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

Abstract

The invention belongs to the technical field of cast aluminum alloys, and particularly relates to a heat-resistant aluminum rare earth alloy material and a preparation method thereof. The heat-resistant aluminum rare earth alloy material comprises the following components in percentage by weight: 6 to 10 percent of Ce, 3 to 5 percent of Ni, 0.6 to 2.0 percent of Si, 0.4 to 0.8 percent of Mg, 0.1 to 0.5 percent of Zr and the balance of Al. Good matching of alloy room-temperature strength and high-temperature resistance is achieved through multi-element eutectic phases, the medium-high-strength heat-resistant aluminum rare earth alloy composed of alpha-Al, eutectic Si, Al-Ce, Al-Ni, Mg-Si, Al-Ce-Si and other multi-element eutectic phases is prepared, the room-temperature tensile strength of the heat-resistant aluminum rare earth alloy is not lower than 320 MPa, the ductility of the heat-resistant aluminum rare earth alloy is not lower than 3%, and the high-temperature tensile strength of the heat-resistant aluminum rare earth alloy at 260 DEG C is not lower than 190 MPa.

Description

Technical Field

[0001] The invention belongs to the technical field of cast aluminum alloys, and more specifically relates to a heat-resistant aluminum rare earth alloy material and a preparation method thereof. Background Art

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

[0003] Traditional cast heat-resistant aluminum alloys are mainly Al-Si and Al-Cu. For example, aluminum for pistons is mainly cast Al-Si alloys, and aluminum for engine cylinders is mainly cast Al-Cu alloys. With the advancement and development of science and technology, the power density of heat-resistant components such as engines is getting higher and higher, and the requirements for high-temperature resistance of materials are also increasing. The high-temperature performance of existing heat-resistant aluminum alloys can no longer meet the use requirements. Therefore, it is urgent to develop heat-resistant aluminum alloys with excellent room temperature performance, good heat resistance and high-temperature stability to meet the application needs of aerospace, automobiles, ships and other fields. Summary of the invention

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

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is to provide a medium-high strength heat-resistant aluminum rare earth alloy material, which, in terms of mass percentage, except for Al, comprises the following components:

[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 comprises the following components by mass percentage:

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

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

[0011] According to the above element ratio, pure aluminum ingots, aluminum-cerium alloys, aluminum-nickel alloys, aluminum-silicon alloys, aluminum-zirconium alloys and pure magnesium ingots are prepared;

[0012] The pure aluminum ingot, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy, and aluminum-zirconium alloy are heated and melted, mixed evenly, continued to heat and keep warm, and after temperature control, a pure magnesium ingot is added to obtain an aluminum melt;

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

[0014] Furthermore, the heating and heat preservation is heating to 800° C. and keeping the temperature for 5 to 10 minutes.

[0015] Furthermore, the temperature control is to control the temperature within the range of 730-750°C.

[0016] Furthermore, the refining and degassing steps are:

[0017] After adding the refining agent to the aluminum melt, the aluminum melt is stirred sufficiently, and the steps of adding the refining agent and stirring are repeated at least once.

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

[0019] Preferably, the mass ratio of the refining agent to the aluminum melt 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 static slagging is:

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

[0023] Preferably, the standing time is 10 min.

[0024] Preferably, the temperature of the static skimming is 740°C.

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

[0026] Furthermore, the casting steps are:

[0027] The aluminum melt is cast 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] The present invention achieves a good match between the room temperature strength and high temperature resistance of the alloy through a multi-eutectic phase, and prepares a mixed eutectic heat-resistant aluminum rare earth alloy composed of multi-eutectic phases such as α-Al, eutectic Si, Al-Ce, Al-Ni, Mg-Si, Al-Ce-Si, etc. The room temperature tensile strength of the medium-high strength heat-resistant aluminum rare earth alloy is not less than 320MPa, the elongation is not less than 3%, and the high temperature tensile strength at 260°C is not less than 190MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0032] Figure 1 These are SEM images of the heat-resistant aluminum rare earth alloys obtained in Example 1 and Comparative Example 6, wherein (a) is Example 1 and (b) is Comparative Example 6. DETAILED DESCRIPTION

[0033] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0034] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0035] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0036] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0037] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0038] The raw materials and reagents used in the specific implementation of the present invention are all commercially available products. The slag remover is provided by Fuzhou Weishi Machinery Co., Ltd., and its main components are sodium salt, potassium salt and fluoride salt.

