Aluminum alloy and preparation method thereof

Abstract

The present invention discloses an aluminum alloy, which is made of the following raw materials in percentage by weight: 6.5-8.5wt% silicon, 0.2-0.4wt% manganese, 0.35-0.85wt% iron, 17.5-21.5wt% zinc, 0.02-0.12wt% titanium, 0.02-0.12wt% chromium, 4.5-5.5wt% Cu-V-La-Ce-Al alloy, and the total mass percentage of other unspecified impurity elements does not exceed 0.15%, with aluminum as the balance. The aluminum alloy has high thermal conductivity, high silicon and zinc content, high fluidity and high strength. The present invention also discloses a preparation method of the aluminum alloy.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum alloys, and specifically relates to an aluminum alloy and a preparation method thereof, in particular to a die-cast aluminum alloy with high thermal conductivity and high strength and a preparation method thereof. Background Art

[0002] With the development of manufacturing technology, many products involve the problems of aluminum alloy strength and thermal conductivity, especially electronic products and electric vehicles. Electronic components, especially CPU, thyristor, and high-power output devices, have a direct impact on the working condition of the terminal product. The performance of the radiator is directly related to the raw materials used to manufacture the radiator. Raw materials with high thermal conductivity are the basis for manufacturing high-performance radiators.

[0003] Traditional cooling methods fall into two main categories: active cooling, which adds a fan or water flow to the radiator to accelerate heat removal; and passive cooling, which relies solely on a metal radiator. The effectiveness of passive cooling depends on the thermal conductivity of the radiator material. Active cooling has certain drawbacks. It requires power and drive, and noise is unavoidable. Failure of the attached fan or other water or oil transport systems can lead to a sharp drop in cooling performance, potentially damaging electronic components. Passive cooling offers stable performance, a simple structure, and is silent. Therefore, passive cooling will be the mainstream cooling method for future electronic products.

[0004] Aluminum is the most abundant metal on Earth and the most cost-effective metal for industrial radiators. Pure aluminum has a thermal conductivity of λ = 237 W / m·K. Pure aluminum is not suitable for product manufacturing; manufactured products are aluminum alloys.

[0005] The addition of other elements significantly reduces the thermal conductivity of aluminum alloys, especially die-cast aluminum alloys. Among die-cast aluminum alloys, the aluminum-silicon-copper series is the most widely used in the manufacturing industry. Chinese grades YL110 and YL113 aluminum alloys, Japanese grades ADC10 and ADC12 aluminum alloys, and American grades 360 and 380 aluminum alloys are all of the same type of die-cast aluminum alloy, yet their thermal conductivity is around 96W / m·K. The thermal conductivity of aluminum-magnesium series such as YL302 (Chinese grade), 518 (American grade), and ADC6 (Japanese grade) is only half that of pure aluminum.

[0006] Therefore, the present invention aims at the thermal conductivity of die-cast aluminum alloys, especially high-silicon and high-zinc cast aluminum alloys used in the high-pressure casting process of metal molds, starting from the basic materials, and exploring a high thermal conductivity aluminum alloy with good strength, good fluidity and suitable for the die-casting process. Summary of the Invention

[0007] The object of the present invention is to provide an aluminum alloy having high thermal conductivity, high silicon and zinc contents, high fluidity and high strength.

[0008] Another object of the present invention is to provide a method for preparing the above-mentioned aluminum alloy.

[0009] The above-mentioned first object of the present invention can be achieved by the following technical solution: an aluminum alloy, which is made of the following raw materials in the following mass percentages: 6.5-8.5wt% silicon, 0.2-0.4wt% manganese, 0.35-0.85wt% iron, 17.5-21.5wt% zinc, 0.02-0.12wt% titanium, 0.02-0.12wt% chromium, 4.5-5.5wt% Cu-V-La-Ce-Al alloy, the total mass percentage of other unspecified impurity elements does not exceed 0.15%, and aluminum is the balance.

[0010] As a preferred embodiment of the present invention, the aluminum alloy of the present invention is made of raw materials with the following mass percentages: 7.50wt% silicon, 0.30wt% manganese, 0.50wt% iron, 19.5wt% zinc, 0.05wt% titanium, 0.05wt% chromium, 5.42wt% Cu-V-La-Ce-Al alloy, and the total mass percentage of other unspecified impurity elements does not exceed 0.15%, with aluminum as the balance.

[0011] Optionally, in the aluminum alloy of the present invention, the mass percentages of Cu, V, and La-Ce mixed rare earth meet the following relationship: copper 2.0-3.0wt%, vanadium 0.005-0.02wt%, and lanthanum-cerium mixed rare earth 0.18-0.22wt%.

