Aluminum alloy with both strength and electrical conductivity and preparation method thereof

Abstract

The present invention provides an aluminum alloy and a preparation method that take both strength and electrical conductivity into consideration, and belongs to the technical field of aluminum alloys. The components and weight percentages of the aluminum alloy are as follows: 0.1 weight % Si, 1.0-2.5 weight % Fe, 0.02-0.08 weight % Co, 1.4-2.0 weight % Ni, 1.5-6 weight % La and Ce, the weight ratio of La to Ce is 1:2, 0.2-0.35 weight % Mn, 0.15-0.2 weight % Ti, 0.08-0.12 weight % Mg, 0.2 weight % Zr, and the rest are Al and unavoidable impurity elements; the aluminum alloy is prepared by a high-pressure die-casting process. The aluminum alloy has high strength, high electrical conductivity, excellent heat resistance and corrosion resistance, can effectively solve the problem of incompatibility between electrical conductivity and mechanical properties, and adapt to more complex environments. The present invention can use more recycled aluminum, greatly reduce carbon emissions, reduce costs, and has a bright application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloys, and in particular relates to an aluminum alloy having both strength and electrical conductivity and a preparation method thereof. Background Art

[0002] In recent years, with the widespread application of aluminum alloys in the fields of automobiles, electric power transportation, etc., higher quality requirements have been put forward for aluminum alloys. High conductivity, high strength, high heat resistance and excellent corrosion resistance have become new requirements for aluminum alloys in the industry; aluminum alloys with high conductivity can improve the power transmission efficiency of parts. High heat resistance aluminum alloys can keep parts working at high temperatures and maintain good performance, increasing the service life of conductor materials.

[0003] However, the mechanical properties (tensile strength, yield strength, elongation) and electrical conductivity of aluminum alloys are contradictory and mutually restrictive, making it difficult to simultaneously obtain aluminum alloy conductor materials with high strength and high electrical conductivity. At the same time, due to poor heat resistance, existing grades of aluminum alloy conductor materials such as 1070, 8030, 6101, etc. cannot adapt to more complex environments.

[0004] Although a lot of research has been done at home and abroad on the composition, preparation methods, plastic processing methods, heat treatment systems, etc. of aluminum alloy conductor materials, how to obtain aluminum alloy conductor materials with high strength, high electrical conductivity, excellent heat resistance and corrosion resistance is still a problem that needs to be solved urgently. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide an aluminum alloy and a preparation method that take into account both strength and conductivity, so that the aluminum alloy simultaneously satisfies the following requirements at room temperature: tensile strength ≥108MPa, yield strength ≥52MPa, elongation ≥18%, and electrical conductivity ≥55%IACS, in particular, the aluminum alloy simultaneously satisfies the following requirements at room temperature: tensile strength ≥115MPa, yield strength ≥60MPa, elongation ≥20%, and electrical conductivity ≥58%IACS, so as to obtain an aluminum alloy conductor material with high strength, high electrical conductivity, excellent heat resistance and corrosion resistance.

[0006] In order to achieve the above advantages, in a first aspect, the present invention discloses an aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are:

[0007] 0.1 wt% Si, 1.0-2.5 wt% Fe, 0.02-0.08 wt% Co, 1.4-2.0 wt% Ni, 1.5-6 wt% La and Ce, the weight ratio of La to Ce is 1:2, 0.2-0.35 wt% Mn, 0.15-0.2 wt% Ti, 0.08-0.12 wt% Mg, 0.2 wt% Zr, and the rest are Al and unavoidable impurity elements;

[0008] The aluminum alloy is prepared by a high-pressure die-casting process.

[0009] As a further improvement of the present invention, the content of a single unavoidable impurity element is at most 0.05 wt%.

[0010] As a further improvement of the present invention, the aluminum alloy meets the following requirements at room temperature: tensile strength ≥ 108 MPa, yield strength ≥ 52 MPa, elongation ≥ 18%, and electrical conductivity ≥ 55% IACS.

