A 6061 aluminum alloy for a gas distribution plate and a method of manufacturing the same

Abstract

The application provides a 6061 aluminum alloy for a gas distribution plate and a preparation method thereof. The preparation method comprises the following steps: (1) obtaining an aluminum alloy round ingot by sequentially performing homogenization annealing, primary heat treatment and forging on a 6061 aluminum alloy blank; (2) obtaining a blank by sequentially performing secondary heat treatment, hot rolling, solid solution treatment, static pressure treatment and aging treatment on the aluminum alloy round ingot; and (3) obtaining the 6061 aluminum alloy for the gas distribution plate by sequentially performing mechanical processing, physical polishing and chemical polishing treatment on the blank. The 6061 aluminum alloy provided by the application has no burrs and dirt on the surface, the overall appearance has uniform and consistent color without color difference, the internal organization is uniform, the corrosion resistance is strong, the cost is low and the process is simple.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor component manufacturing, and relates to a gas distribution plate, in particular to a 6061 aluminum alloy for a gas distribution plate and a preparation method thereof. BACKGROUND

[0002] The plasma etching process is a crucial link in the semiconductor manufacturing process. The plasma is generated by ionizing the reaction gas, and the generated plasma etches the film layer on the wafer surface. The gas distribution plate is usually used in the reaction chamber of the semiconductor equipment. The etching gas can uniformly reach the wafer surface through the gas distribution plate, react with the wafer surface, and etch the required circuit pattern.

[0003] There are relevant researches on the smelting and manufacturing process of aluminum alloys. CN 104451297A discloses an aluminum-copper aluminum alloy round ingot casting process, which specifically includes first selecting low-iron and low-silicon aluminum ingots, aluminum-manganese alloy, aluminum-copper intermediate alloy ingots, aluminum-lead intermediate alloy ingots and magnesium ingots according to the proportion; then smelting the selected raw materials at 710-750 DEG C and fully stirring; then adding a refining agent to the melt for refining, controlling the refining time to be 10-20 min and the temperature to be 730-750 DEG C, and the refining agent is a sodium-free refining agent; then skimming the slag and keeping warm and standing; then online refining and degassing treatment; and finally filtering the melt and casting at 680-730 DEG C to obtain the product.

[0004] CN 102041418A discloses a method for manufacturing a 57% conductivity medium-strength aluminum alloy wire, which specifically includes (1) selecting aluminum matrix and aluminum intermediate alloy ingots; (2) furnace analysis adjustment: placing the selected aluminum ingots into a vertical furnace to melt into aluminum liquid, and refining with a refining agent; (3) casting and crystallization: filtering the aluminum alloy liquid in the tilting holding furnace through a ceramic filter plate, adding rare earth to make the rare earth content 0.05-0.15%, and then continuously casting into an aluminum alloy continuous casting machine to form an aluminum alloy ingot; rolling the aluminum alloy ingot into a medium-strength alloy rod through an aluminum alloy continuous rolling mill; (4) solid solution treatment and quenching: heat homogenizing the aluminum alloy rod; (5) drawing, aging and twisting: drawing the aluminum alloy rod treated in the previous process into an aluminum alloy wire with a required diameter on an aluminum alloy wire drawing machine, and twisting on a frame-type twisting machine to produce a 57% IACS medium-strength aluminum alloy wire.

[0005] However, the above method has not been improved and perfected for 6061 aluminum alloy. CN103205615A discloses a 6061 deformed aluminum alloy and a production process thereof. When the 6061 aluminum alloy is melted, an Al-rare earth intermediate alloy is added. The composition of the 6061 deformed aluminum alloy and the weight percentage are as follows: Si: 0.5% to 0.52%, Fe: 0.19% to 0.21%, Mg: 0.8% to 0.9%, Cu: 0.28% to 0.3%, Cr: 0.15% to 0.18%, Zn: 0.24% to 0.26%, Ti: 0.14% to 0.16%, rare earth element: 0.1% to 0.4%, other impurities: 0 to 0.1%, and Al: the balance, and the sum of the components is 100%. The production process includes smelting, batching, smelting, casting, extrusion molding, and aging treatment. The plastic processing performance and forming performance of the aluminum alloy are improved by adding the Al-rare earth intermediate alloy. The performance of the aluminum alloy is optimized by changing the components, and the cost of the rare earth element is high, and the related corrosion resistance is not involved.

