A kind of Al-Mg-Si alloy plate and its preparation method and application

Abstract

The present invention provides an Al-Mg-Si alloy plate and a preparation method and application thereof. The Al-Mg-Si alloy plate comprises, by mass percentage, Mg 0.50%-1.5%, Si 0.49%-0.53%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤ 0.02%, and the balance Al; wherein the mass ratio of Mg to Si is greater than 1.0. The present invention enables the Al-Mg-Si alloy plate to have both high strength, electrical conductivity and fatigue resistance.

Description

Technical Field

[0001] The invention relates to an Al-Mg-Si alloy plate, in particular to an Al-Mg-Si alloy plate and a preparation method and application thereof, belonging to the technical field of aluminum alloy profile manufacturing. Background Art

[0002] In the electrical / electronics industry or the automotive industry, most conductive materials use copper and its alloys as the main materials. However, copper has a high density and specific gravity, which increases the weight of the conductive material. Especially when used in the automotive industry, it will significantly increase the energy consumption of the vehicle, which is not conducive to achieving green and low-carbon requirements. Due to the abundant aluminum resources and the advantages of light weight and low price, aluminum alloys have received widespread attention, among which Al-Mg-Si aluminum alloys have become the preferred material due to their superior machinability.

[0003] However, there is an inverse relationship between the strength and conductivity, and between the fatigue resistance and conductivity of Al-Mg-Si alloy plates, making it difficult for Al-Mg-Si alloy plates to have good conductivity, strength and fatigue resistance at the same time.

[0004] An Al-Mg-Si alloy plate having good electrical conductivity, strength and fatigue resistance has good application prospects. Summary of the invention

[0005] The present invention provides an Al-Mg-Si alloy plate material and a preparation method and application thereof, which have good electrical conductivity, strength and fatigue resistance and have good application prospects.

[0006] The present invention provides an Al-Mg-Si alloy plate, which comprises, by mass percentage, Mg 0.50%-1.5%, Si 0.49%-0.53%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, and the balance Al; wherein the mass ratio of Mg to Si is greater than 1.0.

[0007] Optionally, the mass ratio of Mg to Si is (1.0-3.0):1, and the mass ratio of Mg to Si is not equal to 1.

[0008] Optionally, the microstructure of the Al-Mg-Si alloy plate includes a Mg2Si phase and a Mg5Si6 phase; the Mg2Si phase accounts for 0.5% to 1% of the microstructure of the Al-Mg-Si alloy plate, and the Mg5Si6 phase accounts for 10% to 15% of the microstructure of the Al-Mg-Si alloy plate.

[0009] Optionally, the Al-Mg-Si alloy plate has a strength of ≥400 MPa, a conductivity of ≥58% IACS, and a crack growth rate curve slope of ≤3.0.

[0010] Optionally, the Al-Mg-Si alloy plate is prepared by a method comprising at least the following processes: performing homogenization treatment, solution heat treatment, aging heat treatment and cold rolling on the ingot in sequence, wherein the aging heat treatment temperature is 155-165°C and the time is 5-10h, and the deformation amount of the cold rolling is 40%-55%, to obtain the Al-Mg-Si alloy plate.

[0011] The present invention also provides a method for preparing the Al-Mg-Si alloy plate as described above, comprising the following steps: subjecting an ingot to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain the Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 0.50%-1.5%, Si 0.49%-0.53%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the remainder being Al, and the mass ratio of Mg to Si is greater than 1.0.

[0012] Optionally, the temperature of the aging heat treatment is 155-165°C and the time is 5-7h; the deformation of the cold rolling process is 40%-55%.

[0013] Optionally, the homogenization treatment is performed at a temperature of 530-550° C. for 12-24 h; and / or the solution heat treatment is performed at a temperature of 510-530° C. for 2-7 h.

[0014] Optionally, the mass ratio of Mg to Si is (1.0-3.0):1, and the mass ratio of Mg to Si is not equal to 1.

[0015] The present invention also provides an equipment, comprising the Al-Mg-Si alloy plate as described above or the Al-Mg-Si alloy plate obtained by the preparation method as described above.

