Aluminum alloy material and preparation method thereof

Abstract

The invention relates to an aluminum alloy material and a preparation method thereof.The aluminum alloy material comprises Mn, Si, Fe, Cr, a first component, rare earth and Al, and the first component comprises at least one of Ti, B, Zr, V and Be; according to the total mass of the aluminum alloy material being 100%, Mn is smaller than or equal to 4%, Si is smaller than or equal to 3%, Fe is smaller than or equal to 3.5%, Cr is smaller than or equal to 6%, the mass fraction of the first component is 1%-2%, and the mass fraction of the rare earth is 7%-12%. The aluminum alloy material provided by the invention has excellent solderability, die-casting property and corrosion resistance, and can meet the requirements of complex part manufacturing and high-reliability connection.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloys, and particularly to an aluminum alloy material and a preparation method thereof. Background Art

[0002] The soldering process is a technology for joining components by locally heating the components. Since it can not damage the overall structure during the joining process, it is widely used in the joining of precision (dissimilar) parts and complex (dissimilar) components in the automotive and military fields. However, with the increasing demand for thin-walled complex and high-precision components formed by one-shot die casting, the problem of precision joining needs to be solved urgently, especially the demand for developing aluminum alloy materials that can be die-cast and soldered is becoming increasingly urgent.

[0003] Currently, die-cast solderable materials usually contain high-potential active metal elements such as Ni and Fe. These elements are likely to cause corrosion failure of die-castings in complex environments (such as coolant), and the coarse dendritic structure in die-casting materials not only affects the die-castability and corrosion resistance of the materials, but also reduces the product qualification rate. In order to improve the die-castability of aluminum alloys, traditional technologies usually choose to add relatively high contents of low-melting-point alloy elements such as Mg, Si, Cu, etc. However, the addition of these elements will reduce the solid-liquid line temperature of the aluminum alloy, thereby weakening the solderability of the aluminum alloy. Summary of the Invention

[0004] Based on this, it is necessary to provide an aluminum alloy material and a preparation method thereof for the above problems; the aluminum alloy material has excellent solderability, die-castability and corrosion resistance, and can meet the requirements of manufacturing complex components and high-reliability connections.

[0005] An aluminum alloy material includes Mn, Si, Fe, Cr, a first component, rare earth, and Al, wherein the first component includes at least one of Ti, B, Zr, V, and Be;

[0006] Calculated based on the total mass of the aluminum alloy material being 100%, Mn≤4%, Si≤3%, Fe≤3.5%, Cr≤6%, the mass fraction of the first component is 1%-2%, and the mass fraction of the rare earth is 7%-12%.

[0007] In one embodiment, the mass ratio of Mn to Fe is (2-3.8):1;

[0008] And / or, the mass ratio of Mn to Si is (1.5-4):1.

[0009] In one embodiment, in the first component, at least one element is within 1% of the total mass of the aluminum alloy material.

[0010] In one embodiment, the rare earth includes at least one of La, Ce, Y, and Sc, and satisfies at least one of the following conditions:

[0011] (1) The mass ratio of Ce to La is 1:1 - 2:1;

[0012] (2) La is 3% - 9% of the total mass of the aluminum alloy material;

[0013] (3) Ce is 3% - 9% of the total mass of the aluminum alloy material;

[0014] (4) Y is within 3% of the total mass of the aluminum alloy material;

[0015] (5) Sc is within 3% of the total mass of the aluminum alloy material.

[0016] In one embodiment, the aluminum alloy material further includes at least one of Cu, Ni, and Zn, and satisfies at least one of the following conditions:

[0017] (1) Cu is within 1% of the total mass of the aluminum alloy material;

[0018] (2) Ni is within 3% of the total mass of the aluminum alloy material;

[0019] (3) Zn is within 3% of the total mass of the aluminum alloy material.

[0020] In one embodiment, the aluminum alloy material further includes a second component, and the second component satisfies at least one of the following conditions:

[0021] (1) The second component is within 0.6% of the total mass of the aluminum alloy material;

[0022] (2) The second component includes at least one of Ga, Sn, and Pb;

[0023] (3) At least one element in the second component is within 0.2% of the total mass of the aluminum alloy material.

[0024] In one embodiment, the aluminum alloy material further includes nanoparticles, and the nanoparticles satisfy at least one of the following conditions:

[0025] (1) The average particle size of the nanoparticles is 5 nm - 40 nm;

[0026] (2) The nanoparticles include at least one of TiC, TiB 2 , Al 2 O 3 , SiC, TiO 2 ;

[0027] (3) At least one kind of nanoparticle is 1%-3% of the total mass of the aluminum alloy material.

[0028] A preparation method of the aluminum alloy material as described above, comprising the following steps:

[0029] Step 1: Under a protective atmosphere, mix the aluminum-rare earth master alloy and the metallic elements of Mn, Si, Fe, Cr, and the first component in proportion for refining to obtain an alloy melt;

[0030] Step 2: After subjecting the alloy melt to ultrasonic treatment, cool it by eccentric rotation treatment, and then die-cast to form an aluminum alloy material.

[0031] In one embodiment, the Step 1 satisfies at least one of the following conditions:

[0032] (1) Before refining, mix boron nitride, alumina, and magnesia with a solvent to make an aqueous emulsion, coat the surface of the refining tool with the aqueous emulsion and keep it warm to complete the surface treatment;

[0033] (2) In the refining, adding nanoparticles is further included;

[0034] (3) In the refining, after the mixture melts, add porous ceramic particles and perform electromagnetic stirring;

[0035] (4) Before obtaining the alloy melt, adding a refining agent is further included, and the refining agent is 0.5%-1% of the total mass of the mixture;

[0036] (5) The refining temperature is 700°C - 790°C.

[0037] In one embodiment, the Step 2 satisfies at least one of the following conditions:

[0038] (1) The power of the ultrasonic treatment is 1kW - 2kW;

[0039] (2) When porous ceramic particles are added in the refining, after ultrasonic treatment and before eccentric rotation treatment, filter the alloy melt to separate out the porous ceramic particles;

[0040] (3) The rotation speed of the eccentric rotation treatment is 50rpm - 150rpm, and the temperature is reduced to 640°C - 690°C.

