Welding method of aluminum heating plate

Abstract

The invention relates to a welding method of an aluminum heating plate, which relates to the field of welding, and comprises the following steps: assembling an aluminum upper plate body, an aluminum lower plate body, a heating wire and a middle layer to obtain an assembly body; the obtained assembly is sequentially subjected to diffusion welding and electron beam welding, and the aluminum heating plate is obtained; wherein the middle layer is arranged between the aluminum upper tray body and the aluminum lower tray body; the hardness of the middle layer is greater than or equal to 4 times of the hardness of the aluminum upper plate body and / or 4 times of the hardness of the aluminum lower plate body; the tensile strength of the middle layer is larger than or equal to four times of the tensile strength of the upper aluminum plate body and / or four times of the tensile strength of the lower aluminum plate body. The diffusion welding comprises the steps of first heating, first heat preservation, second heating, second heat preservation, pressurization, heat and pressure preservation and furnace cooling which are sequentially carried out. According to the welding method, efficient welding of the aluminum heating plate is achieved through cooperation of the middle layer and diffusion welding, and creep deformation of the aluminum heating plate in the high-temperature using environment is remarkably reduced.

Description

Technical Field

[0001] The invention relates to the field of welding, and in particular to a welding method for an aluminum heating plate. Background Art

[0002] Wafer heating plates are key components used in semiconductor manufacturing to precisely control wafer temperature and are widely used in various chip manufacturing fields such as thin film deposition, etching, and photolithography.

[0003] A heating element is provided inside the heating plate, and the temperature of the surface of the heating plate is adjusted by the heating element.

[0004] Currently, many metal heating plates use pure aluminum (Al) or aluminum alloys with high thermal conductivity as the plate body material, and use welding to connect the plate body and the heating element together.

[0005] For example, CN119347017A discloses that vacuum brazing is used to connect the components of a heating plate, wherein the filler in the welding interface is aluminum powder, and after the welding is completed, the entire material of the heating plate is aluminum.

[0006] CN118417661A discloses that various components of a heating plate are connected by hot isostatic pressing welding, thereby realizing the welding of an aluminum wafer heating plate with an irregular structure.

[0007] CN117817160A discloses two welding methods, vacuum brazing and vacuum electron beam welding, which improve the welding pass rate.

[0008] In summary, existing heating plates generally use vacuum brazing or vacuum electron beam welding to connect various components, which has the following disadvantages:

[0009] 1) The poor compatibility between the solder and the base material during welding results in small pore defects in the weld after welding, which affects the welding strength;

[0010] 2) It is difficult to control the thermal deformation of the aluminum heating plate during the welding process. In particular, the local high heat input of electron beam welding can easily cause the overall warping of the aluminum plate, resulting in a low welding yield.

[0011] At the same time, due to the low mechanical strength of aluminum, aluminum heating plates are prone to deformation when working at high temperatures (>300°C) for a long time in semiconductor processes, resulting in uneven wafer temperatures. At the same time, the creep (slow plastic deformation) problem of aluminum at high temperatures is prominent, which reduces the structural stability of aluminum heating plates after long-term use, thus having a great impact on the process accuracy and mass production yield of chip manufacturing.

[0012] In summary, the existing aluminum heating plate still has the defects of low plate strength and easy deformation during the welding process. Summary of the Invention

[0013] In view of the problems existing in the prior art, the purpose of the present invention is to provide a welding method for an aluminum heating plate to solve the defects of the aluminum heating plate in the welding process, such as low plate strength and easy deformation.

[0014] To achieve this object, the present invention adopts the following technical solutions:

[0015] The present invention provides a welding method for an aluminum heating plate, the welding method comprising:

[0016] Assembling an aluminum upper plate, an aluminum lower plate, a heating wire and an intermediate layer to obtain an assembly;

[0017] The resulting assembly is sequentially subjected to diffusion welding and electron beam welding to obtain an aluminum heating plate;

[0018] The intermediate layer is provided between the aluminum upper plate and the aluminum lower plate; the hardness of the intermediate layer satisfies ≥ 4 times the hardness of the aluminum upper plate and / or 4 times the hardness of the aluminum lower plate; the tensile strength of the intermediate layer satisfies ≥ 4 times the tensile strength of the aluminum upper plate and / or 4 times the tensile strength of the aluminum lower plate;

[0019] The diffusion welding comprises: first heating, first heat preservation, second heating, second heat preservation, pressurization, heat preservation and pressure preservation, and furnace cooling performed in sequence.

