Al-mg-zn-zr aluminum alloy round ingot and method for manufacturing the same

Abstract

The application relates to an Al-Mg-Zn-Zr aluminum alloy round ingot and a preparation method thereof, and belongs to the field of aluminum alloys. The application aims to solve the problem of low ingot yield caused by surface crack defects. The method comprises the following steps: S1, ingredients are prepared according to chemical components, and smelting raw materials are weighed; S2, the smelting raw materials with accurate weights are sequentially smelted and the chemical components are adjusted; and S3, the alloy melt with the adjusted chemical components is introduced into a holding furnace to be cast to obtain an aluminum alloy round ingot. The application adopts the existing high-magnesium alloy smelting process and combines scientific proportioning of raw materials, adjusts the casting process parameters and fine operation in the production process according to the influence of Zn on the ingot forming, reduces the generation of ingot crack defects, obtains a relatively pure melt, and makes the comprehensive ingot yield reach 84%.

Description

TECHNICAL FIELD

[0001] The present application particularly relates to an Al-Mg-Zn-Zr aluminum alloy round ingot and a preparation method thereof. BACKGROUND

[0002] The alloy is a high-magnesium aluminum alloy containing 7% of magnesium, which has high strength and good corrosion resistance, and is mostly used as welding wire material for ships. The requirements for the material properties are extremely strict. Traditional high-magnesium alloys such as 5A06 have good corrosion resistance, but the strength cannot meet the requirements of new aluminum alloy ship bodies. In order to meet the requirements of welding and processing, Zn and Zr elements are added to the high-magnesium aluminum alloy, and the content of magnesium is increased, which can improve the strength of the alloy, refine the grains and increase the recrystallization temperature.

[0003] However, in the actual production and application process, the alloy faces a series of serious problems. From the perspective of chemical composition and phase composition, although the addition of Zn element improves the strength, it also increases the tendency of casting cracks, making the casting forming more difficult and increasing the crack waste. In addition, the addition of trace Zr element increases the tendency of coarse compounds. If the casting temperature is not accurately controlled, the size of the compounds will be too large, and the flaw detection qualified rate will be low.

[0004] The alloy has a very narrow range of melting and casting process parameters, which means that the adjustable space of process parameters such as temperature, cooling speed and casting speed is very small during casting. Any slight deviation may cause cracks. In actual production, the occurrence of crack waste not only causes a large amount of raw material waste, but also seriously affects the production efficiency and cost control. At the same time, it is difficult to control the purity of the melt, and impurity elements and inclusions are easily mixed into the melt, which not only affects the uniformity and stability of the alloy, but also further increases the tendency of crack generation. At present, the comprehensive product rate of the ingot is only 52%, which greatly increases the production cost and limits the large-scale application and promotion of the alloy in industry.

[0005] CN113930648A, entitled "Preparation method of high-zinc aluminum alloy flat ingot" discloses a high-zinc aluminum alloy flat ingot composed of Si < 0.06%, Fe < 0.10%, Cu: 2.3%, Mn < 0.10%, Mg: 2.2%, Cr < 0.04%, Ni < 0.05%, Zn: 6.2%, Ti: 0.017%, Zr: 0.10%, Be: 0.02%, and the balance of Al in terms of mass percentage. Different addition times are selected according to the characteristics of different alloy elements to ensure full alloying of each element. The introduction of argon and argon-chlorine mixed gas refining can not only reduce the alkali and alkaline earth metals such as Na, Ca, Li, and K in the melt, but also effectively improve the effect of removing impurities and H2 from the melt. The use of an online degassing device can remove H2 from the melt, and the use of a filtering device can remove impurities from the melt. The use of an adjustable water baffle at the beginning of casting can reduce the crack of the ingot at the beginning. The use of reasonable steady-state process parameters can reduce the crack of the steady-state ingot. The yield of the ingot obtained by the above method can reach more than 90%.

[0006] This patent is a 7-series aluminum alloy, mainly adding Zn, mainly for aircraft panel materials, and the processing technology of this patent is easy to cause local component segregation. There are performance differences and crack tendencies caused by uneven composition. The impurity content in the melt is high, and the ingot is prone to defects. SUMMARY

[0007] The purpose of the present application is to solve the problem of low yield of ingots caused by surface crack defects, and to provide an Al-Mg-Zn-Zr aluminum alloy round ingot and a preparation method thereof.

