Wear-resistant aluminum alloy material and method for manufacturing the same

Abstract

The application provides a wear-resistant aluminum alloy material and a preparation method thereof, and the preparation method comprises the following steps: (1) performing process treatment according to the component proportion of the aluminum alloy to obtain the aluminum alloy; (2) removing the aluminum oxide film layer on the surface of the aluminum alloy by alkali washing, so that the Mg2Sn phase and / or the Mg3Bi2 phase in the aluminum alloy is exposed on the surface to obtain the aluminum alloy after alkali washing; and (3) annealing the aluminum alloy after alkali washing in the step (2) in an oxygen-containing atmosphere, so that a composite oxide layer is formed on the surface of the aluminum alloy, and the wear-resistant aluminum alloy material is obtained, and the thickness of the composite oxide layer is greater than or equal to 5.5 nm. The surface of the wear-resistant aluminum alloy material prepared by the application has the composite oxide layer, and the wear resistance is significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wear resistance improvement of aluminum alloy, and particularly relates to a wear-resistant aluminum alloy material and a preparation method thereof. BACKGROUND

[0002] With the expanding application range and increasing demand of 3C products in economic production and life, the selection of the material is particularly important, which has an important influence on the use performance, safety performance and ornamental value of the products.

[0003] Metal materials have better appearance texture, heat conductivity, electromagnetic radiation shielding and recyclability, and are more popular with users. Currently, the metal materials commonly used in 3C products are mainly conventional 5-series Al-Mg aluminum alloys. However, the appearance requirements for materials are very strict for appearance parts such as 3C product shells, especially in the process of daily use, it is expected that no scratches will be easily generated. Therefore, improving the wear resistance of the existing conventional 5-series Al-Mg aluminum alloys or other alloys is an important modification direction for improving the appearance performance of products. SUMMARY

[0004] In view of the problems in the prior art, the present application provides a wear-resistant aluminum alloy material and a preparation method thereof. Sn and / or Bi elements are introduced into the aluminum alloy material, and the aluminum oxide film layer on the surface of the aluminum alloy is removed by alkali washing, so that the Mg2Sn phase and / or Mg3Bi2 phase in the aluminum alloy is exposed on the surface. After the surface is annealed in an oxygen-containing atmosphere, a composite oxide layer is formed, and the composite oxide layer has high wear resistance.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a preparation method of a wear-resistant aluminum alloy material, which comprises the following steps:

[0007] (1) The aluminum alloy is obtained by process treatment according to the component proportion of the aluminum alloy. The component proportion of the aluminum alloy contains Mg, and the component proportion of the aluminum alloy also contains Sn and / or Bi;

[0008] (2) The aluminum oxide film layer on the surface of the aluminum alloy is removed by alkali washing, so that the Mg2Sn phase and / or Mg3Bi2 phase in the aluminum alloy is exposed on the surface, and an aluminum alloy after alkali washing is obtained;

[0009] (3) after the alkaline cleaning in step (2), the aluminum alloy is annealed in an oxygen-containing atmosphere to form a composite oxide layer on the surface of the aluminum alloy, thereby obtaining the wear-resistant aluminum alloy material; the composite oxide layer comprises a first oxide and a second oxide; the first oxide comprises MgO and Al2O3, and the second oxide comprises SnO2 and / or Bi2O3; and the thickness of the composite oxide layer is greater than or equal to 5.5 nm.

[0010] The present application realizes the purpose by modifying the surface of the aluminum alloy material, specifically, adding Sn and / or Bi elements in the alloy, on the one hand, Sn and / or Bi elements will gradually diffuse from the inside to the surface under long-term heating conditions; on the other hand, Sn and Bi elements generate Mg2Sn and Mg3Bi2 phases with Mg elements during the smelting process, and the original aluminum oxide film on the surface is removed during the alkaline cleaning, and the Mg2Sn and Mg3Bi2 phases are exposed; when the surface composition contains a large amount of Mg and Sn and / or Bi, a high-thickness composite oxide layer is generated on the surface under the continuous heating and oxygen environment, and the surface with such properties is proved to have higher wear resistance.

