Method for Removing Fe Element from Cast Aluminum Alloy

Abstract

The present invention provides a method for removing Fe elements in a cast aluminum alloy. The removal method comprises: step S1, melting the cast aluminum alloy to obtain a first melt; step S2, adding a Si source and / or a Mn source to the first melt to obtain a second melt; step S3, inserting a metal adsorption plate into the second melt for iron absorption treatment; step S4, taking out the metal adsorption plate after the iron absorption treatment to obtain an aluminum alloy melt and a metal adsorption plate adsorbed with an iron-rich phase; wherein the temperature difference between the metal adsorption plate before insertion and the temperature of the second melt is not less than 400°C, and the two-dimensional mismatch between the (100) plane of the base metal in the metal adsorption plate and the (100) plane of the iron-rich phase is not higher than 15°. The removal method of the present application has a significant effect on iron reduction of cast aluminum alloys and solves the problem of separation of the iron-rich phase and the aluminum alloy melt.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloys, and in particular to a method for removing Fe elements in a cast aluminum alloy. Background Art

[0002] In the prior art, the different physical and chemical properties between the Fe-rich phase and the aluminum melt are utilized to remove the Fe-rich phase, including gravity separation, centrifugal separation, electromagnetic separation, pulse current separation and other methods. However, the separation equipment is costly and the separation effect of the Fe-rich phase is poor, and industrial application has not yet been achieved.

[0003] A Chinese patent application with patent application publication number CN117845089A proposes a method for removing Fe from cast aluminum alloys. The method adds an Fe-rich phase precipitator to the melt, the Fe-rich phase precipitator is an Al-Mn master alloy, and the Fe-rich phase is precipitated. However, the cost of removing Fe is high. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for removing Fe elements in cast aluminum alloys to solve the problems of low iron element removal rate and high cost in the prior art methods for removing Fe elements in cast aluminum alloys.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a method for removing Fe elements in a cast aluminum alloy is provided, and the removal method comprises: step S1, melting the cast aluminum alloy to obtain a first melt; step S2, adding a Si source and / or a Mn source to the first melt to obtain a second melt; step S3, inserting a metal adsorption plate into the second melt for iron absorption treatment; step S4, taking out the metal adsorption plate after the iron absorption treatment to obtain an aluminum alloy melt and a metal adsorption plate adsorbed with an iron-rich phase; wherein the temperature difference between the metal adsorption plate before insertion and the temperature of the second melt is not less than 400°C, and the two-dimensional mismatch between the (100) plane of the base metal in the metal adsorption plate and the (100) plane of the iron-rich phase is not higher than 15°.

[0006] Furthermore, in the above step S2, the temperature of the second melt is 700-800°C; preferably, the temperature of the second melt is 740-780°C; and / or, the mass ratio of Si element, Fe element and Mn element in the second melt is 6-13:0.1-2:0.1-3; preferably, it is 6.71-12.04:0.95-1.05:1.26-2.15.

[0007] Furthermore, in the above step S3, the temperature of the metal adsorption plate before insertion is 50-300°C, preferably 50-150°C; and / or the ratio of the surface area of ​​the metal adsorption plate in contact with the second melt to the volume of the second melt is 1 cm 2:1~50cm 3 .

[0008] Furthermore, the surface roughness Sa of the metal adsorption plate is greater than 1 μm, preferably 2.2 to 3.2 μm.

[0009] Furthermore, the above-mentioned iron absorption treatment includes a cooling stage and a holding stage performed in sequence; the cooling rate of the second melt in the cooling stage is 0.1-1°C / s; the temperature of the second melt in the holding stage is 560-660°C; and / or the holding time in the holding stage is 10-120min.

[0010] Furthermore, the two-dimensional mismatch between the (100) plane of the base metal in the above-mentioned metal adsorption plate and the (100) plane of the iron-rich phase is 0.22°~14.7°; and / or, the crystal structure of the base metal is a cubic structure; preferably, the material of the metal adsorption plate is selected from any one or more of 45 steel, nickel-based alloy and metal molybdenum.

[0011] Furthermore, the temperature of the first melt is 700-800°C; preferably, the temperature of the first melt is 740-780°C.

[0012] Furthermore, the melting point of the metal adsorption plate is greater than 800°C.

[0013] Furthermore, the above-mentioned metal adsorption plates are parallel to each other and are arranged in multiple intervals; preferably, the interval between two adjacent metal adsorption plates is not less than 5 mm, preferably 50 to 100 mm.