[0016] The present invention provides an Al-Mg-Si alloy plate and a preparation method and application thereof. The Al-Mg-Si alloy plate has better electrical conductivity, strength and fatigue resistance and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is an electron microscope image of the Mg2Si phase and Mg5Si6 phase in the Al-Mg-Si alloy plate of Example 1. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] An embodiment of the present invention provides an Al-Mg-Si alloy plate, wherein the Al-Mg-Si alloy plate includes, by mass percentage, Mg 0.50%-1.5%, Si 0.49%-0.53%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, and the balance Al; wherein the mass ratio of Mg to Si is greater than 1.0.

[0020] According to the research and analysis of the inventors: a Mg / Si mass ratio greater than 1.0 is conducive to the precipitation of fine dispersed phases in the matrix of the Al-Mg-Si alloy plate, including Mg2Si phase and Mg5Si6 phase, so that it can take into account both high strength and fatigue resistance, and is particularly conducive to obtaining fine Mg5Si6 phase, which more significantly improves the fatigue crack growth resistance of the Al-Mg-Si alloy plate and reduces the fatigue crack growth rate of the Al-Mg-Si alloy plate, which is specifically manifested as the slope of the crack growth rate curve of the Al-Mg-Si alloy plate is ≤3.0. The above-mentioned contents of Mg and Si cooperate with each other to increase the content of the above-mentioned dispersed phase, while effectively refining and rounding harmful coarse precipitated phases such as Al / Fe, further improving the machinability and fatigue resistance of the Al-Mg-Si alloy plate; at the same time, the addition of Fe is beneficial to improving the electrical conductivity of the Al-Mg-Si alloy plate; adding an appropriate amount of La to the above-mentioned Al-Mg-Si alloy plate is beneficial to purifying the melt of the Al-Mg-Si alloy plate, reducing the grain size of the Al-Mg-Si alloy plate, thereby improving the electrical conductivity of the Al-Mg-Si alloy plate; adding the B element helps to refine the grains of the Al-Mg-Si alloy plate, purify the grain boundaries, and is beneficial to improving the strength and electrical conductivity of the Al-Mg-Si alloy plate; the embodiment of the present invention limits Mg0.50-1.5%, Si 0.49-0.53%, Fe 0.11-0.18%, La 0.03-0.05%, B 0.005-0.02%, among which the mass ratio of Mg to Si is greater than 1.0, which makes the synergistic effect of various elements better, so that the Al-Mg-Si alloy plate has better conductivity, strength and fatigue resistance.

[0021] Exemplarily, in the Al-Mg-Si alloy plate, the mass percentage of Mg may be 0.50%, 0.60%, 0.70%, 0.80%, 0.90%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, or a range consisting of any two thereof, the mass percentage of Si may be 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, or a range consisting of any two thereof, the mass percentage of Fe may be 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, or a range consisting of any two thereof, the mass percentage of La may be 0.03%, 0.04%, 0.05%, or a range consisting of any two thereof, and the mass percentage of B may be 0.005%, 0.01%, 0.02%, or a range consisting of any two thereof.

[0022] Furthermore, the impurities include at least one of Ti, Mn, Cr, and V. In the Al-Mg-Si alloy plate, the mass percentage of Ti is ≤0.005%, the mass percentage of Mn is ≤0.005%, the mass percentage of Cr is ≤0.005%, and the mass percentage of V is ≤0.005%, which helps to improve the electrical conductivity, strength and fatigue resistance of the Al-Mg-Si alloy plate.

[0023] In some embodiments, the mass ratio of Mg to Si is (1.0-3.0):1, for example, 1.1:1, 1.5:1, 2.0:1, 2.5:1, 3.0:1 or a range consisting of any two of them, and the mass ratio of Mg to Si is not equal to 1, and the Al-Mg-Si alloy plate has better conductivity, strength and fatigue resistance.

[0024] The microstructure of Al-Mg-Si alloy sheet has a key influence on its performance.

[0025] The microstructure of the Al-Mg-Si alloy plate includes Mg2Si phase and Mg5Si6 phase.

[0026] In some embodiments, the Mg2Si phase accounts for 0.5% to 1% of the microstructure of the Al-Mg-Si alloy plate, such as 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1% or any two of them, and the Mg5Si6 phase accounts for 10% to 15% of the microstructure of the Al-Mg-Si alloy plate, such as 10%, 11%, 12%, 13%, 14%, 15% or any two of them, so that the Al-Mg-Si alloy plate has not only good electrical conductivity but also high strength and fatigue resistance.