[0011] It is worth noting that when the aluminum alloy material contains only one of Sn and / or Bi elements, the element content of Sn or Bi diffused to the surface is lower than that when the Sn and Bi elements are contained simultaneously, and research shows that when the Sn and Bi elements are contained simultaneously, it is beneficial to break the diffusion limit when only a single element is contained, so that under the same total content of Sn and Bi elements, it is preferred to contain Sn and Bi elements simultaneously, which better improves the composite oxide layer on the surface and has better wear resistance.

[0012] Preferably, the component of the aluminum alloy in step (1) comprises Sn and / or Bi: 0.1-1wt%, for example, it can be 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt% or 1wt% and the like; the diffusion limit of Sn and Bi is both 0.1wt%, therefore, it is preferred to comprise Sn≥0.1wt% and Bi≥0.1wt%.

[0013] Too little Sn and Bi in the present application will result in no improvement, and too much Sn and Bi will result in a decrease in the melting point of the material and an increase in brittleness.

[0014] The component of the aluminum alloy in step (1) comprises Mg, and the Mg content in the 5 series alloy commonly used in 3C is 2.2-6.5wt%, for example, it can be 2.2wt%, 3wt%, 4.3wt%, 5.4wt%, 5.5wt%, 5.8wt%, 6.0wt%, 6.2wt% or 6.5wt% and the like, preferably, Mg: 5.0-6.5wt%.

[0015] It is worth mentioning that Mg and Al form Al3Mg2 metal compound in the aluminum alloy, good processability and high strength can be obtained, the content of Mg in the general conventional 5 series aluminum alloy is 2.2wt-6.5wt%, too low Mg element leads to insufficient processability and strength, and too high Mg element will lead to excessive oxidation of the material, resulting in blackening of the surface of the material. The Mg is preferably 5.0-6.5wt%, the best strength can be obtained.

[0016] In the present application, in addition to improving the strength of the material by Al-Mg metal compound, Mg element reacts with Sn and Bi elements to form Mg2Sn and Mg3Bi2 strengthening phase; in the subsequent processing process, the Mg2Sn and Mg3Bi2 strengthening phase exposed by alkali washing is finally converted into new oxides, which contributes to the improvement of surface wear resistance; the unexposed part exists in the form of Mg2Sn and Mg3Bi2 strengthening phase, which contributes to the improvement of strength.

[0017] Preferably, the value of Sn+1 / 3Bi is 0.53-0.7wt%, for example, it can be 0.53wt%, 0.55wt%, 0.56wt%, 0.6wt%, 0.62wt%, 0.65wt% or 0.7wt% and the like, preferably 0.6-0.7wt%.

[0018] Due to the existence of a large amount of Mg element in the system, after adding Sn and / or Bi element, it reacts with Mg to exist in the form of Mg2Sn and / or Mg3Bi2 strengthening phase in the aluminum alloy, and the amount of strengthening phase determines the difference in strength, since the density of strengthening phase obtained by Sn is about 3 times that of Bi under the same quality, when the total content of Sn+1 / 3Bi is controlled at 0.53-0.7wt%, the alloy material has better strength performance.

[0019] When the total content of Sn+1 / 3Bi is more than 0.6wt%, the alloy material has better wear resistance performance, because the more the strengthening phase distributed on the surface, the more the Sn oxide and Bi oxide formed in the later stage; therefore, it is further preferred that the content of Sn+1 / 3Bi is 0.6-0.7wt%.

[0020] Preferably, the pH value of the alkali solution in step (2) is 12-14, for example, it can be 12, 12.2, 12.5, 12.8, 13.0, 13.2, 13.5, 13.8 or 14.0 and the like.