[0006] At present, 6061 aluminum alloy is commonly used as a material for a gas distribution plate, but the internal organization of the ordinary 6061 material is not uniform, the grain is coarse, and the alloy surface has organization precipitation, which easily leads to appearance problems after subsequent chemical washing and cleaning. Therefore, a new 6061 aluminum alloy needs to be developed. SUMMARY

[0007] In view of the deficiencies in the prior art, the purpose of the present application is to provide a 6061 aluminum alloy for a gas distribution plate and a preparation method thereof. The present application can prepare a 6061 aluminum alloy for a gas distribution plate with uniform organization, fine grain (<80 μm), and strong corrosion resistance by adjusting the components of the material and controlling the plastic deformation process.

[0008] To achieve this purpose, the present application adopts the following technical solutions:

[0009] In a first aspect, the present application provides a preparation method of a 6061 aluminum alloy for a gas distribution plate, which comprises the following steps:

[0010] (1) obtaining an aluminum alloy round ingot by sequentially performing homogenization annealing, primary heat treatment, and forging on a 6061 aluminum alloy blank;

[0011] (2) obtaining a blank by sequentially performing secondary heat treatment, hot rolling, solid solution treatment, static pressure treatment, and aging treatment on the aluminum alloy round ingot obtained in step (1);

[0012] (3) obtaining the 6061 aluminum alloy for a gas distribution plate by sequentially performing mechanical processing, physical polishing, and chemical polishing treatment on the blank obtained in step (2).

[0013] The application can improve the corrosion performance of the 6061 aluminum alloy, make the internal organization uniform, and improve the problem of organization segregation of the ordinary 6061 aluminum alloy by precise control of the production process such as the 6061 aluminum alloy blank, forging, hot rolling and the like. In addition, the application makes the appearance of the obtained aluminum alloy uniform by physical polishing and chemical polishing treatment, and solves the problem of organization segregation on the surface of the alloy.

[0014] As one preferred technical scheme of the application, the 6061 aluminum alloy blank in step (1) comprises, in mass percentage: Si 0.6-0.7%, Fe≤0.04%, Cu: 0.15-0.25%, Mn 0.08-0.15%, Mg 0.8-1.2%, Cr 0.04-0.35%, Zn≤0.25, Ti 0.08-0.15%, and the balance is aluminum and inevitable impurities.

[0015] The application limits the specific composition of the 6061 aluminum alloy blank, mainly regulates the Mn and Ti contents, and the purpose is: (1) a small amount of Mn element can improve the morphology of the Fe-rich phase, promote the transformation of the long strip-shaped β-Al9Fe2Si2 phase to the spherical α-Al8(FeMnCr)2Si phase, and reduce the number of β-AlFeSi phase and Mg2Si. At the same time, the dispersed phase Al6Mn can refine the grains, thereby improving the strength and toughness and corrosion resistance of the alloy. Mn can also eliminate the adverse effects of excessive Si, generate Al-Fe-Mn-Si intermetallic compounds, and improve the corrosion resistance. (2) Ti has a significant grain refining effect on aluminum alloy, and can inhibit the precipitation of Mg2Si phase, thereby improving the strength and corrosion resistance of the aluminum alloy. Under the conditions of homogenization and aging, with the increase of the Ti content, the fine needle-shaped Al3Ti inhibits the formation of Mg2Si, so that the corrosion resistance of the aluminum alloy first increases and then decreases. Therefore, the addition amount of Ti is regulated to effectively improve the corrosion resistance of the aluminum alloy.