[0020] The welding method provided by the present invention realizes efficient welding of the aluminum heating plate by adding a specific intermediate layer and cooperating with diffusion welding, so that the obtained aluminum heating plate has the advantages of high strength and not easy to deform, significantly reduces the creep of the aluminum heating plate in a high-temperature use environment, and is conducive to ensuring the use effect of the heating plate.

[0021] As a preferred technical solution of the present invention, the surface roughness of the welding surface of the aluminum upper plate body Ra is less than 0.6 μm.

[0022] Preferably, the flatness of the welding surface of the aluminum upper plate is less than 0.1 mm.

[0023] Preferably, the surface roughness of the welding surface of the intermediate layer is Ra<0.6 μm.

[0024] Preferably, the flatness of the welding surface of the intermediate layer is less than 0.1 mm.

[0025] Preferably, the surface roughness of the welding surface of the aluminum lower plate Ra is less than 0.6 μm.

[0026] Preferably, the flatness of the welding surface of the aluminum lower plate is less than 0.1 mm.

[0027] As a preferred technical solution of the present invention, at least one welding surface of the aluminum upper plate, the aluminum lower plate or the intermediate layer is provided with threads.

[0028] Preferably, the pitch of the thread is 0.3-0.8 mm.

[0029] Preferably, the depth of the thread is 0.1-0.5 mm.

[0030] Preferably, the thickness of the middle layer is 3-8 mm.

[0031] As a preferred technical solution of the present invention, the aluminum upper plate, the aluminum lower plate, the middle layer and the heating wire are all cleaned before the assembly.

[0032] As a preferred technical solution of the present invention, the absolute vacuum degree is controlled to be ≤0.001Pa during the diffusion welding.

[0033] Preferably, the first heating rate is 2-5°C / min.

[0034] Preferably, the pressure during the first heating is controlled to be 2-5t.

[0035] Preferably, the endpoint temperature of the first heating is the insulation temperature of the first insulation.

[0036] Preferably, the first insulation temperature is 300-500°C.

[0037] Preferably, the first insulation time is 1-3 hours.

[0038] As a preferred technical solution of the present invention, the heating rate of the second heating is 2-5°C / min.

[0039] Preferably, the endpoint temperature of the second heating period is the insulation temperature of the second insulation period.

[0040] Preferably, the second insulation temperature is 500-600°C.

[0041] Preferably, the second insulation time is 0.5-1h.

[0042] As a preferred technical solution of the present invention, the terminal pressure of the pressurization is 2-15 MPa.

[0043] Preferably, the pressurization is performed for 0.4-0.6 h.

[0044] Preferably, the heat preservation temperature of the heat preservation and pressure preservation is the heat preservation temperature of the second heat preservation.

[0045] Preferably, the heat-insulating and pressure-maintaining pressure is the terminal pressure of pressurization.

[0046] Preferably, the heat preservation and pressure preservation time is 1-5 hours.

[0047] As a preferred technical solution of the present invention, the furnace cooling includes: maintaining the pressure of heat preservation and pressure preservation to carry out furnace cooling to below 100°C.

[0048] As a preferred technical solution of the present invention, the electron beam welding includes: welding along the circumferential weld of the disk body obtained by diffusion welding.

[0049] As a preferred technical solution of the present invention, the beam current of the electron beam welding is 10-40 mA.

[0050] Preferably, the focus of the electron beam welding is -15 to 10 mm.

[0051] Preferably, the welding speed of the electron beam welding is 10-30 mm / s.

[0052] Compared with the existing technical solutions, the present invention has the following beneficial effects:

[0053] The welding method provided by the present invention can realize effective welding of the heating plate by selecting an intermediate layer with specific mechanical properties and combining it with diffusion welding, and can significantly reduce the creep of the aluminum heating plate when used at high temperatures; at the same time, the welding method can effectively improve the overall strength of the aluminum heating plate and reduce the overall deformation of the aluminum plate after welding. The prepared heating plate has good temperature uniformity, high strength and good durability, and the steady-state creep rate of the obtained aluminum heating plate is ≤0.35×10 -8 / s, welding strength ≥85.4MPa.

