A low-melting-point aluminum-copper master alloy, its preparation method and its uses

Abstract

This invention discloses a low-melting-point aluminum-copper master alloy, its preparation method, and its applications. The raw material composition of the low-melting-point aluminum-copper master alloy includes: copper 48-62%, magnesium 0.2-0.5%, manganese 0.2-0.4%, boron 0.5-0.8%, nickel 0.01-0.2%, cerium 0.1-0.3%, antimony 0.01-0.2%, gallium 0.01-0.2%, unavoidable impurities <1.2%, and the balance being aluminum; the aforementioned percentages are by mass. This low-melting-point aluminum-copper master alloy exhibits good toughness, reducing or avoiding losses such as breakage and damage during packaging and transportation; it has uniform and fine grains, a low melting point, good diffusivity and easy absorption, and good alloying properties, simplifying the preparation of aluminum-copper alloys, saving energy consumption, and significantly improving the corrosion resistance and toughness of aluminum-copper alloys.

Description

Technical Field

[0001] This invention relates to a low-melting-point aluminum-copper master alloy, its preparation method and its uses, belonging to the field of aluminum alloy technology. Background Technology

[0002] Aluminum alloy is a metallic material made by alloying aluminum with other metallic or non-metallic elements. Due to its advantages such as lightweight, corrosion resistance, and plasticity, it is widely used in industrial and civilian fields such as aviation, aerospace, automobiles, construction, and home appliances.

[0003] Aluminum-copper alloys are aluminum alloys with copper as the main alloying element. They are heat-treatable aluminum alloys with high strength, high hardness, light weight, and good heat resistance. They are commonly used in secondary load-bearing components in electronics, transportation, machinery, aerospace, weaponry, aircraft, automobiles, and marine engines. For example, they can be used to manufacture engine cylinder heads, gearbox housings, turbocharger pump bodies, brake reducers, transmission valves, charging valves, wheel hubs, pistons, guide vanes, discs, pulleys, bearings, rivets, bolts, and screws. They have been widely used in aviation, aerospace, high-speed rail, automobiles, and weaponry.

[0004] In recent years, as engine cylinder heads, pump bodies, reducers and other components have developed towards high speed, heavy load, lightweight and multi-purpose, higher requirements have been placed on the mechanical properties of cast aluminum-copper alloys.

[0005] In the manufacturing and application of aluminum-copper alloys, elongation is a crucial material parameter because it measures the alloy's ability to deform under stress. Adding certain elements to aluminum alloys can improve their strength and hardness, but it also affects their elongation. High corrosion resistance is also a long-standing goal for aluminum-copper alloys.

[0006] Master alloys are special alloys made by alloying certain elemental substances to facilitate their addition to other alloys, thus solving problems such as burn-off and the difficulty in melting high-melting-point alloys, while having minimal impact on raw materials. In the preparation of aluminum-copper alloys, directly adding elemental copper results in poor diffusion, high required temperatures, easy burn-off, and porosity, affecting the degree of alloying and consequently the quality of the aluminum-copper alloy product. Therefore, copper is often added in the form of aluminum-copper master alloys during the preparation of aluminum-copper alloys. However, existing aluminum-copper master alloys, such as Aluminum-Copper 50 and Aluminum-Copper 60, have high copper content, are brittle, and are highly susceptible to breakage and damage during packaging and transportation. Summary of the Invention

[0007] This invention provides a low-melting-point aluminum-copper master alloy, its preparation method, and its applications. It lowers the melting point of the aluminum-copper master alloy, improves its toughness, and solves the problems of brittleness and high transportation loss in aluminum-copper master alloys. At the same time, it can promote the improvement of the strength, toughness, and corrosion resistance of aluminum-copper alloys.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0009] A low-melting-point aluminum-copper master alloy comprises the following raw material components: 48-62% copper, 0.2-0.5% magnesium, 0.2-0.4% manganese, 0.5-0.8% boron, 0.01-0.2% nickel, 0.1-0.3% cerium, 0.01-0.2% antimony, 0.01-0.2% gallium, unavoidable impurities <1.2%, and the balance being aluminum; the aforementioned % are mass percentages.

[0010] The aforementioned low-melting-point aluminum-copper master alloy has a low melting temperature; it is uniform and fine-grained with no component segregation, and its fracture surface is dense and free of slag; it has good toughness and is not easily broken during production, packaging, and transportation.