[0016] Preferably, the temperature of the homogenization annealing in step (1) is 550-580℃, for example, it can be 555℃, 560℃, 565℃, 570℃ or 575℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0017] Preferably, the time of the homogenization annealing in step (1) is 12-24h, for example, it can be 14h, 16h, 18h, 20h or 22h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0018] Preferably, the temperature of the one-time heat treatment in step (1) is 350-450℃, for example, it can be 360℃, 380℃, 400℃, 420℃ or 440℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0019] Preferably, the time of the one-time heat treatment in step (1) is 5-30min, for example, it can be 8min, 12min, 16min, 20min, 24min or 28min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0020] As a preferred technical solution of the present application, the number of forging in step (1) is not less than 3 times.

[0021] The forging process in the present application is to first forge the 6061 aluminum alloy blank into a square billet, then upset and stretch along the X, Y and Z directions, and finally obtain a round billet. The three-way forging method can break the original coarse grains and effectively destroy the original lamellar iron-rich phase organization prone to corrosion.

[0022] Preferably, the forging ratio of the single forging in step (1) is 1.5-2.5, for example, it can be 1.6, 1.8, 2.0, 2.2 or 2.4, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0023] As a preferred technical solution of the present application, the temperature of the two-time heat treatment in step (2) is 350-450℃, for example, it can be 360℃, 380℃, 400℃, 420℃ or 440℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0024] Preferably, the time of the two-time heat treatment in step (2) is 5-30min, for example, it can be 8min, 12min, 16min, 20min, 24min or 28min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0025] The preparation process in the present application includes two heat treatment processes, wherein the one-time heat treatment is used to improve the plastic deformation ability of the material, and the subsequent hot forging is facilitated, and the two-time heat treatment is used to improve the plastic deformation ability of the material, and the subsequent hot rolling is facilitated.

[0026] Preferably, the calendering deformation amount of the hot rolling in step (2) is 50-70%, for example, it can be 52%, 56%, 60%, 64% or 68%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0027] Preferably, the pass reduction of the hot rolling in step (2) is 15-20 mm, for example, it can be 16 mm, 17 mm, 18 mm or 19 mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0028] Preferably, the pass reduction of the last 3 passes of the hot rolling in step (2) is 5-10 mm, for example, it can be 6 mm, 7 mm, 8 mm or 9 mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0029] The present application can refine the grain structure by limiting the pass reduction, and at the same time promote the transformation of the original plate-like iron-rich phase structure prone to corrosion into the granular iron-rich phase structure resistant to corrosion. Further controlling the last 3 pass reductions to be 5-10 mm can obtain a uniform and fine grain structure, while avoiding product cracking caused by subsequent hot rolling temperature drop and excessive reduction.

[0030] As a preferred technical solution of the present application, the temperature of the solution treatment in step (2) is 510-520℃, for example, it can be 512℃, 514℃, 516℃ or 518℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0031] Preferably, the time of the solution treatment in step (2) is 2-5 h, for example, it can be 2.4 h, 2.8 h, 3.2 h, 3.6 h, 4 h, 4.4 h or 4.8 h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0032] The present application requires strict control of the solution treatment temperature. If the temperature is too high, it will cause local grain nucleation and re-growth, resulting in uneven structure and hardness drop. If the temperature is too low, many coarse excess phase particles will be left in the matrix, resulting in insufficient solution and reduced strength and hardness of the alloy.

[0033] Preferably, the reduction of the static pressure treatment in step (2) is 1-3%, for example, it can be 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 2.2%, 2.4%, 2.6% or 2.8%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0034] As a preferred technical solution of the present application, the temperature of the aging treatment in step (2) is 150-220℃, for example, it can be 160℃, 170℃, 180℃, 190℃, 200℃ or 210℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0035] Preferably, the holding time of the aging treatment in step (2) is 4-8h, for example, it can be 4.4h, 4.8h, 5.2h, 5.6h, 6h, 6.4h, 6.8h, 7.2h or 7.6h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0036] Preferably, the cooling mode of the aging treatment in step (2) is air cooling.

[0037] The present application requires strict control of the temperature and time of the aging treatment, and too high temperature will lead to grain growth and hardness reduction, and too low temperature will lead to less strengthening phase and insufficient strength.