[0054] The present invention is further described in detail below. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0055] To better illustrate the present invention and facilitate understanding of the technical solutions of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0056] 1. This embodiment provides a welding method for an aluminum heating plate, the welding method comprising:

[0057] Assembling an aluminum upper plate, an aluminum lower plate, a heating wire and an intermediate layer to obtain an assembly;

[0058] The obtained assembly is subjected to diffusion welding and electron beam welding in sequence to obtain an aluminum heating plate.

[0059] Wherein, the middle layer is arranged between the aluminum upper plate body and the aluminum lower plate body.

[0060] Among them, the hardness of the intermediate layer meets ≥ 4 times the hardness of the aluminum upper disk body, and / or 4 times the hardness of the aluminum lower disk body, for example, it can be 4 times, 5 times, 6 times, 7 times, 8 times, 9 times or 10 times, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0061] In the present invention, the hardness of the middle layer is ≥ 4 times the hardness of the aluminum upper disk and 4 times the hardness of the aluminum lower disk, which means that the hardness of the middle layer is ≥ 4 times the hardness of the aluminum upper disk and the hardness of the middle layer is ≥ 4 times the hardness of the aluminum lower disk.

[0062] Among them, the tensile strength of the intermediate layer meets the requirement of ≥ 4 times the tensile strength of the aluminum upper plate, and / or 4 times the tensile strength of the aluminum lower plate, for example, it can be 4 times, 5 times, 6 times, 7 times, 8 times, 9 times or 10 times, etc., but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0063] In the present invention, the tensile strength of the middle layer is ≥ 4 times the tensile strength of the aluminum upper plate and 4 times the tensile strength of the aluminum lower plate, which means that the tensile strength of the middle layer is ≥ 4 times the tensile strength of the aluminum upper plate and the tensile strength of the middle layer is ≥ 4 times the tensile strength of the aluminum lower plate.

[0064] In the present invention, the material of the aluminum upper disk and the aluminum lower disk can be selected as pure aluminum or aluminum alloy, such as 3000 series aluminum alloy, 6000 series aluminum alloy, etc.; the material of the intermediate layer can be selected as a pure nickel layer, a nickel alloy layer, etc., for example, but it needs to meet the limitations of the present invention on the mechanical properties between the disk body and the intermediate layer.

[0065] Among them, the surface roughness of the welding surface of the aluminum upper plate body Ra is less than 0.6μm, for example, it can be 0.5μm, 0.4μm, 0.3μm, 0.2μm, 0.1μm, 0.05μm or 0.01μm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0066] Among them, the flatness of the welding surface of the aluminum upper plate is less than 0.1mm, for example, it can be 0.09mm, 0.08mm, 0.07mm, 0.06mm, 0.05mm, 0.04mm, 0.03mm, 0.02mm or 0.01mm, etc., but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0067] The surface roughness of the welding surface of the intermediate layer Ra is less than 0.6 μm, for example, it can be 0.5 μm, 0.4 μm, 0.3 μm, 0.2 μm, 0.1 μm, 0.05 μm or 0.01 μm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0068] Among them, the flatness of the welding surface of the intermediate layer is less than 0.1mm, for example, it can be 0.09mm, 0.08mm, 0.07mm, 0.06mm, 0.05mm, 0.04mm, 0.03mm, 0.02mm or 0.01mm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0069] Among them, the surface roughness of the welding surface of the aluminum lower plate body Ra is less than 0.6μm, for example, it can be 0.5μm, 0.4μm, 0.3μm, 0.2μm, 0.1μm, 0.05μm or 0.01μm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0070] Among them, the flatness of the welding surface of the aluminum lower plate is less than 0.1mm, for example, it can be 0.09mm, 0.08mm, 0.07mm, 0.06mm, 0.05mm, 0.04mm, 0.03mm, 0.02mm or 0.01mm, etc., but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0071] Wherein, at least one welding surface of the aluminum upper plate body, the aluminum lower plate body or the intermediate layer is provided with threads.

[0072] In the present invention, when threads are provided on ≥2 welding surfaces, the threads of adjacent welding surfaces may be designed to be concave-convex fitting.

[0073] In the present invention, the welding surface refers to the surface to be bonded during diffusion welding.

[0074] Among them, the pitch of the thread is 0.3-0.8mm, for example, it can be 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm or 0.8mm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0075] The depth of the thread is 0.1-0.5 mm, for example, it can be 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm or 0.5 mm, etc., but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0076] In the present invention, the shape of the thread may be, for example, a triangular thread, a rectangular thread, a trapezoidal thread, a serrated thread, or the like.