[0027] The size ranges of the above-mentioned Mg2Si phase and Mg5Si6 phase are 10-50nm in diameter, 40-100nm in length, and 0.5-3nm in width, respectively. These fine dispersed phases help to improve the strength of the Al-Mg-Si alloy sheet. From the proportion of the above-mentioned Mg2Si phase and Mg5Si6 phase in the microstructure of the Al-Mg-Si alloy sheet, it can be seen that a fine dispersed phase with a high number density is formed in the crystal of the Al-Mg-Si alloy sheet, which reduces the fatigue crack growth rate of the Al-Mg-Si alloy sheet. The slope of the crack growth rate curve of the Al-Mg-Si alloy sheet is ≤3.0, so that the Al-Mg-Si alloy sheet not only has good electrical conductivity but also takes into account high strength and fatigue resistance.

[0028] The above proportions are all volume fraction proportions, that is, the volume percentage of the Mg2Si phase to the volume percentage of the microstructure of the Al-Mg-Si alloy plate is 0.5%~1%, and the volume percentage of the Mg5Si6 phase to the volume percentage of the microstructure of the Al-Mg-Si alloy plate is 10%~15%.

[0029] In some embodiments, the Al-Mg-Si alloy plate has a strength of ≥400 MPa, a conductivity of ≥58% IACS, and a crack growth rate curve slope of ≤3.0.

[0030] The slope of the crack growth rate curve refers to the slope of the linear fitting line of the crack growth rate da / dN and the stress field intensity factor ΔK. The smaller the value, the better the fatigue resistance of the material. The slope of the crack growth rate curve of the Al-Mg-Si alloy plate of the present invention is ≤3.0, indicating that the Al-Mg-Si alloy plate has good fatigue resistance and thus has a longer service life.

[0031] The above-mentioned Al-Mg-Si alloy sheet not only has the advantages of light weight and good processing performance, but also has good conductivity, strength and fatigue resistance. It can be processed into conductive sheets, etc., and has good application prospects.

[0032] The Al-Mg-Si alloy plate is prepared by a method comprising at least the following steps:

[0033] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence, wherein the temperature of the aging heat treatment is 155-165°C, for example, 155°C, 156°C, 157°C, 158°C, 159°C, 160°C, 161°C, 162°C, 163°C, 164°C, 165°C or a range consisting of any two thereof, the time of the aging heat treatment is 5-10h, for example, 5h, 6h, 7h, 8h, 9h, 10h or a range consisting of any two thereof, and the deformation amount of the cold rolling is 40%-55%, for example, 40%, 45%, 50%, 55% or a range consisting of any two thereof, to obtain an Al-Mg-Si alloy plate.

[0034] It is understandable that the chemical composition of the above ingot satisfies Mg 0.50-1.5%, Si 0.49-0.53%, Fe 0.11-0.18%, La 0.03-0.05%, B 0.005-0.02%, impurities ≤ 0.02%, the balance is Al, and the mass ratio of Mg to Si is greater than 1.0.

[0035] Through the synergistic effects of homogenization treatment, solution heat treatment, aging heat treatment and cold rolling on the above-mentioned ingot, the treated ingot forms fine dispersed phases such as Mg2Si phase and Mg5Si6 phase, and finally the conductivity, strength and fatigue resistance of the Al-Mg-Si alloy plate are better improved.

[0036] An embodiment of the present invention also provides a method for preparing the above-mentioned Al-Mg-Si alloy plate, comprising the following steps: performing homogenization treatment, solution heat treatment, aging heat treatment and cold rolling on an ingot in sequence to obtain the above-mentioned Al-Mg-Si alloy plate; wherein the chemical composition of the above-mentioned ingot is Mg 0.50-1.5%, Si 0.49-0.53%, Fe 0.11-0.18%, La 0.03-0.05%, B 0.005-0.02%, impurities ≤0.02%, the remainder is Al, and the mass ratio of Mg to Si is greater than 1.0.