[0008] The Al-Mg-Zn-Zr aluminum alloy round ingot of the present application is composed of Si ≤ 0.35%, Fe ≤ 0.35%, Cu ≤ 0.10%, Mn ≤ 0.10%, Mg: 6.0%-7.5%, Cr ≤ 0.05%, Ni ≤ 0.05%, Zn: 0.50%-1.5%, Ti: 0.05-0.15%, Zr: 0.10%-0.30%, Be: 0.0005%-0.005%, and the balance of Al in terms of mass percentage.

[0009] Further, the Al-Mg-Zn-Zr aluminum alloy round ingot is composed of Si ≤ 0.35%, Fe ≤ 0.35%, Cu ≤ 0.10%, Mn ≤ 0.10%, Mg: 7.0%, Cr ≤ 0.05%, Ni ≤ 0.05%, Zn: 1.0%, Ti: 0.10%, Zr: 0.12%, Be: 0.001%, and the balance of Al in terms of mass percentage.

[0010] The application discloses a preparation method of an Al-Mg-Zn-Zr aluminum alloy round ingot.

[0011] I. ingredient and weighing: ingredients are weighed according to the following mass percentage: Si≤0.35%, Fe≤0.35%, Cu≤0.10%, Mn≤0.10%, Mg: 6.0%-7.5%, Cr≤0.05%, Ni≤0.05%, Zn: 0.50%-1.5%, Ti: 0.05-0.15%, Zr: 0.10%-0.30%, Be: 0.0005%-0.005%, and the balance of Al, and Al99.70 aluminum ingot, metal Mg, metal Zn, AlTi6 intermediate alloy, AlZr3 intermediate alloy and AlBe3 intermediate alloy are taken as smelting raw materials;

[0012] II. smelting and chemical component adjustment: the Al99.70 aluminum ingot is first placed into a melting furnace, then the AlZr3 intermediate alloy is added, the smelting temperature is raised to 720-750 DEG C, the metal Mg, the metal Zn, the AlTi6 intermediate alloy and the AlBe3 intermediate alloy are added and stirred for not less than 20 min, then the chemical components are analyzed under the condition that the temperature is 720-750 DEG C, and after the chemical components are qualified, the alloy smelting is obtained by covering a flux;

[0013] III. casting: the alloy smelting with the temperature of 750 DEG C is introduced into a holding furnace, argon-chlorine mixed gas is introduced for refining for not less than 30 min, and then the alloy smelting is obtained by standing for 60 min, the alloy smelting is first introduced into an on-line degassing device, then introduced into a filtering device, and then introduced into a flow disc under the following conditions: the casting speed is 52 mm / min, the smelting pouring temperature is 730 DEG C, the casting cooling water flow is 72 t / h, the casting water temperature is 24 DEG C, and the speed of the on-line seeding AlTi5B0.2 wire is 1050 mm / min, so that the smelting is poured into a crystallizer to carry out semi-continuous casting, and the Al-Mg-Zn-Zr aluminum alloy round ingot is obtained.

[0014] Zn is usually added into the Al alloy as a main alloying element, and can obviously improve the performance of the alloy. Increasing Zn and Mg can simultaneously improve quenching and aging effects, and mainly form MgZn2 strengthening phase in the alloy. The solubility of the MgZn2 phase in the alloy sharply decreases with the decrease of the temperature, and has very strong aging hardening capacity. In the solid solution range, the content of Zn and Mg can be increased to greatly improve the strength.

[0015] Ti is added into the welding wire, can improve the mechanical performance, promote the solidification of the welding seam, improve the corrosion resistance after welding, can obviously refine the alloy grains, and reduces the crack tendency of the alloy.

[0016] The present application improves the purity of the melt, optimizes the melting and casting process parameters to reduce the crack tendency of round ingots and solve the surface crack defects of the ingots, thereby improving the flaw detection yield of the ingots and the overall yield of the ingots, and by adding Be element in the alloy to reduce the burning loss of Mg, the Mg element is more stable, and finally the performance of the rolled plate is improved to meet the urgent needs of the industry for high-performance aluminum alloy materials.

[0017] The casting process parameters of the present application are: casting speed is 52mm / min, melt casting temperature is 730℃, and casting cooling water flow is 72t / h. The casting process parameters of the CN113930648A patent are: casting speed is 40mm / min, melt casting temperature is 690-720℃, and casting cooling water flow is 80t / h, using a water scraper. The process parameters of the two alloys are very different, and the casting process of the CN113930648A patent cannot solve the above problems of the alloy of the present application.

