A method for preparing rare earth aluminum alloy

Abstract

The present invention provides a method for preparing a rare earth aluminum alloy, belonging to the technical field of die-casting aluminum alloys. The components and weight percentages of the rare earth aluminum alloy are as follows: 0.1-0.2 weight % Si, 0.5-1.0 weight % Fe, 0.2-0.9 weight % Mn, 0.05-0.09 weight % Mg, 0.05-0.2 weight % Cr, 0.5-4.0 weight % La, 1.0-8.0 weight % Ce, a single impurity element of up to 0.1 weight %, and the rest is Al; the method for preparing the rare earth aluminum alloy comprises: putting the intermediate rare earth alloy into two batches, and the second time of putting in is after the A00 aluminum ingot is melted, when the aluminum liquid temperature reaches 700°C. The present invention can quickly dissolve rare earth elements, while effectively reducing the burn-out rate of rare earth elements, saving production costs, and improving the overall utilization rate of materials.

Description

Technical Field

[0001] The invention belongs to the technical field of die-casting aluminum alloys, and in particular relates to a preparation method of a rare earth aluminum alloy. Background Art

[0002] In the preparation process of aluminum alloy materials, in order to improve the comprehensive performance of the materials and expand their application areas, the industry generally recognizes the importance of adding rare earth elements. The addition of rare earth elements can effectively refine the grain structure of aluminum alloys, significantly improve the strength, toughness and corrosion resistance of the materials, and thus meet the needs of more high-end applications. However, although rare earth elements have shown great potential in aluminum alloy modification, their high cost has become one of the main factors limiting their widespread application.

[0003] In the actual operation of aluminum alloy smelting, the application of rare earth elements still faces a series of technical difficulties. First, the melting point of rare earth elements is much higher than that of aluminum alloy, which makes their dissolution process difficult and consumes huge energy during the smelting process. Secondly, rare earth elements are very easy to burn during the smelting process, and the burn rate is generally as high as about 15%, which not only further increases production costs, but also seriously reduces the effective utilization rate of rare earth elements.

[0004] To address the rare earth burnout problem, most existing production methods only use asbestos to cover the smelting furnace mouth, attempting to reduce burnout by isolating the solution surface from contact with air. Although this method can reduce the burnout phenomenon to a certain extent, its effect is limited, and the operation process is difficult to accurately control, and it cannot fundamentally solve the high burnout rate problem of rare earth elements.

[0005] In view of the above-mentioned technical bottlenecks, the current aluminum alloy material field urgently needs to develop a new type of aluminum alloy and its preparation method, so as to quickly dissolve rare earth elements, effectively reduce the burn-out rate of rare earth elements, save production costs, and improve the overall utilization rate of materials. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention aims to provide a rare earth aluminum alloy and a preparation method thereof, so as to quickly dissolve the rare earth elements, while effectively reducing the burn-out rate of the rare earth elements, saving production costs, and improving the overall utilization rate of the material.

[0007] The present invention provides a method for preparing a rare earth aluminum alloy, wherein the components and weight percentages of the rare earth aluminum alloy are:

[0008] 0.05-0.15 wt% Si, 0.5-1.0 wt% Fe, 0.2-0.9 wt% Mn, 0.05-0.09 wt% Mg, 0.05-0.2 wt% Cr, 0.5-4.0 wt% La, 1.0-8.0 wt% Ce, a single impurity element of up to 0.1 wt%, the remainder being Al;

[0009] The method for preparing the rare earth aluminum alloy comprises the following steps:

[0010] Step 1: gradually increase the temperature in the furnace according to the weight percentage of the rare earth aluminum alloy, bake out the water vapor in the furnace, and during the heating process, place the A00 aluminum ingot containing Si weighed in proportion beside the furnace for baking, then put it into the furnace, heat it up and melt it into aluminum liquid;

[0011] Step 2: After the A00 aluminum ingot is dissolved, AlFe20, AlMn10, AlCr20 and the intermediate rare earth alloy are placed on the side of the furnace for baking. First, AlFe20, AlMn10 and AlCr20 are put into the furnace and stirred several times. Then, the intermediate rare earth alloy is put into the furnace in two batches. The second time is when the A00 aluminum ingot is melted and the aluminum liquid temperature reaches 700°C.

