A high-conductivity and high-strength rare earth aluminum alloy and preparation method thereof

Abstract

The present invention provides a high-conductivity and high-strength rare earth aluminum alloy and a preparation method thereof, belonging to the technical field of aluminum alloys. Wherein, the components and weight percentages of the aluminum alloy are: 0.5-0.6 weight % of Fe, 0.5-0.6 weight % of Mn, the weight ratio of Fe and Mn is 1:1, 0.15-0.35 weight % of Co, 0.2-0.5 weight % of Ni, 4.5-7.5 weight % of La and Ce, the weight ratio of La and Ce is 1:2, a single impurity element is up to 0.05 weight %, and the rest is Al. The aluminum alloy material provided by the present invention has a tensile strength of more than 145MPa, a yield strength of more than 100MPa, an elongation of more than 9%, and a conductivity of more than 58%IACS. While meeting the conductivity, the mechanical properties of the material can also be guaranteed, and it can be widely used in industries such as 5G communications.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloys, and particularly relates to a high-conductivity and high-strength rare earth aluminum alloy and a preparation method thereof. Background Art

[0002] At present, my country's 5G communications and electronic information industries are experiencing an unprecedented period of rapid development. With the continuous improvement of people's quality of life, the performance requirements for various electronic components are becoming increasingly stringent, which is not only reflected in the pursuit of component performance indicators, but also includes new challenges in material costs, energy conservation and environmental protection, and lightweight. In this context, aluminum alloys have become the preferred material for the manufacture of many components due to their low density, high specific strength, good plasticity and excellent electrical conductivity, and can meet the dual needs of high conductivity and high strength of components.

[0003] In the field of 5G communications, aluminum alloys are widely used in various key components of 5G base stations. Although traditional materials perform well in ensuring the structural strength of base stations, they are obviously insufficient in terms of electronic conductivity. In addition, their high density not only increases the difficulty of transportation, but also leads to an increase in costs. Although the conductivity of pure aluminum can reach about 63% IACS, which basically meets the conduction requirements in the communication field, its low hardness and insufficient mechanical properties make it difficult to meet the harsh conditions in practical applications.

[0004] Therefore, the development of a new type of aluminum alloy material that is lightweight, highly conductive and strong has become a key issue that needs to be urgently addressed in industries such as 5G communications and electronic information. This is of great significance for improving the overall performance of parts and optimizing substrate materials.

[0005] In view of the above background, the present invention is committed to providing an innovative high-conductivity and high-strength rare earth aluminum alloy and a preparation method thereof, aiming to overcome the limitations of existing materials and meet the industry's growing demand for high-performance, low-cost, and lightweight materials. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide a high-conductivity and high-strength rare earth aluminum alloy and a preparation method thereof, so that the tensile strength of the cast aluminum alloy is above 145MPa, the yield strength is above 100MPa, the elongation is above 9%, and the conductivity is above 58%IACS. While meeting the conductivity requirements, the mechanical properties of the material can also be guaranteed, and it can be widely used in industries such as 5G communications.

[0007] In a first aspect, the present invention discloses a high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0008] 0.5-0.6 wt% Fe, 0.5-0.6 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.15-0.35 wt% Co, 0.2-0.5 wt% Ni, 4.5-7.5 wt% La and Ce, the weight ratio of La to Ce is 1:2, a single impurity element is at most 0.05 wt%, and the rest is Al.

[0009] In a second aspect, the present invention discloses a method for preparing a high-conductivity and high-strength rare earth aluminum alloy, which is characterized by comprising the following steps:

[0010] Step 1: Prepare A00 aluminum ingot, AlFe20, AlMn10, AlCo10, AlNi10 master alloy, pure La and Ce as raw materials according to the mass percentage of the aluminum alloy;

[0011] Step 2: gradually increase the temperature in the furnace to bake out the water vapor in the furnace. During the heating process, place the A00 aluminum ingot weighed according to the proportion beside the furnace for baking and then put it into the furnace to heat and melt to obtain aluminum liquid;