[0012] More preferably, in the aluminum alloy of the present invention, the mass percentages of Cu, V, and La-Ce mixed rare earth meet the following relationship: copper 2.5wt%, vanadium 0.01wt%, and lanthanum-cerium mixed rare earth 0.20wt%.

[0013] Optionally, the three components of copper, vanadium, lanthanum-cerium mixed rare earth in the above components must be mixed with a certain amount of aluminum. The Cu-V-La-Ce-Al alloy of the present invention is made of Cu a V b (La x Ce y ) c Al dChemical formula, wherein the mass percentage contents of Cu, V, La-Ce mixed rare earth, and Al, as well as the mass percentage contents of La and Ce in the La-Ce mixed rare earth, meet the following conditions: 1). a:b:c = 46:0.2:3.8, 2). a + b + c = d, 3). x + y = 1, and 0 < x < 1, 0 < y < 1, where a, b, c, and d respectively refer to the mass percentage contents of Cu, V, La-Ce mixed rare earth, and Al in the Cu-V-La-Ce-Al alloy, and x, y refer to the mass percentage contents of La and Ce in the La-Ce mixed rare earth.

[0014] Preferably, in the Cu-V-La-Ce-Al alloy, according to Cu a V b (La x Ce y ) c Al d Chemical formula, wherein the mass percentage contents of Cu, V, La-Ce mixed rare earth, and Al, as well as the mass percentage contents of La and Ce in the La-Ce mixed rare earth, meet the following conditions: 1). a:b:c = 46:0.2:3.8, 2). a + b + c = d, 3). x = 0.65, y = 0.35.

[0015] Optionally, the silicon in the present invention is from an aluminum-silicon master alloy, the manganese is from an aluminum-manganese master alloy, the iron is from an aluminum-iron master alloy, the zinc is from industrial zinc ingots, the titanium is from an aluminum-titanium master alloy, and the chromium is from an aluminum-chromium master alloy.

[0016] Optionally, the Cu-V-La-Ce-Al alloy of the present invention is obtained by the following method: Weigh each raw material of copper, vanadium, La-Ce mixed rare earth, and aluminum according to mass percentages, place each raw material in a vacuum arc melting furnace, adjust the vacuum degree to 5×10 -3 Pa, fill with the protective gas argon, the argon pressure is 0.05 MPa, adjust the current to 90 - 120 A, the melting temperature to 1900 °C - 1950 °C, cool the alloy with the furnace after melting, and take out the alloy after cooling and crush it to obtain.

[0017] In the present invention, the Cu-V-La-Ce-Al alloy is first melted, and then the Cu-V-La-Ce-Al alloy is added in the form of an additive when melting the aluminum alloy of the present invention.

[0018] Optionally, the tensile strength of the aluminum alloy is 410 - 514 MPa, the yield strength is 321 - 364 MPa, the elongation is 3.31 - 3.92%, and the thermal conductivity is 198 - 219 W / m·K.

[0019] The second object of the present invention can be achieved by the following technical solution: The preparation method of the aluminum alloy comprises the following steps:

[0020] (S1) preparing a Cu-V-La-Ce-Al alloy;

[0021] (S2) According to the above-mentioned relationship in terms of amount, the aluminum raw material, silicon raw material, manganese raw material, iron raw material, titanium raw material, and chromium raw material are stacked in a crucible furnace, and the temperature is raised to 710-750° C. After fully melting, the Cu-V-La-Ce-Al alloy and zinc raw material are added, and after complete melting, stirring, slagging, and refining are performed, and the smelting is completed to obtain the product.

[0022] More preferably, step (S2) is: according to the above-mentioned dosage relationship, pure aluminum ingots and aluminum-silicon master alloy, aluminum-manganese master alloy, aluminum-iron master alloy, aluminum-titanium master alloy, and aluminum-chromium master alloy are stacked in a crucible furnace, heated to 710-750°C, and after fully melting, Cu-V-La-Ce-Al alloy and zinc ingot are added, and after complete melting, stirring, slagging and refining are carried out, and the smelting is completed.