[0041] By coordinately regulating the elemental types of Mn, Si, Fe, Cr, the first component, and the ratio with rare earth elements, on the one hand, it promotes grain refinement, inhibits recrystallization, is beneficial to improving thermal stability, while improving fluidity and filling properties, enhancing oxidation resistance and wettability, and optimizing the microstructure and melting point of the aluminum alloy material, promoting metallurgical bonding, thereby improving solderability and die-casting performance; on the other hand, it forms high-melting-point intermetallic compounds and oxide layers, inhibits harmful phases, enhances oxidation resistance, and at the same time avoids the formation of low-melting-point phases, ensuring the stability of the aluminum alloy material, thereby improving corrosion resistance.

[0042] Therefore, by optimizing the elements and ratios in the aluminum alloy material, the present invention can significantly improve solderability, die-casting performance and corrosion resistance while ensuring comprehensive performance, and can meet the requirements of manufacturing complex parts and high-reliability connections. Detailed Embodiments

[0043] To facilitate the understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments or examples and are not intended to limit the present invention.

[0045] The optional scope of the term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of the related listed items. The said any and all combinations include any two related listed items, any more related listed items, or the combination of all related listed items.

[0046] In the present invention, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are considered continuous and include the minimum and maximum values of the range, as well as each value between such minimum and maximum values. Further, when the range refers to integers, it includes each integer between the minimum and maximum values of the range. In addition, when multiple ranges are provided to describe features or characteristics, these ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0047] The present invention provides an aluminum alloy material, which includes Mn, Si, Fe, Cr, a first component, rare earth, and Al. Among them, the first component includes at least one of Ti, B, Zr, V, and Be.

[0048] Calculated based on the total mass of the aluminum alloy material being 100%, Mn ≤ 4%, Si ≤ 3%, Fe ≤ 3.5%, Cr ≤ 6%, the mass fraction of the first component is 1% - 2%, and the mass fraction of the rare earth is 7% - 12%.

[0049] It can be understood that in the aluminum alloy material, the mass fraction of Mn includes, but is not limited to, any point value among 1%, 2%, 3%, 3.5%, 4% or the range value between any two of them, and is preferably 3% - 4%; the mass fraction of Si includes, but is not limited to, any point value among 1%, 1.2%, 1.5%, 2%, 2.2%, 3% or the range value between any two of them, and is preferably 1.2% - 2.2%; the mass fraction of Fe includes, but is not limited to, any point value among 1%, 1.4%, 1.5%, 1.8%, 1.9%, 2%, 3%, 3.5% or the range value between any two of them, and is preferably 1% - 2%; the mass fraction of Cr includes, but is not limited to, any point value among 1%, 2%, 3%, 4%, 5%, 6% or the range value between any two of them, and is preferably 1% - 4%; the mass fraction of the rare earth includes, but is not limited to, any point value among 7%, 8%, 9%, 10%, 11%, 12% or the range value between any two of them, and is preferably 9% - 12%; except for the mass fractions of the above components, the balance is Al.

[0050] In the aluminum alloy material provided by the present invention, by regulating the element types of Mn, Si, Fe, Cr, the first component, and the ratio with the rare earth element, the solderability, die-castability, and corrosion resistance are synergistically improved from the following aspects:

[0051] First, by the first component and the rare earth element precipitating dispersed second-phase particles at the grain boundaries to hinder grain growth, thereby refining the grains. This can not only improve the strength and toughness of the material, inhibit the recrystallization behavior, be beneficial to reducing the generation of hot cracks, thereby improving the reliability and durability of welding, but also reduce the hot cracking tendency during the casting process, improve the integrity and mechanical properties of the die-cast products of the aluminum alloy material, and improve the thermal stability and creep resistance, making it not easy to deform during the die-casting process.

[0052] Second, improve the fluidity and filling property, and at the same time utilize the stable Cr formed between the components 2 O 3The oxide layer can not only improve the wettability of the solder on the substrate, make the metallurgical bonding more uniform, thereby improving the welding strength and sealing performance, but also help reduce surface defects, thus enhancing the surface quality, dimensional accuracy and corrosion resistance of die-cast products made of aluminum alloy materials.

[0053] Thirdly, rare earth elements form intermetallic compounds with elements such as Fe and Mn, optimizing the melting point of the aluminum alloy material. This not only helps promote metallurgical bonding, further improving the welding strength and reliability, but also can improve the fluidity of the aluminum alloy material, making it easier to fill the mold, which is beneficial to the casting and forming of complex parts.

[0054] Fourthly, to improve the mechanical properties and microstructure, the unique ratio of Mn, Fe, and Si is beneficial to reducing brittle phases, thereby improving the toughness, fatigue resistance and corrosion resistance of the aluminum alloy material.

[0055] Based on the synergistic effects of the above aspects, not only can the requirements of the soldering process for material wettability, bonding strength and thermal stability be met, but also the demands of the die-casting process for fluidity, fillability and surface quality can be satisfied. At the same time, the corrosion resistance is significantly improved, enabling the aluminum alloy material to have excellent solderability, die-castability and corrosion resistance, and thus meeting the needs of manufacturing complex parts and high-reliability connections.

[0056] In an embodiment of the present invention, the mass ratio of Mn to Fe is (2 - 3.8):1. By optimizing the ratio of Mn to Fe, Mn can refine the iron-containing phases in the aluminum alloy material to a certain extent, which is beneficial to improving the corrosion resistance. At the same time, it can prevent Fe and Mn from forming brittle phases, thereby improving the plasticity and toughness of the aluminum alloy material.

[0057] It can be understood that the mass ratio of Mn to Fe includes but is not limited to any point value or the range value between any two of 2:1, 2.5:1, 3:1, 3.5:1, 3.8:1, and is preferably 2:1 - 3.5:1.

