Aluminum alloy ring backplate and method of making same

Abstract

The application provides an aluminum alloy annular back plate and a preparation method thereof, and the preparation method comprises the following steps: sequentially performing homogenization annealing, forging, punching and hole expanding on an aluminum alloy ingot to obtain an aluminum blank; the aluminum alloy ingot comprises an aluminum alloy with 4%-6% silicon added in aluminum material; rolling the aluminum blank to obtain an aluminum ring blank; and sequentially performing solid solution treatment and aging treatment on the aluminum ring blank to obtain the aluminum alloy annular back plate. The preparation method greatly reduces the raw material waste caused by a large amount of cutting in the traditional method, improves the material utilization rate, and prepares the aluminum alloy annular back plate with higher hardness.

Description

Technical Field

[0001] This invention belongs to the technical field of annular forging processing, and relates to an aluminum alloy annular back plate and its preparation method. Background Technology

[0002] Sputtering targets are key raw materials for physical vapor deposition (PVD) of electronic thin film materials, mainly composed of a target blank and a backplate. The target blank is the target material bombarded by a high-speed ion beam and performs the core function; the backplate primarily serves as a fixing and support, and must possess good electrical and thermal conductivity. During magnetron sputtering deposition, the target material must simultaneously withstand the combined effects of back-side cooling water pressure and front-side vacuum negative pressure; therefore, the quality of the backplate is particularly critical.

[0003] Since the target blank is usually circular, the annular backplate is a commonly used backplate structure. The processing method of the annular backplate is usually to directly turn or waterjet cut the cut cylindrical ingot or the cylindrical blank after upsetting to remove the excess material in the middle, leaving an outer ring of material. Then, it is machined into an annular backplate for semiconductor sputtering targets. However, this method usually requires more material to be removed from the middle than the part left, resulting in material waste and high processing costs.

[0004] CN105408514A discloses a sputtering target with a back cooling groove, comprising a sputtering plate having a back surface and an annular back plate mounted to the sputtering plate. The back surface has radially inner, middle, and outer regions, and has a plurality of circular grooves and at least one arcuate channel. The plurality of circular grooves are spaced apart from each other, and the arcuate channel cuts through these circular grooves and extends from the radially inner region to the radially outer region of the sputtering plate. The annular back plate defines an opening ring that exposes the back surface of the sputtering plate. However, it does not involve the processing and fabrication of the annular back plate.

[0005] In addition, to improve the thermal conductivity and dimensional stability of the backplate, a high silicon content needs to be added to the aluminum alloy. However, while a high silicon content can improve thermal conductivity, it will significantly reduce the alloy's ductility and toughness, leading to decreased elongation, increased brittleness, and increased susceptibility to cracking during processing.

[0006] Therefore, there is an urgent need to develop a new method for preparing annular back plates to solve the technical problems of easy cracking and serious material waste in the processing of aluminum alloy annular back plates. Summary of the Invention

[0007] The purpose of this invention is to provide an aluminum alloy annular backplate and its preparation method. The preparation method greatly reduces the waste of raw materials caused by the large amount of material cutting in traditional methods, improves the material utilization rate, and produces an aluminum alloy annular backplate with higher hardness.

[0008] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing an aluminum alloy annular back plate, the method comprising: The aluminum alloy ingot is subjected to homogenization annealing, forging, punching and reaming in sequence to obtain aluminum billet; The aluminum alloy ingots include aluminum alloys with 4%-6% silicon added, such as 4.2%, 4.4%, 4.5%, 4.6%, 4.8%, 5%, 5.2%, 5.4%, 5.5%, 5.6%, or 5.8% etc. The aluminum billet is rolled into a ring to obtain an aluminum ring billet; The aluminum ring blank is subjected to solution treatment and aging treatment in sequence to obtain the aluminum alloy ring back plate.

[0009] In this invention, the processing method of aluminum alloy ingots is not specifically limited, and they can be obtained by crushing aluminum and then melting it with silicon powder.