[0011] The above-mentioned combination of manganese and boron with nickel, cerium, antimony, and gallium lowers the melting temperature while improving toughness, overcoming the problems of fragility and breakage during the transportation of aluminum-copper master alloys. It also reduces energy consumption in the alloy preparation process and promotes improvements in the alloy's strength, toughness, and corrosion resistance.

[0012] During preparation, in order to ensure the quality of the aluminum-copper master alloy while facilitating preparation, the manganese was added in the form of potassium permanganate; the boron was added in the form of potassium fluoroborate; and the nickel was added in the form of nickel chloride.

[0013] The preparation method of the above-mentioned low-melting-point aluminum-copper master alloy includes the following steps:

[0014] 1) Add scrap copper (such as electrolytic copper plate) to the crucible of the medium-frequency furnace and preheat the temperature to 760-800℃;

[0015] 2) Add molten aluminum at a temperature of 760-800℃, add metallic cerium, blow argon gas and stir to raise the temperature to 950-1000℃, add nickel chloride, and stir for 8-15 minutes;

[0016] 3) Cool the mixture to 700–750°C, then add magnesium, potassium fluoroborate, and antimony in sequence. Stir with argon gas for 5–8 minutes. Cool the mixture to 650–700°C, then add potassium permanganate and gallium. Stir with argon gas for 1–3 minutes. Finally, heat the mixture to 700–750°C and stir to remove gas for 10–15 minutes.

[0017] 4) Let stand at 700-750℃ for 3-5 minutes, add slag remover, remove slag and skim off the residue;

[0018] 5) Preheat the runner and mold to 100-250℃, start casting, cool, demold, and obtain a low melting point aluminum-copper master alloy.

[0019] In step 1) above, before adding material, ensure that the slag on the inner wall of the induction furnace crucible is completely cleaned and that the furnace is operating in good condition. Cut the scrap copper into pieces with a particle size of less than 8 cm. The scrap copper can be electrolytic copper plates, etc.

[0020] In step 2) above, using molten aluminum can reduce the remelting of aluminum ingots; of course, melting aluminum ingots is also an option.

[0021] In step 4) above, a sodium-free slag remover is used, preferably perlite, with a dosage of 1.5-3 kg / ton of molten aluminum.

[0022] Before preheating in step 5 above, apply a release agent to the mold and apply talc or boron nitride to the flow channel.

[0023] The aforementioned low-melting-point aluminum-copper master alloy can be used to prepare aluminum-copper alloys, thereby reducing the addition temperature, decreasing burn-off, improving dispersibility, and ensuring the degree of alloying. At the same time, it significantly improves the corrosion resistance and toughness of aluminum-copper alloys.

[0024] When preparing aluminum-copper alloys using the low-melting-point aluminum-copper master alloy of this application, a one-step preparation method can be used. Specifically, the low-melting-point aluminum-copper master alloy is added to molten aluminum at a temperature of 680-700℃, stirred with argon gas for 30-40 minutes, slag is removed, the mixture is allowed to stand for 10-15 minutes, poured, and cooled to obtain the aluminum-copper alloy.

[0025] Any techniques not mentioned in this invention are based on existing technologies.

[0026] This invention relates to a low-melting-point aluminum-copper master alloy with good toughness, reducing or avoiding losses such as breakage and damage during packaging and transportation; it has uniform and fine particles, a low melting point, good diffusivity and easy absorption, and good alloying properties, simplifying the preparation of aluminum-copper alloys, saving energy consumption, and at the same time significantly improving the corrosion resistance and toughness of aluminum-copper alloys. Attached Figure Description

[0027] Figure 1 The low-melting-point aluminum-copper master alloy obtained in Example 1 of this invention;

[0028] Figure 2 The image shows the metallographic structure of the low-melting-point aluminum-copper master alloy obtained in Example 1 of this invention.

[0029] Figure 3 This is the low-melting-point aluminum-copper master alloy obtained in Comparative Example 1 of the present invention.

[0030] Figure 4 The image shows the metallographic diagram of the low-melting-point aluminum-copper master alloy obtained in Comparative Example 1 of this invention.

[0031] Figure 5 The image shows the metallographic diagram of the low-melting-point aluminum-copper master alloy obtained in Comparative Example 2 of this invention.