[0058] In an embodiment of the present invention, the mass ratio of Mn to Si is (1.5 - 4):1. By optimizing the ratio of Mn to Si, Si can improve the fluidity of the metal fluid to a certain extent, which is beneficial to reducing casting defects. At the same time, it can prevent Si and Mn from forming hard and brittle phases (such as AlMnSi), thereby improving the mechanical properties of the aluminum alloy material.

[0059] It can be understood that the mass ratio of Mn to Si includes but is not limited to any point value or the range value between any two of 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, and is preferably 1.5:1 - 3:1.

[0060] In an embodiment of the present invention, in the first component, at least one element is within 1% of the total mass of the aluminum alloy material. Specifically, Ti is within 1% of the total mass of the aluminum alloy material, and / or B is within 1% of the total mass of the aluminum alloy material, and / or Zr is within 1% of the total mass of the aluminum alloy material, and / or V is within 1% of the total mass of the aluminum alloy material, and / or Be is within 1% of the total mass of the aluminum alloy material.

[0061] In an embodiment of the present invention, the rare earth includes at least one of La, Ce, Y, and Sc.

[0062] Preferably, the mass ratio of Ce to La is 1:1 - 2:1.

[0063] Specifically, La is 3% - 9% of the total mass of the aluminum alloy material, including but not limited to any value among 3%, 3.5%, 4%, 5%, 6%, 7%, 8%, 9% or the range value between any two of them, and preferably 3% - 5%.

[0064] Specifically, Ce is 3% - 9% of the total mass of the aluminum alloy material, including but not limited to any value among 3%, 4%, 5%, 6%, 7%, 8%, 9% or the range value between any two of them.

[0065] Specifically, Y is within 3% of the total mass of the aluminum alloy material, including but not limited to any value among 1%, 2%, 3% or the range value between any two of them.

[0066] Specifically, Sc is within 3% of the total mass of the aluminum alloy material, including but not limited to any value among 1%, 2%, 3% or the range value between any two of them.

[0067] In an embodiment of the present invention, the aluminum alloy material further includes at least one of Cu, Ni, and Zn.

[0068] Preferably, Cu is within 1% of the total mass of the aluminum alloy material, and / or Ni is within 3% of the total mass of the aluminum alloy material, and / or Zn is within 3% of the total mass of the aluminum alloy material.

[0069] In an embodiment of the present invention, the aluminum alloy material further includes a second component. Preferably, the second component includes at least one of Ga, Sn, and Pb. Among them, the addition of Ga can reduce the melting point of the alloy, improve its fluidity, and is beneficial to the casting and forming of complex-shaped parts; the appropriate addition of Sn and Pb can improve the cutting performance of the alloy, reduce tool wear during the processing, and improve the surface finish at the same time; in addition, these elements can also form eutectic phases with low melting points with the matrix components, which is beneficial to improving the brazing performance and connection reliability of the alloy.

[0070] Preferably, the second component is within 0.6% of the total mass of the aluminum alloy material.

[0071] Preferably, at least one element in the second component is within 0.2% of the total mass of the aluminum alloy material.

[0072] In an embodiment of the present invention, the aluminum alloy material further includes nano-particles. The nano-particles can serve as heterogeneous nucleation sites, hinder grain boundary migration, promote grain refinement, prevent excessive grain growth, and maintain a fine and uniform microstructure, which is beneficial to improving the strength and toughness of the alloy.

[0073] Preferably, the average particle size of the nano-particles is 5nm - 40nm, including but not limited to any point value among 5nm, 10nm, 15nm, 20nm, 30nm, 40nm or the range value between any two of them.

[0074] Preferably, the nano-particles include TiC, TiB 2 、Al 2 O 3 、SiC, TiO 2 and at least one of them.

[0075] Preferably, at least one kind of nano-particles is 1% - 3% of the total mass of the aluminum alloy material.

[0076] The present invention also provides a preparation method of the aluminum alloy material as described above, including the following steps:

[0077] Step 1: Under a protective atmosphere, mix the aluminum rare earth master alloy and the metal elements of Mn, Si, Fe, Cr, and the first component in proportion and refine them to obtain an alloy melt;

[0078] Step 2: After subjecting the alloy melt to ultrasonic treatment, cool it by eccentric rotation treatment, and then die-cast to form an aluminum alloy material.

[0079] In the present invention, ultrasonic treatment is used to cause melt vibration, which can not only promote nucleation, inhibit grain growth, refine grains, reduce compositional segregation, make the structure more uniform, but also help remove gases and inclusions in the melt, improve purity, thereby optimizing melt fluidity, reducing casting defects, and improving the quality of castings. Furthermore, the semi-solid alloy formed after ultrasonic treatment releases part of the latent heat of crystallization, resulting in less thermal shock to the die-casting mold, which is beneficial to extending the service life of the mold. In addition, the semi-solid alloy has a short solidification time and good fluidity, which is conducive to reducing casting defects such as porosity, shrinkage cavity and inclusions, and can better maintain the dimensional accuracy of parts, improving the density and reliability of parts.

[0080] In an embodiment of the present invention, before refining, boron nitride, alumina and magnesia are mixed with a solvent to form an aqueous emulsion. The aqueous emulsion is coated on the surface of the refining tool and kept warm to complete the surface treatment. Through the surface treatment, a high-temperature resistant and oxidation-resistant protective coating can be formed on the surface of the refining tool to extend the service life of the tool and is also beneficial to improving the purity of the obtained aluminum alloy material.

[0081] Preferably, in the aqueous emulsion, the volume ratio of boron nitride, alumina and magnesia is (85 - 95):(5 - 10):3; the temperature for heat preservation is 100°C - 280°C, and the time is 1h - 2h.

[0082] In an embodiment of the present invention, in the refining process, nano-particles are also added. The nano-particles can serve as heterogeneous nucleation sites, hinder grain boundary migration, promote grain refinement, prevent excessive grain growth, and maintain a fine and uniform microstructure, which is beneficial to improving the strength and toughness of the alloy. Preferably, the nano-particles include at least one of TiC, TiB 2 , Al 2 O 3 , SiC, TiO 2 in the alloy.