[0011] As a further improvement of the present invention, the components and weight percentages of the aluminum alloy are:

[0012] 0.1 wt% Si, 1.6 wt% Fe, 0.02 wt% Co, 1.8 wt% Ni, 3.0 wt% La and Ce, the weight ratio of La to Ce being 1:2, 0.2 wt% Mn, 0.15 wt% Ti, 0.08 wt% Mg, 0.2 wt% Zr, and the remainder being Al and unavoidable impurity elements;

[0013] The aluminum alloy is prepared by high pressure die casting process;

[0014] The aluminum alloy meets the following requirements at room temperature: tensile strength ≥115MPa, yield strength ≥60MPa, elongation ≥20%, and electrical conductivity ≥58%IACS.

[0015] In a second aspect, the present invention discloses a method for preparing an aluminum alloy having both strength and electrical conductivity according to the first aspect of the present invention, comprising the following steps:

[0016] Step 1: using A00 aluminum ingot, AlFe20, AlMn20, AlTi5, AlZr10 master alloy, and rare earth calculated and weighed according to the components and weight percentages of the aluminum alloy as raw materials;

[0017] Step 2: gradually heating up the crucible furnace to bake out the water vapor in the furnace, and during the heating process, placing the raw materials on the side of the furnace and baking for 30 minutes;

[0018] Step 3: Put the raw materials into the furnace for melting. After the raw materials are dissolved, stir them several times to obtain aluminum liquid;

[0019] Step 4: Use a bell jar to press the pure Mg block into the aluminum liquid to fully dissolve it;

[0020] Step 5: Use a degasser to press the aluminum alloy sodium-free refining agent into the refining and degassing machine, introduce 99.999% argon gas, then remove the slag and let it stand;

[0021] Step 6: Check whether the aluminum alloy composition meets the use standard, and add corresponding raw materials for correction according to the aluminum alloy composition test results until the aluminum alloy composition reaches the preset weight percentage;

[0022] Step 7: Detect the gas content by using a hydrogen meter to ensure that the density equivalent is ≤0.2%. When the density equivalent is >0.2%, return to step 5 for refining and degassing;

[0023] Step 8: Perform high pressure die casting using a die casting machine to prepare the aluminum alloy.

[0024] As a further improvement of the present invention, the aluminum liquid temperature in step 3 is set to 720°C and the furnace temperature is set to 780°C.

[0025] As a further improvement of the present invention, the weight ratio of the aluminum alloy sodium-free refining agent in the step 5 in the aluminum liquid is 0.1%~0.2%, the components of the aluminum alloy sodium-free refining agent are NaF and NaCl, the weight ratio of the NaF and the NaCl is 1:1, and the degassing time is 15 minutes.

[0026] As a further improvement of the present invention, the process parameters of the high-pressure die-casting in step 8 are: mold cavity vacuum ≤50Mbar, injection speed 2.5±0.5m / s, mold temperature 130±10°C, and aluminum liquid temperature 680±10°C.

[0027] As a further improvement of the present invention, the die-casting machine includes a vacuum system, an oil circulation mold temperature controller, and a barrel heating device. Compared with the prior art, the present invention has the following beneficial effects:

[0028] First, by adding Zr and rare earth elements La and Ce, the material structure distribution is more uniform, the α-Al grains are finer, and the grain boundaries are more complex, which greatly increases the strength and toughness.

[0029] Second, the present invention provides an aluminum alloy that has high strength, high electrical conductivity, excellent heat resistance and corrosion resistance, which can effectively solve the problem of incompatibility between electrical conductivity and mechanical properties and adapt to more complex environments.

[0030] Third, the present invention can use more recycled aluminum, greatly reducing carbon emissions and costs, and has bright application prospects.

[0031] Fourthly, the present invention does not contain elements such as Cu and Zn, has good castability, fluidity, thermal crack resistance, and electrical conductivity, and is suitable for motor rotors and other related parts.