[0018] In the batching stage, the present application accurately weighs various raw materials according to a specific mass percentage. The content of impurity elements such as Si and Fe is strictly controlled (Si≤0.35%, Fe≤0.35%, actual Si content 0.10%, Fe content 0.20%), which reduces factors that may cause performance degradation and crack of the alloy. At the same time, the proportion of main alloy elements such as Mg (6.0%-7.5%) and Zn (0.5%-1.5) is reasonably configured, and the reasonable configuration of these elements helps to form a stable alloy phase structure and improve the strength of the alloy. The alloy composition of the present application is GB / T3190-2020 national standard composition 5A33, and the CN113930648A patent is 7050 alloy, and the chemical compositions are completely different.

[0019] Trace element addition: adding trace elements such as Zr (0.10%-0.30%) and Ti (0.05-0.15%). Zr and Ti can refine the grain structure of the alloy, making the microstructure of the alloy more uniform. The refined grains can effectively hinder dislocation movement, thereby improving the strength and toughness of the alloy. Ti element can form compounds with Al as heterogeneous nucleation core, further refining the grain, and can improve the casting performance of the alloy and reduce the generation of cracks.

[0020] The content of Ti as the welding wire material in the alloy of the present application is relatively high, generally added to 0.10%, while the content of Ti in other alloys is mostly less than 0.05%. The present application adds high content of Ti as the Al3Ti particle content of the welding wire material is more, the number of aluminum alloy grains generated by the peritectic reaction is more, that is, the nucleation rate of the aluminum alloy grains in the reaction process is improved, the number of generated grains is naturally increased, and the effect of refining the grain structure of the aluminum alloy is achieved. The finer the grain, the higher the performance of the aluminum alloy. By adding the aluminum alloy refining element in the welding wire, the added refining element is transferred to the weld through the welding wire during welding.

[0021] Sequential charging and stirring: A specific melting sequence is adopted, Al99.70 aluminum ingot is first put in, then AlZr3 intermediate alloy is added, the melt temperature is raised to 720-750℃, metal Mg, metal Zn, AlTi6 intermediate alloy and AlBe3 intermediate alloy are added for stirring, the stirring time is not less than 20 min, then the chemical composition is analyzed under the condition of 720-750℃, after the chemical composition is qualified, the alloy melt is obtained by covering the flux. This way of sequential charging and sufficient stirring can ensure that various alloy elements are uniformly dissolved in the melt, avoiding local component segregation. Uniform component distribution helps to form a stable alloy phase structure, reduces the performance difference and crack tendency caused by uneven composition. After the chemical composition is qualified, the flux is covered, the main function of the flux is to reduce the oxidation and absorption of the melt, further ensuring the purity of the melt.

[0022] The charging sequence is developed according to the melting point and different functions of the alloy, which is the content of the company's regulations. The comparative document also uses this charging sequence. Without this charging sequence, there may be uneven composition.

[0023] Temperature and stirring control: At 720-750℃, metal Mg, metal Zn, AlTi6 intermediate alloy and AlBe3 intermediate alloy are added, which can make these main alloy elements better melt into the melt, increase the aging property of refinement, and stirring at appropriate temperature can control the solidification process of the alloy, which is beneficial to form good organizational morphology. Sampling and analyzing the chemical composition can timely find the composition deviation and make adjustment, ensuring that the melt composition meets the requirements, thereby laying a foundation for casting high-quality ingots in the subsequent process. Covering the flux can prevent the melt from oxidizing and absorbing, reduce the impurity content in the melt, and improve the purity of the melt, which is very important for reducing defects in the ingot and improving the flaw detection pass rate.

[0024] Refining and standing: the alloy melt temperature is 750℃, the argon-chlorine mixed gas is introduced into the holding furnace for refining for not less than 30 minutes, and then standing for 60 minutes. The refining process can effectively remove the gas and inclusions in the melt, and further improve the purity of the melt. The standing can make the inclusions and bubbles in the melt float up, and reduce the defects such as porosity of the ingot.