[0012] After the aluminum liquid is fully dissolved and allowed to stand, Mg is added into the furnace;

[0013] Step 3: Use a degasser to press the aluminum alloy refining agent into the refining process, introduce 99.999% argon gas, degas, then remove the slag and take samples;

[0014] Step 4: Detect whether the aluminum alloy composition reaches a preset weight percentage. If so, proceed to step 5. If not, add elements that do not reach the preset weight percentage so that the elements that do not reach the preset weight percentage reach the preset weight percentage.

[0015] Step 5: Detect the gas content, and when the density equivalent is ≤0.2%, proceed to step 6, otherwise continue the refining and degassing operation in step 3;

[0016] Step 6: Die casting through die casting equipment.

[0017] As a further improvement of the present invention, the components and weight percentages of the rare earth aluminum alloy are:

[0018] 0.15 wt% Si, 0.75 wt% Fe, 0.7 wt% Mn, 0.07 wt% Mg, 0.15 wt% Cr, 0.5-4.0 wt% La, 1.0-8.0 wt% Ce, a single impurity element of up to 0.1 wt%, and the rest is Al.

[0019] As a further improvement of the present invention, the weight ratio of the La to the Ce is 1:2.

[0020] As a further improvement of the present invention, in step 1, the baking time of the A00 aluminum ingot is 30 minutes.

[0021] As a further improvement of the present invention, in step 1, the temperature of the aluminum liquid is set to 760°C and the temperature in the furnace is set to 800°C.

[0022] As a further improvement of the present invention, in step 2, the baking time of AlFe20, AlMn10, AlCr20 and the intermediate rare earth alloy is 30 minutes, and the standing time of the aluminum liquid is 30 minutes.

[0023] As a further improvement of the present invention, in step 2, the intermediate rare earth alloy comprises La and Ce in a weight ratio of 1:2, and the weight of La and Ce accounts for 40% of the intermediate rare earth alloy.

[0024] As a further improvement of the present invention, in step 2, when the temperature in the furnace reaches above 750° C., the lumps at the bottom of the furnace are scooped out with a spoon and broken into pieces.

[0025] As a further improvement of the present invention, in step 3, 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, the weight ratio of the NaF and the NaCl is 1:1, and the degassing time is 20 minutes.

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

[0027] The invention provides a rare earth aluminum alloy and a preparation method thereof, which can quickly dissolve rare earth elements, effectively reduce the burnout rate of rare earth elements, save production costs, and improve the overall utilization rate of materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a 1000-fold metallographic structure diagram of the rare earth aluminum alloy material disclosed in Example 6 of the present invention. DETAILED DESCRIPTION

[0029] 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.

[0030] The principle of the present invention is that the melting point of rare earth elements is much higher than that of aluminum alloys, which makes the dissolution process difficult and consumes huge energy. In addition, rare earth elements are very easy to burn during the smelting process, which not only further increases the production cost, but also seriously reduces the effective utilization rate of rare earth elements. In order to solve this problem, the present invention puts the rare earth alloy into the smelting stage twice. On this basis, preferably at an appropriate time, the lumps at the bottom of the furnace are scooped out and broken with a spoon, so that the rare earth alloy dissolves faster, reduces the burning rate of rare earth elements, and does not affect the performance of the material.

[0031] A rare earth aluminum alloy is provided in an embodiment of the present invention, and the components and weight percentages of the rare earth aluminum alloy are as follows:

[0032] 0.05-0.15 wt% Si, 0.5-1.0 wt% Fe, 0.2-0.9 wt% Mn, 0.05-0.09 wt% Mg, 0.05-0.2 wt% Cr, 0.5-4.0 wt% La, 1.0-8.0 wt% Ce, a single impurity element of up to 0.1 wt%, the remainder being Al;

[0033] The method for preparing the rare earth aluminum alloy comprises the following steps:

[0034] Step 1: gradually increase the temperature in the furnace according to the weight percentage of the rare earth aluminum alloy, bake out the water vapor in the furnace, and during the heating process, place the A00 aluminum ingot containing Si weighed in proportion beside the furnace for baking, then put it into the furnace, heat it up and melt it into aluminum liquid;

[0035] Step 2: After the A00 aluminum ingot is dissolved, AlFe20, AlMn10, AlCr20 and the intermediate rare earth alloy are placed on the side of the furnace for baking. First, AlFe20, AlMn10 and AlCr20 are put into the furnace and stirred several times. Then, the intermediate rare earth alloy is put into the furnace in two batches. The second time is when the A00 aluminum ingot is melted and the aluminum liquid temperature reaches 700°C.