[0032] Figure 6 The image shows the metallographic diagram of the low-melting-point aluminum-copper master alloy obtained in Comparative Example 3 of this invention. Detailed Implementation

[0033] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0034] Example 1

[0035] Production of aluminum-copper 50:

[0036] A low-melting-point aluminum-copper master alloy comprises the following raw material components: 50% copper, 0.3% magnesium, 0.3% manganese, 0.5% boron, 0.1% nickel, 0.2% cerium, 0.1% antimony, 0.1% gallium, unavoidable impurities <1.2%, and the balance being aluminum.

[0037] The preparation method of the above-mentioned low-melting-point aluminum-copper master alloy includes the following steps:

[0038] 1) Add scrap copper (electrolytic copper plate, cut into blocks with a particle size of less than 8 cm and a copper content of 99.95% or more) to the crucible of the medium frequency furnace and preheat the temperature to 790-800℃;

[0039] 2) Add molten aluminum (aluminum content above 99.70%) at a temperature of 790-800℃, add metallic cerium, stir with argon gas and heat to 980-990℃, add nickel chloride and stir for 10 minutes;

[0040] 3) Cool down to 700-710℃, add magnesium metal (purity ≥99.95%), potassium fluoroborate and antimony metal in sequence, stir with argon gas for 6 minutes, then cool down to 650-660℃ and add potassium permanganate and gallium metal, stir with argon gas for 2 minutes, then heat up to 700-710℃ and stir to remove gas for 10 minutes.

[0041] 4) Let stand at 700~710℃ for 5 minutes, add slag remover (sodium-free aluminum alloy slag remover HS-1A, grade 1, gray powder, particle size <20 mesh, manufacturer: Baimaotong, dosage 2kg / ton of molten aluminum), remove slag and skim off the slag.

[0042] 5) Preheat the casting bath and mold to 210-220℃, begin casting, cool, and demold to obtain a low-melting-point aluminum-copper master alloy ingot (waffle ingot). The actual product looks like... Figure 1 As shown.

[0043] The aluminum-copper master alloy obtained in this example has a clear, fine, dense, and uniform fracture structure, free of slag and compositional segregation, indicating good alloying. A single waffle ingot weighs 7.5 kg, and its surface is free of oil and inclusions. Figure 2It can be seen that the AlCu alloy has a uniform metallographic distribution, with no pores or inclusions.

[0044] After receiving the waffle ingots, they underwent stacking, weighing, transfer, cooling, packaging, labeling, and forklift transfer without any breakage or damage to the surface.

[0045] Example 2

[0046] Producing aluminum-copper 60:

[0047] A low-melting-point aluminum-copper master alloy comprises the following raw material components: 60% copper, 0.3% magnesium, 0.3% manganese, 0.5% boron, 0.1% nickel, 0.2% cerium, 0.1% antimony, 0.1% gallium, unavoidable impurities <1.2%, and the balance being aluminum.

[0048] In this example, the preparation of the low-melting-point aluminum-copper master alloy is as described in Example 1. The aluminum-copper master alloy obtained in this example has a clear, fine, dense, and uniform fracture structure, free of slag and component segregation, and good alloying. The weight of a single waffle ingot is 7.5 kg, and the surface is free of oil stains and inclusions. The internal microstructure has no obvious pores or slag inclusions.

[0049] Comparative Example 1

[0050] An aluminum-copper master alloy, the raw material composition of which includes: 50% copper, 0.3% magnesium, 0.3% manganese, 0.5% boron, 0.1% nickel, 0.2% cerium, unavoidable impurities <1.2%, and the balance being aluminum.

[0051] The preparation method of the aluminum-copper master alloy in this example differs from that in Example 1, except that antimony and gallium are not added in step 3). The specific process is as follows:

[0052] The preparation method of the above-mentioned aluminum-copper master alloy includes the following steps:

[0053] 1) Add scrap copper (electrolytic copper plate, cut into blocks with a particle size of less than 8 cm and a copper content of 99.95% or more) to the crucible of the medium frequency furnace and preheat the temperature to 790-800℃;

[0054] 2) Add molten aluminum (aluminum content above 99.70%) at a temperature of 790-800℃, add metallic cerium, stir with argon gas and heat to 980-990℃, add nickel chloride and stir for 10 minutes;

[0055] 3) Cool down to 700-710℃, add metallic magnesium and potassium fluoroborate in sequence, stir with argon gas for 6 minutes, then cool down to 650-660℃ and add potassium permanganate, stir with argon gas for 2 minutes, then heat up to 700-710℃ and stir to remove gas for 10 minutes.