[0010] The preparation method provided by this invention uses an aluminum alloy with 4%-6% silicon added as the backing material, and combines this with sequential homogenization annealing, forging, punching, reaming, ring rolling, solution treatment, and aging treatment of the aluminum alloy ingot to produce an aluminum alloy ring backing plate with higher hardness. The preparation method is simple to operate, suitable for large-scale industrial production of aluminum alloy ring backing plates, and has great potential for widespread application.

[0011] It should be noted that by adding 4%-6% silicon to aluminum alloys, the silicon particles are dispersed in the aluminum matrix, which improves the hardness, yield strength and thermal conductivity of the aluminum alloy ingot, thereby improving the wear resistance, deformation resistance and thermal conductivity of the back plate made from it, and thus better supporting and fixing the tubular / ring target blank.

[0012] It should also be noted that homogenization annealing eliminates ingot segregation and internal stress, improving material uniformity and thermoplasticity; subsequent forging, punching, and ring rolling reduce material waste caused by boring and grooving in existing technologies and improve material utilization; after forming the aluminum ring blank, solution treatment and aging treatment are carried out to precipitate the strengthening phase, ultimately obtaining a harder aluminum alloy ring back plate.

[0013] Preferably, the aluminum material is of type 6061.

[0014] Preferably, the homogenization annealing temperature is 450℃-500℃, for example, it can be 455℃, 460℃, 465℃, 470℃, 475℃, 480℃, 485℃, 490℃ or 495℃, etc.

[0015] Preferably, the holding time for homogenization annealing is 4h-6h, for example, it can be 4.2h, 4.5h, 4.6h, 4.8h, 5h, 5.2h, 5.5h, 5.6h or 5.8h.

[0016] Preferably, after homogenization annealing, a preheating treatment is also included before forging.

[0017] Preferably, the temperature of the preheating treatment is 440℃-480℃, for example, it can be 445℃, 450℃, 455℃, 460℃, 465℃, 470℃ or 475℃, etc.

[0018] In this invention, by controlling the preheating temperature range before forging, the aluminum alloy forging is heated evenly, softens, reduces deformation resistance, improves plasticity, and inhibits rapid crystal growth.

[0019] Preferably, the heat preservation time of the preheating treatment is 120min-150min, for example, it can be 125min, 130min, 135min, 140min, 145min or 148min.

[0020] Preferably, the forging process includes a single upsetting step.

[0021] Preferably, the forging speed is 5mm / s-6mm / s, for example, it can be 5.2mm / s, 5.4mm / s, 5.5mm / s, 5.6mm / s or 5.8mm / s, etc.

[0022] Preferably, the upsetting ratio of the forging is 2-2.5, for example, it can be 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35, 2.4 or 2.45, etc.

[0023] Preferably, the punch is preheated to 260°C-340°C before punching, for example, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C or 330°C.

[0024] Preferably, the diameter of the punch is 40mm-50mm, for example, it can be 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm or 49mm, etc.

[0025] Preferably, the temperature of the rolling ring is 440℃-480℃, for example, it can be 445℃, 450℃, 455℃, 460℃, 465℃, 470℃ or 475℃, etc.

[0026] In this invention, by controlling the rolling process at a certain temperature, the deformation resistance is further reduced, the plasticity is improved, and the uniformity of the microstructure is enhanced, while avoiding the low-temperature brittle cracking of high-silicon aluminum alloys.

[0027] Preferably, the deformation of the rolling ring per pass is 40%-50%, for example, it can be 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48% or 49%, etc.

[0028] Preferably, the solution treatment temperature is 500℃-530℃, for example, it can be 505℃, 510℃, 515℃, 520℃, 525℃ or 528℃, etc.

[0029] Preferably, the heat treatment time is 5h-6h, for example, it can be 5.1h, 5.2h, 5.3h, 5.4h, 5.5h, 5.6h, 5.7h, 5.8h or 5.9h.

[0030] Preferably, after the solution treatment, the product is cooled to room temperature by water after being removed from the furnace.

[0031] Preferably, the aging treatment temperature is 140℃-160℃, for example, it can be 142℃, 144℃, 145℃, 146℃, 148℃, 150℃, 152℃, 144℃, 145℃, 146℃ or 158℃, etc.