[0021] The pH value in the application is selected at 12-14, if the pH value is too low, the oxide film on the surface of the aluminum roll is not completely removed, the subsequent oxidation cannot be carried out, and the Mg2Sn and Mg3Bi2 phases cannot be highlighted, and if the pH value is too high, the aluminum roll is excessively cleaned, and the material surface is blackened.

[0022] The application does not have special requirements for the alkali material for the alkali cleaning, which can be sodium hydroxide, potassium hydroxide or other strong alkalis commonly used in the art.

[0023] Preferably, the speed of the alkali cleaning in step (2) is 60-80 m / min, for example, it can be 60 m / min, 62 m / min, 65 m / min, 68 m / min, 70 m / min, 72 m / min, 75 m / min, 78 m / min or 80 m / min, etc. If the cleaning speed is too slow, the alkali cleaning is excessive, the material surface is whitened, and the material loses metallic luster; if the cleaning speed is too fast, the oxide film is not completely removed, and the formation of the new oxide film is affected.

[0024] Preferably, the flow rate of oxygen in the oxygen-containing atmosphere in step (3) is 40-80 m 3 / h, for example, it can be 40 m 3 / h, 45 m 3 / h, 50 m 3 / h, 55 m 3 / h, 60 m 3 / h, 65 m 3 / h, 70 m 3 / h, 75 m 3 / h or 80 m 3 / h, etc. The temperature of the annealing in step (3) is 200-250℃, for example, it can be 200℃, 210℃, 220℃, 225℃, 230℃, 235℃, 240℃, 245℃ or 250℃, etc., and the annealing time is 20-25 h, for example, it can be 20 h, 20.5 h, 21 h, 22 h, 23 h, 24 h or 25 h, etc.

[0025] The annealing temperature is 200-250℃, because in this temperature range, Sn, Bi and Mg elements are fully diffused to the surface of the aluminum roll, combined with O2 in the furnace to form a composite oxide layer of MgO, SnO2 and Bi2O3, and the Mg2Sn and Mg3Bi2 phases exposed by the alkali cleaning are also oxidized into MgO, SnO2 and Bi2O3. The oxygen flow rate, the annealing temperature and the annealing time jointly determine the surface oxidation capacity and finally determine the thickness of the oxide layer, and the application can obtain a composite oxide layer with a total oxide layer thickness of 10-20 nm.

[0026] In a second aspect, the present application provides a wear-resistant aluminum alloy material, which is prepared by the method of the first aspect.

[0027] Preferably, the surface of the wear-resistant aluminum alloy material has a composite oxide layer; the composite oxide layer comprises a first oxide and a second oxide; the first oxide comprises MgO and Al2O3, and the second oxide comprises SnO2 and / or Bi2O3. Preferably, the second oxide comprises SnO2 and Bi2O3.

[0028] Preferably, the composite oxide layer contains both SnO2 and Bi2O3, which is beneficial to breaking the limit of single-factor diffusion, improving the surface of the aluminum alloy better, and having higher wear resistance.

[0029] Preferably, the thickness of the composite oxide layer is 10-20 nm, for example, it can be 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm or 20 nm, etc.

[0030] The thickness of the composite oxide layer is controlled to be 10-20 nm in the present application, and the thickness of the composite oxide layer is controlled within the above range by adjusting the oxygen flow rate, the annealing temperature and the annealing time. When the thickness is too low, the wear resistance of the material is not significantly improved, and when the thickness is too thick, the heat conduction performance of the product is affected.

[0031] The process treatment in the above process is not particularly limited in the present application, and any process flow known to those skilled in the art that can be used for aluminum alloy process treatment can be used, and the process can also be adjusted according to the actual process. For example, the process flow comprises: according to the component proportion of the aluminum alloy, sequentially performing melting, refining and casting to obtain an aluminum alloy ingot; and the aluminum alloy ingot is sequentially subjected to homogenization treatment, hot rolling and cold rolling.