[0038] As a preferred technical solution of the present application, the endpoint of the physical polishing in step (3) is that the surface roughness of the blank is 0.4-0.5μm, for example, it can be 0.42μm, 0.44μm, 0.46μm or 0.48μm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0039] As a preferred technical solution of the present application, the chemical polishing treatment in step (3) includes sequentially washing the physically polished blank with alkali, acid and water.

[0040] Preferably, the alkali washing includes washing with an alkali solution with a concentration of 3-8wt% for 2-5min; the concentration is 3-8wt%, for example, it can be 4wt%, 5wt%, 6wt% or 7wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable; the washing time is 2-5min, for example, it can be 2.5min, 3min, 3.5min, 4min or 4.5min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0041] The alkali solution of the present application includes sodium hydroxide and / or potassium hydroxide.

[0042] Preferably, the acid washing includes sequentially washing with first nitric acid, first mixed acid, second nitric acid, second mixed acid and third nitric acid.

[0043] Preferably, the first nitric acid cleaning has a nitric acid concentration of 12-18 wt%, and a cleaning time of 2-5 min; the concentration is 12-18 wt%, for example, it can be 14 wt%, 15 wt%, 16 wt%, 17 wt%, or 18 wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable; the cleaning time is 2-5 min, for example, it can be 2.5 min, 3 min, 3.5 min, 4 min, or 4.5 min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0044] Preferably, the first mixed acid cleaning has a mixed acid including phosphoric acid and sulfuric acid, and a cleaning time of 2-5 min; the cleaning time is 2-5 min, for example, it can be 2.5 min, 3 min, 3.5 min, 4 min, or 4.5 min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0045] Preferably, the second nitric acid cleaning has a nitric acid concentration of 28-35 wt%, and a cleaning time of 2-5 min; the concentration is 28-35 wt%, for example, it can be 30 wt%, 32 wt%, 34 wt%, or 35 wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable; the cleaning time is 2-5 min, for example, it can be 2.5 min, 3 min, 3.5 min, 4 min, or 4.5 min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0046] Preferably, the second mixed acid cleaning has a mixed acid including hydrofluoric acid and nitric acid, and a cleaning time of 10-30 s; the cleaning time is 10-30 s, for example, it can be 12 s, 16 s, 20 s, 24 s, or 28 s, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0047] Preferably, the second nitric acid cleaning has a nitric acid concentration of 28-35 wt%, and a cleaning time of 2-5 min; the concentration is 28-35 wt%, for example, it can be 30 wt%, 32 wt%, 34 wt%, or 35 wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable; the cleaning time is 2-5 min, for example, it can be 2.5 min, 3 min, 3.5 min, 4 min, or 4.5 min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0048] Preferably, the water washing includes ultrasonic cleaning with water until the water tank resistance value is greater than or equal to 2 mΩ, for example, can be 2.2 mΩ, 2.6 mΩ, 3.0 mΩ, 3.4 mΩ, 3.8 mΩ or 4.2 mΩ, but not limited to the listed values, other values not listed in the value range are also applicable.

[0049] The alloy surface can be made free of burrs and dirt, and the overall appearance, texture and color are uniform and consistent without color difference through physical polishing and chemical polishing treatment.

[0050] As a preferred technical solution of the present application, the preparation method comprises the following steps:

[0051] (1) The 6061 aluminum alloy blank is sequentially subjected to homogenization annealing, primary heat treatment and at least three times of forging to obtain an aluminum alloy round ingot;

[0052] The homogenization annealing temperature is 550-580℃, and the time is 12-24h; the primary heat treatment temperature is 350-450℃, and the time is 5-30min; the single forging ratio is 1.5-2.5;

[0053] (2) The aluminum alloy round ingot obtained in step (1) is sequentially subjected to secondary heat treatment, hot rolling, solid solution treatment, static pressure treatment and aging treatment to obtain a blank;

[0054] The secondary heat treatment temperature is 350-450℃, and the time is 5-30min; the hot rolling calendering deformation is 50-70%, the pass reduction is 15-20mm, and the last three pass reductions are 5-10mm; the solid solution treatment temperature is 510-520℃, and the time is 2-5h; the aging treatment temperature is 150-220℃, and the holding time is 4-8h;