[0039] Example 1

[0040] The preparation steps of medium-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 ratio of Ce 8wt.%, Ni 4wt.%, Si 1.4wt.%, Mg 0.6wt.% and Zr 0.3wt.%, with the balance being Al;

[0042] S2. Put pure aluminum ingot, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy and aluminum-zirconium alloy into a melting furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue to heat to 800°C and keep them warm for 5 minutes. Then control the temperature at about 740°C and add pure magnesium ingot. Wrap the pure magnesium ingot tightly with aluminum foil and add it below the liquid level with a colander. Stir slowly to melt the pure magnesium ingot to obtain aluminum melt.

[0043] S3, after pressing the refining agent (a mixture of potassium chloride and hexachloroethane in equal mass ratio) into the bottom of the aluminum melt with a bell jar, fully stirring, completing a refining and degassing, repeating the refining and degassing 2 times, to obtain the aluminum melt after refining and degassing;

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

[0045] S4. Sprinkle slag remover evenly on the surface of the aluminum melt after refining and degassing, let it stand for 10 minutes, scrape off the surface slag to obtain pure aluminum melt. The temperature of this process is kept at about 740℃.

[0046] The mass ratio of the slag remover to the aluminum melt after refining and degassing is 0.5:100;

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

[0048] The room temperature tensile strength of the medium-high strength heat-resistant aluminum rare earth alloy prepared through the above steps is 328MPa, and the elongation is 3.1%; the high temperature tensile strength at 260°C is 202MPa.

[0049] Example 2

[0050] The preparation steps of medium-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 ratio of Ce 10wt.%, Ni 5wt.%, Si 1.5wt.%, Mg 0.6wt.% and Zr 0.2wt.%, and the balance is Al;

[0052] S2. Put pure aluminum ingot, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy and aluminum-zirconium alloy into a melting furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue to heat to 800°C and keep them warm for 5 minutes. Then control the temperature at about 740°C and add pure magnesium ingot. Wrap the pure magnesium ingot tightly with aluminum foil and add it below the liquid level with a colander. Stir slowly to melt the pure magnesium ingot to obtain aluminum melt.

[0053] S3, after pressing the refining agent (a mixture of potassium chloride and hexachloroethane in equal mass ratio) into the bottom of the aluminum melt with a bell jar, fully stirring, completing a refining and degassing, repeating the refining and degassing 2 times, to obtain the aluminum melt after refining and degassing;

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

[0055] S4. Sprinkle slag remover evenly on the surface of the aluminum melt after refining and degassing, let it stand for 10 minutes, scrape off the surface slag to obtain pure aluminum melt. The temperature of this process is kept at about 740℃.

[0056] The mass ratio of the slag remover to the aluminum melt after refining and degassing is 0.5:100;

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

[0058] The room temperature tensile strength of the medium-high strength heat-resistant aluminum rare earth alloy prepared through the above steps is 324MPa, and the elongation is 3.9%; the high temperature tensile strength at 260°C is 197MPa.

[0059] Example 3

[0060] The preparation steps of medium-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 ratio of Ce 7wt.%, Ni 4wt.%, Si 2wt.%, Mg 0.8wt.% and Zr 0.4wt.%, with the balance being Al;

[0062] S2. Put pure aluminum ingot, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy and aluminum-zirconium alloy into a melting furnace and heat to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue to heat to 800°C and keep them warm for 5 minutes. Then control the temperature at about 740°C and add pure magnesium ingot. Wrap the pure magnesium ingot tightly with aluminum foil and add it below the liquid level with a colander. Stir slowly to melt the pure magnesium ingot to obtain aluminum melt.

[0063] S3, after using a bell jar to press a refining agent (a mixture of potassium chloride and hexachloroethane in a ratio of 1:1) into the bottom of the aluminum melt, fully stir it, complete a refining and degassing, repeat the refining and degassing 2 times, and obtain the aluminum melt after refining and degassing;

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

[0065] S4. Sprinkle slag remover evenly on the surface of the aluminum melt after refining and degassing, let it stand for 10 minutes, scrape off the surface slag to obtain pure aluminum melt. The temperature of this process is kept at about 740℃.