[0032] Compared with the prior art, the present application has at least the following beneficial effects:

[0033] (1) The wear-resistant aluminum alloy material provided by the present application has a composite oxide layer on the surface compared with conventional 5-series aluminum alloys, the composite oxide layer contains SnO2 and / or Bi2O3, and also contains MgO and Al2O3, and the composite oxide layer has excellent wear resistance, so that the aluminum alloy material has excellent wear resistance. Under the preferred conditions, the tensile strength of the wear-resistant aluminum alloy material is ≥350 MPa, and the wear resistance is ≤0.8 mg.

[0034] (2) The preparation method of the wear-resistant aluminum alloy material provided by the application exposes Mg2Sn and Mg3Bi2 strengthening phases by introducing Sn and / or Bi elements and removing the original aluminum oxide film on the surface of the aluminum alloy by alkali washing, and then, under the conditions of oxygen atmosphere and heating, the exposed Mg2Sn and Mg3Bi2 strengthening phases and the Mg, Sn, and Bi elements diffused to the surface in the subsequent annealing process generate a new composite oxide layer in the external oxygen environment, thereby improving the wear resistance of the aluminum alloy.

[0035] (3) The wear-resistant aluminum alloy material provided by the application can further increase the content of Mg elements on the basis of the traditional 5-series aluminum alloy, so that the Mg, Sn, and / or Bi, and O elements form a composite oxide layer to strengthen the wear resistance of the surface of the aluminum alloy. DETAILED DESCRIPTION

[0036] The technical solutions of the application will be further described below through specific embodiments.

[0037] As one specific embodiment of the application, the components of the wear-resistant aluminum alloy material provided by the application include, by mass fraction: Si: 0.1% to 0.3%, Fe: 0.1% to 0.5%, Cu: 0 to 0.05%, Mn: 0.15% to 0.6%, Cr: 0.05% to 0.2%, Zn: 0.1% to 0.25%, Mg: 5.0% to 6.5%, Sn and / or Bi: 0.1% to 1%, and the rest is Al or unavoidable impurities.

[0038] As one specific embodiment of the application, the process treatment of the wear-resistant aluminum alloy material provided by the application includes the following steps: according to the component ratio of the aluminum alloy, alloy elements and aluminum metal raw materials are added to a smelting furnace for smelting, refining, and stirring treatment, and then a semi-continuous casting is performed through a casting machine to obtain an aluminum alloy ingot; the aluminum alloy ingot is subjected to heat soaking treatment; the ingot after heat soaking treatment is subjected to preheating treatment before hot rolling, and an aluminum alloy coil with a thickness of 6 to 8 mm is obtained through hot rolling; the aluminum alloy coil after hot rolling is subjected to cold rolling to obtain an aluminum coil with a finished thickness of 0.1 mm to 0.3 mm.

[0039] The setting of the smelting temperature is a conventional process, and those skilled in the art can adjust it according to the specific alloy formula, for example, for 5XXX series Al-Mg alloy, the smelting temperature is 750°C to 780°C.

[0040] The setting of the heat soaking treatment temperature is a conventional process, and those skilled in the art can adjust it according to the specific alloy formula, for example, for 5XXX series Al-Mg alloy, a typical process window is 605-625°C, and the heat soaking time is 12-15h to ensure the hot working performance of the ingot and prevent the high-Mg alloy from producing edge cracks.

[0041] The temperature of pre-heating before hot rolling is set as a conventional process, and the 5-series aluminum alloy has a high hardening degree, so it needs to be pre-heated. After heating, the alloy becomes soft, so that the hot-rolled coil can be stably rolled out. For example, it can be set to 490-520°C, and the holding time is 2-3h.