[0077] The thickness of the intermediate layer is 3-8 mm, for example, it can be 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm or 8 mm, but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0078] Wherein, the aluminum upper plate body, the aluminum lower plate body, the middle layer and the heating wire are all cleaned before the assembly.

[0079] In the present invention, the purpose of cleaning is to remove impurities such as oil, dust, rust, oxide layer, etc. on the surface of the workpiece that affect the welding effect.

[0080] Exemplarily, the cleaning process of the aluminum upper plate, the aluminum lower plate, and the intermediate layer is as follows: alkali cleaning: soaking in an alkali solution with a mass concentration of 5-15% for 1-5 minutes, and then ultrasonically cleaning with water for 1-5 minutes; acid cleaning: soaking in an acid solution with a mass concentration of 5-15% for 2-5 minutes, and then ultrasonically cleaning with water for 1-5 minutes after acid cleaning, and then repeating the acid cleaning at least twice. After the acid cleaning is completed, rinse with a high-pressure water gun for 1-3 minutes, and then use alcohol ultrasonic cleaning for 5-10 minutes, and then blow dry and put into a vacuum drying oven (70-80°C) to dry for 1-2 hours;

[0081] Exemplarily, the cleaning process of the heating wire is as follows: ultrasonic cleaning in an alkaline solution with a mass concentration of 1-5% for 2-5 minutes, then ultrasonic cleaning in water for 5-10 minutes, and finally ultrasonic cleaning in alcohol for 5-10 minutes, and finally drying in a vacuum drying oven (70-80°C) for 1-2 hours.

[0082] In the present invention, alkali solution refers to alkali solutions such as sodium hydroxide solution, potassium hydroxide solution and their mixed solutions.

[0083] In the present invention, acid solution refers to acid solutions such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and their mixed solutions.

[0084] In the present invention, alcohol refers to methanol, ethanol, isopropanol and other alcohol solutions commonly used in alcohol washing in the art.

[0085] The diffusion welding comprises: first heating, first heat preservation, second heating, second heat preservation, pressurization, heat preservation and pressure preservation, and furnace cooling in sequence.

[0086] In the diffusion welding, the absolute vacuum degree is controlled to be less than or equal to 0.001 Pa, for example, 0.001 Pa, 0.0009 Pa, 0.0008 Pa, 0.0007 Pa, 0.0006 Pa, 0.0005 Pa, 0.0004 Pa, 0.0003 Pa, 0.0002 Pa, or 0.0001 Pa, but not limited to the listed values, and other values not listed in the range are also required.

[0087] In the first temperature rising, the temperature rising rate is 2-5 ℃ / min, for example, 2 ℃ / min, 2.2 ℃ / min, 2.4 ℃ / min, 2.6 ℃ / min, 2.8 ℃ / min, 3 ℃ / min, 3.2 ℃ / min, 3.4 ℃ / min, 3.6 ℃ / min, 3.8 ℃ / min, 4 ℃ / min, 4.2 ℃ / min, 4.4 ℃ / min, 4.6 ℃ / min, 4.8 ℃ / min, or 5 ℃ / min, but not limited to the listed values, and other values not listed in the range are also required.

[0088] In the first temperature rising, the pressure is controlled to be 2-5 t, for example, 2 t, 2.5 t, 3 t, 3.5 t, 4 t, 4.5 t, or 5 t, but not limited to the listed values, and other values not listed in the range are also required.

[0089] In the first temperature rising, the end temperature is the holding temperature of the first holding.

[0090] In the first holding, the holding temperature is 300-500 ℃, for example, 300 ℃, 320 ℃, 340 ℃, 360 ℃, 380 ℃, 400 ℃, 420 ℃, 440 ℃, 460 ℃, 480 ℃, or 500 ℃, but not limited to the listed values, and other values not listed in the range are also required.

[0091] In the first holding, the time is 1-3 h, for example, 1 h, 1.2 h, 1.4 h, 1.6 h, 1.8 h, 2 h, 2.2 h, 2.4 h, 2.6 h, 2.8 h, or 3 h, but not limited to the listed values, and other values not listed in the range are also required.