[0036] After the aluminum liquid is fully dissolved and allowed to stand, Mg is added into the furnace;

[0037] Step 3: Use a degasser to press the aluminum alloy refining agent into the refining process, introduce 99.999% argon gas, degas, then remove the slag and take samples;

[0038] Step 4: Detect whether the aluminum alloy composition reaches a preset weight percentage. If so, proceed to step 5. If not, add elements that do not reach the preset weight percentage so that the elements that do not reach the preset weight percentage reach the preset weight percentage.

[0039] Step 5: Detect the gas content, and when the density equivalent is ≤0.2%, proceed to step 6, otherwise continue the refining and degassing operation in step 3;

[0040] Step 6: Die casting through die casting equipment.

[0041] In a preferred embodiment, the components and weight percentages of the rare earth aluminum alloy are:

[0042] 0.15 wt% Si, 0.75 wt% Fe, 0.7 wt% Mn, 0.07 wt% Mg, 0.15 wt% Cr, 0.5-4.0 wt% La, 1.0-8.0 wt% Ce, a single impurity element of up to 0.1 wt%, and the rest is Al.

[0043] In a preferred embodiment, the weight ratio of La to Ce is 1:2.

[0044] 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 Si can be 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, and 0.15. For example, the weight percentage of Fe can be 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.0. Illustratively, the weight % of Mn may 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, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9. For example, the weight % of Mg may be 0.05, 0.06, 0.07, 0.08, 0.09. Illustratively, the weight % of Cr may be 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2.Illustratively, the weight % of La may be 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4. For example, the weight percent of Ce may be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3 , 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.

[0045] In a preferred embodiment, in step 1, the baking time of the A00 aluminum ingot is 30 minutes.

[0046] In a preferred embodiment, in step 1, the temperature of the aluminum liquid is set to 760°C and the temperature in the furnace is set to 800°C.

[0047] In a preferred embodiment, in step 2, the baking time of AlFe20, AlMn10, AlCr20 and the intermediate rare earth alloy is 30 minutes, and the standing time of the aluminum liquid is 30 minutes.

[0048] In a preferred embodiment, in step 2, the intermediate rare earth alloy comprises La and Ce in a weight ratio of 1:2, and the weight of La and Ce accounts for 40% of the intermediate rare earth alloy.

[0049] It should be noted that the intermediate rare earth alloy can be put into the feed in not only two batches but also three batches or more. Other technical solutions obtained by those skilled in the art without creative work but only on the basis of the present invention shall constitute the scope of protection of the present invention.

[0050] In a preferred embodiment, in step 2, when the temperature in the furnace reaches above 750° C., the lumps at the bottom of the furnace are scooped out and broken into pieces using a spoon.

[0051] In a preferred embodiment, in step 3, 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, the weight ratio of the NaF and the NaCl is 1:1, and the degassing time is 20 minutes.

[0052] Example 1

[0053] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are:

[0054] 0.15 wt% Si, 0.75 wt% Fe, 0.7 wt% Mn, 0.07 wt% Mg, 0.15 wt% Cr, 2.0 wt% La and Ce, the weight ratio of La to Ce is 1:2, a single impurity element is at most 0.1 wt%, and the rest is Al.

[0055] A method for preparing the rare earth aluminum alloy of this embodiment comprises the following steps:

[0056] Step 1: According to the weight percentage of the rare earth aluminum alloy, each furnace is charged with 500 kg of ingredients, the furnace is gradually heated up, and the water vapor in the furnace is baked. During the heating process, the A00 aluminum ingot containing Si weighed in proportion is placed on the side of the furnace and baked for 30 minutes, and then put into the furnace, and the temperature is raised to melt into aluminum liquid. The aluminum liquid temperature is set to 760°C, and the temperature in the furnace is set to 800°C;

[0057] Step 2: After the A00 aluminum ingot is dissolved, AlFe20, AlMn10, AlCr20 and the intermediate rare earth alloy are placed on the furnace side for baking for 30 minutes. AlFe20, AlMn10 and AlCr20 are first put into the furnace and stirred several times. Then the intermediate rare earth alloy is put into the furnace in two batches. The second time is when the A00 aluminum ingot is melted and the aluminum liquid temperature reaches 700°C. After the aluminum liquid is fully dissolved and left to stand for 30 minutes, Mg is put into the furnace. The intermediate rare earth alloy includes La and Ce with a weight ratio of 1:2, and the weight of La and Ce accounts for 40% of the intermediate rare earth alloy.