[0055] (3) The blank obtained in step (2) is sequentially subjected to mechanical processing, physical polishing to a surface roughness of 0.4-0.5μm and chemical polishing treatment to obtain the 6061 aluminum alloy for gas distribution plate;

[0056] The chemical polishing treatment comprises: sequentially cleaning with alkali solution for 2-5min, cleaning with 12-18wt% nitric acid for 2-5min, cleaning with mixed acid of phosphoric acid and sulfuric acid for 2-5min, cleaning with 28-35wt% nitric acid for 2-5min, cleaning with mixed acid of hydrofluoric acid and nitric acid for 10-30s, cleaning with 28-35wt% nitric acid for 2-5min, and then ultrasonic cleaning with water until the water tank resistance value is greater than or equal to 2 mΩ.

[0057] In a second aspect, the present application provides a 6061 aluminum alloy for a gas distribution plate, which is prepared by the method provided in the first aspect.

[0058] The numerical ranges recited herein are inclusive of the endpoints and of any range that would be formed in between and of any value that would be formed by rounding up or down to the nearest significant figure, which is done for the sake of brevity and clarity in presenting the application.

[0059] Compared with the prior art, the present application has the following beneficial effects:

[0060] (1) The 6061 aluminum alloy for a gas distribution plate provided by the present application has no burrs and dirt on the surface, and the overall appearance has uniform and consistent color without color difference.

[0061] (2) The 6061 aluminum alloy for a gas distribution plate provided by the present application has uniform internal structure and strong corrosion resistance.

[0062] (3) The gas distribution plate made of the 6061 aluminum alloy for a gas distribution plate provided by the present application has a long service life and a stable air flow rate.

[0063] (4) The preparation method of the 6061 aluminum alloy for a gas distribution plate provided by the present application can optimize the performance without secondary annealing treatment, and has low cost and simple process. DETAILED DESCRIPTION

[0064] The technical solutions of the present application will be further described by specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present application, and should not be regarded as a specific limitation on the present application.

[0065] Example 1

[0066] The present embodiment provides a 6061 aluminum alloy for a gas distribution plate, and the preparation method comprises the following steps:

[0067] (1) The 6061 aluminum alloy blank is sequentially subjected to homogenization annealing, primary heat treatment and at least 3 times of forging to obtain an aluminum alloy round ingot.

[0068] The homogenization annealing temperature is 565℃, and the time is 18h; the primary heat treatment temperature is 400℃, and the time is 20min; the forging ratio of each single forging is 2.1.

[0069] The 6061 aluminum alloy blank comprises: Si 0.65%, Fe≤0.04%, Cu 0.2%, Mn 0.12%, Mg 1.0%, Cr 0.21%, Zn≤0.20, Ti 0.12%, and the balance is aluminum and unavoidable impurities.

[0070] (2) the aluminum alloy round ingot obtained in step (1) is sequentially subjected to secondary heat treatment, hot rolling, solid solution treatment, static pressure treatment, and aging treatment to obtain a blank;

[0071] The temperature of the secondary heat treatment is 400°C, and the time is 20 min; the calendering deformation of the hot rolling is 60%, the pass reduction is 18 mm, and the last three pass reductions are 8 mm; the temperature of the solid solution treatment is 515°C, and the time is 3.5 h; the temperature of the aging treatment is 185°C, and the holding time is 6 h;

[0072] (3) the blank obtained in step (2) is sequentially subjected to mechanical processing, physical polishing to a surface roughness of 0.45 μm, and chemical polishing treatment to obtain the 6061 aluminum alloy for a gas distribution plate;

[0073] The chemical polishing treatment comprises: sequentially cleaning with 5 wt% sodium hydroxide for 3.5 min, cleaning with 15 wt% nitric acid for 3.5 min, cleaning with a mixed acid of phosphoric acid and sulfuric acid for 3.5 min, cleaning with 30 wt% nitric acid for 3.5 min, cleaning with a mixed acid of hydrofluoric acid and nitric acid for 20 s, cleaning with 30 wt% nitric acid for 3.5 min, and then cleaning with water by ultrasonic until the water tank resistance value is 2.5 mΩ.