[0092] Wherein, the heating rate of the second heating is 2-5°C / min, for example, it can be 2°C / min, 2.2°C / min, 2.4°C / min, 2.6°C / min, 2.8°C / min, 3°C / min, 3.2°C / min, 3.4°C / min, 3.6°C / min, 3.8°C / min, 4°C / min, 4.2°C / min, 4.4°C / min, 4.6°C / min, 4.8°C / min or 5°C / min, etc., but is not limited to the listed values, and other values ​​not listed in this range also meet the requirements.

[0093] Wherein, the end temperature of the second heating is the insulation temperature of the second insulation.

[0094] The second insulation temperature is 500-600°C, for example, it can be 500°C, 510°C, 520°C, 530°C, 540°C, 550°C, 560°C, 570°C, 580°C, 590°C or 600°C, but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0095] The second insulation time is 0.5-1h, for example, 0.5h, 0.55h, 0.6h, 0.65h, 0.7h, 0.75h, 0.8h, 0.85h, 0.9h, 0.95h or 1h, etc., but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0096] The terminal pressure of the pressurization is 2-15 MPa, for example, it can be 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa or 15 MPa, but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0097] The pressurization time is 0.4-0.6h, for example, it can be 0.4h, 0.42h, 0.44h, 0.46h, 0.48h, 0.5h, 0.52h, 0.54h, 0.56h, 0.58h or 0.6h, but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0098] Wherein, the insulation temperature of the heat preservation and pressure preservation is the insulation temperature of the second insulation.

[0099] The heat preservation and pressure maintaining pressure is the terminal pressure of the pressurization.

[0100] Among them, the insulation and pressure holding time is 1-5h, for example, it can be 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h or 5h, but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0101] Among them, the furnace cooling includes: maintaining the pressure of heat preservation and pressure preservation to carry out furnace cooling to below 100℃, for example, it can be 100℃, 90℃, 80℃, 70℃, 60℃, 50℃, 40℃, 30℃, 20℃ or 10℃, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0102] Wherein, the electron beam welding comprises: welding along the circumferential weld of the disk body obtained by diffusion welding.

[0103] The beam current of the electron beam welding is 10-40 mA, for example, 10 mA, 15 mA, 20 mA, 25 mA, 30 mA, 35 mA or 40 mA, but is not limited to the listed values. Other values ​​not listed within the range also meet the requirements.

[0104] The focus of the electron beam welding is -15 to 10 mm, for example, it can be -15 mm, -14 mm, -12 mm, -10 mm, -8 mm, -6 mm, -4 mm, -2 mm, 0 mm, 2 mm, 4 mm, 6 mm, 8 mm or 10 mm, etc., but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0105] The welding speed of the electron beam welding is 10-30 mm / s, for example, 10 mm / s, 12 mm / s, 14 mm / s, 16 mm / s, 18 mm / s, 20 mm / s, 22 mm / s, 24 mm / s, 26 mm / s, 28 mm / s or 30 mm / s, but is not limited to the listed values. Other values ​​not listed within this range also meet the requirements.

[0106] 2. In order to illustrate the good use effect of the aluminum heating plate obtained by the welding method provided by the present invention, the following actual example is used for illustration, as follows:

[0107] Example 1

[0108] This embodiment provides a welding method for an aluminum heating plate, the welding method comprising:

[0109] Assemble an aluminum upper plate (pure aluminum), an aluminum lower plate (pure aluminum), a heating wire, and a 6 mm thick intermediate layer (pure nickel layer) to obtain an assembly;

[0110] The resulting assembly is sequentially subjected to diffusion welding and electron beam welding to obtain an aluminum heating plate;

[0111] The middle layer is arranged between the aluminum upper plate and the aluminum lower plate;

[0112] Before the assembly, the aluminum upper plate body, the aluminum lower plate body, the middle layer and the heating wire are all cleaned; the cleaning process of the aluminum upper plate body, the aluminum lower plate body and the middle layer is as follows: alkaline cleaning: soak in a sodium hydroxide solution with a mass concentration of 10% for 2 minutes, and then perform water ultrasonic cleaning for 2 minutes; pickling: soak in a nitric acid solution with a mass concentration of 10% for 3 minutes, and then perform water ultrasonic cleaning for 2 minutes after pickling, and then repeat the pickling twice. After the pickling is completed, rinse with a high-pressure water gun for 2 minutes, and then use isopropyl alcohol ultrasonic cleaning for 6 minutes, then blow dry and put into a vacuum drying oven to dry at 75°C for 1.5 hours; the cleaning process of the heating wire is as follows: ultrasonic cleaning in a sodium hydroxide solution with a mass concentration of 2% for 3 minutes, then perform water ultrasonic cleaning for 6 minutes, and finally perform isopropyl alcohol ultrasonic cleaning for 6 minutes, and finally blow dry and put into a vacuum drying oven to dry at 75°C for 1.5 hours.