[0023] As a preferred embodiment of the present invention, the aluminum alloy smelting of the present invention must be carried out in two steps, as follows:

[0024] Step 1: Prepare Cu-V-La-Ce-Al alloy. According to the chemical formula Cu a V b (La x Ce y ) c Al d and conditions, weighing each component by weight percentage (wt%), placing it in a vacuum arc melting furnace for high-temperature melting at 1900° C., cooling it after melting, and crushing it at room temperature to be used as a smelting addition for the aluminum alloy of the present invention;

[0025] Step 2: Melting the aluminum alloy of the present invention. According to the weight percentage (wt%) of the components of the aluminum alloy of the present invention, weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, and aluminum-chromium master alloy are stacked in a crucible furnace, heated to 730°C, and fully melted. Cu-V-La-Ce-Al alloy and zinc ingot are added. After complete melting, stirring, slagging, and refining are performed. After smelting is completed, the aluminum alloy melt can be cast into ingots and transferred to storage, or directly used for die-casting production.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] (1) In the present invention, the weight percentage of copper, vanadium, lanthanum, cerium and aluminum is the sum of the weight percentages of these four components. a V b (Lax Ce y ) c Al d The chemical expressions and requirements are combined, and a Cu-V-La-Ce-Al alloy is obtained by high-temperature smelting at 1900° C., and then added when smelting the aluminum alloy of the present invention;

[0028] (2) The present invention uses Cu-V-La-Ce-Al alloy as an additive in smelting high-silicon and high-zinc aluminum alloys, which can effectively improve the thermal conductivity of the aluminum alloy;

[0029] (3) The addition of Cu-V-La-Ce-Al alloy in the present invention can more effectively refine the alloy structure and improve the performance of aluminum alloy, especially the aluminum alloy is prone to thermal cracking due to rapid cooling during the metal die casting process, and can significantly reduce the viscosity of aluminum liquid and improve the fluidity of aluminum liquid;

[0030] (4) The Cu-V-La-Ce-Al alloy in the present invention is not only a good additive in the smelting of aluminum-based alloys with a silicon content of 6.5 to 8.5 wt% and a zinc content of 17.5 to 21.5 wt% in the present invention, but is also a good additive in the smelting of aluminum-based alloys with a silicon content of, for example, 4.0 to 17.0 wt% and a zinc content of 3.0 to 30.0 wt%, and can effectively improve the properties of the alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the metallographic diagram of sample 1# in Example 1;

[0032] Figure 2 This is the metallographic diagram of the sample in Example 6. DETAILED DESCRIPTION

[0033] The composition of the high-silicon and high-zinc aluminum alloy in the prior art is shown in Table 1.

[0034] Table 1 High silicon high zinc aluminum alloy formula in the prior art

[0035]

[0036]

[0037] Notes to Table 1: 1. The chemical compositions in the above table are expressed in weight percentages (wt.%). 2. The aluminum alloy data and parameters for the application numbers in the above table are obtained from the website of the State Intellectual Property Office.

[0038] The properties of the high-silicon and high-zinc aluminum alloys in the prior art are shown in Table 2.

[0039] Table 2 Properties of high silicon and high zinc aluminum alloys in the prior art

[0040]

[0041] Notes to Table 2: 1. The data in the above table (except thermal conductivity / analysis data) are obtained from the website of the State Intellectual Property Office. 2. The thermal conductivity / analysis data in the above table are based on analysis of samples produced using patented technology.

[0042] The high-silicon and high-zinc aluminum alloys in existing technologies have the characteristics of high strength performance, but their thermal conductivity is generally low, which makes it difficult to meet the new era manufacturing industry's requirements for multiple performance of basic materials.

[0043] The die-cast aluminum alloys familiar to people in the industry also include high-silicon and high-zinc aluminum alloys. Many people use the addition of a certain amount of lanthanum-cerium mixed rare earth to refine the microstructure of the castings, which also helps to improve the mechanical properties, but has little effect on thermal conductivity.

[0044] The key technology of the present invention is to use Cu, V, La, Ce and Al with the sum of the mass percentage of Cu+V+La+Ce to form a Cu-V-La-Ce-Al alloy through high temperature smelting at 1900°C, and then add the alloy when smelting the aluminum alloy of the present invention. This can more effectively refine the metallographic structure of the aluminum alloy, improve the mechanical properties of the aluminum alloy, and significantly improve the thermal conductivity.

[0045] Thermal conductivity of solid materials is the conduction of energy through media such as electrons, phonons, and photons. In metal materials, free electrons are the main heat energy conduction medium. The thermal conductivity of metal materials mainly consists of two parts: electronic thermal conductivity and phonon thermal conductivity.

[0046] The thermal conductivity of metal materials is closely related to the material's organizational composition and microstructure. Defects and impurities, grain size, and second phases all affect thermal conductivity.

[0047] There are many factors that affect the thermal conductivity of aluminum alloys. The thermal conductivity of aluminum alloys is closely related to the organizational composition and microstructure of the material. Defects and impurities, grain size, second phases, etc. all affect the thermal conductivity. The composition ratio of aluminum alloys, melting temperature, modification treatment, heat treatment method, etc. all have an impact, and different processes and parameters have different effects.