[0037] By combining the above homogenization treatment, solution heat treatment, aging heat treatment and cold rolling, a better synergistic effect is exerted, so that the Al-Mg-Si alloy plate has good electrical conductivity, strength and fatigue resistance. The preparation method of the Al-Mg-Si alloy plate is simple to operate, low in cost, and easy to promote. By preparing the method, an Al-Mg-Si alloy plate with good electrical conductivity, strength and fatigue resistance can be obtained.

[0038] The embodiment of the present invention does not limit the preparation process of the above-mentioned ingot, and it can be carried out in a manner commonly used in the art.

[0039] In some embodiments, the temperature of the aging heat treatment is 155-165°C and the time is 5-7h; the deformation of the cold rolling process is 40%-55%. The aging heat treatment process allows the alloy elements to further precipitate, forming fine dispersed phases such as Mg2Si phase and Mg5Si6 phase, which is beneficial to improve the strength of the Al-Mg-Si alloy plate and significantly reduce the fatigue crack growth rate of the Al-Mg-Si alloy plate. By further limiting the temperature of the aging heat treatment to 155-165°C and the time to 5-7h, it is helpful to improve the number density and uniformity of fine dispersed phases such as Mg2Si phase and Mg5Si6 phase, thereby significantly improving the strength and fatigue resistance of the Al-Mg-Si alloy plate. Cold rolling can improve the deformation energy storage of the Al-Mg-Si alloy plate, increase the number of dislocations, greatly improve the strength of the Al-Mg-Si alloy plate, and further limit the deformation of the cold rolling process to 40%-55%, so that the conductivity, strength and fatigue resistance of the Al-Mg-Si alloy plate are better improved.

[0040] Exemplarily, the temperature of the aging heat treatment may be 155°C, 158°C, 160°C, 162°C, 165°C or a range consisting of any two thereof, and the time of the aging heat treatment may be 5h, 5.5h, 6h, 6.5h, 7h or a range consisting of any two thereof, preferably 160°C and 7h, and the precipitation effect of fine dispersed phases such as Mg2Si phase and Mg5Si6 phase is better, especially the precipitation effect of Mg5Si6 phase is better, so that the conductivity, strength and fatigue resistance of the Al-Mg-Si alloy plate are better improved.

[0041] The homogenization treatment can improve the inhomogeneous state of the crystal structure of the above-mentioned ingot, reduce or eliminate the intracrystalline segregation, and help the fine dispersed phases such as Mg2Si phase and Mg5Si6 phase to precipitate more uniformly.

[0042] In some embodiments, the temperature of the above homogenization treatment is 530-550°C and the time is 12-24h, which is more conducive to improving the uneven crystal structure of the above ingot, reducing or eliminating intracrystalline segregation, and further contributing to more uniform precipitation of fine dispersed phases such as Mg2Si phase and Mg5Si6 phase.

[0043] Since the heating rate and cooling rate of the homogenization treatment will also affect the effect of the homogenization treatment and thus affect the performance of the product, when the heating rate of the above-mentioned homogenization treatment is 100-300°C / h, for example, 100°C / h, 150°C / h, 200°C / h, 250°C / h, 300°C / h or a range consisting of any two thereof, and the cooling rate is 50-70°C / s, for example, 50°C / s, 55°C / s, 60°C / s, 65°C / s, 70°C / s or a range consisting of any two thereof, the effect of the homogenization treatment is better, thereby further improving the performance of the product.

[0044] The purpose of solution heat treatment is to obtain the maximum supersaturation, which is beneficial to improve the effect of the subsequent aging heat treatment. Through solution heat treatment, the excess phase in the Al-Mg-Si alloy plate is fully dissolved into the matrix, and the eutectic silicon phase is spheroidized, so that the Al-Mg-Si alloy plate obtains better strength and fatigue resistance. Selecting appropriate solution temperature and holding time can ensure that the matrix of the Al-Mg-Si alloy plate is strengthened to a greater extent. When the temperature of the above-mentioned solution heat treatment is 510-530°C, such as 510°C, 515°C, 520°C, 525°C, 530°C or a range composed of any two thereof, and the time of the solution heat treatment is 2-7h, such as 2h, 3h, 4h, 5h, 6h, 7h or a range composed of any two thereof, the effect of the solution heat treatment is better.

