 2.4%; and a high-temperature tensile strength of 103 MPa at 260℃.

[0080] Comparative Example 2

[0081] Al-Ce-Ni ternary alloy using Al-Ti-B as a refining agent:

[0082] S1. Prepare pure aluminum ingots, aluminum-cerium alloy, aluminum-nickel alloy and grain refiner Al-Ti-B according to the following proportions: Ce 10wt.%, Ni 5wt.%, Ti 0.12wt.%, B < 0.05wt.%, with the balance being Al.

[0083] S2. Place pure aluminum ingots, aluminum-cerium alloy, and aluminum-nickel alloy into a furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue heating to 800°C and hold for 5 minutes. Then control the temperature at around 740°C.

[0084] S3. After pressing the refining agent (a mixture of potassium chloride and hexachloroethane in a mass ratio) under the aluminum melt using a bell jar, stir thoroughly to complete one refining and degassing cycle. Repeat the refining and degassing cycle once to obtain the refined and degassed aluminum melt.

[0085] The refining and degassing temperature is maintained at around 740℃, and the refining and degassing time is 15 minutes each time. The mass ratio of refining agent to aluminum melt is 1:100.

[0086] S4. Sprinkle the slag remover evenly on the surface of the refined and degassed aluminum melt, let it stand for 10 minutes, remove the surface slag to obtain pure aluminum melt, and keep the temperature at around 740℃ during this process.

[0087] The mass ratio of slag remover to refined and degassed aluminum melt is 0.5:100;

[0088] S5. Add the Al-Ti-B wire to the furnace and stir thoroughly for 5 minutes, keeping the temperature at around 720℃.

[0089] S6. Preheat the mold to about 280°C, and then pour the pure aluminum molten material into the mold to obtain the Al-Ce-Ni alloy material.

[0090] The Al-Ce-Ni alloy prepared by the above steps has a room temperature tensile strength of 206 MPa and an elongation of 2.1%; and a high-temperature tensile strength of 121 MPa at 260℃.

[0091] Comparative Example 3

[0092] Al-Ce-Si ternary alloy using Al-Ti-B as a refining agent:

[0093] S1. Prepare pure aluminum ingots, aluminum-cerium alloy, aluminum-silicon alloy and grain refiner Al-Ti-B according to the following proportions: Ce 8wt.%, Si 4wt.%, Ti 0.15wt.%, B < 0.05wt.%, with the balance being Al.

[0094] S2. Place pure aluminum ingots, aluminum-cerium alloy, and aluminum-silicon alloy into a furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue heating to 800°C and hold for 5 minutes. Then control the temperature at around 740°C.

[0095] S3. After pressing the refining agent (a mixture of potassium chloride and hexachloroethane in a mass ratio) under the aluminum melt using a bell jar, stir thoroughly to complete one refining and degassing cycle. Repeat the refining and degassing cycle once to obtain the refined and degassed aluminum melt.

[0096] The refining and degassing temperature is maintained at around 740℃, and the refining and degassing time is 15 minutes each time. The mass ratio of refining agent to aluminum melt is 1:100.

[0097] S4. Sprinkle the slag remover evenly on the surface of the refined and degassed aluminum melt, let it stand for 10 minutes, remove the surface slag to obtain pure aluminum melt, and keep the temperature at around 740℃ during this process.

[0098] The mass ratio of slag remover to refined and degassed aluminum melt is 0.5:100;

[0099] S5. Add the Al-Ti-B wire to the furnace and stir thoroughly for 5 minutes, keeping the temperature at around 720℃.

[0100] S6. Preheat the mold to about 280°C, and then pour the pure aluminum molten material into the mold to obtain the Al-Ce-Si alloy material.

[0101] The Al-Ce-Si alloy prepared by the above steps has a room temperature tensile strength of 226 MPa and an elongation of 2.8%; and a high-temperature tensile strength of 134 MPa at 260℃.

[0102] Comparative Example 4

[0103] Al-Ce-Ni-Mg alloy using Al-Ti-B as a refining agent:

[0104] S1. Prepare pure aluminum ingots, aluminum-cerium alloy, aluminum-nickel alloy, pure magnesium ingots and grain refiner Al-Ti-B according to the following proportions: Ce 10wt.%, Ni 5wt.%, Mg 1.2wt.%, Ti 0.14wt.%, B < 0.05wt.%, with the balance being Al.

[0105] S2. Place pure aluminum ingots, aluminum-cerium alloy, and aluminum-nickel alloy into a furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue heating to 800°C and hold for 5 minutes. Then, control the temperature at about 740°C and add pure magnesium ingots. The pure magnesium ingots are wrapped tightly in aluminum foil and added below the liquid surface using a strainer. Stir slowly to melt the pure magnesium ingots and obtain aluminum melt.

[0106] S3. After pressing the refining agent (a mixture of potassium chloride and hexachloroethane in a 1:1 mass ratio) under the aluminum melt using a bell jar, stir thoroughly to complete one refining and degassing step. Repeat the refining and degassing process twice to obtain the refined and degassed aluminum melt.