[0014] Furthermore, the above step S1 also includes measuring the Fe element content, Si element content and Mn element content in the first melt to calculate the amount of Si source and / or Mn source that needs to be added.

[0015] By applying the technical solution of the present invention, in step S2, by adding Si source and / or Mn source to the first melt to adjust the mass ratio between Fe element, Si element and Mn element in the second melt, it is helpful to promote the formation of iron-rich phase nuclei. In step S3, by controlling the temperature difference between the metal adsorption plate before insertion and the second melt to be not less than 400°C, it is helpful to improve the adsorption effect of the metal adsorption plate on the iron-rich phase, thereby helping to further promote the formation of more iron-rich phase nuclei on the surface of the metal adsorption plate, and then helping to improve the removal rate of Fe elements in the cast aluminum alloy. Controlling the two-dimensional mismatch between the (100) plane of the base metal in the metal adsorption plate and the (100) plane of the iron-rich phase to be not higher than 15° helps to improve the interaction force between the metal adsorption plate and the iron-rich phase, thereby helping to promote the formation of nuclei of the iron-rich phase on the metal adsorption plate. The removal method of the present application has a significant iron reduction effect on cast aluminum alloys, solves the separation problem of iron-rich phase and aluminum alloy melt, and the equipment used is simple. The metal adsorption plate can be reused after the iron-rich phase is stripped, which helps to reduce the cost of Fe element removal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A schematic diagram of the iron absorption process in Example 1 of the present application is shown;

[0018] Figure 2 A morphological photograph of the iron-rich phase on the metal adsorption plate in Example 1 of the present application is shown.

[0019] The above drawings include the following reference numerals:

[0020] 1. Smelting furnace; 2. Metal adsorption plate; 3. Second melt; 4. Iron-rich phase. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0022] As analyzed in the background technology of this application, the different physical and chemical properties between the Fe-rich phase and the aluminum melt are used to remove the Fe-rich phase, including gravity separation, centrifugal separation, electromagnetic separation, pulse current separation and other methods, but the cost of separation equipment is high, the separation effect of the Fe-rich phase is poor, and industrial application has not yet been achieved. The existing method for removing Fe elements from cast aluminum alloys has the problems of low iron element removal rate and high cost. In order to solve the above problems, this application provides a method for removing Fe elements from cast aluminum alloys.

[0023] It should be noted that the iron-rich phase refers to Al 15 (FeMn)3Si2 phase. The matrix metal refers to the main element or the dominant metal in the alloy.

[0024] In a typical embodiment of the present application, a method for removing Fe elements in a cast aluminum alloy is provided, and the removal method comprises: step S1, melting the cast aluminum alloy to obtain a first melt; step S2, adding a Si source and / or a Mn source to the first melt to obtain a second melt; step S3, inserting a metal adsorption plate into the second melt for iron absorption treatment; step S4, taking out the metal adsorption plate after the iron absorption treatment to obtain an aluminum alloy melt and a metal adsorption plate adsorbed with an iron-rich phase; wherein the temperature difference between the metal adsorption plate before insertion and the second melt is not less than 400°C, and the two-dimensional mismatch between the (100) plane of the base metal in the metal adsorption plate and the (100) plane of the iron-rich phase is not higher than 15°.

[0025] In step S2, by adding Si source and / or Mn source to the first melt to regulate the mass ratio between Fe element, Si element and Mn element in the second melt, it helps to promote the formation of iron-rich phase nuclei. In step S3, by controlling the temperature difference between the metal adsorption plate before insertion and the second melt to be not less than 400°C, it helps to improve the adsorption effect of the metal adsorption plate on the iron-rich phase, thereby helping to further promote the formation of more iron-rich phase nuclei on the surface of the metal adsorption plate, and then helping to improve the removal rate of Fe elements in the cast aluminum alloy. Controlling the two-dimensional mismatch between the (100) surface of the base metal in the metal adsorption plate and the (100) surface of the iron-rich phase to be not higher than 15° helps to improve the interaction force between the metal adsorption plate and the iron-rich phase, thereby helping to promote the formation of nuclei of the iron-rich phase on the metal adsorption plate. The removal method of the present application has a significant iron reduction effect on cast aluminum alloys, solves the separation problem of iron-rich phases and aluminum alloy melts, and the equipment used is simple. The metal adsorption plate can be reused after the iron-rich phase is stripped, which helps to reduce the cost of Fe element removal.