[0045] A third aspect of the present invention provides an apparatus comprising the above-mentioned Al-Mg-Si alloy plate or the Al-Mg-Si alloy plate obtained by the above-mentioned preparation method.

[0046] The present invention is described in more detail below through specific examples and comparative examples.

[0047] Example 1

[0048] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0049] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 0.8%, Si 0.53%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the balance is Al, and the mass ratio of Mg to Si is 1.5; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0050] Example 2

[0051] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0052] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 1.0%, Si 0.5%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the remainder is Al, and the mass ratio of Mg to Si is 2; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0053] Example 3

[0054] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0055] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 1.5%, Si 0.49%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the balance is Al, and the mass ratio of Mg to Si is 3.06; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0056] Example 4

[0057] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0058] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 1.0%, Si 0.5%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the balance is Al, and the mass ratio of Mg to Si is 2; the temperature of the aging heat treatment is 165°C and the time is 5h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0059] Example 5

[0060] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0061] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 1.0%, Si 0.5%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the remainder is Al, and the mass ratio of Mg to Si is 2; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 40%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0062] Example 6

[0063] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0064] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 1.0%, Si 0.5%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the remainder is Al, and the mass ratio of Mg to Si is 2; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 550°C and the time is 12h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0065] Example 7

[0066] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0067] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 1.0%, Si 0.5%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the remainder is Al, and the mass ratio of Mg to Si is 2; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 530°C and the time is 2h.

[0068] Example 8

[0069] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0070] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 1.0%, Si 0.5%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the remainder is Al, and the mass ratio of Mg to Si is 2; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 560°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0071] Example 9

[0072] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0073] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 1.0%, Si 0.5%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the balance is Al, and the mass ratio of Mg to Si is 2; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 550°C and the time is 7h.

[0074] Example 10

[0075] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0076] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 0.8%, Si 0.53%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the balance is Al, and the mass ratio of Mg to Si is 1.5; the temperature of the aging heat treatment is 180°C and the time is 3h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0077] Embodiment 11

[0078] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0079] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 0.8%, Si 0.53%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the balance is Al, and the mass ratio of Mg to Si is 1.5; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 35%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0080] Example 12

[0081] This embodiment is basically the same as Embodiment 10, except that:

[0082] The temperature of the aging heat treatment is 145°C.

[0083] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0084] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 0.8%, Si 0.53%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the balance is Al, and the mass ratio of Mg to Si is 1.5; the temperature of the aging heat treatment is 145°C and the time is 3h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0085] Example 13

[0086] This embodiment is basically the same as Embodiment 10, except that:

[0087] The deformation amount of cold rolling is 65%.

[0088] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0089] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 0.8%, Si 0.53%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the balance is Al, and the mass ratio of Mg to Si is 1.5; the temperature of the aging heat treatment is 180°C and the time is 3h; the deformation of the cold rolling is 65%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0090] Comparative Example 1

[0091] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0092] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 0.8%, Si 0.8%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the remainder is Al, and the mass ratio of Mg to Si is 1; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0093] Comparative Example 2

[0094] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0095] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 0.5%, Si 0.55%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, the balance is Al, and the mass ratio of Mg to Si is 0.9; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0096] Comparative Example 3

[0097] This embodiment provides a method for preparing an Al-Mg-Si alloy plate, comprising the following steps:

[0098] The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain an Al-Mg-Si alloy plate; wherein the chemical composition of the ingot is Mg 0.4%, Si 2.0%, Fe 1.0%, La 0.03%-0.05%, B0.005%-0.02%, impurities ≤0.02%, the remainder is Al, and the mass ratio of Mg to Si is 0.2; the temperature of the aging heat treatment is 155°C and the time is 7h; the deformation of the cold rolling is 55%; the temperature of the homogenization treatment is 530°C and the time is 24h; the temperature of the solution heat treatment is 510°C and the time is 7h.