[0113] The surface roughness Ra of the welding surface of the aluminum upper plate is 0.3 μm, and the flatness is 0.01 mm; the surface roughness Ra of the welding surface of the intermediate layer is 0.3 μm, and the flatness is 0.01 mm; the surface roughness Ra of the welding surface of the aluminum lower plate is 0.3 μm, and the flatness is 0.01 mm;

[0114] The welding surface of the intermediate layer is provided with a thread, the pitch of the thread is 0.5 mm, and the depth is 0.3 mm;

[0115] The diffusion welding comprises: first heating, first heat preservation, second heating, second heat preservation, pressurization, heat preservation and pressure preservation, and furnace cooling in sequence;

[0116] The absolute vacuum degree during the diffusion welding is controlled to be 0.001 Pa;

[0117] The heating rate of the first heating is 3°C / min, the control pressure is 3t, the end temperature is the holding temperature of the first insulation, the holding temperature of the first insulation is 400°C, and the first insulation time is 2h;

[0118] The heating rate of the second heating is 3°C / min, the end temperature of the second heating is the holding temperature of the second insulation, the holding temperature of the second insulation is 550°C, and the holding time of the second insulation is 0.75h;

[0119] The terminal pressure of the pressurization is 5 MPa, and the pressurization time is 0.5 h;

[0120] The holding temperature of the holding and pressurizing is the holding temperature of the second holding, the pressure of the holding and pressurizing is the terminal pressure of the pressurizing, and the time of the holding and pressurizing is 2 h;

[0121] The in-furnace cooling comprises: maintaining the pressure of the holding and pressurizing to perform in-furnace cooling to 25℃.

[0122] The electron beam welding comprises: welding along the circumferential weld of the diffusion-welded disc body, the beam current of the electron beam welding is 20 mA, the focus is -5 mm, and the welding speed is 20 mm / s.

[0123] Embodiment 2

[0124] The embodiment provides a welding method of an aluminum heating disc, and the welding method comprises the following steps:

[0125] An aluminum upper disc body (pure aluminum), an aluminum lower disc body (pure aluminum), a heating wire and an intermediate layer (a pure nickel layer) with a thickness of 5 mm are assembled to obtain an assembly;

[0126] The obtained assembly is sequentially subjected to diffusion welding and electron beam welding to obtain the aluminum heating disc.

[0127] The intermediate layer is arranged between the aluminum upper disc body and the aluminum lower disc body.

[0128] Before the assembling, the aluminum upper disc body, the aluminum lower disc body, the intermediate layer and the heating wire are all cleaned; the cleaning process of the aluminum upper disc body, the aluminum lower disc body and the intermediate layer is as follows: alkali cleaning: soaking in a sodium hydroxide solution with a mass concentration of 12% for 3 min, and then performing water ultrasonic cleaning for 3 min; acid cleaning: soaking in a nitric acid solution with a mass concentration of 8% for 2 min, and then performing water ultrasonic cleaning for 3 min, and then repeating the acid cleaning for 2 times, and then cleaning with a high-pressure water gun for 2 min, and then performing isopropyl alcohol ultrasonic cleaning for 8 min, and then drying and placing in a vacuum drying box at 75 ℃ for 1.5 h; the cleaning process of the heating wire is as follows: isopropyl alcohol ultrasonic cleaning for 4 min in a sodium hydroxide solution with a mass concentration of 3%, and then performing water ultrasonic cleaning for 8 min, and finally performing isopropyl alcohol ultrasonic cleaning for 8 min, and finally drying and placing in a vacuum drying box at 75 ℃ for 1.5 h;

[0129] The surface roughness Ra of the welding surface of the aluminum upper disc body is 0.2 μm, and the flatness is 0.05 mm; the surface roughness Ra of the welding surface of the intermediate layer is 0.2 μm, and the flatness is 0.05 mm; and the surface roughness Ra of the welding surface of the aluminum lower disc body is 0.2 μm, and the flatness is 0.05 mm.