[0056] 4) Let stand at 700~710℃ for 5 minutes, add slag remover (sodium-free aluminum alloy slag remover HS-1A, grade 1, gray powder, particle size <20 mesh, manufacturer: Baimaotong, dosage 2kg / ton of molten aluminum), remove slag and skim off the slag.

[0057] 5) Preheat the casting bath and mold to 210-220℃, begin casting, cool, and demold to obtain a low-melting-point aluminum-copper master alloy ingot (waffle ingot). The actual product looks like... Figure 3 As shown, it is brittle and easily broken. Compared to the product obtained in Example 1, it is significantly rougher, with poorer uniformity of the fracture surface and a small amount of slag. Figure 4 It can be seen that there are a few pores and inclusions.

[0058] Comparative Example 2

[0059] An aluminum-copper master alloy, the raw material composition of which includes: 50% copper, 0.3% magnesium, 0.3% manganese, 0.5% boron, 0.1% nickel, unavoidable impurities <1.2%, and the balance being aluminum.

[0060] The preparation method is the same as Comparative Example 1, except that metallic cerium was not added in step 2). The specific process is as follows:

[0061] The preparation method of the above-mentioned aluminum-copper master alloy includes the following steps:

[0062] 1) Add scrap copper (electrolytic copper plate, cut into blocks with a particle size of less than 8 cm and a copper content of 99.95% or more) to the crucible of the medium frequency furnace and preheat the temperature to 790-800℃;

[0063] 2) Add molten aluminum (aluminum content above 99.70%) at a temperature of 790-800℃, stir with argon gas to raise the temperature to 980-990℃, add nickel chloride, and stir for 10 minutes;

[0064] 3) Cool down to 700-710℃, add metallic magnesium and potassium fluoroborate in sequence, stir with argon gas for 6 minutes, then cool down to 650-660℃ and add potassium permanganate, stir with argon gas for 2 minutes, then heat up to 700-710℃ and stir to remove gas for 10 minutes.

[0065] 4) Let stand at 700~710℃ for 5 minutes, add slag remover (sodium-free aluminum alloy slag remover HS-1A, grade 1, gray powder, particle size <20 mesh, manufacturer: Baimaotong, dosage 2kg / ton of molten aluminum), remove slag and skim off the slag.

[0066] 5) Preheat the casting bath and mold to 210-220℃, begin casting, cool, and demold to obtain a low-melting-point aluminum-copper master alloy ingot (waffle ingot), which is brittle and easily broken. Figure 5 It can be seen that, compared with Comparative Example 1, the pores and inclusions are significantly larger and coarser.

[0067] Comparative Example 3

[0068] A low-melting-point aluminum-copper master alloy, the raw material composition of which includes: 50% copper, 0.3% magnesium, 0.3% manganese, 0.5% boron, unavoidable impurities <1.2%, and the balance being aluminum.

[0069] The preparation method is the same as Comparative Example 2, except that nickel chloride was not added in step 2). The specific process is as follows:

[0070] The preparation method of the above-mentioned aluminum-copper master alloy includes the following steps:

[0071] 1) Add scrap copper (electrolytic copper plate, cut into blocks with a particle size of less than 8 cm and a copper content of 99.95% or more) to the crucible of the medium frequency furnace and preheat the temperature to 790-800℃;

[0072] 2) Add molten aluminum (aluminum content above 99.70%) at a temperature of 790-800℃, stir with argon gas to raise the temperature to 980-990℃, and stir for 10 minutes;

[0073] 3) Cool down to 700-710℃, add metallic magnesium and potassium fluoroborate in sequence, stir with argon gas for 6 minutes, then cool down to 650-660℃ and add potassium permanganate, stir with argon gas for 2 minutes, then heat up to 700-710℃ and stir to remove gas for 10 minutes.

[0074] 4) Let stand at 700~710℃ for 5 minutes, add slag remover (sodium-free aluminum alloy slag remover HS-1A, grade 1, gray powder, particle size <20 mesh, manufacturer: Baimaotong, dosage 2kg / ton of molten aluminum), remove slag and skim off the slag.

[0075] 5) Preheat the casting bath and mold to 210-220℃, begin casting, cool, and demold to obtain a low-melting-point aluminum-copper master alloy ingot (waffle ingot), which is brittle and easily broken. Figure 6 It can be seen that, compared with Comparative Example 2, the pores and inclusions are further enlarged and coarsened.