[0066] The mass ratio of the slag remover to the aluminum melt after refining and degassing is 0.3:100;

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

[0068] The room temperature tensile strength of the medium-high strength heat-resistant aluminum rare earth alloy prepared through the above steps is 326MPa, and the elongation is 3.4%; the high temperature tensile strength at 260°C is 190MPa.

[0069] Comparative Example 1

[0070] Al-Ce binary heat-resistant alloy using Al-Ti-B as refiner:

[0071] S1. Prepare pure aluminum ingot, aluminum-cerium alloy and grain refiner Al-Ti-B according to the ratio of Ce 12wt.%, Ti 0.12wt.%, B<0.05wt.%, and the balance is Al;

[0072] S2, put the pure aluminum ingot and aluminum-cerium alloy into the furnace and heat them to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue to heat to 800°C, keep warm for 5 minutes, and then control the temperature at about 740°C.

[0073] S3, after pressing the refining agent (a mixture of potassium chloride and hexachloroethane in equal mass ratio) into the bottom of the aluminum melt with a bell jar, fully stirring, completing a refining and degassing, repeating the refining and degassing once, to obtain the aluminum melt after refining and degassing;

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

[0075] S4. Sprinkle slag remover evenly on the surface of the aluminum melt after refining and degassing, let it stand for 10 minutes, scrape off the surface slag to obtain pure aluminum melt. The temperature of this process is kept at about 740℃.

[0076] The mass ratio of the slag remover to the aluminum melt after refining and degassing is 0.5:100;

[0077] S5. Add Al-Ti-B wire into the furnace, stir thoroughly for 5 minutes, and keep the temperature at about 720°C;

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

[0079] The Al-Ce alloy prepared through 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°C.

[0080] Comparative Example 2

[0081] Al-Ce-Ni ternary alloy using Al-Ti-B as refiner:

[0082] S1. Prepare pure aluminum ingots, aluminum-cerium alloy, aluminum-nickel alloy and grain refiner Al-Ti-B according to the ratio of Ce 10wt.%, Ni 5wt.%, Ti 0.12wt.%, B<0.05wt.%, and the balance is Al;

[0083] S2, put the pure aluminum ingot, aluminum-cerium alloy and aluminum-nickel alloy into the furnace and heat them to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue to heat to 800°C, keep warm for 5 minutes, and then control the temperature to about 740°C.

[0084] S3, after pressing the refining agent (a mixture of potassium chloride and hexachloroethane in equal mass ratio) into the bottom of the aluminum melt with a bell jar, fully stirring, completing a refining and degassing, repeating the refining and degassing once, to obtain the aluminum melt after refining and degassing;

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

[0086] S4. Sprinkle slag remover evenly on the surface of the aluminum melt after refining and degassing, let it stand for 10 minutes, scrape off the surface slag to obtain pure aluminum melt. The temperature of this process is kept at about 740℃.

[0087] The mass ratio of the slag remover to the aluminum melt after refining and degassing is 0.5:100;

[0088] S5. Add Al-Ti-B wire into the furnace, stir thoroughly for 5 minutes, and keep the temperature at about 720°C;

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

[0090] The Al-Ce-Ni alloy prepared through 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°C.

[0091] Comparative Example 3

[0092] Al-Ce-Si ternary alloy using Al-Ti-B as refiner:

[0093] S1. Prepare pure aluminum ingot, aluminum-cerium alloy, aluminum-silicon alloy and grain refiner Al-Ti-B according to the ratio of Ce 8wt.%, Si 4wt.%, Ti 0.15wt.%, B<0.05wt.%, and the balance is Al;

[0094] S2, put the pure aluminum ingot, aluminum-cerium alloy and aluminum-silicon alloy into the furnace and heat them to 750°C. After they are completely melted, stir them thoroughly to make them evenly mixed. Continue to heat to 800°C, keep warm for 5 minutes, and then control the temperature to about 740°C.

[0095] S3, after pressing the refining agent (a mixture of potassium chloride and hexachloroethane in equal mass ratio) into the bottom of the aluminum melt with a bell jar, fully stirring, completing a refining and degassing, repeating the refining and degassing once, to obtain the aluminum melt after refining and degassing;

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

[0097] S4. Sprinkle slag remover evenly on the surface of the aluminum melt after refining and degassing, let it stand for 10 minutes, scrape off the surface slag to obtain pure aluminum melt. The temperature of this process is kept at about 740℃.