[0012] Step 3: After the A00 aluminum ingot is dissolved, place AlFe20, AlMn10, AlCo10, AlNi10 master alloys, pure La and Ce on the side of the furnace for baking, then put them into the furnace, stir several times, fully dissolve, and let stand;

[0013] Step 4: Use a degasser to press the aluminum alloy refining agent into the refining machine, pass 99.999% argon gas, degas, then remove the slag and let it stand;

[0014] Step 5: Detect whether the aluminum alloy composition reaches a preset mass percentage. If so, proceed to step 6. If not, add elements that do not reach the preset mass percentage so that the elements that do not reach the preset mass percentage reach the preset mass percentage.

[0015] Step 6: Perform high pressure die casting through high pressure die casting equipment.

[0016] As a further improvement of the present invention, in step 2, the furnace side baking time of the A00 aluminum ingot is 30 minutes.

[0017] As a further improvement of the present invention, in step 2, the temperature of the aluminum liquid is set to 750°C and the temperature in the furnace is set to 780°C.

[0018] As a further improvement of the present invention, in step 3, the furnace-side baking time of the AlFe20, AlMn10, AlCo10, AlNi10 intermediate alloys, pure La and Ce is 20 minutes.

[0019] As a further improvement of the present invention, in step 3, the standing time is 30 minutes.

[0020] As a further improvement of the present invention, in step 4, the weight ratio of the aluminum alloy refining agent in the aluminum liquid is 0.1%~0.2%, the components of the aluminum alloy refining agent are NaF and NaCl, and the weight ratio of the NaF and the NaCl is 1:1.

[0021] As a further improvement of the present invention, in step 4, the degassing time is 20 minutes.

[0022] As a further improvement of the present invention, in step 6, the high-pressure die-casting equipment includes a vacuum system, an oil circulation mold temperature controller, and a barrel heating device.

[0023] As a further improvement of the present invention, in step 6, 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 alloy liquid temperature 680±10℃.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The aluminum alloy material provided by the present invention has a tensile strength of more than 145 MPa, a yield strength of more than 100 MPa, an elongation of more than 9%, and an electrical conductivity of more than 58% IACS. While satisfying the electrical conductivity, the mechanical properties of the material can also be guaranteed; further, the tensile strength can reach 173.4 MPa, the yield strength can reach 121.6 MPa, the elongation can reach 11.2%, and the electrical conductivity can reach 62.7% IACS, and the electrical conductivity and mechanical properties are further improved.

[0026] The present invention can refine the grains of the aluminum alloy material and increase the mechanical properties of the material by adding rare earth elements. The present invention controls the weight % of the rare earth elements La and Ce between 4.5 and 7.5, which can further refine the grains of the aluminum alloy material, increase the material properties, and ensure high electrical conductivity.

[0027] The present invention controls the contents of Fe and Mn to be between 0.5% and 0.6%, and the weight ratio of Fe to Mn is 1:1, which can further improve the mechanical properties and electrical conductivity of the material.

[0028] The present invention refines alloy grains and improves mechanical properties by adding 0.15% to 0.35% by weight of Co, and adjusts the arrangement order of grains while adding 0.2% to 0.5% by weight of Ni to ensure more uniform grain size and improve the electrical conductivity of the alloy while refining the grains.

[0029] The aluminum alloy of the present invention not only meets the electrical conductivity requirements but also ensures the mechanical properties of the material, and can be widely used in industries such as 5G communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a 200-fold metallographic phase diagram of the high-conductivity and high-strength rare earth aluminum alloy material disclosed in Example 10 of the present invention;

[0031] Figure 2 This is a 200-fold metallographic phase diagram of the aluminum alloy material disclosed in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0032] 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.

[0033] In a first aspect, an embodiment of the present invention discloses a high-conductivity and high-strength rare earth aluminum alloy, wherein the components and weight percentages of the aluminum alloy are:

[0034] 0.5-0.6 wt% Fe, 0.5-0.6 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.15-0.35 wt% Co, 0.2-0.5 wt% Ni, 4.5-7.5 wt% La and Ce, the weight ratio of La to Ce is 1:2, a single impurity element is at most 0.05 wt%, and the rest is Al.