[0083] In an embodiment of the present invention, in the refining process, after the mixture is melted, porous ceramic particles are added and electromagnetic stirring is carried out, which can break dendrites, promote grain refinement, improve the strength and toughness of the aluminum alloy material. At the same time, the interfacial reaction between the porous ceramic particles and the alloy melt during stirring is beneficial to improving the purity of the melt, thereby improving the corrosion resistance of the aluminum alloy material.

[0084] Preferably, the particle size of the porous ceramic particles is 5nm - 10nm; the stirring speed is 150rpm - 250rpm, and the time is 15min - 25min.

[0085] In an embodiment of the present invention, before obtaining the alloy melt, a refining agent is further added, and the refining agent is 0.5%-1% of the total mass of the mixture. Preferably, the refining agent includes chloride salt and fluoride salt, and the mass ratio of chloride salt to fluoride salt is (3-5):1.

[0086] In an embodiment of the present invention, the refining temperature is preferably 700°C-790°C.

[0087] In an embodiment of the present invention, the power of the ultrasonic treatment is preferably 1kW-2kW.

[0088] In an embodiment of the present invention, when porous ceramic particles are added during refining, after the ultrasonic treatment and before the eccentric rotation treatment, the alloy melt is filtered to separate the porous ceramic particles.

[0089] It can be understood that the present invention does not limit the specific filtration method of the alloy melt. For example, a porous ceramic filter sheet with a diameter of 150mm-220mm and a thickness of 3mm-5mm can be used for filtration to separate the porous ceramic particles.

[0090] Through the eccentric rotation treatment, the composition and temperature of the melt are homogenized, which is beneficial to further promoting grain refinement, improving the microstructure of the aluminum alloy material, and reducing defects. Preferably, the rotation speed of the eccentric rotation treatment is 50rpm-150rpm, and the temperature is reduced to 640°C-690°C.

[0091] Hereinafter, the aluminum alloy material and its preparation method will be further described through the following specific examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. For those not specified in the examples, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified for the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0092] Example 1

[0093] Under the atmosphere of a protective gas, the inside of the graphite crucible, the inside of the billet crucible, and the ladle are kept warm in an oven at 140°C for 1h, and then a water-based emulsion is sprayed under high pressure. The water-based emulsion includes boron nitride, alumina, and magnesia with a volume ratio of 90:7:3, and it is kept warm for another 1h.

[0094] Under the atmosphere of a protective gas, according to the weight percentage, 3% of Mn, 2% of Si, 1.8% of Fe, 1% of Ni, 1% of Cr, 1% of Zr, 3% of TiC (average particle size of 8nm), 3% of TiB 2(The average particle size is 8 nm) and the balance of the aluminum rare earth master alloy (where the content of La is 4% of the total weight of the raw materials and the content of Ce is 5% of the total weight of the raw materials) are added to a graphite crucible and placed in a holding furnace. The refining temperature is controlled at 720 °C. After melting, porous ceramic particles with a diameter of 8 mm are added. Electromagnetic stirring is carried out at 180 rpm for 17 min, and a refining agent accounting for 0.6% of the total weight ratio of the total ingredients (where the mass ratio of chloride salt to fluoride salt is 4:1) is added. After refining, an alloy melt is obtained.

[0095] After the alloy melt is treated by a 1.2 kW ultrasonic pulse device, it is filtered through a porous ceramic filter plate with a diameter of 200 mm and a thickness of 3 mm and then slowly poured into a billet-making crucible. After the alloy melt returns to a horizontal position, eccentric rotation at 60 rpm is started and the melt is waited to cool down to 660 °C. When the billet is demolded from the billet-making crucible and poured into the injection chamber of a die-casting machine, the melt is filled completely, without voids and unfilled areas, and the forming quality of the die-cast part is excellent, proving that the aluminum alloy material prepared in this example has excellent castability. Through ICP-AES detection, the total content of Ga, Sn, and Pb in this aluminum alloy material is less than 0.05%, and Ga, Sn, and Pb are all less than 0.02%, with a relatively high purity.

[0096] After two die-cast parts are brazed by gas protection at 585 °C, the weld is firm and reliable, without bubble inclusions, proving that the aluminum alloy material prepared in this example has excellent brazability.

[0097] After 3600 h of neutral salt spray corrosion, obvious galvanic corrosion in the weld area is not found, proving that the aluminum alloy material prepared in this example has excellent corrosion resistance.

[0098] Example 2

[0099] Under the atmosphere of a protective gas, the inside of the graphite crucible, the inside of the billet-making crucible, and the ladle are kept in an oven at 130 °C for 2 h and then high-pressure sprayed with an aqueous emulsion. The aqueous emulsion includes boron nitride, alumina, and magnesia with a volume ratio of 90:7:3, and the holding is continued for 1.5 h.

[0100] Under the atmosphere of a protective gas, by weight percentage, 4% of Mn, 1.5% of Si, 1.9% of Fe, 2% of Ni, 2% of Cr, 1% of Cu, 1% of Ti, 1% of Zr, 4% of TiC (average particle size is 15 nm), 1% of Al 2 O 3(The average particle size is 15 nm) and the balance of aluminum rare earth master alloy (where the content of La is 5% of the total weight of the raw materials, the content of Ce is 5% of the total weight of the raw materials, and the content of Y is 2% of the total weight of the raw materials) are added to a graphite crucible and placed in a holding furnace. The refining temperature is controlled at 730 °C. After melting, porous ceramic particles with a diameter of 7 mm are added. After electromagnetic stirring at 170 rpm for 18 min, a refining agent accounting for 0.7% of the total weight ratio of the total ingredients (where the mass ratio of chloride salt to fluoride salt is 4:1) is added, and an alloy melt is obtained after refining.