[0026] The aluminum alloy melt obtained in the present application can be cast into a mold to obtain an aluminum alloy ingot, and the metal adsorption plate adsorbing the iron-rich phase can strip the iron-rich phase. After collecting the aluminum alloy, the aluminum alloy is remelted for use in multi-component master alloys and high entropy alloys.

[0027] Including but not limited to, the Si source is Al-Si master alloy; the Mn source is Al-Mn master alloy.

[0028] In one embodiment of the present application, in the above step S2, the temperature of the second melt is 700-800°C; preferably, the temperature of the second melt is 740-780°C; and / or, the mass ratio of Si element, Fe element and Mn element in the second melt is 6-13:0.1-2:0.1-3; preferably, it is 6.71-12.04:0.95-1.05:1.26-2.15.

[0029] It is preferred to control the temperature of the second melt within the above range, which helps to further improve the solubility of each component in the second melt, thereby helping to improve the uniformity of the second melt. It is preferred to control the mass ratio of Si element, Fe element and Mn element in the second melt within the above range, which helps to further promote Al 15 The formation of (FeMn)3Si2 iron-rich phase nuclei helps to improve the removal rate of iron elements.

[0030] In one embodiment of the present application, in the above step S3, the temperature of the metal adsorption plate before insertion is 50-300°C, preferably 50-150°C; and / or the ratio of the surface area of ​​the metal adsorption plate in contact with the second melt to the volume of the second melt is 1cm 2 :1~50cm 3 .

[0031] It is preferred to control the temperature of the metal adsorption plate before insertion within the above range, which helps to control the temperature difference between the metal adsorption plate and the second melt, thereby helping to form more iron-rich phase nuclei on the surface of the metal adsorption plate, thereby helping to further improve the removal rate of Fe elements in the cast aluminum alloy. Controlling the ratio of the surface area of ​​the metal adsorption plate in contact with the second melt to the volume of the second melt within the above range helps to improve the efficiency of iron absorption.

[0032] In one embodiment of the present application, the surface roughness Sa of the metal adsorption plate is greater than 1 μm, preferably 2.2 to 3.2 μm.

[0033] It is preferred to control the surface roughness Sa of the metal adsorption plate within the above range, which helps reduce the risk of the iron-rich phase detaching from the metal adsorption plate, thereby helping to improve the removal rate of the Fe element in the cast aluminum alloy.

[0034] In one embodiment of the present application, the above-mentioned iron absorption treatment includes a cooling stage and a heat preservation stage performed sequentially; the cooling rate of the second melt in the cooling stage is 0.1~1℃ / s; the temperature of the second melt in the heat preservation stage is 560~660℃; and / or the heat preservation time in the heat preservation stage is 10~120min.

[0035] It is preferred to control the temperature and time of the iron absorption treatment within the above range, which helps to form an iron-rich phase with larger crystals, thereby helping to improve the removal rate of the Fe element in the cast aluminum alloy.

[0036] In order to further improve the removal rate of Fe elements in cast aluminum alloys, in one embodiment of the present application, the two-dimensional mismatch between the (100) plane of the base metal in the above-mentioned metal adsorption plate and the (100) plane of the iron-rich phase is preferably 0.22°~14.7°; and / or, the crystal structure of the base metal is a cubic structure; the material of the metal adsorption plate is preferably selected from any one or more of 45 steel, nickel-based alloy and metal molybdenum.

[0037] In one embodiment of the present application, the temperature of the first melt is 700-800°C; preferably, the temperature of the first melt is 740-780°C.

[0038] Preferably, the temperature of the first melt is controlled within the above range, which helps to further increase the solubility of each component in the first melt, thereby helping to improve the uniformity of the first melt.

[0039] In one embodiment of the present application, the melting point of the metal adsorption plate is greater than 800°C.

[0040] Since the temperature of the first melt and the second melt does not exceed 800° C., controlling the melting point of the metal adsorption plate to be greater than 800° C. helps to improve the stability of the metal adsorption plate in the melt, thereby helping to improve the removal efficiency of the iron element.

[0041] In order to further improve the removal efficiency of iron elements, in one embodiment of the present application, the above-mentioned metal adsorption plates are preferably parallel and spaced apart to form a plurality of plates; the spacing between two adjacent metal adsorption plates is preferably not less than 5 mm, preferably 50 to 100 mm.

[0042] In one embodiment of the present application, the bottom of the metal adsorption plate is arranged in contact with the bottom of the smelting furnace, and the metal adsorption plate is preferably evenly distributed in the smelting furnace; the height of the metal adsorption plate is greater than the height of the second melt.