[0058] Step 3: 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 for degassing for 20 minutes, and then the slag is removed and the sample is taken.

[0059] Step 4: Detect whether the aluminum alloy composition reaches a preset weight percentage. If so, proceed to step 5. If not, add elements that do not reach the preset weight percentage so that the elements that do not reach the preset weight percentage reach the preset weight percentage.

[0060] Step 5: Detect the gas content, and when the density equivalent is ≤0.2%, proceed to step 6, otherwise continue the refining and degassing operation in step 3;

[0061] Step 6: Die casting through die casting equipment.

[0062] Example 2

[0063] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 1.

[0064] A method for preparing the rare earth aluminum alloy of this embodiment comprises the following steps:

[0065] Step 1: According to the weight percentage of the rare earth aluminum alloy, each furnace is charged with 500 kg of ingredients, the furnace is gradually heated up, and the water vapor in the furnace is baked. During the heating process, the A00 aluminum ingot containing Si weighed in proportion is placed on the side of the furnace and baked for 30 minutes, and then put into the furnace, and the temperature is raised to melt into aluminum liquid. The aluminum liquid temperature is set to 760°C, and the temperature in the furnace is set to 800°C;

[0066] Step 2: After the A00 aluminum ingot is dissolved, place AlFe20, AlMn10, AlCr20 and the intermediate rare earth alloy on the furnace side and bake for 30 minutes. First, put AlFe20, AlMn10 and AlCr20 into the furnace, stir them several times, and then put the intermediate rare earth alloy in one go. When the temperature in the furnace reaches above 750°C, use a spoon to scoop out the lumps at the bottom of the furnace and break them. After the aluminum liquid is fully dissolved and standing for 30 minutes, put Mg into the furnace; the intermediate rare earth alloy includes La and Ce with a weight ratio of 1:2, and the weight of La and Ce accounts for 40% of the intermediate rare earth alloy;

[0067] Step 3: 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 for degassing for 20 minutes, and then the slag is removed and the sample is taken.

[0068] Step 4: Detect whether the aluminum alloy composition reaches a preset weight percentage. If so, proceed to step 5. If not, add elements that do not reach the preset weight percentage so that the elements that do not reach the preset weight percentage reach the preset weight percentage.

[0069] Step 5: Detect the gas content, and when the density equivalent is ≤0.2%, proceed to step 6, otherwise continue the refining and degassing operation in step 3;

[0070] Step 6: Die casting through die casting equipment.

[0071] Example 3

[0072] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 1.

[0073] A method for preparing the rare earth aluminum alloy of this embodiment comprises the following steps:

[0074] Step 1: According to the weight percentage of the rare earth aluminum alloy, each furnace is charged with 500 kg of ingredients, the furnace is gradually heated up, and the water vapor in the furnace is baked. During the heating process, the A00 aluminum ingot containing Si weighed in proportion is placed on the side of the furnace and baked for 30 minutes, and then put into the furnace, and the temperature is raised to melt into aluminum liquid. The aluminum liquid temperature is set to 760°C, and the temperature in the furnace is set to 800°C;

[0075] Step 2: After the A00 aluminum ingot is dissolved, place AlFe20, AlMn10, AlCr20 and the intermediate rare earth alloy by the furnace and bake for 30 minutes. First, put AlFe20, AlMn10 and AlCr20 into the furnace, stir them several times, and then put the intermediate rare earth alloy into the furnace in two batches. The second time is when the A00 aluminum ingot is melted and the aluminum liquid temperature reaches 700°C. When the temperature in the furnace reaches above 750°C, use a spoon to scoop out the lumps at the bottom of the furnace and break them. After the aluminum liquid is fully dissolved and standing for 30 minutes, put Mg into the furnace; the intermediate rare earth alloy includes La and Ce with a weight ratio of 1:2, and the weight of La and Ce accounts for 40% of the intermediate rare earth alloy;

[0076] Step 3: 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 for degassing for 20 minutes, and then the slag is removed and the sample is taken.

[0077] Step 4: Detect whether the aluminum alloy composition reaches a preset weight percentage. If so, proceed to step 5. If not, add elements that do not reach the preset weight percentage so that the elements that do not reach the preset weight percentage reach the preset weight percentage.