[0048] Die-cast aluminum alloys have a high silicon content because silicon as a small plane phase in the α (Al) matrix tends to grow into a plate-like shape along the (111) crystal plane. This plate-like structure has a strong scattering effect on moving electrons and a large resistance to electron transmission, thereby reducing electrical conductivity and thermal conductivity.

[0049] The aluminum alloy die-casting process is to melt the aluminum alloy to 650-720℃ aluminum liquid, and then quickly send the aluminum liquid into the metal mold cavity through the die-casting machine. It is filled with high pressure, cooled with the mold, and solidified into shape. The demolding temperature of aluminum alloy parts is generally 250-350℃. Most of the aluminum alloy products after demolding are subjected to natural aging treatment.

[0050] Lanthanum-cerium mischmetal elements exist in aluminum alloys primarily in three forms: 1. solid solution in the α(Al) matrix; 2. segregation at phase boundaries, grain boundaries, and dendrite boundaries; and 3. solid solution in or as compounds. The strengthening effects of lanthanum-cerium mischmetal elements in aluminum alloys primarily include grain refinement, limited solid solution strengthening, and secondary phase strengthening of rare earth compounds.

[0051] Vanadium forms VAl in aluminum alloy 11 As a refractory compound, vanadium plays a role in refining grains during the melting and casting process. Vanadium also has the effect of refining the recrystallized structure and increasing the recrystallization temperature.

[0052] The melting point of vanadium is 1890℃. It is fully interfused with copper, lanthanum-cerium mixed rare earth and aluminum at 1900-1950℃, and the active performance of lanthanum-cerium mixed rare earth reaches the extreme. The formed Cu-V-La-Ce-Al alloy effectively modifies the lamellar structure in the aluminum alloy, transforming it into fine fibers, weakening scattering and reducing electron transmission resistance, thereby improving electrical and thermal conductivity.

[0053] On the other hand, the lanthanum-cerium mixed rare earth refines the grains and increases the grain boundaries of the alloy. The grain boundaries, as a surface defect, hinder the movement of heat-conducting electrons and reduce the thermal conductivity of the alloy to a certain extent. The appropriate amount of Cu-V-La-Ce-Al alloy can effectively control the grain size and make its thermal conductivity reach the optimal value.

[0054] During the natural aging process of high-silicon and high-zinc aluminum alloy die castings, the Cu-V-La-Ce-Al alloy stabilizes the internal structure of the alloy and maintains good thermal conductivity.

[0055] One of the characteristics of the present invention is that the three components of copper, vanadium, lanthanum and cerium mixed rare earth are combined with aluminum of the total mass percentage of the four components. a V b (La x Ce y ) c Al d The chemical expressions and requirements are combined, and a Cu-V-La-Ce-Al alloy is obtained by high-temperature smelting at 1900° C., and then added when smelting the aluminum alloy of the present invention.

[0056] The second feature of the present invention is the addition method of using Cu-V-La-Ce-Al alloy as a smelting high-silicon high-zinc aluminum alloy to effectively improve the thermal conductivity of the high-zinc aluminum alloy.

[0057] The third feature of the present invention is that the addition of Cu-Va-Ce-A1 alloy can more effectively improve the cracking phenomenon of high-zinc aluminum alloy during the metal mold die-casting process due to rapid cooling, reduce the viscosity of the aluminum liquid, and improve the fluidity of the aluminum alloy liquid.

[0058] The fourth feature of the present invention is that the Cu-V-La-Ce-Al alloy is not only a good additive in the smelting of aluminum-based alloys with a silicon content of 6.5 to 8.5 wt% and a zinc content of 17.5 to 21.5 wt% in the present invention, but is also a good additive in the smelting of aluminum-based alloys with a silicon content of, for example, 4.0 to 17.0 wt% and a zinc content of 3.0 to 30.0 wt%, thereby effectively improving the properties of the alloy.

[0059] After searching the prior art and reviewing the standards and patents on die-cast aluminum alloys in Europe, the United States and Japan, no similar melting methods and addition methods were found. Therefore, the present invention will not conflict with existing global aluminum alloy patents.

[0060] The aluminum alloy of the present invention boasts a thermal conductivity, λ, of up to 219 W / m·K, surpassing the performance of many high-impurity aluminum-based alloys. This performance is more than double the thermal conductivity of well-known die-cast aluminum alloys, such as YL112, 380.0, and ADC12, and approaches the thermal conductivity, λ, of pure aluminum, at 237 W / m·K. Furthermore, the aluminum alloy of the present invention exhibits excellent mechanical properties, including a tensile strength of ≥410 MPa, a yield strength of ≥321 MPa, and an elongation of ≥3.0%.