[0032] Fifth, the present invention strictly controls the contents of Fe, Ni, and Co to form a certain proportion of multi-phases, significantly improving the organizational morphology and phase distribution of the original alloy, and transforming the coarse needle-shaped Al3Fe phase into a fine spherical Al-(Fe, Ni)-Si phase, significantly improving the mechanical properties, while making the arrangement of the grains in the material more orderly, thereby improving the electrical conductivity of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A 500-fold metallographic structure diagram of the aluminum alloy material having both strength and conductivity properties disclosed in Example 9 of the present invention is shown. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the present invention will combine the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments, wherein step 1, step 2... in the embodiments described in the present invention do not limit the only execution steps of the present invention; the basic principles of the present invention defined in the description of the present invention can be applied to other implementation schemes, variant schemes, improved schemes, equivalent schemes and other technical schemes that do not deviate from the spirit and scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0035] The principle of the present invention is that, by adding trace amounts of rare earth La and Ce, the present invention can improve the microstructure of the aluminum alloy, make the grain boundary more stable, and penetrate into the grain boundary to avoid the phenomenon of slip and dislocation; by adding trace amounts of Zr, the stability of material performance is increased, α-Al grains are refined, and the strength and toughness of the material are further improved; the contents of Fe, Ni, and Co are strictly controlled to form a certain proportion of multi-phases, which significantly improves the microstructure and phase distribution of the original alloy, so that the coarse needle-shaped Al3Fe phase is transformed into a fine spherical Al-(Fe, Ni)-Si phase, which significantly improves the mechanical properties, and at the same time, the arrangement of grains in the material can be made more orderly, thereby improving the electrical conductivity of the material; the morphology of the iron-rich phase is regulated by Mn, and the needle-shaped β iron-rich phase is transformed into a more rounded one, thereby improving the elongation; Mg and Si are added to form a Mg2Si strengthening phase to ensure the mechanical properties of the material; no strengthening elements such as copper and zinc are added, so as to reduce the thermal cracking tendency and aging effect of the material and increase the casting performance of the material.

[0036] In a first aspect, an embodiment of the present invention discloses an aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are:

[0037] 0.1 wt% Si, 1.0-2.5 wt% Fe, 0.02-0.08 wt% Co, 1.4-2.0 wt% Ni, 1.5-6 wt% La and Ce, 0.2-0.35 wt% Mn, 0.15-0.2 wt% Ti, 0.08-0.12 wt% Mg, 0.2 wt% Zr, and the remainder is Al and unavoidable impurity elements;

[0038] The aluminum alloy is prepared by a high-pressure die-casting process.

[0039] In a preferred embodiment, the weight ratio of La to Ce is 1:2.

[0040] In a preferred embodiment, the content of a single unavoidable impurity element is at most 0.05 wt%.

[0041] In a preferred embodiment, the aluminum alloy meets the following requirements at room temperature: tensile strength ≥108 MPa, yield strength ≥52 MPa, elongation ≥18%, and electrical conductivity ≥55% IACS.

[0042] In a preferred embodiment, the components and weight percentages of the aluminum alloy are:

[0043] 0.1 wt% Si, 1.6 wt% Fe, 0.02 wt% Co, 1.8 wt% Ni, 3.0 wt% La and Ce, the weight ratio of La to Ce being 1:2, 0.2 wt% Mn, 0.15 wt% Ti, 0.08 wt% Mg, 0.2 wt% Zr, and the remainder being Al and unavoidable impurity elements;

[0044] The aluminum alloy is prepared by high pressure die casting process;

[0045] The aluminum alloy meets the following requirements at room temperature: tensile strength ≥115MPa, yield strength ≥60MPa, elongation ≥20%, and electrical conductivity ≥58%IACS.

[0046] It should be noted that any numerical value within the weight percentage range of the aluminum alloy components belongs to the protection scope of the present invention. For example, the weight percentage of Fe can be 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5; the weight percentage of Co can be 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08; the weight percentage of Ni can be 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0; when the weight ratio of La to Ce is 1:2, the weight percentages of La and Ce can be 0.5 and 1.0, 0.6 and 1.2, 0.7 and 1.4, 0. .8 and 1.6, 0.9 and 1.8, 1.0 and 2.0, 1.1 and 2.2, 1.2 and 2.4, 1.3 and 2.6, 1.4 and 2.8, 1.5 and 3.0, 1.6 and 3.2, 1.7 and 3.4, 1.8 and 3.6, 1.9 and 3.8, 2.0 and 4.0, 2.1 and 4.2, 2.2 and 4.4, 2.3 and 4.6 ; The weight % of Mn can be 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35; The weight % of Ti can be 0.15, 0.16, 0.17, 0.18, 0.19, 0.20.