[0035] In a second aspect, an embodiment of the present invention discloses a method for preparing a high-conductivity and high-strength rare earth aluminum alloy, comprising the following steps:

[0036] Step 1: Prepare A00 aluminum ingot, AlFe20, AlMn10, AlCo10, AlNi10 master alloy, pure La and Ce as raw materials according to the mass percentage of the aluminum alloy;

[0037] Step 2: gradually increase the temperature in the furnace to bake out the water vapor in the furnace. During the heating process, place the A00 aluminum ingot weighed according to the proportion beside the furnace for baking and then put it into the furnace to heat and melt to obtain aluminum liquid;

[0038] Step 3: After the A00 aluminum ingot is dissolved, place AlFe20, AlMn10, AlCo10, AlNi10 master alloys, pure La and Ce on the side of the furnace for baking, then put them into the furnace, stir several times, fully dissolve, and let stand;

[0039] Step 4: Use a degasser to press the aluminum alloy refining agent into the refining machine, pass 99.999% argon gas, degas, then remove the slag and let it stand;

[0040] Step 5: Detect whether the aluminum alloy composition reaches a preset mass percentage. If so, proceed to step 6. If not, add elements that do not reach the preset mass percentage so that the elements that do not reach the preset mass percentage reach the preset mass percentage.

[0041] Step 6: Perform high pressure die casting through high pressure die casting equipment.

[0042] Preferably, in step 2, the furnace side baking time of the A00 aluminum ingot is 30 minutes.

[0043] Preferably, in step 2, the temperature of the aluminum liquid is set to 750°C and the temperature in the furnace is set to 780°C.

[0044] Preferably, in step 3, the furnace-side baking time of AlFe20, AlMn10, AlCo10, AlNi10 master alloy, pure La and Ce is 20 minutes.

[0045] Preferably, in step 3, the standing time is 30 minutes.

[0046] Preferably, in step 4, the weight ratio of the aluminum alloy refining agent in the aluminum liquid is 0.1%-0.2%, the components of the aluminum alloy refining agent are NaF and NaCl, and the weight ratio of the NaF to the NaCl is 1:1.

[0047] Preferably, in step 4, the degassing time is 20 minutes.

[0048] Preferably, in step 6, the high-pressure die-casting equipment includes a vacuum system, an oil circulation mold temperature controller, and a barrel heating device.

[0049] Preferably, in step 6, the process parameters of high pressure die casting are: mold cavity vacuum degree ≤50Mbar, injection speed is 2.5±0.5m / s, mold temperature is 130±10°C, and aluminum alloy liquid temperature is 680±10°C.

[0050] The following are specific embodiments and comparative examples provided by the present invention:

[0051] Example 1

[0052] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0053] 1.5 wt% La, 3 wt% Ce, the weight ratio of La to Ce is 1:2, 0.5 wt% Fe, 0.5 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.15 wt% Co, 0.2 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[0054] A method for preparing the aluminum alloy of this embodiment comprises the following steps:

[0055] Step 1: Prepare A00 aluminum ingot, AlFe20, AlMn10, AlCo10, AlNi10 master alloy, pure La and Ce as raw materials according to the mass percentage of the aluminum alloy;

[0056] Step 2: Gradually heat up the furnace to bake out the water vapor in the furnace. During the heating process, place the A00 aluminum ingot weighed according to the proportion on the side of the furnace and bake for 30 minutes before putting it into the furnace to heat and melt to obtain aluminum liquid. The aluminum liquid temperature is set to 750°C and the furnace temperature is set to 780°C.