[0061] The aluminum alloy of the present invention is allowed to contain: 6.5-8.5wt% silicon, 0.2-0.4wt% manganese, 0.35-0.85wt% iron, 17.5-21.5wt% zinc, 0.02-0.12wt% titanium, 0.02-0.12wt% chromium, 4.5-5.5wt% Cu-V-La-Ce-Al alloy, and the total wt% of other unspecified impurity elements is ≤0.15%, with aluminum as the balance.

[0062] In the aluminum alloy of the present invention, the allowable mass percentage of copper is about 2.0-3.0 wt%, the mass percentage of vanadium is about 0.005-0.02 wt%, and the mass percentage of lanthanum-cerium mixed rare earth is about 0.18-0.22 wt%.

[0063] More preferably, in the aluminum alloy of the present invention, the mass percentage of copper is about 2.5 wt%, the mass percentage of vanadium is about 0.01 wt%, and the mass percentage of lanthanum-cerium mixed rare earth is about 0.2 wt%.

[0064] In order to make the technology of the present invention concrete, the following experiments are used to prove it, and the embodiments of the experiments are used to verify the technology of the present invention.

[0065] Cu-V-La-Ce-Al alloy smelting of embodiment:

[0066] According to the step 1 of the smelting method described in the present invention, a Cu-V-La-Ce-Al alloy is prepared as follows: a V b (La x Ce y ) c Al d Chemical expressions and requirements are as shown in Table 3. Weigh each element by mass percentage, and select La for rare earth. 65 Ce 35 (The mass percentage of La is 65%, the mass percentage of Ce is 35%) mixed rare earth.

[0067] Table 3 Mass percentage of each raw material in Cu-V-La-Ce-Al alloy

[0068] Element copper vanadium Lanthanum-cerium mixed rare earth aluminum wt% 46 0.2 3.8 50

[0069] The weighed copper, vanadium, lanthanum, cerium mixed rare earth and aluminum were placed in a vacuum arc melting furnace and the vacuum degree was adjusted to 5×10 -3 Pa, fill with protective gas argon, argon pressure is 0.05MPa, adjust the current to 90-120A, smelting temperature to 1900-1950℃, cool with the furnace after smelting. After cooling, take out the alloy, crush it, and use it as the smelting addition for the aluminum alloy of the present invention.

[0070] Example 1

[0071] According to step 2 of the smelting method described in the present invention, the aluminum alloy described in the present invention is smelted, and the components are weighed as shown in Table 4.

[0072] Table 4 Relationship between raw materials and dosage of die-cast aluminum alloy in Example 1

[0073] Element silicon iron manganese zinc titanium chromium Cu-V-La-Ce-Al alloy aluminum wt% 7.5 0.5 0.3 19.5 0.05 0.03 5.42 margin

[0074] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, and aluminum-chromium master alloy are stacked in a crucible furnace and heated to 730°C. After fully melting, Cu-V-La-Ce-Al alloy and zinc ingots are added. After complete melting, stirring, slagging, and refining are performed. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine and numbered 1#. The metallographic image of sample 1# is shown in FIG. Figure 1 shown.

[0075] Example 2

[0076] According to step 2 of the smelting method described in the present invention, the aluminum alloy described in the present invention is smelted, and the components are weighed as shown in Table 5.

[0077] Table 5 Relationship between raw materials and dosage of die-cast aluminum alloy in Example 2

[0078] Element silicon iron manganese zinc titanium chromium Cu-V-La-Ce-Al alloy aluminum wt% 8.5 0.5 0.3 21.5 0.03 0.05 5.0 margin

[0079] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, and aluminum-chromium master alloy are stacked in a crucible furnace, heated to 730°C, and fully melted. Then, Cu-V-La-Ce-Al alloy and zinc ingot are added. After complete melting, stirring, slagging, and refining are performed. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine, which is numbered 2#.

[0080] Example 3

[0081] According to step 2 of the smelting method described in the present invention, the aluminum alloy described in the present invention is smelted, and the components are weighed as shown in Table 6.

[0082] Table 6 Relationship between raw materials and dosage of die-cast aluminum alloy in Example 3

[0083] Element silicon iron manganese zinc titanium chromium Cu-V-La-Ce-Al alloy aluminum wt% 6.5 0.6 0.3 21.5 0.03 0.08 5.0 margin

[0084] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, and aluminum-chromium master alloy are stacked in a crucible furnace, heated to 730°C, and fully melted. Cu-V-La-Ce-Al alloy and zinc ingots are then added. After complete melting, stirring, slagging, and refining are performed. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine, numbered 3#.

[0085] Example 4

[0086] According to step 2 of the smelting method described in the present invention, the aluminum alloy described in the present invention is smelted, and the components are weighed as shown in Table 7.