[0101] After the alloy melt is treated by a 1.3 kW ultrasonic pulse device, it is slowly poured into a billet-making crucible after being filtered through a porous ceramic filter plate with a diameter of 180 mm and a thickness of 4 mm. After the alloy melt returns to a horizontal position, eccentric rotation at 70 rpm is started and the melt is waited to cool down to 670 °C. When the billet is demolded from the billet-making crucible and poured into the pressure chamber of a die-casting machine, the melt is filled completely, without cavities and unfilled regions, and the forming quality of the die-cast part is excellent, proving that the aluminum alloy material prepared in this example has excellent castability. After ICP-AES detection, the content of Ga + Sn + Pb in this aluminum alloy material is lower than 0.05%, and Ga, Sn, and Pb are all lower than 0.02%, with a relatively high purity.

[0102] After two die-cast parts are brazed by gas shielded brazing at 590 °C, the weld is firm and reliable, without bubble inclusions, proving that the aluminum alloy material prepared in this example has excellent brazability.

[0103] After 3600 h of neutral salt spray corrosion, no obvious galvanic corrosion in the weld area is found, proving that the aluminum alloy material prepared in this example has excellent corrosion resistance.

[0104] Example 3

[0105] Under the atmosphere of a protective gas, the inside of the graphite crucible, the inside of the billet-making crucible, and the ladle are kept warm in an oven at 120 °C for 1.5 h, and then a water-based emulsion is sprayed under high pressure. The water-based emulsion includes boron nitride, alumina, and magnesia with a volume ratio of 90:7:3, and the insulation is continued for 1.5 h.

[0106] Under the atmosphere of a protective gas, according to weight percentage, 3.5% of Mn, 1.2% of Si, 1% of Fe, 3% of Cr, 1% of Ni, 1% of Ti, 1% of V, 2% of TiC (average particle size is 20 nm), 1% of Al 2 O 3 (average particle size is 15 nm), 1% of TiB 2(The average particle size is 7 nm) and the balance of aluminum rare earth master alloy (where the content of La is 3% of the total weight of the raw materials, the content of Ce is 6% of the total weight of the raw materials, and the content of Sc is 2% of the total weight of the raw materials) are added to a graphite crucible and placed in a holding furnace. The refining temperature is controlled at 735 °C. After melting, porous ceramic particles with a diameter of 5 mm are added. It is stirred electromagnetically at 160 rpm for 20 min, and a refining agent accounting for 0.8% of the total weight ratio of the total ingredients (where the mass ratio of chloride salt to fluoride salt is 4:1) is added. After refining, an alloy melt is obtained.

[0107] After the alloy melt is treated by a 1.8 kW ultrasonic pulse device, it is filtered through a porous ceramic filter plate with a diameter of 160 mm and a thickness of 5 mm and then slowly poured into a billet-making crucible. After the alloy melt returns to a horizontal position, eccentric rotation at 80 rpm is started and the melt is waited to cool down to 675 °C. When the billet is demolded from the billet-making crucible and poured into the injection chamber of a die-casting machine, the melt is filled completely, without cavities and unfilled areas, and the quality of the die-cast part is excellent, proving that the aluminum alloy material prepared in this example has excellent castability. After detection by ICP-AES, the content of Ga + Sn + Pb in this aluminum alloy material is lower than 0.05%, and the contents of Ga, Sn, and Pb are all lower than 0.02%, with a relatively high purity.

[0108] After two die-cast parts are brazed by gas shielded brazing at 590 °C, the weld seam is firm and reliable, without bubble inclusions, proving that the aluminum alloy material prepared in this example has excellent brazability.

[0109] After 3600 h of neutral salt spray corrosion, obvious galvanic corrosion in the weld area is not found, proving that the aluminum alloy material prepared in this example has excellent corrosion resistance.

[0110] Example 4

[0111] Under the atmosphere of a protective gas, the inside of the graphite crucible, the inside of the billet-making crucible, and the ladle are kept warm in an oven at 160 °C for 1 h and then sprayed with a water-based emulsion under high pressure. The water-based emulsion includes boron nitride, alumina, and magnesia with a volume ratio of 90:7:3, and it is kept warm for another 1 h.

[0112] Under the atmosphere of a protective gas, according to the weight percentage, 3% of Mn, 1.5% of Si, 1.5% of Fe, 2% of Ni, 3% of Cr, 1% of Cu, 0.8% of Ti, 3% of TiC (the average particle size is 10 nm) and the balance of aluminum rare earth master alloy (where the content of La is 5% of the total weight of the raw materials and the content of Ce is 5% of the total weight of the raw materials) are added to a graphite crucible and placed in a holding furnace. The refining temperature is controlled at 730 °C. After melting, porous ceramic particles with a diameter of 7.5 mm are added. It is stirred electromagnetically at 185 rpm for 18 min, and a refining agent accounting for 0.75% of the total weight ratio of the total ingredients (where the mass ratio of chloride salt to fluoride salt is 4:1) is added. After refining, an alloy melt is obtained.

[0113] After the alloy melt is treated by a 1.25 kW ultrasonic pulse device, it is filtered through a porous ceramic filter plate with a diameter of 180 mm and a thickness of 4 mm and then slowly poured into the blank-making crucible. After the alloy melt returns to a horizontal position, it starts to perform eccentric rotation at 85 rpm and waits for the melt to cool down to 665 °C. When the blank is demolded from the blank-making crucible and poured into the pressure chamber of the die-casting machine, the melt is filled completely, without voids and unfilled areas, and the forming quality of the die-casting part is excellent, proving that the aluminum alloy material prepared in this example has excellent castability. Through ICP-AES detection, the content of Ga + Sn + Pb in this aluminum alloy material is lower than 0.05%, and the contents of Ga, Sn, and Pb are all lower than 0.02%, with a relatively high purity.

[0114] After two die-casting parts are brazed by gas protection at 582 °C, the weld is firm and reliable, without bubble inclusions, proving that the aluminum alloy material prepared in this example has excellent brazability.

[0115] After 3600 h of neutral salt spray corrosion, no obvious galvanic corrosion in the weld area is found, proving that the aluminum alloy material prepared in this example has excellent corrosion resistance.