[0047] In a second aspect, an embodiment of the present invention discloses a method for preparing an aluminum alloy having both strength and electrical conductivity according to the first aspect of the present invention, comprising the following steps:

[0048] Step 1: using A00 aluminum ingot, AlFe20, AlMn20, AlTi5, AlZr10 master alloy, and rare earth calculated and weighed according to the components and weight percentages of the aluminum alloy as raw materials;

[0049] Step 2: gradually heating up the crucible furnace to bake out the water vapor in the furnace, and during the heating process, placing the raw materials on the side of the furnace and baking for 30 minutes;

[0050] Step 3: Put the raw materials into the furnace for melting. After the raw materials are dissolved, stir them several times to obtain aluminum liquid;

[0051] Step 4: Use a bell jar to press the pure Mg block into the aluminum liquid to fully dissolve it;

[0052] Step 5: Use a degasser to press the aluminum alloy sodium-free refining agent into the refining and degassing machine, introduce 99.999% argon gas, then remove the slag and let it stand;

[0053] Step 6: Check whether the aluminum alloy composition meets the use standard, and add corresponding raw materials for correction according to the aluminum alloy composition test results until the aluminum alloy composition reaches the preset weight percentage;

[0054] Step 7: Detect the gas content by using a hydrogen meter to ensure that the density equivalent is ≤0.2%. When the density equivalent is >0.2%, return to step 5 for refining and degassing;

[0055] Step 8: Perform high pressure die casting using a die casting machine to prepare the aluminum alloy.

[0056] In a preferred embodiment, the aluminum liquid temperature in step 3 is set to 720°C and the furnace temperature is set to 780°C.

[0057] In a preferred embodiment, the weight ratio of the aluminum alloy sodium-free refining agent in the step 5 in the aluminum liquid is 0.1%~0.2%, the components of the aluminum alloy sodium-free refining agent are NaF and NaCl, the weight ratio of the NaF and the NaCl is 1:1, and the degassing time is 15min.

[0058] In a preferred embodiment, the process parameters of the high pressure die casting in step 8 are: mold cavity vacuum ≤ 50 Mbar, injection speed 2.5±0.5 m / s, mold temperature 130±10°C, and aluminum liquid temperature 680±10°C.

[0059] In a preferred embodiment, the die-casting machine includes a vacuum system, an oil circulation mold temperature controller, and a barrel heating device.

[0060] Example 1

[0061] An aluminum alloy having both strength and electrical conductivity, the components and weight percentages of the aluminum alloy being: 0.1 weight % Si, 1.0 weight % Fe, 0.02 weight % Co, 1.4 weight % Ni, 0.5 weight % La, 1.0 weight % Ce, 0.2 weight % Mn, 0.15 weight % Ti, 0.08 weight % Mg, 0.2 weight % Zr, and the remainder being Al and unavoidable impurity elements, wherein the content of a single unavoidable impurity element is at most 0.05 weight %.

[0062] A method for preparing the aluminum alloy of this embodiment comprises the following steps:

[0063] Step 1: A00 aluminum ingot, AlFe20, AlMn20, AlTi5, AlZr10 master alloy, and rare earth calculated and weighed according to the composition and weight percentage of the aluminum alloy in this embodiment are used as raw materials;

[0064] Step 2: gradually heating up the crucible furnace to bake out the water vapor in the furnace, and during the heating process, placing the raw materials on the side of the furnace and baking for 30 minutes;

[0065] Step 3: Put the raw materials into the furnace for melting. After the raw materials are dissolved, stir them several times to obtain molten aluminum. The temperature of the molten aluminum is set to 760°C and the furnace temperature is set to 800°C.