[0107] The refining and degassing temperature is maintained at around 740℃, and the refining and degassing time is 10 minutes each time. The mass ratio of refining agent to aluminum melt is 1:100.

[0108] S4. Sprinkle the slag remover evenly on the surface of the refined and degassed aluminum melt, let it stand for 10 minutes, remove the surface slag to obtain pure aluminum melt, and keep the temperature at around 740℃ during this process.

[0109] The mass ratio of slag remover to refined and degassed aluminum melt is 0.5:100;

[0110] S5. Add the Al-Ti-B wire to the furnace and stir thoroughly for 5 minutes, keeping the temperature at around 720℃.

[0111] S6. Preheat the mold to about 280°C, and then pour the pure aluminum molten material into the mold to obtain the Al-Ce-Ni-Mg alloy material.

[0112] The Al-Ce-Ni-Mg alloy prepared by the above steps has a room temperature tensile strength of 239 MPa and an elongation of 2.7%; and a high-temperature tensile strength of 157 MPa at 260℃.

[0113] Comparative Example 5

[0114] Al-Ce-Ni-Si-Mg alloy using Al-Ti-B as a refining agent:

[0115] S1. Prepare pure aluminum ingots, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy, pure magnesium ingots, and grain refiner Al-Ti-B according to the following proportions: Ce 10wt.%, Ni 5wt.%, Si 3wt.%, Mg 1.2wt.%, Ti 0.15wt.%, B < 0.05wt.%, with the balance being Al.

[0116] S2. Place pure aluminum ingots, aluminum-cerium alloy, aluminum-nickel alloy, and aluminum-silicon alloy into a furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue heating to 800°C and hold for 5 minutes. Then, control the temperature at about 740°C and add pure magnesium ingots. The pure magnesium ingots are wrapped tightly in aluminum foil and added to the liquid surface using a strainer. Stir slowly to melt the pure magnesium ingots and obtain aluminum melt.

[0117] S3. After pressing the refining agent (a mixture of potassium chloride and hexachloroethane in a mass ratio) under the aluminum melt using a bell jar, stir thoroughly to complete one refining and degassing step. Repeat the refining and degassing process twice to obtain the refined and degassed aluminum melt.

[0118] The refining and degassing temperature is maintained at around 740℃, and the refining and degassing time is 10 minutes each time. The mass ratio of refining agent to aluminum melt is 1:100.

[0119] S4. Sprinkle the slag remover evenly on the surface of the refined and degassed aluminum melt, let it stand for 10 minutes, remove the surface slag to obtain pure aluminum melt, and keep the temperature at around 740℃ during this process.

[0120] The mass ratio of slag remover to refined and degassed aluminum melt is 0.5:100;

[0121] S5. Add the Al-Ti-B wire to the furnace and stir thoroughly for 5 minutes, keeping the temperature at around 720℃.

[0122] S6. Preheat the mold to about 280°C, and then pour the pure aluminum molten material into the mold to obtain the Al-Ce-Ni-Si-Mg alloy material.

[0123] The Al-Ce-Ni-Si-Mg alloy prepared by the above steps has a room temperature tensile strength of 266 MPa and an elongation of 1.9%; and a high-temperature tensile strength of 138 MPa at 260℃.

[0124] Comparative Example 6

[0125] S1. Prepare pure aluminum ingots, aluminum-cerium alloys, aluminum-nickel alloys, aluminum-silicon alloys, and pure magnesium ingots according to the proportions of Ce 8wt.%, Ni 4wt.%, Si 1.4wt.%, and Mg 0.6wt.%, with the balance being Al.

[0126] S2. Place pure aluminum ingots, aluminum-cerium alloy, aluminum-nickel alloy, and aluminum-silicon alloy into a furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue heating to 800°C and hold for 5 minutes. Then, control the temperature at about 740°C and add pure magnesium ingots. The pure magnesium ingots are wrapped tightly in aluminum foil and added to the liquid surface using a strainer. Stir slowly to melt the pure magnesium ingots and obtain aluminum melt.

[0127] S3. After pressing the refining agent (a mixture of potassium chloride and hexachloroethane in a mass ratio) under the aluminum melt using a bell jar, stir thoroughly to complete one refining and degassing step. Repeat the refining and degassing process twice to obtain the refined and degassed aluminum melt.

[0128] The refining and degassing temperature is maintained at around 740℃, and the refining and degassing time is 15 minutes each time. The mass ratio of refining agent to aluminum melt is 1:100.

[0129] S4. Sprinkle the slag remover evenly on the surface of the refined and degassed aluminum melt, let it stand for 10 minutes, remove the surface slag to obtain pure aluminum melt, and keep the temperature at around 740℃ during this process.

[0130] The mass ratio of slag remover to refined and degassed aluminum melt is 0.5:100;

[0131] S5. Preheat the mold to about 300℃, and then pour the pure aluminum molten material into the mold to obtain medium and high strength heat-resistant aluminum rare earth alloy material.

[0132] The medium-high strength heat-resistant aluminum rare earth alloy prepared by the above steps has a room temperature tensile strength of 293 MPa and an elongation of 1.7%; and a high temperature tensile strength of 176 MPa at 260℃.