[0042] The cold rolling is a conventional process. Due to the different rolling control capabilities of existing equipment rolling mills, the usual rolling process needs to be carried out in multiple passes, and cold rough rolling, medium rolling and foil rolling are carried out respectively. For example, the cold rough rolling controls the thickness of the aluminum coil to be 1.1-1.5mm, the medium rolling mill is used for medium rolling, and the thickness of the aluminum coil is controlled to be 0.55-0.6mm. The aluminum coil after medium rolling is foil rolled to the finished product thickness of 0.1-0.3mm aluminum coil.

[0043] The application will be further described in detail below. However, the following examples are only simple examples of the application and do not represent or limit the protection scope of the application. The protection scope of the application is subject to the claims.

[0044] For the convenience of the experiment, the process treatment of the wear-resistant aluminum alloy material in the following examples includes the following steps: according to the component proportion of the aluminum alloy, alloy elements and aluminum metal raw materials are added to a melting furnace for melting, the melting temperature is 760°C, then refining and stirring treatment are carried out, and then a semi-continuous casting machine is used for semi-continuous casting to obtain an aluminum alloy ingot; the aluminum alloy ingot is subjected to 500°C soaking treatment for 10h; the ingot after soaking treatment is pre-heated to 490°C for 2h before hot rolling, and an aluminum alloy coil with a thickness of 7mm is obtained by hot rolling; the aluminum alloy coil after hot rolling is cold-rolled to obtain an aluminum coil with a finished product thickness of 0.1-0.5mm.

[0045] It is worth noting that the finished product aluminum coil is generally controlled in the thickness range of 0.1-0.5mm. In this range, experimental verification shows that the thickness of the aluminum coil does not substantially affect the thickness of the oxidation layer of the final material and the wear resistance of the material surface, so examples of other thicknesses are not listed.

[0046] The components of the aluminum alloy used in the following examples and comparative examples include, by mass fraction: Si: 0.2%, Fe: 0.1%, Cu: 0.05%, Mn: 0.3%, Cr: 0.1%, Zn: 0.1%, Mg: 5.0%-6.5%, Sn and / or Bi: 0.1%-1%, and the rest is Al or unavoidable impurities. The specific parameters of the examples and comparative examples are shown in Table 1.

[0047] Table 1

[0048]

[0049] The same as 1 in Table 1 indicates the same setting as that of Example 1, and the same as 6 indicates the same setting as that of Example 6.

[0050] Element composition test: a sample with a width of 20 mm and a length of 100 mm is taken, and an ARLeasySpark full-spectrum direct-reading spark analyzer is used to detect the composition of the sample to determine whether the content of each element is within the design range and whether it is qualified.

[0051] Oxide film thickness test: a sample with a size of thickness (0.1-0.5) * width 20 mm * length 20 mm is taken, and a Talos F200i field emission projection electron microscope is used to observe the cross-sectional morphology and measure the thickness of the oxide film.

[0052] Mechanical property test: according to GB / T228.1-2010 Metal Materials Tensile Test Part 1: Room Temperature Test Method, a Zwick universal material testing machine is used to test the tensile strength of the material.

[0053] Wear resistance test: according to the standard of ASTM D5706, a sample with a size of 50 mm in length * 20 mm in width * 0.1-0.5 mm in thickness is taken, a UMT2 type friction and wear testing machine is used, a linear reciprocating motion is adopted, the friction contact mode is spherical contact, and the counterpart is a GCr15 steel ball. The friction time is 20 min. Before the experiment, the sample is polished to 3500# with sandpaper to ensure the uniformity of the surface roughness of the workpiece. The loading load is 10 N, and the speed is 12 mm / s. Then, a BalanceXPR106DUHQ / AC electronic analytical balance is used to measure the mass wear amount of the sample, and the wear resistance of the material is judged according to the size of the wear amount. The greater the wear amount, the lower the wear resistance, and vice versa, the smaller the wear amount, the higher the wear resistance.

[0054] The test results of the examples and comparative examples are shown in Table 2.