[0099] Test example

[0100] 1. The following parameters of the Al-Mg-Si alloy plates of the above embodiments and comparative examples were tested:

[0101] 1) Strength: tensile test method using a universal testing machine; see Table 1 for specific results;

[0102] 2) Conductivity: bridge method; see Table 1 for specific results;

[0103] 3) Slope of crack growth rate curve: tension-compression cyclic loading method; specific results are shown in Table 1;

[0104] 4) Proportion of Mg2Si phase and Mg5Si6 phase: Image Pro statistical method; specific results are shown in Table 1;

[0105] 5) Electron micrographs of Mg2Si phase and Mg5Si6 phase: Electron micrographs of Mg2Si phase and Mg5Si6 phase in the Al-Mg-Si alloy plate of Example 1 are shown in FIG. Figure 1 As shown;

[0106] 6) Chemical composition: Fluorescence spectrum test method, specific results are shown in Table 2.

[0107] 2. Test results

[0108] Table 1 Properties of Al-Mg-Si alloy sheet

[0109]

[0110] Data Analysis:

[0111] It can be seen from the above table that the Al-Mg-Si alloy plates of Examples 1 to 13 of the present invention have good electrical conductivity, strength and fatigue resistance.

[0112] Table 2 Chemical composition of Al-Mg-Si alloy plate (mass percentage of each element (%))

[0113]

[0114] Note: The mass percentage of each element in Examples 1 to 13 and Comparative Examples 1 to 3 are the average values ​​of multiple repeated measurements.

[0115] Data Analysis:

[0116] The chemical composition of the Al-Mg-Si alloy plate of the embodiment of the present invention is helpful to improve the electrical conductivity, strength and fatigue resistance of the Al-Mg-Si alloy plate.

[0117] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An Al-Mg-Si alloy plate, characterized in that: The Al-Mg-Si alloy plate comprises, by mass percentage, Mg 0.50%-1.5%, Si 0.49%-0.53%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, and the balance is Al; wherein the mass ratio of Mg to Si is greater than 1.0; The microstructure of the Al-Mg-Si alloy plate includes a Mg2Si phase and a Mg5Si6 phase; The Mg2Si phase accounts for 0.5% to 1% of the microstructure of the Al-Mg-Si alloy plate, and the Mg5Si6 phase accounts for 10% to 15% of the microstructure of the Al-Mg-Si alloy plate; The Al-Mg-Si alloy plate has a strength of ≥400 MPa, a conductivity of ≥58% IACS, and a crack growth rate curve slope of ≤3.

0.

2. The Al-Mg-Si alloy sheet according to claim 1, characterized in that: The mass ratio of Mg to Si is (1.0-3.0):1, and the mass ratio of Mg to Si is not equal to 1.

3. The Al-Mg-Si alloy sheet according to claim 1 or 2, characterized in that: The Al-Mg-Si alloy plate is prepared by a method comprising at least the following processes: The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence, wherein the aging heat treatment is performed at a temperature of 155-165°C and a time of 5-10 hours, and the deformation amount of the cold rolling is 40%-55%, to obtain the Al-Mg-Si alloy plate.

4. A method for preparing the Al-Mg-Si alloy sheet according to any one of claims 1 to 3, characterized in that: The following steps are involved: The ingot is subjected to homogenization treatment, solution heat treatment, aging heat treatment and cold rolling in sequence to obtain the Al-Mg-Si alloy plate; The chemical composition of the ingot is Mg 0.50%-1.5%, Si 0.49%-0.53%, Fe 0.11%-0.18%, La 0.03%-0.05%, B 0.005%-0.02%, impurities ≤0.02%, and the balance is Al, and the mass ratio of Mg to Si is greater than 1.

0.

5. The preparation method according to claim 4, characterized in that: The aging heat treatment temperature is 155-165°C and the time is 5-7h; The deformation amount of the cold rolling process is 40%-55%.

6. The preparation method according to claim 4, characterized in that: The homogenization treatment is performed at a temperature of 530-550°C and for a time of 12-24 hours; And / or, the solution heat treatment is performed at a temperature of 510-530° C. and for a time of 2-7 h.

7. The preparation method according to any one of claims 4 to 6, characterized in that: The mass ratio of Mg to Si is (1.0-3.0):1, and the mass ratio of Mg to Si is not equal to 1.

8. A device, characterized in that: The invention comprises the Al-Mg-Si alloy plate material as described in any one of claims 1 to 3 or the Al-Mg-Si alloy plate material obtained by the preparation method as described in any one of claims 4 to 7.

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