[0133] Figure 1 SEM images of the heat-resistant aluminum rare earth alloys obtained in Example 1 and Comparative Example 6 are shown, where (a) is from Example 1 and (b) is from Comparative Example 6. Figure 1 It can be seen that the size and spacing of the eutectic phase become more uniform after the addition of Zr.

[0134] Test case

[0135] Table 1 shows the elemental proportions of the medium-high strength heat-resistant aluminum rare earth alloy materials prepared in Examples 1-3 and Comparative Examples 1-6.

[0136] Table 1

[0137]

[0138]

[0139] Table 2 shows the mechanical properties of the medium-high strength heat-resistant aluminum rare earth alloy materials prepared in Examples 1-3 and Comparative Examples 1-5. The test methods are as follows:

[0140] Mechanical property testing: The prepared specimens are tested for mechanical properties on a universal testing machine, including tensile strength and elongation. The tensile rate is 2 mm / min, and the ambient temperature is 23℃ (room temperature) or 260℃ (high temperature).

[0141] Table 2

[0142]

[0143] As can be seen from the data in Table 2, the type, composition, and morphology of the eutectic significantly affect the mechanical and heat resistance properties of the alloy. Ce can form an Al-Ce eutectic phase, Ni can form an Al-Ni eutectic phase, and Si and Mg can form phases while improving the morphology of the eutectic phase. Al-Ce-Ni-Si-Mg alloys can form multiple eutectic phases, and under the influence of Zr, the size and spacing of the eutectic phases become more uniform. The combined effect of Ce, Ni, Mg, Si, and Zr can improve the heat resistance of the alloy.

[0144] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0145] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A medium-to-high strength heat-resistant aluminum-rare earth alloy material, characterized in that, By mass percentage, the components, excluding Al, include: Ce 6~10wt.%, Ni 3~5wt.%, Si 0.6~2.0wt.%, Mg 0.4~0.8 wt.% and Zr 0.1~0.5wt.%; The preparation steps of the medium-high strength heat-resistant aluminum rare earth alloy material include: Prepare aluminum ingots, aluminum-cerium alloys, aluminum-nickel alloys, aluminum-silicon alloys, aluminum-zirconium alloys, and pure magnesium ingots according to the stated components; The aluminum ingot, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy, and aluminum-zirconium alloy are heated and melted, mixed evenly, heated and held at the same temperature, and after temperature control, magnesium ingots are added to obtain aluminum melt. The aluminum melt is refined, degassed, allowed to stand to remove slag, and then cast to obtain the medium-high strength heat-resistant aluminum-rare earth alloy.

2. The medium-high strength heat-resistant aluminum-rare earth alloy material according to claim 1, characterized in that, The medium-high strength heat-resistant aluminum-rare earth alloy material, by mass percentage, has the following composition: Ce 8 wt.%, Ni 4 wt.%, Si 1.4 wt.%, Mg 0.6 wt.% and Zr 0.3 wt.%, with the balance being Al and unavoidable impurities.

3. A method for preparing a medium-to-high strength heat-resistant aluminum-rare earth alloy material, characterized in that the steps include... include: Prepare aluminum ingots, aluminum-cerium alloys, aluminum-nickel alloys, aluminum-silicon alloys, aluminum-zirconium alloys, and pure magnesium ingots according to the element ratios of claim 1 or 2. The aluminum ingot, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy, and aluminum-zirconium alloy are heated and melted, mixed evenly, heated and held at the same temperature, and after temperature control, magnesium ingots are added to obtain aluminum melt. The aluminum melt is refined, degassed, allowed to stand to remove slag, and then cast to obtain the medium-high strength heat-resistant aluminum-rare earth alloy.

4. The preparation method according to claim 3, characterized in that, The heating and heat preservation process involves heating to 800℃ and holding for 5-10 minutes; the temperature control process involves maintaining the temperature at 730-750℃.

5. The preparation method according to claim 3, characterized in that, The refining and degassing steps are as follows: After adding the refining agent to the aluminum melt, stir thoroughly, and repeat the refining agent addition and thorough stirring step at least once.

6. The preparation method according to claim 5, characterized in that, The refining and degassing temperature is 740℃, and the refining and degassing time is 10~20min each time; the mass ratio of the refining agent to the aluminum melt is 1~1.5:100; the refining agent is a mixture of potassium chloride and hexachloroethane in equal mass ratios.

7. The preparation method according to claim 5, characterized in that, The step of allowing the slag to stand still and then removing it is as follows: A slag remover is added to the molten aluminum, and after standing, the surface slag is removed to obtain a pure molten aluminum.

8. The preparation method according to claim 7, characterized in that, The settling time is 10 minutes; the temperature for slag removal during settling is 740°C; and the mass ratio of the slag remover to the molten aluminum is 0.2~0.5:

100.

9. The preparation method according to claim 7, characterized in that, The casting steps are as follows: The aluminum molten material is poured into a preheated mold to obtain the medium-high strength heat-resistant aluminum rare earth alloy material.

10. The preparation method according to claim 9, characterized in that, The preheating temperature is 300°C.

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