[0074] Example 2

[0075] The present embodiment provides a 6061 aluminum alloy for a gas distribution plate, and the preparation method comprises the following steps:

[0076] (1) a 6061 aluminum alloy blank is sequentially subjected to homogenization annealing, primary heat treatment, and at least three times of forging to obtain an aluminum alloy round ingot;

[0077] The temperature of the homogenization annealing is 550°C, and the time is 24 h; the temperature of the primary heat treatment is 350°C, and the time is 30 min; the single forging ratio of the forging is 1.5;

[0078] The 6061 aluminum alloy blank comprises: Si 0.6%, Fe≤0.03%, Cu 0.15-0.4%, Mn 0.08%, Mg 0.8%, Cr 0.04%, Zn≤0.25, Ti 0.08%, and the balance is aluminum and unavoidable impurities;

[0079] (2) the aluminum alloy round ingot obtained in step (1) is sequentially subjected to secondary heat treatment, hot rolling, solid solution treatment, static pressure treatment, and aging treatment to obtain a blank;

[0080] The temperature of the secondary heat treatment is 350 DEG C, and the time is 30 min; the calendering deformation of the hot rolling is 50%, the pass reduction is 15 mm, and the last three pass reductions are 5 mm; the temperature of the solid solution treatment is 510 DEG C, and the time is 5 h; the temperature of the aging treatment is 150 DEG C, and the holding time is 8 h;

[0081] (3) the 6061 aluminum alloy for the gas distribution plate is obtained by sequentially performing mechanical processing, physical polishing to a surface roughness of 0.4 μm, and chemical polishing on the blank obtained in step (2);

[0082] The chemical polishing treatment comprises: sequentially cleaning with 3 wt% potassium hydroxide for 5 min, cleaning with 12 wt% nitric acid for 5 min, cleaning with a mixed acid of phosphoric acid and sulfuric acid for 5 min, cleaning with 28 wt% nitric acid for 5 min, cleaning with a mixed acid of hydrofluoric acid and nitric acid for 30 s, cleaning with 28 wt% nitric acid for 5 min, and then cleaning with water by ultrasonic wave until the water tank resistance value is 2 mΩ.

[0083] Example 3

[0084] The embodiment provides a 6061 aluminum alloy for a gas distribution plate, and the preparation method comprises the following steps:

[0085] (1) the 6061 aluminum alloy blank is sequentially subjected to homogenization annealing, primary heat treatment, and at least three times of forging to obtain an aluminum alloy round ingot;

[0086] The temperature of the homogenization annealing is 580 DEG C, and the time is 12 h; the temperature of the primary heat treatment is 450 DEG C, and the time is 5 min; the single forging ratio of the forging is 2.5;

[0087] The 6061 aluminum alloy blank comprises: Si 0.7%, Fe≤0.02%, Cu 0.25%, Mn 0.15%, Mg 1.2%, Cr 0.35%, Zn≤0.15, Ti 0.15%, and the balance is aluminum and inevitable impurities;

[0088] (2) the aluminum alloy round ingot obtained in step (1) is sequentially subjected to secondary heat treatment, hot rolling, solid solution treatment, static pressure treatment, and aging treatment to obtain a blank;

[0089] The temperature of the secondary heat treatment is 450 DEG C, and the time is 5 min; the calendering deformation of the hot rolling is 70%, the pass reduction is 20 mm, and the last three pass reductions are 10 mm; the temperature of the solid solution treatment is 520 DEG C, and the time is 2 h; the temperature of the aging treatment is 220 DEG C, and the holding time is 4 h;

[0090] (3) sequentially performing mechanical processing, physical polishing to a surface roughness of 0.4-0.5 μm and chemical polishing on the blank obtained in step (2) to obtain the 6061 aluminum alloy for the gas distribution plate;

[0091] The chemical polishing treatment comprises: sequentially cleaning with 8 wt% sodium hydroxide for 2 min, cleaning with 18 wt% nitric acid for 2 min, cleaning with a mixed acid of phosphoric acid and sulfuric acid for 2 min, cleaning with 35 wt% nitric acid for 2 min, cleaning with a mixed acid of hydrofluoric acid and nitric acid for 10 s, cleaning with 35 wt% nitric acid for 2 min, and then cleaning with water by ultrasonic cleaning until the water tank resistance value is 5.2 mΩ.