[0055] Table 2

[0056]

[0057] From Tables 1-2, the following points can be seen:

[0058] (1) As can be seen from Examples 1-7, the preparation method of the wear-resistant aluminum alloy material provided by the present application removes the aluminum oxide film layer by using alkali washing, and then adds Sn and / or Bi elements and anneals in an oxygen-containing atmosphere to form a composite oxide layer on the surface of the aluminum alloy, thereby obtaining a wear-resistant aluminum alloy material. The tensile strength of the wear-resistant aluminum alloy material is ≥350 MPa, and the wear resistance is ≤0.8 mg.

[0059] (2) The effect of oxide film removal on the wear resistance of the aluminum alloy material

[0060] From the comprehensive example 1 and comparative examples 2-3, it can be seen that the pH value of the alkali washing in comparative example 2 is only 11, and the alkali concentration is too low, which leads to incomplete removal of the aluminum oxide film on the surface of the aluminum coil, and the subsequent oxidation is difficult to carry out, and the surface cannot form a composite oxide layer, and after subsequent annealing, the surface is still aluminum oxide, and finally the wear resistance of comparative example 2 increases from 0.25mg in example 1 to 6.8mg, and the wear resistance is significantly reduced; the speed of the alkali washing in comparative example 3 is 90m / min, and the alkali washing speed is too fast, and compared with example 1, the aluminum oxide film is not completely removed, which seriously affects the formation of the new composite oxide layer, and finally the wear resistance and tensile strength are significantly reduced compared with example 1, which shows that the removal of the surface aluminum oxide film by controlling the pH and the speed of the alkali washing can be beneficial to the formation of the subsequent composite oxide layer, and finally improve the wear resistance and tensile strength of the aluminum alloy.

[0061] (3) The influence of the thickness of the composite oxide on the wear resistance of the aluminum alloy material

[0062] From the comprehensive example 6 and examples 8-13, it can be seen that in example 6, the surface forms a 10nm thick MgO+Al2O3+SnO2+Bi2O3 composite oxide layer, while in examples 8-13, the thickness of the surface composite oxide layer is less than 10nm, about 5.5-8nm, and under the same conditions, the wear resistance of example 6 is significantly improved compared with examples 8-13, which shows that by controlling the process parameters, the thickness of the composite oxide layer is controlled in the range of 10-20nm, which significantly improves the wear resistance of the aluminum alloy.

[0063] From the comprehensive examples 1-3, it can be seen that in example 1, Sn and Bi elements are added at the same time, while in examples 2-3, only a single element Sn or Bi is added in equal amount, and the wear resistance of example 1 is 0.25mg, while the wear resistance of examples 2-3 is only 0.8mg and 0.5mg respectively, and the wear resistance is reduced; from the thickness of the oxide layer, it can be known that the addition of Sn and Bi elements has a more significant diffusion effect than the addition of equal amount of Sn elements or Bi elements, and the addition of Sn and Bi elements is beneficial to breaking the diffusion limit when only a single element is contained, thereby having a better effect under the same total content of Sn and Bi elements.

[0064] (4) The influence of the process parameters of the formation process of the composite oxide

[0065] From the comprehensive example 1 and examples 8-9, it can be seen that the oxygen flow rate in example 1 is 50m 3 / h, while the oxygen flow rates in examples 8-9 are 20m 3 / h and 90m 3 / h, wherein the oxygen flow in Example 8 is too low, resulting in too little generation of the amount of oxide, and the thickness of the composite oxide layer is relatively thin; in Example 9, the oxygen flow is too large, resulting in the thickness of the oxide film being less than 10 nm; similarly, it can be seen from the combination of Example 1 and Examples 10-13 that insufficient or excessively long annealing temperature and annealing time can result in a thin oxide film, and ultimately result in the improvement of the wear resistance of the aluminum alloy material not being as significant as that of Example 1; thus, the present application provides a more precise control of the parameter ranges of the oxygen flow, annealing temperature and time during the annealing process, which can better control the thickness of the composite oxide layer within the desired range, thereby ensuring that the tensile strength and wear resistance of the aluminum alloy are at the optimal level.