[0043] In one embodiment of the present application, the above step S1 further includes measuring the Fe element content, Si element content and Mn element content in the first melt to calculate the amount of Si source and / or Mn source that needs to be added.

[0044] Measuring the Fe element content, Si element content and Mn element content in the first melt in step S1 helps to accurately control the mass ratio of Fe element, Si element and Mn element in the second melt, thereby helping to promote the formation of the iron-rich phase.

[0045] The beneficial effects of the present application will be further illustrated below in conjunction with embodiments.

[0046] Example 1

[0047] The cast aluminum alloy is melted in a melting furnace to obtain a first melt, the temperature of the first melt is 740°C, the Fe element content, Si element content and Mn element content in the first melt are measured, and Al-Mn master alloy is added to the first melt to obtain a second melt, the temperature of the second melt is 740°C, and in terms of mass percentage, the Si element content in the second melt is 6.71wt%, the Fe element content is 0.96wt%, and the Mn element content is 1.92wt%. The material of the metal adsorption plate is 45 steel, the base metal is Fe, the crystal structure of Fe is a cubic structure, and the surface roughness Sa of the metal adsorption plate is 3.2μm. The two-dimensional mismatch between the (100) plane of Fe and the (100) plane of the iron-rich phase is 8.7°. The surface temperature of the metal adsorption plate is heated to 150°C, and the metal adsorption plate is inserted into the second melt for iron absorption treatment. The ratio of the surface area of ​​the metal adsorption plate in contact with the second melt to the volume of the second melt is 1cm 2 : 20cm 3 , the schematic diagram of the iron absorption treatment is as follows Figure 1 As shown, the metal adsorption plate 2 is placed in a smelting furnace 1 containing a second melt 3, and an iron-rich phase 4 is formed on the metal adsorption plate 1. The cooling rate of the second melt during the iron absorption treatment is 0.5°C / s. After the temperature of the second melt is reduced to 620°C, the insulation time is 10 minutes. The distance between two adjacent metal adsorption plates is 100 mm. After the iron absorption treatment, the metal adsorption plate is taken out from the melt to obtain an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase. The morphology of the iron-rich phase is as shown in FIG. Figure 2 shown.

[0048] Example 2

[0049] The difference from Example 1 is that the Si content in the second melt is 6.83wt%, the Fe content is 0.95wt%, the Mn content is 1.96wt%, and the ratio of the surface area of ​​the metal adsorption plate in contact with the second melt to the volume of the second melt is 1cm 2 : 10cm 3 The distance between two adjacent adsorption plates is 50 mm, and finally an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase are obtained.

[0050] Example 3

[0051] The difference from Example 2 is that the Si content in the second melt is 7.12wt%, the Fe content is 1.04wt%, and the Mn content is 2.15wt%. The material of the metal adsorption plate is a nickel-based alloy, the base metal is Ni, the crystal structure of Ni is a cubic structure, and the surface roughness Sa of the metal adsorption plate is 2.6μm. The two-dimensional mismatch between the (100) plane of Ni and the (100) plane of the iron-rich phase is 14.7°, and finally an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase are obtained.

[0052] Example 4

[0053] The difference from Example 2 is that the Si element content in the second melt is 6.89wt%, the Fe element content is 0.99wt%, the Mn element content is 1.98wt%, the material of the metal adsorption plate is metallic molybdenum, the base metal is metallic molybdenum, the crystal structure of metallic molybdenum is cubic structure, the surface roughness Sa of the metal adsorption plate is 2.2μm, and the two-dimensional mismatch between the (100) plane of metallic molybdenum and the (100) plane of the iron-rich phase is 0.22°, and finally an aluminum alloy melt and a metal adsorption plate with adsorbed iron-rich phase are obtained.

[0054] Example 5

[0055] The difference from Example 2 is that the Si element content in the second melt is 7.01wt%, the Fe element content is 1.02wt%, the Mn element content is 2.04wt%, the material of the metal adsorption plate is metal molybdenum, the base metal is metal molybdenum, the crystal structure of metal molybdenum is cubic structure, the surface roughness Sa of the metal adsorption plate is 2.2μm, the two-dimensional mismatch between the (100) plane of metal molybdenum and the (100) plane of the iron-rich phase is 0.22°, and the holding time of the second melt in the iron absorption treatment is 60min, and finally an aluminum alloy melt and a metal adsorption plate adsorbed with an iron-rich phase are obtained.