[0130] The welding surface of the intermediate layer is provided with a thread, the pitch of the thread is 0.6 mm, and the depth is 0.4 mm.

[0131] The diffusion welding comprises: first heating, first heat preservation, second heating, second heat preservation, pressurization, heat preservation and pressure preservation, and furnace cooling in sequence;

[0132] The absolute vacuum degree during the diffusion welding is controlled to be 0.0001 Pa;

[0133] The first heating rate is 4°C / min, the control pressure is 4t, the end temperature is the first insulation temperature, the first insulation temperature is 450°C, and the first insulation time is 1.5h;

[0134] The heating rate of the second heating is 4°C / min, the end temperature of the second heating is the holding temperature of the second insulation, the holding temperature of the second insulation is 580°C, and the holding time of the second insulation is 0.6h;

[0135] The terminal pressure of the pressurization is 10 MPa, and the pressurization time is 0.55 h;

[0136] The heat preservation and pressure holding temperature is the heat preservation temperature of the second heat preservation, the heat preservation and pressure holding pressure is the end pressure of the pressurization, and the heat preservation and pressure holding time is 3 hours;

[0137] The furnace cooling includes: maintaining the pressure of heat preservation and pressure preservation and cooling the furnace to 30°C;

[0138] The electron beam welding comprises: welding along the circumferential weld of the disc body obtained by diffusion welding, the beam current of the electron beam welding is 30 mA, the focus is 5 mm, and the welding speed is 25 mm / s.

[0139] Example 3

[0140] This embodiment provides a welding method for an aluminum heating plate, the welding method comprising:

[0141] Assemble an aluminum upper plate (pure aluminum), an aluminum lower plate (pure aluminum), a heating wire, and an intermediate layer (pure nickel layer) with a thickness of 8 mm to obtain an assembly;

[0142] The resulting assembly is sequentially subjected to diffusion welding and electron beam welding to obtain an aluminum heating plate;

[0143] The middle layer is arranged between the aluminum upper plate and the aluminum lower plate;

[0144] Before the assembly, the aluminum upper plate body, the aluminum lower plate body, the middle layer and the heating wire are all cleaned; the cleaning process of the aluminum upper plate body, the aluminum lower plate body and the middle layer is as follows: alkali cleaning: soaking in a sodium hydroxide solution with a mass concentration of 5 minutes, and then performing water ultrasonic cleaning for 5 minutes; pickling: soaking in a nitric acid solution with a mass concentration of 5 minutes, and then performing water ultrasonic cleaning for 5 minutes after pickling, and then repeating the pickling twice. After the pickling is completed, rinse with a high-pressure water gun for 3 minutes, and then use isopropyl alcohol ultrasonic cleaning for 10 minutes, and then blow dry and put into a vacuum drying oven to dry at 80°C for 1 hour; the cleaning process of the heating wire is as follows: ultrasonic cleaning in a sodium hydroxide solution with a mass concentration of 5% for 2 minutes, then water ultrasonic cleaning for 10 minutes, and finally isopropyl alcohol ultrasonic cleaning for 10 minutes, and finally blow dry and put into a vacuum drying oven to dry at 80°C for 1 hour;

[0145] The surface roughness Ra of the welding surface of the aluminum upper plate is 0.3 μm, and the flatness is 0.01 mm; the surface roughness Ra of the welding surface of the intermediate layer is 0.3 μm, and the flatness is 0.01 mm; the surface roughness Ra of the welding surface of the aluminum lower plate is 0.3 μm, and the flatness is 0.01 mm;

[0146] The welding surfaces of the aluminum lower plate and the middle layer are both provided with threads, the pitch of the threads is 0.8 mm and the depth is 0.5 mm;

[0147] The diffusion welding comprises: first heating, first heat preservation, second heating, second heat preservation, pressurization, heat preservation and pressure preservation, and furnace cooling in sequence;

[0148] The absolute vacuum degree during the diffusion welding is controlled to be 0.001 Pa;

[0149] The heating rate of the first heating is 5°C / min, the control pressure is 5t, the end temperature is the holding temperature of the first insulation, the holding temperature of the first insulation is 500°C, and the first insulation time is 1h;

[0150] The heating rate of the second heating is 5°C / min, the end temperature of the second heating is the holding temperature of the second insulation, the holding temperature of the second insulation is 600°C, and the holding time of the second insulation is 0.5h;

[0151] The terminal pressure of the pressurization is 15 MPa, and the pressurization time is 0.6 h;

[0152] The heat preservation and pressure holding temperature is the heat preservation temperature of the second heat preservation, the heat preservation and pressure holding pressure is the end pressure of the pressurization, and the heat preservation and pressure holding time is 1 hour;

[0153] The furnace cooling includes: maintaining the pressure of heat preservation and pressure preservation and cooling the furnace to 15°C;

[0154] The electron beam welding comprises: welding along the circumferential weld of the disc body obtained by diffusion welding, the beam current of the electron beam welding is 40 mA, the focus is 10 mm, and the welding speed is 30 mm / s.