[0098] The mass ratio of the slag remover to the aluminum melt after refining and degassing is 0.5:100;

[0099] S5. Add Al-Ti-B wire into the furnace, stir thoroughly for 5 minutes, and keep the temperature at about 720°C;

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

[0101] The Al-Ce-Si alloy prepared through 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°C.

[0102] Comparative Example 4

[0103] Al-Ce-Ni-Mg alloy using Al-Ti-B as refiner:

[0104] S1. Prepare pure aluminum ingots, aluminum-cerium alloys, aluminum-nickel alloys, pure magnesium ingots and grain refiner Al-Ti-B according to the ratio of Ce 10wt.%, Ni 5wt.%, Mg 1.2wt.%, Ti 0.14wt.%, B<0.05wt.%, and the balance is Al;

[0105] S2. Put pure aluminum ingot, 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 to heat to 800°C and keep them warm for 5 minutes. Then control the temperature at about 740°C and add pure magnesium ingot. Wrap the pure magnesium ingot tightly with aluminum foil and add it below the liquid level with a colander. Stir slowly to melt the pure magnesium ingot to obtain aluminum melt.

[0106] S3, after pressing the refining agent (a mixture of potassium chloride and hexachloroethane in a mass ratio of 1:1) into the bottom of the aluminum melt with a bell jar, fully stirring, completing a refining and degassing, repeating the refining and degassing twice, to obtain the aluminum melt after refining and degassing;

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

[0108] S4. Sprinkle slag remover evenly on the surface of the aluminum melt after refining and degassing, let it stand for 10 minutes, scrape off the surface slag to obtain pure aluminum melt. The temperature of this process is kept at about 740℃.

[0109] The mass ratio of the slag remover to the aluminum melt after refining and degassing is 0.5:100;

[0110] S5. Add Al-Ti-B wire into the furnace, stir thoroughly for 5 minutes, and keep the temperature at about 720°C;

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

[0112] The Al-Ce-Ni-Mg alloy prepared through 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°C.

[0113] Comparative Example 5

[0114] Al-Ce-Ni-Si-Mg alloy using Al-Ti-B as refiner:

[0115] S1. Prepare pure aluminum ingots, aluminum-cerium alloys, aluminum-nickel alloys, aluminum-silicon alloys, pure magnesium ingots and grain refiner Al-Ti-B according to the ratio of Ce 10wt.%, Ni 5wt.%, Si 3wt.%, Mg 1.2wt.%, Ti 0.15wt.%, B<0.05wt.%, and the balance is Al;

[0116] S2. Put pure aluminum ingot, 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 to heat to 800°C and keep them warm for 5 minutes. Then control the temperature at about 740°C and add pure magnesium ingot. Wrap the pure magnesium ingot tightly with aluminum foil and add it below the liquid level with a colander. Stir slowly to melt the pure magnesium ingot to obtain aluminum melt.

[0117] S3, after pressing the refining agent (a mixture of potassium chloride and hexachloroethane in equal mass ratio) into the bottom of the aluminum melt with a bell jar, fully stirring, completing a refining and degassing, repeating the refining and degassing 2 times, to obtain the aluminum melt after refining and degassing;

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

[0119] S4. Sprinkle slag remover evenly on the surface of the aluminum melt after refining and degassing, let it stand for 10 minutes, scrape off the surface slag to obtain pure aluminum melt. The temperature of this process is kept at about 740℃.

[0120] The mass ratio of the slag remover to the aluminum melt after refining and degassing is 0.5:100;

[0121] S5. Add Al-Ti-B wire into the furnace, stir thoroughly for 5 minutes, and keep the temperature at about 720°C;

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

[0123] The Al-Ce-Ni-Si-Mg alloy prepared through 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°C.

[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 ratio of Ce 8wt.%, Ni 4wt.%, Si 1.4wt.% and Mg 0.6wt.%, with the balance being Al;

[0126] S2. Put pure aluminum ingot, 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 to heat to 800°C and keep them warm for 5 minutes. Then control the temperature at about 740°C and add pure magnesium ingot. Wrap the pure magnesium ingot tightly with aluminum foil and add it below the liquid level with a colander. Stir slowly to melt the pure magnesium ingot to obtain aluminum melt.