[0076] As shown above, the combination of nickel, cerium, antimony, gallium, manganese, and boron can significantly promote the alloying, refinement, homogenization, and purification of the metallographic structure. The waffle ingots obtained in Comparative Examples 1-3 all exhibited varying degrees of fracture and chipping during operation. The inventors evaluated the elongation after fracture and melting temperature of each example, and the results are shown in Table 1.

[0077] Table 1. Performance of the aluminum-copper master alloys obtained in each example.

[0078] Example 1 6.6 545 Example 2 6.7 551 Comparative Example 1 2.3 580 Comparative Example 2 3.2 589 Comparative Example 3 4.1 591

[0079] As can be seen from Table 1, the elongation of the improved aluminum-copper master alloy in this application has been significantly improved, which facilitates operation and transportation, reduces losses during operation and transportation, and does not affect the use of the aluminum-copper master alloy; in addition, the melting temperature of this application has been significantly reduced, which facilitates diffusion and absorption, improves alloy quality, and can reduce energy consumption and save costs.

[0080] Application examples

[0081] Preparation of aluminum-copper alloy (5% copper content):

[0082] The low-melting-point aluminum-copper master alloys obtained in each example were added to molten aluminum (aluminum content above 99.70%) at a temperature of 680-690℃, stirred with argon gas for 35 minutes, slag was removed, the mixture was allowed to stand for 10 minutes, poured, and cooled to obtain the aluminum-copper alloy. The performance evaluation is shown in Table 2.

[0083] Table 2 Performance Evaluation Table of Aluminum-Copper Alloys Prepared Using Intermediate Alloys in Each Example

[0084] Example 1 632 14.9 0.1365 excellent Comparative Example 1 576 12.3 0.1978 good Comparative Example 2 543 13.8 0.1836 good Comparative Example 3 552 12.1 0.2072 good

[0085] Corrosion weight loss rate test method: After polishing, the sample was subjected to neutral salt spray etching with a 5% (wt) NaCl solution for 5 days. The weight-loss sample after etching was then cleaned with 5 wt% HNO3 for 10 minutes, and the corrosion weight loss rate was calculated. The uniformity of the alloys obtained in each example was compared. Overall, the uniformity of all examples was acceptable, but Example 1 was the best, exhibiting uniformity, fineness, absence of impurities and porosity, and the highest degree of alloying.

Claims

1. The use of a low-melting-point aluminum-copper master alloy, characterized in that: The raw material composition of the low-melting-point aluminum-copper master alloy includes: copper 48~62%, magnesium 0.2~0.5%, manganese 0.2~0.4%, boron 0.5~0.8%, nickel 0.01~0.2%, cerium 0.1~0.3%, antimony 0.01~0.2%, gallium 0.01~0.2%, unavoidable impurities <1.2%, and the balance being aluminum; the aforementioned percentages are by mass. The preparation method of low-melting-point aluminum-copper master alloy includes the following steps: 1) Add copper to the crucible of the medium-frequency furnace and preheat the temperature to 760~800℃; 2) Add molten aluminum at a temperature of 760~800℃, add metallic cerium, blow argon gas and stir to raise the temperature to 950~1000℃, add nickel chloride, and stir for 8~15 minutes; 3) Cool down to 700~750℃, add metallic magnesium, potassium fluoroborate and metallic antimony in sequence, stir with argon gas for 5~8 minutes, then cool down to 650~700℃ and add potassium permanganate and gallium, stir with argon gas for 1~3 minutes, then heat up to 700~750℃ and stir to remove gas for 10~15 minutes. 4) Let stand at 700~750℃ for 3~5 minutes, add slag remover, remove slag and skim off the residue; 5) Preheat the runner and mold to 100-250℃, start casting, cool, demold, and obtain a low melting point aluminum-copper master alloy. Low-melting-point aluminum-copper master alloys are used to prepare aluminum-copper alloys.

2. The use as described in claim 1, characterized in that: In step 4), the slag remover is perlite, and the dosage is 1.5-3 kg / ton of molten aluminum.

3. The use as described in claim 1 or 2, characterized in that: Step 5) Before preheating, apply a release agent to the mold and apply talc or boron nitride to the flow channel.

4. The use as described in claim 1 or 2, characterized in that: The preparation method of aluminum-copper alloy is as follows: add low melting point aluminum-copper master alloy to molten aluminum at a temperature of 680~700℃, stir with argon gas for 30~40 minutes, remove slag, let stand for 10-15 minutes, cast, and cool to obtain aluminum-copper alloy.

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