[0066] Step 4: Use a bell jar to press the pure Mg block into the aluminum liquid to fully dissolve it;

[0067] Step 5: Use a mobile rotary degasser to press the aluminum alloy sodium-free refining agent into the aluminum liquid for refining and degassing. The weight ratio of the aluminum alloy sodium-free refining agent in the aluminum liquid is 0.1%-0.2%. The components of the aluminum alloy sodium-free refining agent are NaF and NaCl. The weight ratio of the NaF and the NaCl is 1:1. 99.999% argon is introduced for a degassing time of 15 minutes, and then the slag is removed and allowed to stand.

[0068] Step 6: Use an electric spark direct reading spectrometer to detect whether the aluminum alloy composition meets the use standard, and add corresponding raw materials for correction according to the aluminum alloy composition test results until the aluminum alloy composition reaches a preset weight percentage;

[0069] Step 7: Detect the gas content by using a hydrogen meter to ensure that the density equivalent is ≤0.2%. When the density equivalent is >0.2%, return to step 5 for refining and degassing;

[0070] Step 8: High-pressure die-casting is performed by a LK 280T die-casting machine. The die-casting machine includes a vacuum system, an oil circulation mold temperature controller, and a barrel heating device. A bone-shaped standard test rod with a diameter of 6 mm and an effective length of 70 mm is prepared. The process parameters of high-pressure die-casting are: mold cavity vacuum ≤50Mbar, injection speed 2.5±0.5m / s, mold temperature 130±10℃, and aluminum liquid temperature 680±10℃.

[0071] Step 9: Take a test bar to test the tensile strength, yield strength, elongation and conductivity of the material.

[0072] Example 2

[0073] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.0 weight % Fe, 0.04 weight % Co, 1.6 weight % Ni, 1.0 weight % La, 2.0 weight % Ce, 0.25 weight % Mn, 0.2 weight % Ti, 0.09 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the maximum amount of a single unavoidable impurity element is 0.05 weight %.

[0074] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0075] Example 3

[0076] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.0 weight % Fe, 0.06 weight % Co, 1.8 weight % Ni, 1.5 weight % La, 3.0 weight % Ce, 0.3 weight % Mn, 0.15 weight % Ti, 0.1 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the content of a single unavoidable impurity element is at most 0.05 weight %.

[0077] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0078] Example 4

[0079] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.0 weight % Fe, 0.08 weight % Co, 2.0 weight % Ni, 2.0 weight % La, 4.0 weight % Ce, 0.35 weight % Mn, 0.2 weight % Ti, 0.12 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the maximum amount of a single unavoidable impurity element is 0.05 weight %.

[0080] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0081] Example 5

[0082] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.3 weight % Fe, 0.02 weight % Co, 1.6 weight % Ni, 2.0 weight % La, 4.0 weight % Ce, 0.2 weight % Mn, 0.15 weight % Ti, 0.08 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the maximum amount of a single unavoidable impurity element is 0.05 weight %.

[0083] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0084] Example 6

[0085] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.3 weight % Fe, 0.04 weight % Co, 1.4 weight % Ni, 1.5 weight % La, 3.0 weight % Ce, 0.25 weight % Mn, 0.2 weight % Ti, 0.09 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the maximum amount of a single unavoidable impurity element is 0.05 weight %.

[0086] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0087] Example 7

[0088] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.3 weight % Fe, 0.06 weight % Co, 2.0 weight % Ni, 1.0 weight % La, 2.0 weight % Ce, 0.3 weight % Mn, 0.15 weight % Ti, 0.1 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the content of a single unavoidable impurity element is at most 0.05 weight %.

[0089] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0090] Example 8

[0091] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.3 weight % Fe, 0.08 weight % Co, 1.8 weight % Ni, 0.5 weight % La, 1.0 weight % Ce, 0.35 weight % Mn, 0.2 weight % Ti, 0.12 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the maximum amount of a single unavoidable impurity element is 0.05 weight %.

[0092] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0093] Example 9

[0094] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.6 weight % Fe, 0.02 weight % Co, 1.8 weight % Ni, 1.0 weight % La, 2.0 weight % Ce, 0.2 weight % Mn, 0.15 weight % Ti, 0.08 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the maximum amount of a single unavoidable impurity element is 0.05 weight %.