[0025] Casting parameter control: after further purifying the melt by the online double degassing device and filtering device, the melt is injected into the crystallizer for semi-continuous casting under the conditions of a specific casting speed (52 mm / min), a melt pouring temperature (730℃), a casting cooling water flow (72 t / h), a casting water temperature (24℃), and online seeding of AlTi5B0.2 wire (speed 1050 mm / min). These accurate casting parameters can control the solidification speed and cooling speed of the alloy, reduce the generation of thermal stress, thereby reducing the crack tendency of the round ingot, the use of the double degassing device can remove more hydrogen in the melt, and the ingot can reduce the porosity defects. The appropriate pouring temperature and cooling speed can avoid cracks caused by too fast temperature change, and the online seeding of AlTi5B0.2 wire can further refine the grains, improve the quality of the ingot, solve the surface crack defects of the ingot, and thereby improve the overall yield of the ingot.

[0026] Selection of ingot specification: a diameter φ405 mm round ingot is used for casting, and a larger specification crystallizer is not used for casting. The main consideration is that the smaller specification round ingot can effectively reduce the macrosegregation of chemical composition (Mg element can reduce 5% segregation), so that the composition is relatively uniform. If a smaller specification crystallizer is used for casting, the amount of ingot car and the amount of head and tail sawing will increase, thereby affecting the improvement of the overall yield. After comprehensive consideration, the diameter φ405 mm specification crystallizer is the optimal scheme.

[0027] Further, the grade of the Al99.70 primary aluminum ingot in step one is 99.70%, the content of Ti in the AlTi6 intermediate alloy is 6%, the content of Zr in the AlZr3 intermediate alloy is 3%, and the content of Be in the AlBe3 intermediate alloy is 3%.

[0028] Further, the flux in step two is composed of 35-40% KCl, 45-55% MgCl2, 5-10% BaCl2, and 1-5% NaCl+CaCl2 by mass percentage, and the addition amount of the flux is 2 kg / t of the melt.

[0029] Further, the argon-chlorine mixed gas in step three is composed of 94% argon and 6% chlorine by volume percentage; the purity of the argon and chlorine is 99.999%, and the introduction rate of the argon-chlorine mixed gas is 0.35-0.40 m 3 / min.

[0030] Further, the degassing device in step three is a double-rotor on-line degassing device, and two degassing devices are used, and the gas in the degassing device is Ar gas with a purity of 99.996%; the filter device adopts double-stage ceramic filter sheets for filtering, and the first-stage ceramic filter sheet has a mesh number of 30 ppi, and the second-stage ceramic sheet has a mesh number of 50 ppi.

[0031] Further, the Ti content in the on-line seeding AlTi5B0.2 wire in step three is 5%, and the B content is 0.2%.

[0032] Further, the shape of the melt injection crystallizer in step three is a circle with a diameter of 405 mm.

[0033] Further, the size of the Al-Mg-Zn-Zr aluminum alloy round ingot in step three is φ405 mm*6000 mm-7000 mm.

[0034] The present application has the following beneficial effects:

[0035] The present application selects different adding time according to the characteristics of different alloys, solves the problem of full alloying of each element; the element Zn can improve the performance after rolling; the element Zr can refine the grain and increase the recrystallization temperature, the element Be can effectively reduce the burning loss of Mg element, and ensure the stability of the composition; the argon-chlorine mixed gas refining can effectively reduce the alkali and alkaline earth metals such as Na and Ca in the melt; the melt flows into the double on-line degassing device, which can effectively remove H2 in the melt; and flows into the filter device, which can effectively remove slag; the yield of the ingot product obtained by the above method is improved to 84%, solving the problem of low yield of the ingot prepared by the existing method. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is the chemical composition detection and physical map of the Al-Mg-Zn-Zr aluminum alloy round ingot of example one.

[0037] Figure 2 It is the chemical composition detection and physical map of the Al-Mg-Zn-Zr aluminum alloy round ingot of example two. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear and explicit, the spirit of the present application will be described in detail below, and any person skilled in the art can make changes and modifications to the technology taught by the present application content without departing from the spirit and scope of the present application content.

[0039] The illustrative embodiments of the present application and their descriptions are used to explain the present application, but not as a limitation of the present application.