[0078] Step 5: Detect the gas content, and when the density equivalent is ≤0.2%, proceed to step 6, otherwise continue the refining and degassing operation in step 3;

[0079] Step 6: Die casting through die casting equipment.

[0080] Example 4

[0081] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are:

[0082] 0.15 wt% Si, 0.75 wt% Fe, 0.7 wt% Mn, 0.07 wt% Mg, 0.15 wt% Cr, 5.0 wt% La and Ce, the weight ratio of La to Ce is 1:2, a single impurity element is at most 0.1 wt%, and the rest is Al.

[0083] A method for preparing the rare earth aluminum alloy of this embodiment, the preparation method is the same as that of Example 1.

[0084] Example 5

[0085] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 4.

[0086] A method for preparing the rare earth aluminum alloy of this embodiment, the preparation method is the same as that of Example 2.

[0087] Example 6

[0088] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 4.

[0089] A method for preparing the rare earth aluminum alloy of this embodiment, the preparation method is the same as that of Example 3.

[0090] Example 7

[0091] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are:

[0092] 0.15 wt% Si, 0.75 wt% Fe, 0.7 wt% Mn, 0.07 wt% Mg, 0.15 wt% Cr, 8.0 wt% La and Ce, the weight ratio of La to Ce is 1:2, a single impurity element is at most 0.1 wt%, and the rest is Al.

[0093] A method for preparing the rare earth aluminum alloy of this embodiment, the preparation method is the same as that of Example 1.

[0094] Example 8

[0095] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 7.

[0096] A method for preparing the rare earth aluminum alloy of this embodiment, the preparation method is the same as that of Example 2.

[0097] Example 9

[0098] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 7.

[0099] A method for preparing the rare earth aluminum alloy of this embodiment, the preparation method is the same as that of Example 3.

[0100] Example 10

[0101] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are:

[0102] 0.15 wt% Si, 0.75 wt% Fe, 0.7 wt% Mn, 0.07 wt% Mg, 0.15 wt% Cr, 11.0 wt% La and Ce, the weight ratio of La to Ce is 1:2, a single impurity element is at most 0.1 wt%, and the rest is Al.

[0103] A method for preparing the rare earth aluminum alloy of this embodiment, the preparation method is the same as that of Example 1.

[0104] Embodiment 11

[0105] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 10.

[0106] A method for preparing the rare earth aluminum alloy of this embodiment, the preparation method is the same as that of Example 2.

[0107] Example 12

[0108] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 10.

[0109] A method for preparing the rare earth aluminum alloy of this embodiment, the preparation method is the same as that of Example 3.

[0110] Comparative Example 1

[0111] An aluminum alloy, the components and weight percentages of the aluminum alloy are:

[0112] 0.15 wt% Si, 0.75 wt% Fe, 0.7 wt% Mn, 0.07 wt% Mg, 0.15 wt% Cr, a single impurity element of up to 0.1 wt%, and the remainder is Al.

[0113] A method for preparing the aluminum alloy of this comparative example comprises the following steps:

[0114] Step 1: According to the weight percentage of the aluminum alloy, each furnace is charged with 500 kg of ingredients, the furnace is gradually heated up, and the water vapor in the furnace is baked. During the heating process, the A00 aluminum ingot containing Si weighed in proportion is placed on the side of the furnace and baked for 30 minutes, and then put into the furnace, and the temperature is raised to melt into aluminum liquid. The aluminum liquid temperature is set to 760°C, and the temperature in the furnace is set to 800°C;

[0115] Step 2: After the A00 aluminum ingot is dissolved, place AlFe20, AlMn10, and AlCr20 on the side of the furnace and bake for 30 minutes. Put AlFe20, AlMn10, and AlCr20 into the furnace and stir several times. After the aluminum liquid is fully dissolved, let it stand for 30 minutes before putting Mg into the furnace.

[0116] Step 3: 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 for degassing for 20 minutes, and then the slag is removed and the sample is taken.

[0117] Step 4: Detect whether the aluminum alloy composition reaches a preset weight percentage. If so, proceed to step 5. If not, add elements that do not reach the preset weight percentage so that the elements that do not reach the preset weight percentage reach the preset weight percentage.

[0118] Step 5: Detect the gas content, and when the density equivalent is ≤0.2%, proceed to step 6, otherwise continue the refining and degassing operation in step 3;

[0119] Step 6: Die casting through die casting equipment.