[0095] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0096] Example 10

[0097] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.6 weight % Fe, 0.04 weight % Co, 2.0 weight % Ni, 0.5 weight % La, 1.0 weight % Ce, 0.25 weight % Mn, 0.2 weight % Ti, 0.09 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the maximum amount of a single unavoidable impurity element is 0.05 weight %.

[0098] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0099] Embodiment 11

[0100] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.6 weight % Fe, 0.06 weight % Co, 1.4 weight % Ni, 2.0 weight % La, 4.0 weight % Ce, 0.3 weight % Mn, 0.15 weight % Ti, 0.1 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the content of a single unavoidable impurity element is at most 0.05 weight %.

[0101] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0102] Example 12

[0103] An aluminum alloy having both strength and electrical conductivity, the components and weight percentages of the aluminum alloy being: 0.1 weight % Si, 1.6 weight % Fe, 0.08 weight % Co, 1.6 weight % Ni, 1.5 weight % La, 3.0 weight % Ce, 0.35 weight % Mn, 0.2 weight % Ti, 0.12 weight % Mg, 0.2 weight % Zr, and the remainder being Al and unavoidable impurity elements, wherein the content of a single unavoidable impurity element is at most 0.05 weight %.

[0104] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0105] Example 13

[0106] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.9 weight % Fe, 0.02 weight % Co, 2.0 weight % Ni, 1.5 weight % La, 3.0 weight % Ce, 0.2 weight % Mn, 0.15 weight % Ti, 0.08 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the content of a single unavoidable impurity element is at most 0.05 weight %.

[0107] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0108] Embodiment 14

[0109] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.9 weight % Fe, 0.04 weight % Co, 1.8 weight % Ni, 2.0 weight % La, 4.0 weight % Ce, 0.25 weight % Mn, 0.2 weight % Ti, 0.09 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the maximum amount of a single unavoidable impurity element is 0.05 weight %.

[0110] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0111] Embodiment 15

[0112] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.9 weight % Fe, 0.06 weight % Co, 1.6 weight % Ni, 0.5 weight % La, 1.0 weight % Ce, 0.3 weight % Mn, 0.15 weight % Ti, 0.1 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the content of a single unavoidable impurity element is at most 0.05 weight %.

[0113] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0114] Example 16

[0115] An aluminum alloy having both strength and electrical conductivity, wherein the components and weight percentages of the aluminum alloy are: 0.1 weight % Si, 1.9 weight % Fe, 0.08 weight % Co, 1.4 weight % Ni, 1.0 weight % La, 2.0 weight % Ce, 0.35 weight % Mn, 0.2 weight % Ti, 0.12 weight % Mg, 0.2 weight % Zr, and the remainder are Al and unavoidable impurity elements, wherein the maximum amount of a single unavoidable impurity element is 0.05 weight %.

[0116] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0117] Embodiment 17

[0118] An aluminum alloy having both strength and electrical conductivity, the components and weight percentages of the aluminum alloy being: 0.1 weight % Si, 2.5 weight % Fe, 0.02 weight % Co, 1.8 weight % Ni, 1.0 weight % La, 2.0 weight % Ce, 0.2 weight % Mn, 0.15 weight % Ti, 0.08 weight % Mg, 0.2 weight % Zr, and the remainder being Al and unavoidable impurity elements, wherein the content of a single unavoidable impurity element is at most 0.05 weight %.

[0119] A method for preparing the aluminum alloy of this embodiment, the steps are the same as the method for preparing the aluminum alloy of Example 1.

[0120] Comparative Example 1

[0121] An aluminum alloy, which differs from Example 9 in that it contains 0.1 wt % Fe and 0.1 wt % Ni, and the remaining components and weight percentages are the same as those of Example 9.

[0122] A method for preparing the aluminum alloy of this comparative example, the steps are the same as the method for preparing the aluminum alloy of Example 9.

[0123] Comparative Example 2

[0124] An aluminum alloy, which differs from Example 9 in that La and Ce are not added, and the remaining components and weight percentages are the same as those of Example 9.

[0125] A method for preparing the aluminum alloy of this comparative example, the steps are the same as the method for preparing the aluminum alloy of Example 9.