[0116] Example 5

[0117] Under the atmosphere of protective gas, the inside of the graphite crucible, the inside of the blank-making crucible, and the ladle are kept warm in an oven at 165 °C for 1 h and then sprayed with an aqueous emulsion under high pressure. The aqueous emulsion includes boron nitride, alumina, and magnesia with a volume ratio of 90:7:3, and it continues to be kept warm for 1 h.

[0118] Under the atmosphere of protective gas, according to weight percentage, 3.5% of Mn, 2.2% of Si, 1.4% of Fe, 4% of Cr, 1% of B, 0.2% of Zn, 2% of TiC (average particle size of 7.5 nm), 2% of TiB 2 (average particle size of 8 nm) and the remaining aluminum rare earth master alloy (where the content of La is 3% of the total weight of the raw materials, the content of Ce is 3% of the total weight of the raw materials, and the content of Y is 3% of the total weight of the raw materials) are added to the graphite crucible and placed in a holding furnace. The refining temperature is controlled at 725 °C. After melting, porous ceramic particles with a diameter of 6 mm are added, and electromagnetic stirring is carried out at 170 rpm for 20 min, and a refining agent with a weight ratio of 0.85% of the total batching weight is added (where the mass ratio of chloride salt to fluoride salt is 4:1). After refining, an alloy melt is obtained.

[0119] After the alloy melt is treated by a 1.5 kW ultrasonic pulse device, it is slowly poured into a blank-making crucible after being filtered by a porous ceramic filter plate with a diameter of 185 mm and a thickness of 4 mm. After the alloy melt returns to a horizontal position, it starts to perform eccentric rotation at 80 rpm and waits for the melt to cool down to 660 °C. When the blank is demolded from the blank-making crucible and poured into the pressure chamber of the die-casting machine, the melt is filled completely, without voids and unfilled areas, and the formed quality of the die-casting is excellent, which proves that the aluminum alloy material prepared in this example has excellent castability. Through ICP-AES detection, the content of Ga+Sn+Pb in this aluminum alloy material is lower than 0.05%, and Ga, Sn, and Pb are all lower than 0.02%, with a relatively high purity.

[0120] After two die-castings are brazed by gas protection at 580 °C, the weld is firm and reliable, without bubble inclusions, which proves that the aluminum alloy material prepared in this example has excellent brazability.

[0121] After 3600 h of neutral salt spray corrosion, no obvious galvanic corrosion in the weld area is found, which proves that the aluminum alloy material prepared in this example has excellent corrosion resistance.

[0122] Example 6

[0123] In the atmosphere of protective gas, after the inside of the graphite crucible, the inside of the blank-making crucible and the ladle are kept warm in an oven at 170 °C for 1.5 h, a water-based emulsion is sprayed under high pressure, and the water-based emulsion includes boron nitride, alumina, and magnesia with a volume ratio of 90:7:3, and then keep warm for 2 h.

[0124] In the atmosphere of protective gas, according to the weight percentage, 4% of Mn, 2% of Si, 1.5% of Fe, 2% of Ni, 3% of Cr, 1% of Cu, 1% of Ti, 4% of TiC (average particle size of 15 nm), 2% of Al 2 O 3 (average particle size of 10 nm) and the remaining aluminum rare earth master alloy (where the content of La is 3.5% of the total weight of the raw materials and the content of Ce is 7% of the total weight of the raw materials) are added to the graphite crucible and placed in a holding furnace. The refining temperature is controlled at 730 °C. After melting, porous ceramic particles with a diameter of 9 mm are added, and electromagnetic stirring is carried out at 180 rpm for 19 min, and a refining agent with a weight ratio of 0.8% of the total batching weight is added (where the mass ratio of chloride salt to fluoride salt is 4:1). After refining, an alloy melt is obtained.

[0125] After the alloy melt is treated by a 1.4 kW ultrasonic pulse device, it is slowly poured into the blank-making crucible after being filtered through a porous ceramic filter plate with a diameter of 190 mm and a thickness of 4 mm. After the alloy melt returns to a horizontal position, it starts to perform eccentric rotation at 82 rpm and waits for the melt to cool down to 665 °C. When the blank is demolded from the blank-making crucible and poured into the pressure chamber of the die-casting machine, the melt is filled completely, without voids and unfilled regions, and the quality of the die-cast part is excellent, proving that the aluminum alloy material prepared in this example has excellent die-casting performance. After ICP-AES detection, the content of Ga + Sn + Pb in this aluminum alloy material is less than 0.05%, and the contents of Ga, Sn, and Pb are all less than 0.02%, with a relatively high purity.

[0126] After two die-cast parts are brazed by gas protection at 595 °C, the weld seam is firm and reliable, without bubble inclusions, proving that the aluminum alloy material prepared in this example has excellent brazing performance.

[0127] After 3600 h of neutral salt spray corrosion, no obvious galvanic corrosion in the weld area is found, proving that the aluminum alloy material prepared in this example has excellent corrosion resistance.

[0128] Example 7

[0129] The difference between Example 7 and Example 6 is that 1% of Ti and 1% of Al in the aluminum rare earth master alloy accounting for the total weight of the raw materials are respectively replaced by 1% of V and 1% of Be.

[0130] When the blank is demolded from the blank-making crucible and poured into the pressure chamber of the die-casting machine, the melt is filled completely, without voids and unfilled regions, and the quality of the die-cast part is excellent, proving that the aluminum alloy material prepared in this example has excellent die-casting performance.

[0131] After two die-cast parts are brazed by gas protection at 595 °C, the weld seam is firm and reliable, without bubble inclusions, proving that the aluminum alloy material prepared in this example has excellent brazing performance.

[0132] After 3600 h of neutral salt spray corrosion, no obvious galvanic corrosion in the weld area is found, proving that the aluminum alloy material prepared in this example has excellent corrosion resistance.

[0133] Example 8

[0134] The difference between Example 8 and Example 6 is that no nano-particles are added during the preparation of the raw materials.