[0127] S3, after pressing the refining agent (a mixture of potassium chloride and hexachloroethane in equal mass ratio) into the bottom of the aluminum melt with a bell jar, fully stirring, completing a refining and degassing, repeating the refining and degassing 2 times, to obtain the aluminum melt after refining and degassing;

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

[0129] S4. Sprinkle slag remover evenly on the surface of the aluminum melt after refining and degassing, let it stand for 10 minutes, scrape off the surface slag to obtain pure aluminum melt. The temperature of this process is kept at about 740℃.

[0130] The mass ratio of the slag remover to the aluminum melt after refining and degassing is 0.5:100;

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

[0132] The room temperature tensile strength of the medium-high strength heat-resistant aluminum rare earth alloy prepared through the above steps is 293MPa, and the elongation is 1.7%; the high temperature tensile strength at 260°C is 176MPa.

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

[0134] Test example

[0135] Table 1 shows the element proportions of the medium-high strength heat-resistant aluminum rare earth alloy materials prepared in Examples 1 to 3 and Comparative Examples 1 to 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 to 3 and Comparative Examples 1 to 5. The test method is as follows:

[0140] Mechanical properties test: The prepared samples were tested for mechanical properties on a universal testing machine, including tensile strength and elongation, with a tensile rate of 2 mm / min and an ambient temperature of 23 °C (room temperature) or 260 °C (high temperature).

[0141] Table 2

[0142]

[0143] It can be seen from the data in Table 2 that from the above embodiments and comparative examples, the type, composition and morphology of eutectic seriously affect the mechanical properties and heat resistance of the alloy. The Ce element can form an Al-Ce eutectic phase, the Ni element can form an Al-Ni eutectic phase, the Si element and the Mg element can form a phase while improving the morphology of the eutectic phase. The Al-Ce-Ni-Si-Mg alloy can form a variety of eutectic phases, and under the action of the element Zr, the size and spacing of the eutectic phase become more uniform. Under the joint action of Ce, Ni, Mg, Si and Zr, the heat resistance of the alloy can be improved.

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

[0145] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one 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 present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A medium-high strength heat-resistant aluminum rare earth alloy material, characterized in that: In terms of mass percentage, in addition to Al, the components include: Ce 6~10wt.%, Ni 3~5wt.%, Si 0.6~2.0wt.%, Mg 0.4~0.8wt.% and Zr 0.1~0.5wt.%.

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 comprises the following components by mass percentage: Ce 8wt.%, Ni 4wt.%, Si 1.4wt.%, Mg 0.6wt.% and Zr 0.3wt.%, and the balance is Al and inevitable impurities.

3. A method for preparing a medium-high strength heat-resistant aluminum rare earth alloy material, characterized in that the steps include: According to the element ratio of claim 1 or 2, prepare aluminum ingots, aluminum-cerium alloys, aluminum-nickel alloys, aluminum-silicon alloys, aluminum-zirconium alloys and pure magnesium ingots; The aluminum ingot, aluminum-cerium alloy, aluminum-nickel alloy, aluminum-silicon alloy, and aluminum-zirconium alloy are heated and melted, mixed evenly, and heated and kept warm. After the temperature is controlled, a magnesium ingot is added to obtain an aluminum melt; The aluminum melt is refined and degassed, statically slag-stripped, and 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 is to heat to 800° C. and keep the temperature for 5 to 10 minutes; the temperature control is to control the temperature at 730 to 750° C.

5. The preparation method according to claim 3, characterized in that: The steps of refining and degassing are: After adding the refining agent to the aluminum melt, the aluminum melt is fully stirred, and the steps of adding the refining agent and fully stirring are repeated at least once.

6. The preparation method according to claim 5, characterized in that: The refining and degassing temperature is 740° C., and the refining and degassing time for each time is 10 to 20 minutes. The mass ratio of the refining agent to the aluminum melt is 1 to 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 steps of static slagging are: A slag remover is added to the aluminum melt, and the surface slag is scraped off after standing to obtain a pure aluminum melt.

8. The preparation method according to claim 7, characterized in that: The standing time is 10 minutes; the standing slagging temperature is 740° C.; the mass ratio of the slagging agent to the aluminum melt is 0.2-0.5:

100.

9. The preparation method according to claim 7, characterized in that: The steps of casting are: The aluminum melt is cast 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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