[0040] The beneficial effects of the present application are verified by the following examples:

[0041] Example 1: A preparation method of an Al-Mg-Zn-Zr aluminum alloy round ingot is completed according to the following steps:

[0042] I. Ingredients and weighing: ingredients are weighed according to the following proportions: Si≤0.35%, Fe≤0.35%, Cu≤0.10%, Mn≤0.10%, Mg: 7.0%, Cr≤0.05%, Ni≤0.05%, Zn: 1.0%, Ti: 0.10%, Zr: 0.12%, Be: 0.001%, and the balance is Al, Al99.70 aluminum ingot, metal Mg, metal Zn, AlTi6 intermediate alloy, AlZr3 intermediate alloy, and AlBe3 intermediate alloy are taken as smelting raw materials;

[0043] II. Smelting and chemical composition adjustment: Al99.70 aluminum ingot is first placed in a melting furnace, then AlZr3 intermediate alloy is added, and when the melt temperature reaches 740℃, metal Mg, metal Zn, AlTi6 intermediate alloy, and AlBe3 intermediate alloy are added for stirring, the stirring time is 20 min, then the chemical composition is analyzed under the condition of 730℃, and after the chemical composition is qualified, the alloy melt is obtained after covering with flux;

[0044] III. Casting: the alloy melt with a temperature of 750℃ is introduced into a holding furnace, argon-chlorine mixed gas refining is performed for not less than 30 min, and then the melt is placed for 60 min to obtain a refined alloy melt, the refined alloy melt is first passed through an online degassing device, then passed through a filtering device, and then passed through a flow disc under the following conditions: a casting speed of 52 mm / min, a melt pouring temperature of 730℃, a casting cooling water flow of 72 t / h, a casting water temperature of 24℃, and an online seeding AlTi5B0.2 wire speed of 1050 mm / min, the melt is poured into a crystallizer to perform semi-continuous casting to obtain an Al-Mg-Zn-Zr aluminum alloy round ingot.

[0045] The Al-Mg-Zn-Zr aluminum alloy round ingot obtained in this example has qualified chemical composition, and the surface is free of cracks, slag inclusions, and other defects (as shown in Figure 1 The yield of finished products reaches 85%.

[0046] Example 2: A preparation method of an Al-Mg-Zn-Zr aluminum alloy round ingot is completed according to the following steps:

[0047] I. Batching and Weighing: Weigh Al99.70 aluminum ingots, metallic Mg, metallic Zn, AlTi6 master alloy, AlZr3 master alloy, and AlBe3 master alloy as smelting raw materials according to the following mass percentages: Si≤0.35%, Fe≤0.35%, Cu≤0.10%, Mn≤0.10%, Mg:7.10%, Cr≤0.05%, Ni≤0.05%, Zn:1.10%, Ti:0.10%, Zr:0.12%, Be:0.0011%, and the balance being Al.

[0048] II. Melting and Chemical Composition Adjustment: First, put Al99.70 aluminum ingots into the melting furnace, then add AlZr3 master alloy. When the melt temperature reaches 740℃, add metallic Mg, metallic Zn, AlTi6 master alloy and AlBe3 master alloy and stir for 25 minutes. Then, take samples at 725℃ to analyze the chemical composition. After the chemical composition is qualified, cover with flux to obtain the alloy melt.

[0049] III. Casting: The alloy melt is introduced into a holding furnace at a temperature of 750℃ and refined by argon-chlorine mixed gas for no less than 30 minutes, then allowed to stand for 60 minutes to obtain a refined alloy melt. The refined alloy melt is first passed through an online degassing device, then through a filtration device, and then through a flow plate. Under the conditions of casting speed of 52 mm / min, melt casting temperature of 730℃, casting cooling water flow rate of 72 t / h, casting water temperature of 24.3℃, and online seeding speed of AlTi5B0.2 wire of 1050 mm / min, the melt is injected into the crystallizer for semi-continuous casting to obtain Al-Mg-Zn-Zr aluminum alloy round ingots.

[0050] In this embodiment, the Al-Mg-Zn-Zr aluminum alloy round ingot obtained has a qualified chemical composition and no defects such as cracks or inclusions on the surface (e.g., Figure 2 As shown in the figure, the yield rate reached 84.2%.