[0087] Table 7 Relationship between raw materials and dosage of die-cast aluminum alloy in Example 4

[0088] Element silicon iron manganese zinc titanium chromium Cu-V-La-Ce-Al alloy aluminum wt% 8.5 0.6 0.3 17.5 0.10 0.02 4.5 margin

[0089] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, and aluminum-chromium master alloy are stacked in a crucible furnace, heated to 730°C, and fully melted. Then, Cu-V-La-Ce-Al alloy and zinc ingot are added. After complete melting, stirring, slagging, and refining are performed. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine, which is numbered 4#.

[0090] Example 5

[0091] According to step 2 of the smelting method described in the present invention, the aluminum alloy described in the present invention is smelted, and the components are weighed as shown in Table 8.

[0092] Table 8 Relationship between raw materials and dosage of die-cast aluminum alloy in Example 5

[0093] Element silicon iron manganese zinc titanium chromium Cu-V-La-Ce-Al alloy aluminum wt% 6.5 0.7 0.3 17.5 0.02 0.05 5.5 margin

[0094] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, and aluminum-chromium master alloy are stacked in a crucible furnace, heated to 730°C, and fully melted. Then, Cu-V-La-Ce-Al alloy and zinc ingot are added. After complete melting, stirring, slagging, and refining are performed. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine, which is numbered 5#.

[0095] Example 6

[0096] According to step 2 of the smelting method described in the present invention, the aluminum alloy described in the present invention is smelted, and the components are weighed as shown in Table 9.

[0097] Table 9 Relationship between raw materials and dosage of die-cast aluminum alloy in Example 5

[0098] Element silicon iron manganese zinc titanium chromium Cu-V-La-Ce-Al alloy aluminum wt% 7.5 0.5 0.3 21.5 0.04 0.06 5.5 margin

[0099] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, and aluminum-chromium master alloy are stacked in a crucible furnace and heated to 730°C. After fully melting, Cu-V-La-Ce-Al alloy and zinc ingots are added. After complete melting, stirring, slagging, and refining are performed. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine, numbered 6#. The metallographic image of sample 6# is shown in FIG. Figure 2 shown.

[0100] The experimental examples are to verify the technology of the present invention, while the comparative examples are to illustrate the technology of the present invention. In the comparative examples, Cu, V, and La-Ce mixed rare earth are added directly or as an intermediate alloy to the aluminum alloy.

[0101] Comparative Example 1

[0102] The weight percentages of the components of the aluminum alloy described in the present invention are shown in Table 10.

[0103] Table 10 Relationship between raw materials and dosage of die-cast aluminum alloy in comparative example 1

[0104] Element silicon iron manganese zinc titanium chromium copper vanadium Lanthanum-cerium mixed rare earth aluminum wt% 7.5 0.5 0.3 19.5 0.05 0.03 2.5 0.01 0.20 margin

[0105] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, aluminum-chromium master alloy, aluminum-copper master alloy, aluminum-vanadium master alloy and aluminum-lanthanum-cerium mixed rare earth master alloy are stacked in a crucible furnace, heated to 730°C, and fully melted. Then, a zinc ingot is added. After complete melting, stirring, slagging and refining are carried out. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine, which is numbered 01#.

[0106] Comparative Example 2

[0107] The weight percentages of the components of the aluminum alloy described in the present invention are shown in Table 11.

[0108] Table 11 Relationship between raw materials and dosage of die-cast aluminum alloy in comparative example 2

[0109] Element silicon iron manganese zinc titanium chromium copper vanadium Lanthanum-cerium mixed rare earth aluminum wt% 8.5 0.5 0.3 21.5 0.03 0.05 2.3 0.01 0.19 margin

[0110] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, aluminum-chromium master alloy, aluminum-copper master alloy, aluminum-vanadium master alloy and aluminum-lanthanum-cerium mixed rare earth master alloy are stacked in a crucible furnace, heated to 730°C, and fully melted. Then, a zinc ingot is added. After complete melting, stirring, slagging and refining are carried out. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine, which is numbered 02#.

[0111] Comparative Example 3

[0112] The weight percentages of the components of the aluminum alloy described in the present invention are shown in Table 12.

[0113] Table 12 Relationship between raw materials and dosage of die-cast aluminum alloy in comparative example 3

[0114] Element silicon iron manganese zinc titanium chromium copper vanadium Lanthanum-cerium mixed rare earth aluminum wt% 6.5 0.6 0.3 21.5 0.03 0.08 2.3 0.01 0.19 margin

[0115] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, aluminum-chromium master alloy, aluminum-copper master alloy, aluminum-vanadium master alloy and aluminum-lanthanum-cerium mixed rare earth master alloy are stacked in a crucible furnace, heated to 730°C, and fully melted. Then, a zinc ingot is added. After complete melting, stirring, slagging and refining are carried out. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine, which is numbered 03#.