[0135] When the blank is demolded from the blank-making crucible and poured into the pressure chamber of the die-casting machine, the melt is filled completely, without voids and unfilled regions, and the quality of the die-cast part is excellent, but the strength of the die-cast part is slightly lower than that of Example 6, proving that the aluminum alloy material prepared in this example has excellent die-casting performance.

[0136] After gas shielded brazing two die-castings at 595 °C, the weld seam is relatively firm and there are no bubble inclusions, proving that the aluminum alloy material prepared in this example has excellent brazability.

[0137] After 3600 h of neutral salt spray corrosion, no obvious galvanic corrosion in the weld area is found, proving that the aluminum alloy material prepared in this example has excellent corrosion resistance.

[0138] Comparative Example 1

[0139] The difference between Comparative Example 1 and Example 1 is that 1.5% of Al in the Al-rare earth master alloy is replaced by 1.5% of Mn, so that the Mn content in the prepared aluminum alloy material is 4.5%.

[0140] When the blank is demolded from the billet crucible and poured into the injection chamber of the die-casting machine, the melt fluidity is poor and it fails to fully fill the mold cavity, and the forming quality of the die-casting is low, proving that the aluminum alloy material prepared in this comparative example has poor die-castability.

[0141] After cutting off the unfilled area in the die-casting by wire cutting, and then gas shielded brazing two die-castings at 585 °C, the weld seam is firm and reliable and there are no bubble inclusions, proving that the aluminum alloy material prepared in this comparative example has excellent brazability.

[0142] After 3600 h of neutral salt spray corrosion, galvanic corrosion is found in the weld area, proving that the aluminum alloy material prepared in this comparative example has poor corrosion resistance.

[0143] Comparative Example 2

[0144] The difference between Comparative Example 2 and Example 1 is that 2% of Al in the Al-rare earth master alloy is replaced by 2% of Si, so that the Si content in the prepared aluminum alloy material is 4%.

[0145] When the blank is demolded from the billet crucible and poured into the injection chamber of the die-casting machine, the melt fills the mold cavity completely without cavities and unfilled areas, and the forming quality of the die-casting is excellent, proving that the aluminum alloy material prepared in this comparative example has excellent die-castability.

[0146] After gas shielded brazing two die-castings at 585 °C, dissolution of the base metal into the filler metal area occurs, proving that the aluminum alloy material prepared in this comparative example has poor brazability.

[0147] After 3600 h of neutral salt spray corrosion, no obvious galvanic corrosion in the weld area is found, proving that the aluminum alloy material prepared in this comparative example has excellent corrosion resistance.

[0148] Comparative Example 3

[0149] The difference between Comparative Example 3 and Example 1 is that 2% of Al in the Al-rare earth master alloy is replaced by 2% of Fe, so that the Fe content in the prepared aluminum alloy material is 3.8%.

[0150] When the blank is demolded from the blank-making crucible and poured into the pressure chamber of the die-casting machine, the melt has poor fluidity and fails to completely fill the mold, resulting in a low forming quality of the die-cast part, proving that the aluminum alloy material obtained in this comparative example has poor die-casting performance.

[0151] After two die-cast parts are brazed by gas protection at 585 °C, the weld is firm and reliable without bubble inclusions, proving that the aluminum alloy material obtained in this comparative example has excellent brazing performance.

[0152] After 3600 h of neutral salt spray corrosion, obvious galvanic corrosion is found in the weld area, proving that the aluminum alloy material obtained in this comparative example has poor corrosion resistance.

[0153] Comparative Example 4

[0154] The difference between Comparative Example 4 and Example 1 is that 5.5% of Al in the aluminum-rare earth master alloy is replaced by 5.5% of Cr, so that the Cr content in the obtained aluminum alloy material is 6.5%.

[0155] When the blank is demolded from the blank-making crucible and poured into the pressure chamber of the die-casting machine, the melt has poor fluidity and fails to completely fill the mold, resulting in a low forming quality of the die-cast part, proving that the aluminum alloy material obtained in this comparative example has poor die-casting performance.

[0156] After two die-cast parts are brazed by gas protection at 585 °C, the weld is firm and reliable without bubble inclusions, proving that the aluminum alloy material obtained in this comparative example has excellent brazing performance.

[0157] After 3600 h of neutral salt spray corrosion, obvious galvanic corrosion is found in the weld area, proving that the aluminum alloy material obtained in this comparative example has poor corrosion resistance.

[0158] Comparative Example 5

[0159] The difference between Comparative Example 5 and Example 1 is that 1.5% of Al in the aluminum-rare earth master alloy is replaced by 1.5% of Ti, so that the total content of Ti and Zr in the obtained aluminum alloy material is 2.5%.

[0160] When the blank is demolded from the blank-making crucible and poured into the pressure chamber of the die-casting machine, the melt has poor fluidity and fails to completely fill the mold, resulting in a low forming quality of the die-cast part, proving that the aluminum alloy material obtained in this comparative example has poor die-casting performance.

[0161] After two die-cast parts are brazed by gas protection at 585 °C, the weld is firm and reliable without bubble inclusions, proving that the aluminum alloy material obtained in this comparative example has excellent brazing performance.

[0162] After 3600 h of neutral salt spray corrosion, no obvious galvanic corrosion is found in the weld area, proving that the aluminum alloy material obtained in this comparative example has excellent corrosion resistance.

[0163] Comparative Example 6

[0164] The difference between Comparative Example 6 and Example 1 is that Zr was not added.

[0165] When the blank was demolded from the billet crucible and poured into the pressure chamber of the die-casting machine, the melt was filled completely, without voids and unfilled regions. The quality of the die-cast parts was excellent, but the strength of the die-cast parts decreased compared with Example 1, which proved that the aluminum alloy material obtained in this comparative example had excellent die-casting performance.

[0166] After two die-cast parts were brazed by gas protection at 585°C, the weld was firm and reliable, without bubble inclusions, which proved that the aluminum alloy material obtained in this comparative example had excellent brazing performance.