Claims

1. An Al-Mg-Zn-Zr aluminum alloy round ingot, characterized in that... The Al-Mg-Zn-Zr aluminum alloy round ingot is composed of, by mass percentage: Si≤0.35%, Fe≤0.35%, Cu≤0.10%, Mn≤0.10%, Mg: 6.0%~7.5%, Cr≤0.05%, Ni≤0.05%, Zn: 0.50%~1.5%, Ti: 0.05%~0.15%, Zr: 0.10%~0.30%, Be: 0.0005%~0.005%, and the balance Al; the preparation method of the Al-Mg-Zn-Zr aluminum alloy round ingot is as follows: I. Batching and Weighing: Weigh Al99.70 aluminum ingots, metallic Mg, metallic Zn, AlTi6 master alloy, AlZr3 master alloy, and AlBe3 master alloy as smelting raw materials according to the following mass percentages: Si≤0.35%, Fe≤0.35%, Cu≤0.10%, Mn≤0.10%, Mg: 6.0%~7.5%, Cr≤0.05%, Ni≤0.05%, Zn: 0.50%~1.5%, Ti: 0.05%~0.15%, Zr: 0.10%~0.30%, Be: 0.0005%~0.005%, and the balance Al. II. Melting and Chemical Composition Adjustment: First, place Al99.70 aluminum ingots into a melting furnace, then add AlZr3 master alloy. When the melt temperature reaches 720℃~750℃, add metallic Mg, metallic Zn, AlTi6 master alloy and AlBe3 master alloy and stir for no less than 20 minutes. Then, take samples to analyze the chemical composition under the condition of 720℃~750℃. After the chemical composition is qualified, cover with flux to obtain alloy melt. III. Casting: The alloy melt is introduced into a holding furnace at a temperature of 750℃ and refined by argon-chlorine mixed gas for no less than 30 minutes, then allowed to stand for 60 minutes to obtain a refined alloy melt. The refined alloy melt is first passed through an online degassing device, then through a filtration device, and then through a flow plate. Under the conditions of casting speed of 52 mm / min, melt pouring temperature of 730℃, casting cooling water flow rate of 72 t / h, casting water temperature of 24℃, and online seeding speed of AlTi5B0.2 wire of 1050 mm / min, the melt is injected into the crystallizer for semi-continuous casting to obtain Al-Mg-Zn-Zr aluminum alloy round ingots.

2. The Al-Mg-Zn-Zr aluminum alloy round ingot according to claim 1, characterized in that... The Al-Mg-Zn-Zr aluminum alloy round ingot is composed of Si≤0.35%, Fe≤0.35%, Cu≤0.10%, Mn≤0.10%, Mg: 7.0%, Cr≤0.05%, Ni≤0.05%, Zn: 1.0%, Ti: 0.10%, Zr: 0.12%, Be: 0.001%, and the balance Al by mass percentage.

3. The Al-Mg-Zn-Zr aluminum alloy round ingot according to claim 1, characterized in that... The Al99.70 primary aluminum ingot mentioned in step one has a grade of 99.70%, the content of Ti in AlTi6 master alloy is 6%, the content of Zr in AlZr3 master alloy is 3%, and the content of Be in AlBe3 master alloy is 3%.

4. The Al-Mg-Zn-Zr aluminum alloy round ingot according to claim 1, characterized in that... The flux described in step two consists of 35-40% KCl, 45-55% MgCl2, 5-10% BaCl2, and 1-5% NaCl+CaCl2 by mass percentage, and the amount of flux added is 2 kg / ton of melt.

5. An Al-Mg-Zn-Zr aluminum alloy round ingot according to claim 1, characterized in that... The argon-chlorine mixed gas in step three consists of 94% argon and 6% chlorine by volume; both argon and chlorine have a purity of 99.999%, and the argon-chlorine mixed gas is introduced at a rate of 0.35–0.40 m / s. 3 / min.

6. The Al-Mg-Zn-Zr aluminum alloy round ingot according to claim 1, characterized in that... The degassing device mentioned in step three is a dual-rotor online degassing device, and two degassing devices are used. The gas in the degassing device is Ar gas with a purity of 99.996%. The filtration device uses two-stage ceramic filter sheets for filtration. The first-stage ceramic filter sheet has a mesh size of 30ppi, and the second-stage ceramic filter sheet has a mesh size of 50ppi.

7. The Al-Mg-Zn-Zr aluminum alloy round ingot according to claim 1, characterized in that... In step three, the online seeding of AlTi5B0.2 filaments resulted in a Ti content of 5% and a B content of 0.2%.

8. The Al-Mg-Zn-Zr aluminum alloy round ingot according to claim 1, characterized in that... In step three, the melt is injected into the crystallizer in a circular shape with a diameter of 405 mm.

9. An Al-Mg-Zn-Zr aluminum alloy round ingot according to claim 1, characterized in that... The dimensions of the Al-Mg-Zn-Zr aluminum alloy round ingot mentioned in step three are φ405mm×6000mm~7000mm.

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