[0056] Example 6

[0057] The difference from Example 2 is that the temperatures of the first melt and the second melt are each independently 780°C, the Si element content in the second melt is 7.11wt%, the Fe element content is 1.02wt%, the Mn element content is 2.05wt%, and the surface temperature of the metal adsorption plate is 50°C, finally obtaining an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase.

[0058] Example 7

[0059] The difference from Example 2 is that the temperatures of the first melt and the second melt are each independently 780°C, the Si element content in the second melt is 9.32wt%, the Fe element content is 1.05wt%, and the Mn element content is 1.65wt%. During the iron absorption treatment, the temperature of the second melt is reduced to 600°C, and finally an aluminum alloy melt and a metal adsorption plate adsorbed with an iron-rich phase are obtained.

[0060] Example 8

[0061] The difference from Example 2 is that the temperatures of the first melt and the second melt are each independently 780°C, the Si element content in the second melt is 12.04wt%, the Fe element content is 1.02wt%, and the Mn element content is 1.26wt%. During the iron absorption treatment, the temperature of the second melt is reduced to 580°C, and finally an aluminum alloy melt and a metal adsorption plate adsorbed with an iron-rich phase are obtained.

[0062] Example 9

[0063] The difference from Example 2 is that the temperature of the second melt is 700° C., the surface temperature of the metal adsorption plate is 300° C., and finally an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase are obtained.

[0064] Example 10

[0065] The difference from Example 8 is that the cooling rate of the second melt in the iron absorption treatment is 0.1°C / s, and after the temperature of the second melt is reduced to 660°C, the insulation time is 10 minutes, and finally an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase are obtained.

[0066] Embodiment 11

[0067] The difference from Example 8 is that the cooling rate of the second melt in the iron absorption treatment is 1°C / s, and after the temperature of the second melt is reduced to 560°C, the insulation time is 120 minutes, and finally an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase are obtained.

[0068] Example 12

[0069] The difference from Example 8 is that the cooling rate of the second melt in the iron absorption treatment is 2°C / s, and after the temperature of the second melt is reduced to 670°C, the insulation time is 5 minutes, and finally an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase are obtained.

[0070] Example 13

[0071] The difference from Example 2 is that the ratio of the surface area of ​​the metal adsorption plate in contact with the second melt to the volume of the second melt is 1 cm 2 : 1cm 3 , and finally an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase are obtained.

[0072] Embodiment 14

[0073] The difference from Example 2 is that the ratio of the surface area of ​​the metal adsorption plate in contact with the second melt to the volume of the second melt is 1 cm 2 : 50cm 3 , and finally an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase are obtained.

[0074] Embodiment 15

[0075] The difference from Example 2 is that the ratio of the surface area of ​​the metal adsorption plate in contact with the second melt to the volume of the second melt is 1 cm 2 : 55cm 3 , and finally an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase are obtained.

[0076] Comparative Example 1

[0077] The difference from Example 2 is that the surface temperature of the metal adsorption plate is 600° C., and finally an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase are obtained.

[0078] Comparative Example 2

[0079] The difference from Example 2 is that the material of the adsorption plate is graphite, the material of the matrix is ​​C, the crystal structure of C is a hexagonal crystal structure, the surface roughness Sa is 5.8 μm, and finally an aluminum alloy melt and an adsorption plate are obtained.

[0080] The mass content of Fe element in the aluminum alloy melts prepared in the embodiment and the comparative example was measured, and the reduction rate of the iron element content in the aluminum alloy melt compared with the iron element content in the second melt was calculated. The measurement results are shown in Table 1.

[0081] Table 1

[0082]

[0083]

[0084] As can be seen from Table 1, compared with Example 2, the surface temperature of the adsorption plate in Comparative Example 1 is increased from 150°C in Example 1 to 600°C in Comparative Example 1, resulting in a smaller difference between the surface temperature of the adsorption plate and the melt temperature, which is reduced from 590°C in Example 2 to 140°C in Comparative Example 1. The temperature difference in Comparative Example 1 is too small, resulting in a poor removal effect of the Fe element.

[0085] In Comparative Example 2 compared with Example 2, the material of the adsorption plate is replaced by the 45 steel in Example 2 with the high-purity graphite of Comparative Example 2, which results in an increase in the two-dimensional mismatch between the adsorption plate and the primary Fe-rich phase. The lower the two-dimensional mismatch, the easier it is for the primary Fe-rich phase to nucleate on the adsorption plate. A high two-dimensional mismatch, such as in Comparative Example 2, will result in the primary Fe-rich phase being unable to effectively nucleate on the adsorption plate, making it impossible to remove Fe in the aluminum alloy melt.