[0120] Comparative Example 2

[0121] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 1.

[0122] A method for preparing the rare earth aluminum alloy of this comparative example comprises the following steps:

[0123] Step 1: According to the weight percentage of the rare earth aluminum alloy, each furnace is charged with 500 kg of ingredients, the furnace is gradually heated up, and the water vapor in the furnace is baked. During the heating process, the A00 aluminum ingot containing Si weighed in proportion is placed on the side of the furnace and baked for 30 minutes, and then put into the furnace, and the temperature is raised to melt into aluminum liquid. The aluminum liquid temperature is set to 760°C, and the temperature in the furnace is set to 800°C;

[0124] Step 2: After the A00 aluminum ingot is dissolved, AlFe20, AlMn10, AlCr20 and the intermediate rare earth alloy are placed on the furnace side for baking for 30 minutes. AlFe20, AlMn10 and AlCr20 are first put into the furnace, stirred several times, and then the intermediate rare earth alloy is put in at one time. After the aluminum liquid is fully dissolved and allowed to stand for 30 minutes, Mg is put into the furnace. The intermediate rare earth alloy includes La and Ce in a weight ratio of 1:2, and the weight of La and Ce accounts for 40% of the intermediate rare earth alloy.

[0125] Step 3: 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 for degassing for 20 minutes, and then the slag is removed and the sample is taken.

[0126] Step 4: Detect whether the aluminum alloy composition reaches a preset weight percentage. If so, proceed to step 5. If not, add elements that do not reach the preset weight percentage so that the elements that do not reach the preset weight percentage reach the preset weight percentage.

[0127] Step 5: Detect the gas content, and when the density equivalent is ≤0.2%, proceed to step 6, otherwise continue the refining and degassing operation in step 3;

[0128] Step 6: Die casting through die casting equipment.

[0129] Comparative Example 3

[0130] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 4.

[0131] A preparation method of the rare earth aluminum alloy of this comparative example, the preparation method is the same as that of comparative example 2.

[0132] Comparative Example 4

[0133] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 7.

[0134] A preparation method of the rare earth aluminum alloy of this comparative example, the preparation method is the same as that of comparative example 2.

[0135] Comparative Example 5

[0136] A rare earth aluminum alloy, the components and weight percentages of the rare earth aluminum alloy are the same as those of Example 10.

[0137] A preparation method of the rare earth aluminum alloy of this comparative example, the preparation method is the same as that of comparative example 2.

[0138] For the above-mentioned embodiments and comparative examples, by testing the smelting time, rare earth test content, and rare earth burnout rate, the test results are shown in Table 1:

[0139] Table 1:

[0140]

[0141] In the test results of Table 1, it can be seen from the smelting time of Comparative Examples 1-5 that the smelting time of the alloy with rare earth added is increased compared with the intermediate alloy without rare earth added.

[0142] Through the test results of Example 1 and Comparative Example 2, Example 4 and Comparative Example 3, Example 7 and Comparative Example 4, Example 10 and Comparative Example 5, it can be seen that the smelting time when rare earth is added twice is shorter than when it is added once, and the burn-off rate is also greatly reduced, which further ensures that the content is better controlled and the composition is more stable during alloy smelting. Through the test results of Example 2 and Comparative Example 2, Example 5 and Comparative Example 3, Example 8 and Comparative Example 4, Example 11 and Comparative Example 5, it can be seen that whether it is necessary to break it at the bottom of the furnace after dissolution directly affects the smelting time. This step can reduce the smelting time and save energy consumption.

[0143] It can be seen from the test results of Examples 1-3 and Comparative Example 2, Examples 4-6 and Comparative Example 3, Examples 7-9 and Comparative Example 4, and Examples 10-12 and Comparative Example 5 that the rare earth aluminum alloy and preparation method thereof provided by the present invention can make the rare earth elements dissolve quickly, greatly shorten the smelting time, and effectively reduce the burn-out rate of the rare earth elements.

[0144] Further, for Example 6, a 3mm×80mm×200mm flat die test piece was prepared, and the mechanical properties were measured by a Sansi tensile machine and an imported extensometer. The tensile test specimens were processed strictly in accordance with the proportional specimens in GB / T228.1 2010, and the test results showed that the tensile strength was above 265MPa, the yield strength was above 145MPa, and the elongation was above 6%; combined with Figure 1 From the 1000 times metallographic structure diagram of the rare earth aluminum alloy material disclosed in Example 6 of the present invention, it can be seen that the rare earth aluminum alloy material provided by the embodiment of the present invention has good mechanical properties, and the tensile strength, yield strength and elongation all meet the industry standards.