[0057] Step 3: After the A00 aluminum ingot is dissolved, place the AlFe20, AlMn10, AlCo10, AlNi10 master alloys, pure La and Ce on the side of the furnace and bake for 20 minutes, then put them into the furnace, stir several times, fully dissolve, and let stand for 30 minutes;

[0058] Step 4: Use a degasser to press an aluminum alloy refining agent into the aluminum liquid for refining, the weight ratio of the aluminum alloy refining agent in the aluminum liquid is 0.1% to 0.2%, the components of the aluminum alloy refining agent are NaF and NaCl, the weight ratio of the NaF to the NaCl is 1:1, 99.999% argon is introduced, degassing for 20 minutes, then slag is removed, and the mixture is allowed to stand;

[0059] Step 5: Detect whether the aluminum alloy composition reaches a preset mass percentage by using an electric spark direct reading spectrometer. If so, proceed to step 6. If not, add elements that do not reach the preset mass percentage so that the elements that do not reach the preset mass percentage reach the preset mass percentage.

[0060] Step 6: High-pressure die-casting is performed using a LJ 280T die-casting machine. The LJ 280T die-casting machine includes a vacuum system, an oil circulation mold temperature controller, and a barrel heating device. The process parameters for high-pressure die-casting are: mold cavity vacuum ≤ 50Mbar, injection speed 2.5±0.5m / s, mold temperature 130±10℃, and aluminum alloy liquid temperature 680±10℃.

[0061] Example 2

[0062] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0063] 1.5 wt% La, 3 wt% Ce, the weight ratio of La to Ce is 1:2, 0.53 wt% Fe, 0.53 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.2 wt% Co, 0.3 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[0064] 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.

[0065] Example 3

[0066] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0067] 1.5 wt% La, 3 wt% Ce, the weight ratio of La to Ce is 1:2, 0.58 wt% Fe, 0.58 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.3 wt% Co, 0.45 wt% Ni, a single impurity element is at most 0.05 wt%, and the rest is Al.

[0068] 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.

[0069] Example 4

[0070] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0071] 1.5 wt% La, 3 wt% Ce, the weight ratio of La to Ce is 1:2, 0.6 wt% Fe, 0.6 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.35 wt% Co, 0.5 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[0072] 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.

[0073] Example 5

[0074] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0075] 1.5 wt% La, 3 wt% Ce, the weight ratio of La to Ce is 1:2, 0.58 wt% Fe, 0.58 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.2 wt% Co, 0.2 wt% Ni, a single impurity element is at most 0.05 wt%, and the rest is Al.

[0076] 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.

[0077] Example 6

[0078] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0079] 1.5 wt% La, 3 wt% Ce, the weight ratio of La to Ce is 1:2, 0.6 wt% Fe, 0.6 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.15 wt% Co, 0.3 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[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 7

[0082] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0083] 1.5 wt% La, 3 wt% Ce, the weight ratio of La to Ce is 1:2, 0.5 wt% Fe, 0.5 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.35 wt% Co, 0.45 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[0084] 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.

[0085] Example 8

[0086] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0087] 1.5 wt% La, 3 wt% Ce, the weight ratio of La to Ce is 1:2, 0.53 wt% Fe, 0.53 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.3 wt% Co, 0.5 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[0088] 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.

[0089] Example 9

[0090] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0091] 2 wt% La, 4 wt% Ce, the weight ratio of La to Ce is 1:2, 0.6 wt% Fe, 0.6 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.3 wt% Co, 0.2 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[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 10

[0094] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0095] 2 wt% La, 4 wt% Ce, the weight ratio of La to Ce is 1:2, 0.58 wt% Fe, 0.58 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.35 wt% Co, 0.3 wt% Ni, a single impurity element is at most 0.05 wt%, and the rest is Al.

[0096] 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.

[0097] Embodiment 11

[0098] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0099] 2 wt% La, 4 wt% Ce, the weight ratio of La to Ce is 1:2, 0.53 wt% Fe, 0.53 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.15 wt% Co, 0.45 wt% Ni, a single impurity element is at most 0.05 wt%, and the rest is Al.

[0100] 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.

[0101] Example 12

[0102] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0103] 2 wt% La, 4 wt% Ce, the weight ratio of La to Ce is 1:2, 0.5 wt% Fe, 0.5 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.2 wt% Co, 0.5 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[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] Embodiment 13

[0106] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0107] 2.5 wt% La, 5 wt% Ce, the weight ratio of La to Ce is 1:2, 0.53 wt% Fe, 0.53 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.35 wt% Co, 0.2 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[0108] 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.