[0032] In this invention, by controlling the temperature range of solution treatment and aging treatment, the internal stress of the aluminum ring blank is eliminated, further increasing the hardness and yield strength of the aluminum ring blank, thereby improving the overall performance of the material.

[0033] Preferably, the heat preservation time for the aging treatment is 11h-12h, for example, it can be 11.1h, 11.2h, 11.3h, 11.4h, 11.5h, 11.6h, 11.7h, 11.8h or 11.9h.

[0034] Preferably, after the aging treatment, the product is cooled to room temperature by water after being removed from the furnace.

[0035] In a second aspect, the present invention provides an aluminum alloy annular backplate, which is prepared by the preparation method described in the first aspect.

[0036] Preferably, the hardness of the aluminum alloy annular back plate is >430HL, for example, it can be 435HL, 440HL, 445HL, 450HL, 455HL, 460HL, 465HL, 470HL or 480HL, etc.

[0037] The aluminum alloy annular backplate obtained by this invention has high hardness and high thermal conductivity, which solves the problem that aluminum alloy backplates are prone to deformation during sputtering in the prior art.

[0038] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0039] Compared with the prior art, the present invention has the following beneficial effects: (1) The preparation method provided by the present invention uses aluminum alloy with 4%-6% silicon added to aluminum material as the back plate material, and combines the aluminum alloy ingot with homogenization annealing, forging, punching, hole expansion, ring rolling, solution treatment and aging treatment in sequence to obtain aluminum alloy ring back plate with higher hardness, making it suitable for the high temperature environment in which a large amount of heat is generated in the semiconductor target sputtering process, providing a high-quality back plate material for the manufacture of semiconductor sputtering targets and ensuring the production of high-quality sputtering targets.

[0040] (2) The aluminum alloy annular back plate provided by the present invention can enhance the hardness of the aluminum alloy annular back plate by adjusting the composition of the components and the preparation process, and the hardness can reach 430HL or more. Detailed Implementation

[0041] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0042] All materials used in the specific embodiments of this invention are commercially available or prepared using conventional methods in the prior art. All methods employed are conventional techniques in the field.

[0043] Example 1 This embodiment provides a method for preparing an aluminum alloy annular back plate, the method comprising the following steps: (1) The aluminum alloy ingot is subjected to homogenization annealing, preheating treatment, forging, punching and reaming in sequence, and then cooled to room temperature to obtain an aluminum billet; The aluminum alloy ingot is an aluminum alloy with 5% silicon added to 6061 aluminum material; The homogenization annealing temperature is 480℃ and the holding time is 5h; The preheating treatment temperature is 450℃ and the holding time is 130min; The forging process is a single upsetting process with a pressing speed of 5.3 mm / s and an upsetting ratio of 2.2. The punch is preheated to 300°C before punching; the diameter of the punch is 45mm. (2) The aluminum billet is rolled into a ring and cooled to room temperature to obtain an aluminum ring billet; The temperature of the rolling ring is 460℃, and the deformation per pass is 43%. (3) The aluminum ring blank is subjected to solution treatment and aging treatment in sequence to obtain the aluminum alloy ring back plate; The solution treatment temperature is 520℃ and the holding time is 5.6h; after the solution treatment, the product is removed from the furnace and water-cooled to room temperature. The aging treatment temperature is 150℃ and the holding time is 11.4h; after the aging treatment, the furnace is removed and water-cooled to room temperature.