[0145] Furthermore, in combination with the test results in Table 1, it can be seen that the rare earth aluminum alloy and the preparation method thereof provided by the present invention, on the basis of the mechanical properties of the rare earth aluminum alloy material meeting the industry standards, can quickly dissolve the rare earth elements, greatly shorten the smelting time, and effectively reduce the burn-out rate of the rare earth elements, save production costs, and improve the overall utilization rate of the material.

Claims

1. A method for preparing a rare earth aluminum alloy, characterized in that: The components and weight percentages of the rare earth aluminum alloy are: 0.05-0.15 wt% Si, 0.5-1.0 wt% Fe, 0.2-0.9 wt% Mn, 0.05-0.09 wt% Mg, 0.05-0.2 wt% Cr, 0.5-4.0 wt% La, 1.0-8.0 wt% Ce, a single impurity element of up to 0.1 wt%, the remainder being Al; The method for preparing the rare earth aluminum alloy comprises the following steps: Step 1: gradually increase the temperature in the furnace according to the weight percentage of the rare earth aluminum alloy, bake out the water vapor in the furnace, and during the heating process, place the A00 aluminum ingot containing Si weighed in proportion beside the furnace for baking, then put it into the furnace, heat it up and melt it into aluminum liquid; Step 2: After the A00 aluminum ingot is melted, AlFe20, AlMn10, AlCr20 and the intermediate rare earth alloy are placed on the side of the furnace for baking. First, AlFe20, AlMn10 and AlCr20 are put into the furnace and stirred several times. Then, the intermediate rare earth alloy is put into the furnace in two batches. The second time is when the A00 aluminum ingot is melted and the aluminum liquid temperature reaches 700°C. When the temperature in the furnace reaches above 750°C, use a spoon to scoop out the lumps at the bottom of the furnace and break them up; After the aluminum liquid is fully dissolved and allowed to stand, Mg is added into the furnace; Step 3: Use a degasser to press the aluminum alloy refining agent into the refining process, introduce 99.999% argon gas, degas, then remove the slag and take samples; Step 4: Detect whether the aluminum alloy composition reaches a preset weight percentage. If so, proceed to step 5. If not, add elements that do not reach the preset weight percentage so that the elements that do not reach the preset weight percentage reach the preset weight percentage. Step 5: Detect the gas content, and when the density equivalent is ≤0.2%, proceed to step 6, otherwise continue the refining and degassing operation in step 3; Step 6: Die casting through die casting equipment.

2. The method for preparing the rare earth aluminum alloy according to claim 1, characterized in that: The components and weight percentages of the rare earth aluminum alloy are: 0.15 wt% Si, 0.75 wt% Fe, 0.7 wt% Mn, 0.07 wt% Mg, 0.15 wt% Cr, 0.5-4.0 wt% La, 1.0-8.0 wt% Ce, a single impurity element of up to 0.1 wt%, and the rest is Al.

3. The method for preparing a rare earth aluminum alloy according to claim 1 or 2, characterized in that: The weight ratio of the La to the Ce is 1:

2.

4. The method for preparing the rare earth aluminum alloy according to claim 1, characterized in that: In the step 1, the baking time of the A00 aluminum ingot is 30 minutes.

5. The method for preparing the rare earth aluminum alloy according to claim 1, characterized in that: In step 1, the temperature of the aluminum liquid is set to 760°C and the temperature in the furnace is set to 800°C.

6. The method for preparing the rare earth aluminum alloy according to claim 1, characterized in that: In the step 2, the baking time of AlFe20, AlMn10, AlCr20 and the intermediate rare earth alloy is 30 minutes, and the standing time of the aluminum liquid is 30 minutes.

7. The method for preparing the rare earth aluminum alloy according to claim 1, characterized in that: In the step 2, the intermediate rare earth alloy includes La and Ce in a weight ratio of 1:2, and the weight of La and Ce accounts for 40% of the intermediate rare earth alloy.

8. The method for preparing the rare earth aluminum alloy according to claim 1, characterized in that: In the step 3, 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 and the NaCl is 1:1, and the degassing time is 20 minutes.

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