[0109] Embodiment 14

[0110] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0111] 2.5 wt% La, 5 wt% Ce, the weight ratio of La to Ce is 1:2, 0.5 wt% Fe, 0.5 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.3 wt% Co, 0.3 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[0112] 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.

[0113] Embodiment 15

[0114] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0115] 2.5 wt% La, 5 wt% Ce, the weight ratio of La to Ce is 1:2, 0.6 wt% Fe, 0.6 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.2 wt% Co, 0.45 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[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] Example 16

[0118] A high-conductivity and high-strength rare earth aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0119] 2.5 wt% La, 5 wt% Ce, the weight ratio of La to Ce is 1:2, 0.58 wt% Fe, 0.58 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.15 wt% Co, 0.5 wt% Ni, a single impurity element is up to 0.05 wt%, and the rest is Al.

[0120] 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.

[0121] Comparative Example 1

[0122] An aluminum alloy, which is different from Example 10 in that the components and weight percentages of the aluminum alloy in this comparative example do not contain La and Ce.

[0123] 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 1.

[0124] Comparative Example 2

[0125] An aluminum alloy, which is different from Example 10 in that the components and weight percentages of the aluminum alloy in this comparative example do not contain La and Ce, and contain 0.4 weight % of Fe and 0.8 weight % of Mn, and the weight ratio of Fe to Mn is 1:2.

[0126] 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 1.

[0127] Comparative Example 3

[0128] An aluminum alloy, which is different from Example 6 in that the composition and weight percentage of the aluminum alloy in this comparative example contain 3 weight % La and 6 weight % Ce.

[0129] 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 1.

[0130] Comparative Example 4

[0131] An aluminum alloy, which is different from Example 10 in that the components and weight percentages of the aluminum alloy in this comparative example contain 0.4 weight % Fe and 0.8 weight % Mn, and the weight ratio of Fe to Mn is 1:2.

[0132] 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 1.

[0133] Comparative Example 5

[0134] An aluminum alloy, which differs from Example 14 in that the components and weight percentages of the aluminum alloy in this comparative example contain 0.35 weight % Fe and 0.7 weight % Mn, and the weight ratio of Fe to Mn is 1:2.

[0135] 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 1.

[0136] Comparative Example 6

[0137] An aluminum alloy, which is different from Example 10 in that the composition and weight percentage of the aluminum alloy in this comparative example contain 0.3 weight % Fe and 0.3 weight % Mn.

[0138] 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 1.

[0139] Comparative Example 7

[0140] An aluminum alloy, which is different from Example 10 in that the composition and weight percentage of the aluminum alloy in this comparative example contain 0.4 weight % Fe and 0.4 weight % Mn.

[0141] 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 1.

[0142] Comparative Example 8

[0143] An aluminum alloy, which is different from Example 10 in that the composition and weight percentage of the aluminum alloy in this comparative example contain 0.7 weight % Fe and 0.7 weight % Mn.

[0144] 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 1.

[0145] Comparative Example 9

[0146] An aluminum alloy, which is different from Example 10 in that the composition and weight percentage of the aluminum alloy in this comparative example contain 0.8 weight % Fe and 0.8 weight % Mn.

[0147] 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 1.

[0148] Comparative Example 10

[0149] An aluminum alloy, which is different from Example 10 in that the composition and weight percentage of the aluminum alloy in this comparative example contain 0.1 weight % Co and 0.1 weight % Ni.

[0150] 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 1.