[0086] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0087] In step S2, by adding Si source and / or Mn source to the first melt to regulate the mass ratio between Fe element, Si element and Mn element in the second melt, it helps to promote the formation of iron-rich phase nuclei. In step S3, by controlling the temperature difference between the metal adsorption plate before insertion and the second melt to be not less than 400°C, it helps to improve the adsorption effect of the metal adsorption plate on the iron-rich phase, thereby helping to further promote the formation of more iron-rich phase nuclei on the surface of the metal adsorption plate, and then helping to improve the removal rate of Fe elements in the cast aluminum alloy. Controlling the two-dimensional mismatch between the (100) surface of the base metal in the metal adsorption plate and the (100) surface of the iron-rich phase to be not higher than 15° helps to improve the interaction force between the metal adsorption plate and the iron-rich phase, thereby helping to promote the formation of nuclei of the iron-rich phase on the metal adsorption plate. The removal method of the present application has a significant iron reduction effect on cast aluminum alloys, solves the separation problem of iron-rich phases and aluminum alloy melts, and the equipment used is simple. The metal adsorption plate can be reused after the iron-rich phase is stripped, which helps to reduce the cost of Fe element removal.

[0088] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for removing Fe element from cast aluminum alloy, characterized in that: The removal method comprises: Step S1, melting the cast aluminum alloy to obtain a first melt; Step S2, adding Si source and / or Mn source to the first melt to obtain a second melt; Step S3, inserting a metal adsorption plate into the second melt to perform iron absorption treatment; Step S4, taking out the metal adsorption plate after the iron absorption treatment to obtain an aluminum alloy melt and a metal adsorption plate adsorbing an iron-rich phase; The temperature difference between the metal adsorption plate before insertion and the second melt is not less than 400°C, and the two-dimensional mismatch between the (100) plane of the base metal in the metal adsorption plate and the (100) plane of the iron-rich phase is not higher than 15°.

2. The removal method according to claim 1, characterized in that: In step S2, the temperature of the second melt is 700-800°C; preferably, the temperature of the second melt is 740-780°C; and / or, the mass ratio of Si element, Fe element and Mn element in the second melt is 6-13:0.1-2:0.1-3; preferably, it is 6.71-12.04:0.95-1.05:1.26-2.

15.

3. The removal method according to claim 1 or 2, characterized in that: In step S3, the temperature of the metal adsorption plate before insertion is 50-300°C, preferably 50-150°C; and / or the ratio of the surface area of ​​the metal adsorption plate in contact with the second melt to the volume of the second melt is 1 cm 2 :1~50cm 3 .

4. The removal method according to any one of claims 1 to 3, characterized in that: The surface roughness Sa of the metal adsorption plate is greater than 1 μm, preferably 2.2 to 3.2 μm.

5. The removal method according to any one of claims 1 to 4, characterized in that: The iron absorption treatment includes a cooling stage and a heat preservation stage performed sequentially; the cooling rate of the second melt in the cooling stage is 0.1-1°C / s; the temperature of the second melt in the heat preservation stage is 560-660°C; and / or the heat preservation time in the heat preservation stage is 10-120min.

6. The removal method according to any one of claims 1 to 5, characterized in that: The two-dimensional mismatch between the (100) plane of the base metal in the metal adsorption plate and the (100) plane of the iron-rich phase is 0.22° to 14.7°; and / or, the crystal structure of the base metal is a cubic structure; preferably, the material of the metal adsorption plate is selected from any one or more of 45 steel, nickel-based alloy and metal molybdenum.

7. The removal method according to any one of claims 1 to 6, characterized in that: The temperature of the first melt is 700-800°C; preferably, the temperature of the first melt is 740-780°C.

8. The removal method according to any one of claims 1 to 7, characterized in that: The melting point of the metal adsorption plate is greater than 800°C.

9. The removal method according to any one of claims 1 to 8, characterized in that: The metal adsorption plates are parallel to each other and are arranged in multiple intervals; preferably, the distance between two adjacent metal adsorption plates is not less than 5 mm, preferably 50-100 mm.

10. The removal method according to any one of claims 1 to 9, characterized in that: The step S1 further includes measuring the Fe element content, the Si element content and the Mn element content in the first melt to calculate the amount of the Si source and / or the Mn source that needs to be added.

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