[0126] Comparative Example 3

[0127] An aluminum alloy, which differs from Example 9 in that it contains 0.006 weight % Mn and 0.01 weight % Zr, and the remaining components and weight percentages are the same as those of Example 9.

[0128] A method for preparing the aluminum alloy of this comparative example, the steps are the same as the method for preparing the aluminum alloy of Example 9.

[0129] For the above embodiment, the mechanical properties were measured by a Sansi tensile machine and an imported extensometer, and the tensile rate was 2 mm / s. The specimens for the tensile test were processed strictly in accordance with the proportional specimens in GB / T228.1 2010. The conductivity was measured using a conductivity meter and then converted into the international unit IACS. The test results are shown in the following table:

[0130]

[0131] It can be seen from the test results in the above table that the mechanical properties and electrical conductivity of the aluminum alloy materials in Examples 1-17 of the present invention meet the following requirements at room temperature: tensile strength ≥ 108MPa, yield strength ≥ 52MPa, elongation ≥ 18%, and electrical conductivity ≥ 55%IACS. Preferably, the mechanical properties of the aluminum alloy materials in Examples 2, 3, 4, 6, 9, 11, and 15 of the present invention can meet the following requirements at room temperature: tensile strength ≥ 115MPa, yield strength ≥ 60MPa, elongation ≥ 20%, and electrical conductivity ≥ 58%IACS. Preferably, the mechanical properties and electrical conductivity of the aluminum alloy material in Example 9 of the present invention can reach a tensile strength of 127.6MPa, a yield strength of 68.1MPa, an elongation of 20.3%, and an electrical conductivity of 62.4%IACS at room temperature. It can be seen from the test results in the above table that the aluminum alloy provided by the present invention has both high mechanical properties and high electrical conductivity, which can effectively solve the problem of incompatibility between electrical conductivity and mechanical properties.

[0132] From the test results in the above table, it can be seen that compared with Example 9, the aluminum alloy with low Fe, Ni and Co content in Comparative Example 1 has significantly poorer mechanical properties and electrical conductivity; compared with Example 9, the aluminum alloy without rare earth La and Ce added in Comparative Example 2 has significantly poorer mechanical properties, so adding rare earth La and Ce can refine the grains of the material and improve the mechanical properties of the material. Compared with Example 9, the aluminum alloy with low Mn and Zr content in Comparative Example 3 has significantly poorer mechanical properties, so Mn and Zr elements can help improve the mechanical properties of the material to a certain extent.

[0133] The present invention can improve the microstructure of the aluminum alloy by adding trace rare earth La and Ce, making the grain boundary more stable, and at the same time penetrate into the grain boundary to avoid the phenomenon of slip and dislocation; by adding trace Zr, the stability of material performance is increased, α-Al grains are refined, and the strength and toughness of the material are further improved; the Fe, Ni, and Co contents are strictly controlled to form a certain proportion of multi-phases, which significantly improves the microstructure and phase distribution of the original alloy, so that the coarse needle-shaped Al3Fe phase is transformed into a fine spherical Al-(Fe, Ni)-Si phase, which significantly improves the mechanical properties, and at the same time, the arrangement of the grains in the material can be made more orderly, thereby improving the electrical conductivity of the material; the morphology of the iron-rich phase is regulated by Mn, and the needle-shaped β iron-rich phase is transformed into a more rounded one, thereby improving the elongation; Mg and Si are added to form a Mg2Si strengthening phase to ensure the mechanical properties of the material; no strengthening elements such as copper and zinc are added, so that the hot cracking tendency and aging effect of the material are reduced, and the casting performance of the material is increased.

[0134] The aluminum alloy provided by the present invention has high strength, high electrical conductivity, excellent heat resistance and corrosion resistance, can effectively solve the problem of incompatibility between electrical conductivity and mechanical properties, and adapt to more complex environments. The present invention can use more recycled aluminum, greatly reduce carbon emissions, reduce costs, and has a bright application prospect.