[0151] For the above examples and comparative examples, 3mm×80mm×200mm flat die test pieces were prepared, and the mechanical properties were measured by Sansi tensile testing machine and imported extensometer, with a tensile rate of 1mm / s. The tensile test specimens were processed strictly according to the proportion specimens in GB / T228.12010, and the conductivity of the material was measured by a conductivity meter. The composition and test results of the above examples and comparative examples are shown in Table 1:

[0152] Table 1:

[0153]

[0154] It can be seen from the test results of Examples 1 to 16 in Table 1 that the aluminum alloy material provided by the embodiments of the present invention has a tensile strength of more than 145 MPa, a yield strength of more than 100 MPa, an elongation of more than 9%, and a conductivity of more than 58% IACS. While meeting the conductivity, the mechanical properties of the material can also be guaranteed; especially by using the components and proportions of Example 10, the tensile strength reaches 173.4 MPa, the yield strength reaches 121.6 MPa, the elongation reaches 11.2%, and the conductivity reaches 62.7% IACS, and the conductivity and mechanical properties are further improved.

[0155] Comparative Example 1 provides an aluminum alloy, which differs from Example 10 in that it does not contain La and Ce. From the test results of Example 10 and Comparative Example 1 in Table 1, it can be seen that the electrical conductivity and mechanical properties of Comparative Example 1 are both lower than those of Example 10. It can be seen that the present invention can refine the grains of the aluminum alloy material and increase the mechanical properties of the material by adding rare earth elements.

[0156] Comparative Example 3 provides an aluminum alloy, which is different from Example 6 in that the weight of La and Ce exceeds 7.5%. From the test results of Example 6 and Comparative Example 3 in Table 1, it can be seen that the conductivity of Comparative Example 3 is greatly reduced. It can be seen that when the weight of La and Ce exceeds 7.5%, the conductivity of the aluminum alloy will be affected and gradually decrease. The present invention controls the weight % of the rare earth elements La and Ce between 4.5 and 7.5, which can further refine the grains of the aluminum alloy material, increase the material performance, and ensure high conductivity.

[0157] The difference between the aluminum alloy provided in Comparative Examples 4 and 5 and the embodiment of the present invention is that the weight ratio of Fe and Mn is not 1:1. It can be seen from the test results of Example 10 and Comparative Example 4, Example 14 and Comparative Example 5 in Table 1 that when the technical solution of the present invention in which the weight ratio of Fe and Mn is 1:1 is adopted, the mechanical properties and conductive properties of the material are greatly improved.

[0158] The aluminum alloy provided in Comparative Example 3 further shows that when no rare earth elements are added and the technical solution of the present invention in which the weight ratio of Fe and Mn is 1:1 is not used, the mechanical properties and electrical conductivity of the material will be further reduced, further proving that the present invention can further improve the mechanical properties and electrical conductivity of the material by controlling the weight ratio of Fe and Mn to 1:1 while adding rare earths.

[0159] The difference between the aluminum alloys provided in Comparative Examples 6, 7, 8, and 9 and Example 10 of the present invention is that the Fe and Mn contents are not 0.5-0.6 weight % Fe and 0.5-0.6 weight % Mn. It can be seen from the test results of Example 10 and Comparative Examples 6, 7, 8, and 9 in Table 1 that when the technical solution of 0.5-0.6 weight % Fe and 0.5-0.6 weight % Mn provided by the present invention is adopted, the mechanical properties and conductive properties of the material are greatly improved.

[0160] The present invention controls the contents of Fe and Mn between 0.5% and 0.6%. A certain amount of Fe can effectively improve the mechanical properties of the material. Excessive Fe exists in the alloy in the form of flaky or needle-like structures of FeAl3, Fe2Al7 and AlSiFe. An equal proportion of Mn is added to adjust the morphology of the iron-rich phase, so that the needle-like β iron-rich phase is transformed into a more rounded state, and a stable Fe-Mn phase can be formed. The ratio of Fe to Mn in the Fe-Mn phase is 1:1. The flaky or needle-like structure formed by iron in the aluminum alloy can be transformed into a fine crystalline structure. When the Mn content is too high, segregation will be formed, which will reduce the mechanical properties and electrical conductivity of the material. Therefore, excessive addition is not suitable.

[0161] The difference between the aluminum alloy provided in comparative example 10 and embodiment 10 of the present invention is that the weight of Co is less than 0.15% and the weight of Ni is less than 0.2%. It can be seen from the test results of embodiment 10 and comparative example 10 in Table 1 that the addition of appropriate Co and Ni in the present invention can improve the mechanical properties and conductive properties.