[0167] After 3600 h of neutral salt spray corrosion, obvious galvanic corrosion and intergranular corrosion were found in the weld zone, which proved that the aluminum alloy material obtained in this comparative example had poor corrosion resistance.

[0168] Comparative Example 7

[0169] The difference between Comparative Example 7 and Example 1 is that in the remaining aluminum-rare earth master alloy, only 4% of La by the total weight of the raw materials was contained.

[0170] When the blank was demolded from the billet crucible and poured into the pressure chamber of the die-casting machine, the melt was filled completely, without voids and unfilled regions. The quality of the die-cast parts was excellent, which proved that the aluminum alloy material obtained in this comparative example had excellent die-casting performance.

[0171] After two die-cast parts were brazed by gas protection at 585°C, the base metal in the welding area dissolved into the filler metal area, which proved that the aluminum alloy material obtained in this comparative example had poor brazing performance.

[0172] After 3600 h of neutral salt spray corrosion, obvious galvanic corrosion in the weld zone was not found, which proved that the aluminum alloy material obtained in this comparative example had excellent corrosion resistance.

[0173] Comparative Example 8

[0174] The difference between Comparative Example 8 and Example 1 is that in the aluminum-rare earth master alloy, 4% of Y by the total weight of the raw materials was also contained.

[0175] When the blank was demolded from the billet crucible and poured into the pressure chamber of the die-casting machine, the fluidity of the melt was poor and it could not be filled completely. The quality of the die-cast parts was low, which proved that the aluminum alloy material obtained in this comparative example had poor die-casting performance.

[0176] After two die-cast parts were brazed by gas protection at 585°C, the weld was firm and reliable, without bubble inclusions, which proved that the aluminum alloy material obtained in this comparative example had excellent brazing performance.

[0177] After 3600 h of neutral salt spray corrosion, obvious galvanic corrosion and intergranular corrosion were found in the weld area, proving that the aluminum alloy material prepared by this comparative example has poor corrosion resistance.

[0178] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0179] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. An aluminum alloy material, characterized in that: The aluminum alloy material includes Mn, Si, Fe, Cr, a first component, rare earth and Al, wherein the first component includes at least one of Ti, B, Zr, V and Be; Taking the total mass of the aluminum alloy material as 100%, Mn≤4%, Si≤3%, Fe≤3.5%, Cr≤6%, the mass fraction of the first component is 1%-2%, and the mass fraction of the rare earth is 7%-12%.

2. The aluminum alloy material according to claim 1, characterized in that: The mass ratio of Mn to Fe is (2-3.8):1; And / or, the mass ratio of Mn to Si is (1.5-4):

1.

3. The aluminum alloy material according to claim 1, characterized in that: In the first component, at least one element is within 1% of the total mass of the aluminum alloy material.

4. The aluminum alloy material according to claim 1, characterized in that: The rare earth includes at least one of La, Ce, Y, and Sc, and satisfies at least one of the following conditions: (1) The mass ratio of Ce to La is 1:1-2:1; (2) La is 3% to 9% of the total mass of the aluminum alloy material; (3) Ce is 3%-9% of the total mass of the aluminum alloy material; (4) Y is within 3% of the total mass of the aluminum alloy material; (5) Sc is within 3% of the total mass of the aluminum alloy material.

5. The aluminum alloy material according to claim 1, characterized in that: The aluminum alloy material further includes at least one of Cu, Ni, and Zn, and satisfies at least one of the following conditions: (1) Cu is within 1% of the total mass of the aluminum alloy material; (2) Ni is within 3% of the total mass of the aluminum alloy material; (3) Zn is within 3% of the total mass of the aluminum alloy material.

6. The aluminum alloy material according to claim 1, characterized in that: The aluminum alloy material further includes a second component, and the second component satisfies at least one of the following conditions: (1) The second component is within 0.6% of the total mass of the aluminum alloy material; (2) The second component includes at least one of Ga, Sn, and Pb; (3) At least one element in the second component is within 0.2% of the total mass of the aluminum alloy material.

7. The aluminum alloy material according to any one of claims 1 to 6, characterized in that: The aluminum alloy material further includes nanoparticles, and the nanoparticles meet at least one of the following conditions: (1) The average particle size of the nanoparticles is 5nm-40nm; (2) The nanoparticles include at least one of TiC, TiB2, Al2O3, SiC, and TiO2; (3) At least one nanoparticle accounts for 1% to 3% of the total mass of the aluminum alloy material.

8. A method for preparing the aluminum alloy material according to any one of claims 1 to 7, characterized in that: The steps include: Step 1: Under a protective atmosphere, the aluminum rare earth master alloy and the metal elements of Mn, Si, Fe, Cr and the first component are mixed and refined in proportion to obtain an alloy melt; Step 2: subjecting the alloy melt to ultrasonic treatment, cooling it through eccentric rotation treatment, and then die-casting it to obtain an aluminum alloy material.

9. The method for preparing the aluminum alloy material according to claim 8, characterized in that: The step 1 satisfies at least one of the following conditions: (1) Before refining, boron nitride, aluminum oxide and magnesium oxide are mixed with a solvent to form an aqueous emulsion, and the aqueous emulsion is coated on the surface of the refining tool and kept warm to complete the surface treatment; (2) during the refining, further comprising adding nanoparticles; (3) During the refining, after the mixture is melted, porous ceramic particles are added and electromagnetic stirring is performed; (4) before obtaining the alloy melt, a refining agent is added, wherein the refining agent is 0.5% to 1% of the total mass of the mixture; (5) The refining temperature is 700℃-790℃.

10. The method for preparing the aluminum alloy material according to claim 8 or 9, characterized in that: The step 2 satisfies at least one of the following conditions: (1) The power of the ultrasonic treatment is 1kW-2kW; (2) When porous ceramic particles are added during refining, the alloy melt is filtered after ultrasonic treatment and before eccentric rotation treatment to separate the porous ceramic particles; (3) The rotation speed of the eccentric rotation treatment is 50 rpm-150 rpm, and the temperature is reduced to 640°C-690°C.