[0066] (5) Influence of the composition of the composite oxide layer

[0067] It can be seen from the combination of Example 1 and Comparative Example 1 that the composite oxide layer in Example 1 contains SnO2 and Bi2O3 in addition to MgO and Al2O3, while in Comparative Example 1, only MgO and Al2O3 are contained, and the wear resistance is significantly decreased, thus indicating that the presence of SnO2 or Bi2O3 in the composite oxide layer can significantly improve the wear resistance.

[0068] (6) Influence of the addition amount of Sn and Bi elements

[0069] In Examples 1, 4 and 5, the Sn+1 / 3*Bi content is 0.53%, 0.6% and 0.73%, respectively, and compared with Example 1, the wear resistance of Examples 4 and 5 is better, and compared with Example 5, the strength of Examples 4 and 1 is better, thus indicating that the matching of Sn and Bi elements can simultaneously affect the strength and wear resistance, and further optimizing the Sn+1 / 3*Bi content to be controlled within the range of 0.6-0.7% is beneficial to obtaining the best strength and wear resistance effect.

[0070] The applicant declares that the above description is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and those skilled in the art should understand that any changes or replacements within the technical scope disclosed by the present application can be easily thought of by those skilled in the art, and all fall within the protection scope and disclosure scope of the present application.

Claims

1. A method for preparing a wear-resistant aluminum alloy material, characterized in that, The preparation method includes the following steps: (1) The aluminum alloy is obtained by processing according to the composition ratio of the aluminum alloy; the composition ratio of the aluminum alloy contains Mg, and the composition ratio of the aluminum alloy also contains Sn and / or Bi. (2) The aluminum alloy is subjected to alkaline washing to remove the aluminum oxide film layer on the surface of the aluminum alloy, exposing the Mg2Sn phase and / or Mg3Bi2 phase in the aluminum alloy to the surface, and thus obtaining the alkaline-washed aluminum alloy. (3) After the alkaline washing in step (2), the aluminum alloy is annealed in an oxygen-containing atmosphere to form a composite oxide layer on the surface of the aluminum alloy, thereby obtaining the wear-resistant aluminum alloy material; the composite oxide layer includes a first oxide and a second oxide; the first oxide includes MgO and Al2O3, and the second oxide includes SnO2 and / or Bi2O3; The thickness of the composite oxide layer is ≥5.5 nm; The pH value of the alkaline solution used for alkaline washing in step (2) is 12~14; The alkaline washing rate in step (2) is 60~80 m / min; The aluminum alloy mentioned in step (1) is a 5-series aluminum alloy, and the composition includes Sn and / or Bi: 0.1~1wt%; the composition of the aluminum alloy mentioned in step (1) includes Mg: 2.2~6.5wt%; the annealing temperature mentioned in step (3) is 200℃~250℃, and the annealing time is 20~25h.

2. The preparation method according to claim 1, characterized in that, The aluminum alloy in step (1) comprises Mg: 5.0~6.5wt%.

3. The preparation method according to claim 1, characterized in that, The value of Sn+1 / 3Bi mentioned in step (1) is 0.53~0.7wt%.

4. The preparation method according to claim 3, characterized in that, The value of Sn+1 / 3Bi mentioned in step (1) is 0.6~0.7wt%.

5. The preparation method according to claim 1, characterized in that, The oxygen flow rate in the oxygen-containing atmosphere described in step (3) is 40~80m³. 3 / h.

6. A wear-resistant aluminum alloy material, characterized in that, The wear-resistant aluminum alloy material is prepared by the method described in any one of claims 1 to 5.

7. The wear-resistant aluminum alloy material according to claim 6, characterized in that, The thickness of the composite oxide layer is 10~20nm.

Images