[0162] The present invention refines alloy grains and improves mechanical properties by adding 0.15% to 0.35% by weight of Co, and adjusts the arrangement order of grains while adding 0.2% to 0.5% by weight of Ni to ensure more uniform grain size and improve the electrical conductivity of the alloy while refining the grains.

Claims

1. A high-conductivity and high-strength rare earth aluminum alloy, characterized in that: The components and weight percentages of the aluminum alloy are: 0.5-0.6 wt% Fe, 0.5-0.6 wt% Mn, the weight ratio of Fe to Mn is 1:1, 0.15-0.35 wt% Co, 0.2-0.5 wt% Ni, 4.5-7.5 wt% La and Ce, the weight ratio of La to Ce is 1:2, a single impurity element is at most 0.05 wt%, and the rest is Al.

2. A method for preparing a high-conductivity and high-strength rare earth aluminum alloy according to claim 1, characterized in that: The following steps are involved: Step 1: Prepare A00 aluminum ingot, AlFe20, AlMn10, AlCo10, AlNi10 master alloy, pure La and Ce as raw materials according to the mass percentage of the aluminum alloy; Step 2: gradually increase the temperature in the furnace to bake out the water vapor in the furnace. During the heating process, place the A00 aluminum ingot weighed according to the proportion beside the furnace for baking and then put it into the furnace to heat and melt to obtain aluminum liquid; Step 3: After the A00 aluminum ingot is dissolved, place AlFe20, AlMn10, AlCo10, AlNi10 master alloys, pure La and Ce on the side of the furnace for baking, then put them into the furnace, stir several times, fully dissolve, and let stand; Step 4: Use a degasser to press the aluminum alloy refining agent into the refining machine, pass 99.999% argon gas, degas, then remove the slag and let it stand; Step 5: Detect whether the aluminum alloy composition reaches a preset mass percentage. If so, proceed to step 6. If not, add elements that do not reach the preset mass percentage so that the elements that do not reach the preset mass percentage reach the preset mass percentage. Step 6: Perform high pressure die casting through high pressure die casting equipment.

3. The method for preparing a high-conductivity and high-strength rare earth aluminum alloy according to claim 2, characterized in that: In step 2, the furnace side baking time of the A00 aluminum ingot is 30 minutes.

4. The method for preparing a high-conductivity and high-strength rare earth aluminum alloy according to claim 2, characterized in that: In step 2, the aluminum liquid temperature is set to 750°C and the furnace temperature is set to 780°C.

5. The method for preparing a high-conductivity and high-strength rare earth aluminum alloy according to claim 2, characterized in that: In the step 3, the furnace-side baking time of the AlFe20, AlMn10, AlCo10, AlNi10 master alloys, pure La and Ce is 20 minutes.

6. The method for preparing a high-conductivity and high-strength rare earth aluminum alloy according to claim 2, characterized in that: In step 3, the standing time is 30 minutes.

7. The method for preparing a high-conductivity and high-strength rare earth aluminum alloy according to claim 2, characterized in that: In the step 4, the weight ratio of the aluminum alloy refining agent in the aluminum liquid is 0.1% to 0.2%, the components of the aluminum alloy refining agent are NaF and NaCl, and the weight ratio of the NaF to the NaCl is 1:

1.

8. The method for preparing a high-conductivity and high-strength rare earth aluminum alloy according to claim 2, characterized in that: In step 4, the degassing time is 20 minutes.

9. The method for preparing a high-conductivity and high-strength rare earth aluminum alloy according to claim 2, characterized in that: In step 6, the high pressure die casting equipment includes a vacuum system, an oil circulation mold temperature controller, and a barrel heating device.

10. The method for preparing a high-conductivity and high-strength rare earth aluminum alloy according to claim 2, characterized in that: In step 6, the process parameters of high pressure die casting are: mold cavity vacuum ≤ 50 Mbar, injection speed 2.5±0.5 m / s, mold temperature 130±10°C, and aluminum alloy liquid temperature 680±10°C.

Images