[0116] Comparative Example 4

[0117] The weight percentages of the components of the aluminum alloy described in the present invention are shown in Table 13.

[0118] Table 13 Relationship between raw materials and dosage of die-cast aluminum alloy in comparative example 4

[0119] Element silicon iron manganese zinc titanium chromium copper vanadium Lanthanum-cerium mixed rare earth aluminum wt% 8.5 0.6 0.3 17.5 0.10 0.02 2.07 0.009 0.171 margin

[0120] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, aluminum-chromium master alloy, aluminum-copper master alloy, aluminum-vanadium master alloy and aluminum-lanthanum-cerium mixed rare earth master alloy are stacked in a crucible furnace, heated to 730°C, and fully melted. Then, a zinc ingot is added. After complete melting, stirring, slagging and refining are carried out. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine, which is numbered 04#.

[0121] Comparative Example 5

[0122] The weight percentages of the components of the aluminum alloy described in the present invention are shown in Table 14.

[0123] Table 14 Relationship between raw materials and dosage of die-cast aluminum alloy in comparative example 5

[0124] Element silicon iron manganese zinc titanium chromium copper vanadium Lanthanum-cerium mixed rare earth aluminum wt% 6.5 0.7 0.3 17.5 0.02 0.05 2.53 0.011 0.209 margin

[0125] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, aluminum-chromium master alloy, aluminum-copper master alloy, aluminum-vanadium master alloy and aluminum-lanthanum-cerium mixed rare earth master alloy are stacked in a crucible furnace, heated to 730°C, and fully melted. Then, a zinc ingot is added. After complete melting, stirring, slagging and refining are carried out. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine, which is numbered 05#.

[0126] Comparative Example 6

[0127] The weight percentages of the components of the aluminum alloy described in the present invention are shown in Table 15.

[0128] Table 15 Relationship between raw materials and dosage of die-cast aluminum alloy in comparative example 6

[0129] Element silicon iron manganese zinc titanium chromium copper vanadium Lanthanum-cerium mixed rare earth aluminum wt% 7.5 0.5 0.3 21.5 0.04 0.06 2.53 0.011 0.209 margin

[0130] The weighed pure aluminum ingots and aluminum-silicon master alloy, aluminum-iron master alloy, aluminum-manganese master alloy, aluminum-titanium master alloy, aluminum-chromium master alloy, aluminum-copper master alloy, aluminum-vanadium master alloy and aluminum-lanthanum-cerium mixed rare earth master alloy are stacked in a crucible furnace, heated to 750°C, and fully melted. Then, a zinc ingot is added. After complete melting, stirring, slagging and refining are carried out. After smelting is completed, the aluminum alloy ingot of the present invention is obtained by die casting using a die casting machine, numbered 06#.

[0131] The die-cast aluminum blocks No. 1#, No. 2#, No. 3#, No. 4#, No. 5#, and No. 6 of the embodiment were taken respectively, and the tensile strength, yield strength, and elongation were tested according to the national standard "GB / T 228.1-2010 Tensile Tests on Metal Materials Part 1: Room Temperature Test Method". The test data are shown in Table 16.

[0132] The die-cast aluminum blocks No. 1#, No. 2#, No. 3#, No. 4#, No. 5#, and No. 6 of the embodiment were respectively taken and thermal conductivity analysis was performed according to the national standard "GB / T 22588-2008 Flash Method for Measurement of Thermal Diffusivity or Thermal Conductivity". The data obtained by the analysis are shown in Table 16.

[0133] Table 16 Performance parameters of the die-cast aluminum alloys prepared in Examples 1-6

[0134]

[0135] The die-cast aluminum blocks No. 01#, No. 02#, No. 03#, No. 04#, No. 05#, and No. 06# of the comparative example were respectively taken and the tensile strength, yield strength, and elongation were tested according to the national standard "GB / T 228.1-2010 Tensile Tests on Metallic Materials Part 1: Room Temperature Test Methods". The test data are shown in Table 17.

[0136] The die-cast aluminum blocks No. 01#, No. 02#, No. 03#, No. 04#, No. 05#, and No. 06# of the comparative example were respectively taken and thermal conductivity analysis was performed according to the national standard "GB / T 22588-2008 Flash Method for Measurement of Thermal Diffusivity or Thermal Conductivity". The data obtained by the analysis are shown in Table 17.