[0044] Example 2 This embodiment provides a method for preparing an aluminum alloy annular back plate, the method comprising the following steps: (1) The aluminum alloy ingot is subjected to homogenization annealing, preheating treatment, forging, punching and reaming in sequence, and then cooled to room temperature to obtain an aluminum billet; The aluminum alloy ingot is an aluminum alloy with 4.2% silicon added to 6061 aluminum material; The homogenization annealing temperature is 450℃ and the holding time is 4h; The preheating treatment temperature is 480℃ and the holding time is 120min; The forging process is a single upsetting process with a pressing speed of 6 mm / s and an upsetting ratio of 2. The punch is preheated to 270°C before punching; the diameter of the punch is 42mm. (2) The aluminum billet is rolled into a ring and cooled to room temperature to obtain an aluminum ring billet; The temperature of the rolling ring is 440℃, and the deformation per pass is 40%. (3) The aluminum ring blank is subjected to solution treatment and aging treatment in sequence to obtain the aluminum alloy ring back plate; The solution treatment temperature is 530℃ and the holding time is 5h; after the solution treatment, the product is removed from the furnace and water-cooled to room temperature. The aging treatment is performed at a temperature of 160°C for 11 hours; after aging treatment, the product is removed from the furnace and cooled to room temperature by water.

[0045] Example 3 This embodiment provides a method for preparing an aluminum alloy annular back plate, the method comprising the following steps: (1) The aluminum alloy ingot is subjected to homogenization annealing, preheating treatment, forging, punching and reaming in sequence, and then cooled to room temperature to obtain an aluminum billet; The aluminum alloy ingot is an aluminum alloy with 5.6% silicon added to 6061 aluminum material; The homogenization annealing temperature is 500℃ and the holding time is 6h; The preheating treatment temperature is 440℃ and the holding time is 150min; The forging process is a single upsetting process with a pressing speed of 5.1 mm / s and an upsetting ratio of 2.5. The punch is preheated to 340°C before punching; the diameter of the punch is 50mm. (2) The aluminum billet is rolled into a ring and cooled to room temperature to obtain an aluminum ring billet; The temperature of the rolling ring is 480℃, and the deformation per pass is 48%. (3) The aluminum ring blank is subjected to solution treatment and aging treatment in sequence to obtain the aluminum alloy ring back plate; The solution treatment temperature is 500℃ and the holding time is 6 hours; after the solution treatment, the product is removed from the furnace and water-cooled to room temperature. The aging treatment is performed at a temperature of 140°C for 12 hours; after aging treatment, the product is removed from the furnace and cooled to room temperature by water.

[0046] Example 4 This embodiment provides a method for preparing an aluminum alloy annular back plate. Except for the preheating temperature of 400°C, all other conditions are the same as in Embodiment 1.

[0047] Example 5 This embodiment provides a method for preparing an aluminum alloy annular back plate. Except for the preheating temperature of 550°C, all other conditions are the same as in Embodiment 1.

[0048] Example 6 This embodiment provides a method for preparing an aluminum alloy annular back plate. Except for the rolling temperature of the ring being 380°C, all other conditions are the same as in Embodiment 1.

[0049] Example 7 This embodiment provides a method for preparing an aluminum alloy annular back plate. Except for the rolling temperature of the ring being 550°C, all other conditions are the same as in Embodiment 1.

[0050] Example 8 This embodiment provides a method for preparing an aluminum alloy annular back plate. Except for the solution treatment temperature of 400°C, all other conditions are the same as in Embodiment 1.

[0051] Example 9 This embodiment provides a method for preparing an aluminum alloy annular back plate. Except for the solution treatment temperature of 600°C, all other conditions are the same as in Embodiment 1.

[0052] Comparative Example 1 This comparative example provides a method for preparing an aluminum alloy annular back plate. Except that the aluminum alloy ingot is made of 6061 aluminum alloy, all other conditions are the same as in Example 1.

[0053] Comparative Example 2 This comparative example provides a method for preparing an aluminum alloy annular backplate. Except that the aluminum alloy ingot is an aluminum alloy with 7% silicon added to 6061 aluminum material, all other conditions are the same as in Example 1.

[0054] Comparative Example 3 This comparative example provides a method for preparing an aluminum alloy annular back plate, except that the homogenization annealing is not performed, and all other conditions are the same as in Example 1.

[0055] The hardness of the aluminum alloy annular back plates prepared in the above embodiments and comparative examples was tested using a hardness tester. The test results are shown in Table 1.