Claims

1. An aluminum alloy having both strength and electrical conductivity, characterized in that: The components and weight percentages of the aluminum alloy are: 0.1 wt% Si, 1.0-2.5 wt% Fe, 0.02-0.08 wt% Co, 1.4-2.0 wt% Ni, 1.5-6 wt% La and Ce, the weight ratio of La to Ce is 1:2, 0.2-0.35 wt% Mn, 0.15-0.2 wt% Ti, 0.08-0.12 wt% Mg, 0.2 wt% Zr, and the rest are Al and unavoidable impurity elements; The aluminum alloy is prepared by a high-pressure die-casting process.

2. The aluminum alloy having both strength and electrical conductivity according to claim 1, characterized in that: The content of a single unavoidable impurity element is at most 0.05% by weight.

3. The aluminum alloy having both strength and electrical conductivity according to claim 1, characterized in that: The aluminum alloy meets the following requirements at room temperature: tensile strength ≥108MPa, yield strength ≥52MPa, elongation ≥18%, and electrical conductivity ≥55%IACS.

4. The aluminum alloy having both strength and electrical conductivity according to claim 1, characterized in that: The components and weight percentages of the aluminum alloy are: 0.1 wt% Si, 1.6 wt% Fe, 0.02 wt% Co, 1.8 wt% Ni, 3.0 wt% La and Ce, the weight ratio of La to Ce being 1:2, 0.2 wt% Mn, 0.15 wt% Ti, 0.08 wt% Mg, 0.2 wt% Zr, and the remainder being Al and unavoidable impurity elements; The aluminum alloy is prepared by high pressure die casting process; The aluminum alloy meets the following requirements at room temperature: tensile strength ≥115MPa, yield strength ≥60MPa, elongation ≥20%, and electrical conductivity ≥58%IACS.

5. A method for preparing an aluminum alloy having both strength and electrical conductivity according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step (1): using A00 aluminum ingot, AlFe20, AlMn20, AlTi5, AlZr10 master alloy and rare earth calculated and weighed according to the composition and weight percentage of the aluminum alloy as raw materials; Step (2): gradually heating up the crucible furnace to bake out the water vapor in the furnace, and during the heating process, placing the raw material on the side of the furnace and baking for 30 minutes; Step (3): putting the raw materials into a furnace for melting, and after the raw materials are dissolved, stirring them several times to obtain aluminum liquid; Step (4): press the pure Mg block into the aluminum liquid using a bell jar to fully dissolve it; Step (5): using a degasser to pressurize the aluminum alloy sodium-free refining agent for refining and degassing, introducing 99.999% argon gas, then slagging and standing; Step (6): Detecting whether the aluminum alloy composition meets the use standard, and adding corresponding raw materials for correction according to the aluminum alloy composition detection result until the aluminum alloy composition reaches a preset weight percentage; Step (7): Detect the gas content by using a hydrogen meter to ensure that the density equivalent is ≤ 0.2%. When the density equivalent is > 0.2%, return to step (5) for refining and degassing; Step (8): Perform high pressure die casting using a die casting machine to prepare the aluminum alloy.

6. The method for preparing an aluminum alloy having both strength and electrical conductivity according to claim 5, characterized in that: The aluminum liquid temperature in step (3) is set to 720°C and the furnace temperature is set to 780°C.

7. The method for preparing an aluminum alloy having both strength and electrical conductivity according to claim 5, characterized in that: The weight ratio of the aluminum alloy sodium-free refining agent in the step (5) in the aluminum liquid is 0.1%-0.2%, the components of the aluminum alloy sodium-free refining agent are NaF and NaCl, the weight ratio of the NaF and the NaCl is 1:1, and the degassing time is 15 minutes.

8. The method for preparing an aluminum alloy having both strength and electrical conductivity according to claim 5, characterized in that: The process parameters of the high pressure die casting in step (8) are: mold cavity vacuum ≤ 50 Mbar, injection speed 2.5±0.5 m / s, mold temperature 130±10°C, and aluminum liquid temperature 680±10°C.

9. The method for preparing an aluminum alloy having both strength and electrical conductivity according to claim 5, characterized in that: The die-casting machine comprises a vacuum system, an oil circulation mold temperature controller, and a barrel heating device.

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