[0137] Table 17 Performance parameters of the die-cast aluminum alloys prepared in Comparative Examples 1-6

[0138]

[0139]

[0140] As can be seen from the above examples, the aluminum alloy of the present invention adopts the method of preparing Cu-V-La-Ce-Al alloy in step 1 and smelting the aluminum alloy of the present invention in step 2, which can effectively refine the alloy structure (such as Figure 1 、 Figure 2 ), can obtain excellent mechanical properties and high thermal conductivity, and significantly reduce the viscosity of aluminum liquid, improve the fluidity of aluminum alloy, improve the high temperature strength performance of aluminum alloy, and help improve the quality of aluminum alloy die castings.

[0141] From the comparative example of the experiment, it can be seen that the effect of adding Cu, V, La-Ce mixed rare earth independently to aluminum alloy melting is far inferior to that of adding Cu-V-La-Ce-Al alloy to aluminum alloy melting.

[0142] In summary, the aluminum alloy of the present invention is not only novel and progressive, but also has industrial applicability, which is the significance of the invention.

[0143] The description of the embodiments of the present invention is only an explanation of the technology. Any modifications and changes based on the technology of the present invention should still be included in the scope of this patent application.

[0144] While some specific embodiments have been cited above to illustrate the present invention, it is important to note that the above specific embodiments are intended only to further illustrate the present invention and are not intended to limit the scope of protection of the present invention. Any non-essential modifications and adjustments made by others based on the present invention remain within the scope of protection of the present invention.

Claims

1. An aluminum alloy characterized by The aluminum alloy is made of the following raw materials in percentage by weight: 6.5-8.5% silicon, 0.2-0.4% manganese, 0.35-0.85% iron, 17.5-21.5% zinc, 0.02-0.12% titanium, 0.02-0.12% chromium, 4.5-5.5% Cu-V-La-Ce-Al alloy, the total mass percentage of other unspecified impurity elements does not exceed 0.15%, and aluminum is the balance; In the aluminum alloy, the mass percentages of Cu, V, and La-Ce mixed rare earth meet the following relationship: copper 2.5wt%, vanadium 0.01wt%, and lanthanum-cerium mixed rare earth 0.2wt%; The Cu-V-La-Ce-Al alloy is a V b (La x Ce y ) c Al d Chemical expression, where the mass percentages of Cu, V, La-Ce mixed rare earth, and Al, as well as the mass percentages of La and Ce in the La-Ce mixed rare earth, meet the following conditions: 1) a:b:c = 46:0.2:3.8, 2) a+b+c = d, 3) x = 0.65, y = 0.35; The Cu-V-La-Ce-Al alloy is prepared by the following method: weighing raw materials of copper, vanadium, La-Ce mixed rare earth and aluminum according to mass percentage, placing the raw materials in a vacuum arc melting furnace, and adjusting the vacuum degree to 5×10 -3 Pa, fill with protective gas argon, the argon pressure is 0.05MPa, adjust the current to 90~120A, the melting temperature to 1900℃~1950℃, cool with the furnace after melting, take out the alloy after cooling, and crush it.

2. The aluminum alloy according to claim 1, characterized in that The aluminum alloy is made of raw materials with the following mass percentages: 7.50% silicon, 0.30% manganese, 0.50% iron, 21.5% zinc, 0.04% titanium, 0.06% chromium, 5.42% Cu-V-La-Ce-Al alloy, the total mass percentage of other unspecified impurity elements does not exceed 0.15%, and aluminum is the balance.

3. The aluminum alloy according to claim 1, wherein: The silicon comes from an aluminum-silicon master alloy, the manganese comes from an aluminum-manganese master alloy, the iron comes from an aluminum-iron master alloy, the zinc comes from an industrial zinc ingot, the titanium comes from an aluminum-titanium master alloy, and the chromium comes from an aluminum-chromium master alloy.

4. The aluminum alloy according to any one of claims 1 to 3, characterized in that: The aluminum alloy has a tensile strength of 410-514 MPa, a yield strength of 321-364 MPa, an elongation of 3.31-3.92%, and a thermal conductivity of 198-219 W / m•K.

5. The method for preparing the aluminum alloy according to claim 1 or 2, characterized in that The following steps are involved: (S1) Preparation of Cu-V-La-Ce-Al alloy; (S2) According to the above-mentioned relationship in terms of amount, aluminum raw material, silicon raw material, manganese raw material, iron raw material, titanium raw material and chromium raw material are piled in a crucible furnace, heated to 710-750°C, and fully melted. Then, Cu-V-La-Ce-Al alloy and zinc raw material are added. After complete melting, stirring, slagging and refining are performed. The smelting is completed and the product is obtained.

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