[0092] Example 4

[0093] The present example provides a 6061 aluminum alloy for a gas distribution plate, and the difference between the preparation method and that of Example 1 is only that:

[0094] In the present example, the temperature of the solution treatment in step (2) is modified to 500°C.

[0095] Example 5

[0096] The present example provides a 6061 aluminum alloy for a gas distribution plate, and the difference between the preparation method and that of Example 1 is only that:

[0097] In the present example, the temperature of the solution treatment in step (2) is modified to 530°C.

[0098] Example 6

[0099] The present example provides a 6061 aluminum alloy for a gas distribution plate, and the difference between the preparation method and that of Example 1 is only that:

[0100] In the present example, the temperature of the aging treatment in step (2) is modified to 140°C.

[0101] Example 7

[0102] The present example provides a 6061 aluminum alloy for a gas distribution plate, and the difference between the preparation method and that of Example 1 is only that:

[0103] In the present example, the temperature of the aging treatment in step (2) is modified to 240°C.

[0104] Example 8

[0105] The present example provides a 6061 aluminum alloy for a gas distribution plate, and the difference between the preparation method and that of Example 1 is only that:

[0106] In this example, the last three pass reductions described in step (2) are modified to be 18 mm.

[0107] Example 9

[0108] In this example, a 6061 aluminum alloy for a gas distribution plate is provided, the method of preparation differing from Example 1 only in that:

[0109] In this example, the pass reduction described in step (2) is modified to be 8 mm, i.e., the same reduction per pass.

[0110] Example 10

[0111] In this example, a 6061 aluminum alloy for a gas distribution plate is provided, the method of preparation differing from Example 1 only in that:

[0112] In this example, the calendering deformation amount of the hot rolling described in step (2) is modified to be 40%.

[0113] Example 11

[0114] In this example, a 6061 aluminum alloy for a gas distribution plate is provided, the method of preparation differing from Example 1 only in that:

[0115] In this example, the calendering deformation amount of the hot rolling described in step (2) is modified to be 70%.

[0116] Example 12

[0117] In this example, a 6061 aluminum alloy for a gas distribution plate is provided, the method of preparation differing from Example 1 only in that:

[0118] In this example, the composition of the 6061 aluminum alloy blank described in step (1) is modified to be: Si: 0.4%; Fe: 0.03%; Cu: 0.25%; Mn: 0.50%; Mg: 1.2%; Cr: 0.04%; Zn: 0.25%; Ti: 0.15%, with the balance being aluminum and unavoidable impurities.

[0119] Example 13

[0120] In this example, a 6061 aluminum alloy for a gas distribution plate is provided, the method of preparation differing from Example 1 only in that:

[0121] In this example, the pickling in the chemical polishing treatment described in step (3) is modified to be: cleaning with nitric acid having a concentration of 18 wt% for 5 min.

[0122] Comparative Example 1

[0123] In this comparative example, a 6061 aluminum alloy for a gas distribution plate is provided, the method of preparation differing from Example 1 only in that:

[0124] The comparative example modifies the preparation process of step (2) as follows: sequentially performing secondary heat treatment, hot rolling, aging treatment, static pressure treatment, and solid solution treatment.

[0125] Comparative Example 2

[0126] The comparative example provides a 6061 aluminum alloy for a gas distribution plate, and the difference between the preparation method and Example 1 is only that:

[0127] The comparative example omits the forging process described in step (1).

[0128] Comparative Example 3

[0129] The comparative example provides a 6061 aluminum alloy for a gas distribution plate, and the difference between the preparation method and Example 1 is only that:

[0130] The comparative example omits the physical polishing process described in step (3).