[0056] Table 1 As shown in Table 1: The method for preparing the aluminum alloy annular backplate provided in Embodiments 1-3 of the present invention improves the material utilization rate and obtains a high-quality aluminum alloy annular backplate by using an aluminum alloy with a specific silicon content and controlling the preparation process and parameters; under preferred conditions, the hardness reaches more than 430HL, which meets the performance requirements of the high-temperature environment in the semiconductor sputtering process.

[0057] A comparison of Examples 1 and 4-5 shows that if the preheating temperature before forging is too low, the hardness of the annular back plate will decrease due to insufficient deformation during the forging and stamping process; if the preheating temperature before forging is too high, the hardness of the annular back plate will decrease due to excessive heat absorption by the material.

[0058] A comparison of Examples 1 and 6-7 shows that if the temperature during the ring rolling process is too low, the ring back plate is at risk of cracking due to insufficient heating and high stress; if the temperature during the ring rolling process is too high, the hardness of the ring back plate decreases because the material absorbs too much heat.

[0059] A comparison of Examples 1 and 8-9 shows that if the solution treatment temperature is too low, the solution will not dissolve sufficiently, resulting in a decrease in the hardness of the annular back plate; if the solution treatment temperature is too high, the plasticity and toughness will decrease due to overheating caused by exceeding the upper limit of the temperature.

[0060] A comparison of Example 1 and Comparative Examples 1-2 shows that when 6061 aluminum alloy is used as the raw material, the hardness of the annular back plate is low due to the different material composition; if the silicon content in the aluminum alloy ingot is too high, the annular back plate is prone to cracking.

[0061] A comparison of Example 1 and Comparative Example 3 shows that if homogenization annealing is not performed, component segregation will not be eliminated, making the annular back plate prone to cracking.

[0062] The present invention has been illustrated with the above embodiments to illustrate its detailed structural features. However, the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing an aluminum alloy annular back plate, characterized in that, The preparation method includes: The aluminum alloy ingot is subjected to homogenization annealing, forging, punching and reaming in sequence to obtain aluminum billet; The aluminum alloy ingot comprises an aluminum alloy with 4%-6% silicon added to the aluminum material; The aluminum billet is rolled into a ring to obtain an aluminum ring billet; The aluminum ring blank is subjected to solution treatment and aging treatment in sequence to obtain the aluminum alloy ring back plate.

2. The preparation method according to claim 1, characterized in that, The aluminum material is of type 6061; Preferably, the homogenization annealing temperature is 450℃-500℃; Preferably, the holding time for homogenization annealing is 4h-6h.

3. The preparation method according to claim 1 or 2, characterized in that, The homogenization annealing process, followed by preheating before forging, also includes a preheating treatment. Preferably, the temperature of the preheating treatment is 440℃-480℃; Preferably, the heat preservation time of the preheating treatment is 120 min to 150 min.

4. The preparation method according to any one of claims 1-3, characterized in that, The forging process includes a single upsetting step; Preferably, the forging speed is 5 mm / s-6 mm / s; Preferably, the upsetting ratio of the forging is 2-2.

5.

5. The preparation method according to any one of claims 1-4, characterized in that, The punch is preheated to 260°C-340°C before punching; Preferably, the diameter of the punch is 40mm-50mm.

6. The preparation method according to any one of claims 1-5, characterized in that, The temperature of the rolling ring is 440℃-480℃; Preferably, the deformation of the rolling ring per pass is 40%-50%.

7. The preparation method according to any one of claims 1-6, characterized in that, The solution treatment temperature is 500℃-530℃; Preferably, the heat treatment time is 5-6 hours; Preferably, after the solution treatment, the product is cooled to room temperature by water after being removed from the furnace.

8. The preparation method according to any one of claims 1-7, characterized in that, The aging treatment temperature is 140℃-160℃; Preferably, the heat preservation time for the aging treatment is 11-12 hours; Preferably, after the aging treatment, the product is cooled to room temperature by water after being removed from the furnace.

9. An aluminum alloy annular back plate, characterized in that, The aluminum alloy annular back plate is prepared by the preparation method described in any one of claims 1-8.

10. The aluminum alloy annular back plate according to claim 9, characterized in that, The hardness of the aluminum alloy annular back plate is >430HL.

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