[0131] Comparative Example 4

[0132] The comparative example provides a 6061 aluminum alloy for a gas distribution plate, and the difference between the preparation method and Example 1 is only that:

[0133] The comparative example omits the chemical polishing process described in step (3).

[0134] Performance testing:

[0135] The 6061 aluminum alloys for a gas distribution plate provided by the above examples and comparative examples are observed for appearance, grain detection, and observation after chemical polishing of the gas distribution plate, to observe whether the color is uneven, and whether color spots are generated. The test results are shown in Table 1.

[0136] Table 1

[0137]

[0138]

[0139] From Table 1, the following points can be seen:

[0140] (1) From Examples 1-3, it can be seen that the 6061 aluminum alloy for a gas distribution plate provided by the present application has uniform color and no color spots;

[0141] (2) From Examples 1 and 4-7, it can be seen that changing the temperature of the solid solution treatment and the aging treatment will affect the grain size and the appearance of the chemical polishing;

[0142] (3) From the combination of Example 1 and Examples 8-9, it can be seen that the last three passes require lower reduction than the previous passes, the purpose being to reduce rolling cracks while obtaining a fine and uniform grain structure;

[0143] (4) From the combination of Example 1 and Comparative Example 4, it can be seen that the surface of the gas distribution plate that has not been chemically polished is rough and has scratches, and the color is dark.

[0144] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above-described embodiments are merely specific embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a gas distribution plate using 6061 aluminum alloy, characterized in that, The preparation method includes the following steps: (1) The 6061 aluminum alloy billet is subjected to homogenization annealing, one heat treatment and at least three forgings in sequence to obtain aluminum alloy round ingots. The homogenization annealing temperature is 550~580℃ and the time is 12~24h; the primary heat treatment temperature is 350~450℃ and the time is 5~30min; the forging ratio of a single forging is 1.5~2.

5. (2) The aluminum alloy round ingot obtained in step (1) is subjected to secondary heat treatment, hot rolling, solution treatment, static pressing and aging treatment in sequence to obtain the billet; The secondary heat treatment is performed at a temperature of 350-450℃ for 5-30 minutes; the hot rolling deformation is 50-68%, with a reduction of 15-20 mm for the last three passes and a reduction of 5-10 mm for the last three passes; the solution treatment is performed at a temperature of 510-520℃ for 2-5 hours; and the aging treatment is performed at a temperature of 150-220℃ for 4-8 hours. (3) The blank obtained in step (2) is subjected to mechanical processing, physical polishing to a surface roughness of 0.4~0.5μm and chemical polishing treatment in sequence to obtain the 6061 aluminum alloy for the gas distribution disk; The chemical polishing process includes: sequentially cleaning with an alkaline solution of 3-8 wt% for 2-5 min, cleaning with nitric acid of 12-18 wt% for 2-5 min, cleaning with a mixed acid of phosphoric acid and sulfuric acid for 2-5 min, cleaning with nitric acid of 28-35 wt% for 2-5 min, cleaning with a mixed acid of hydrofluoric acid and nitric acid for 10-30 s, cleaning with nitric acid of 28-35 wt% for 2-5 min, and then ultrasonically cleaning with water until the resistance value of the water tank is ≥2 mΩ.

2. The preparation method according to claim 1, characterized in that, By mass percentage, the 6061 aluminum alloy billet in step (1) comprises: Si 0.6-0.7%, Fe≤0.04%, Cu 0.15-0.25%, Mn 0.08-0.15%, Mg 0.8-1.2%, Cr0.04-0.35%, Zn≤0.25%, Ti 0.08-0.15%, with the balance being aluminum and unavoidable impurities.

3. The preparation method according to claim 1, characterized in that, The reduction amount of the static pressure treatment in step (2) is 1~3%.

4. The preparation method according to claim 1, characterized in that, The cooling method for the aging process in step (2) is air cooling.

5. A gas distribution disc made of 6061 aluminum alloy, characterized in that, The gas distribution disk is made of 6061 aluminum alloy using the preparation method described in any one of claims 1-4.

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