[0155] Example 4

[0156] This embodiment provides a welding method for an aluminum heating plate, the welding method comprising:

[0157] An aluminum upper plate (pure aluminum), an aluminum lower plate (pure aluminum), a heating wire, and a 3 mm thick intermediate layer (pure nickel layer) are assembled to obtain an assembly;

[0158] The resulting assembly is sequentially subjected to diffusion welding and electron beam welding to obtain an aluminum heating plate;

[0159] The intermediate layer is arranged between the aluminum upper plate and the aluminum lower plate;

[0160] Before the assembly, the aluminum upper plate body, the aluminum lower plate body, the middle layer and the heating wire are all cleaned; the cleaning process of the aluminum upper plate body, the aluminum lower plate body and the middle layer is as follows: alkali cleaning: soaking in a sodium hydroxide solution with a mass concentration of 15% for 1 minute, and then performing water ultrasonic cleaning for 1 minute; pickling: soaking in a nitric acid solution with a mass concentration of 15% for 1 minute, and then performing water ultrasonic cleaning for 1 minute after pickling, and then repeating the pickling twice. After the pickling is completed, rinse with a high-pressure water gun for 1 minute, and then use isopropyl alcohol ultrasonic cleaning for 5 minutes, and then blow dry and put into a vacuum drying oven to dry at 70°C for 2 hours; the cleaning process of the heating wire is as follows: ultrasonic cleaning in a sodium hydroxide solution with a mass concentration of 1% for 5 minutes, then water ultrasonic cleaning for 5 minutes, and finally isopropyl alcohol ultrasonic cleaning for 5 minutes, and finally blow dry and put into a vacuum drying oven to dry at 70°C for 2 hours;

[0161] The surface roughness Ra of the welding surface of the aluminum upper plate is 0.1 μm, and the flatness is 0.02 mm; the surface roughness Ra of the welding surface of the intermediate layer is 0.1 μm, and the flatness is 0.02 mm; the surface roughness Ra of the welding surface of the aluminum lower plate is 0.1 μm, and the flatness is 0.02 mm;

[0162] The welding surfaces of the aluminum upper plate and the middle layer are both provided with threads, the pitch of the threads is 0.3mm and the depth is 0.1mm;

[0163] The diffusion welding comprises: first heating, first heat preservation, second heating, second heat preservation, pressurization, heat preservation and pressure preservation, and furnace cooling in sequence;

[0164] The absolute vacuum degree during the diffusion welding is controlled to be 0.001 Pa;

[0165] The heating rate of the first heating is 2°C / min, the control pressure is 2t, the end temperature is the holding temperature of the first insulation, the holding temperature of the first insulation is 300°C, and the first insulation time is 3h;

[0166] The heating rate of the second heating is 2°C / min, the end temperature of the second heating is the holding temperature of the second insulation, the holding temperature of the second insulation is 500°C, and the holding time of the second insulation is 1h;

[0167] The terminal pressure of the pressurization is 2 MPa, and the pressurization time is 0.4 h;

[0168] The heat preservation and pressure holding temperature is the heat preservation temperature of the second heat preservation, the heat preservation and pressure holding pressure is the end pressure of the pressurization, and the heat preservation and pressure holding time is 5 hours;

[0169] The furnace cooling includes: maintaining the pressure of heat preservation and pressure preservation and cooling the furnace to 30°C;

[0170] The electron beam welding comprises: welding along the circumferential weld of the disc body obtained by diffusion welding, the beam current of the electron beam welding is 10 mA, the focus is -15 mm, and the welding speed is 10 mm / s.

[0171] Comparative Example 1

[0172] The only difference from Example 1 is that the pure nickel intermediate layer is replaced by a 1050 aluminum alloy layer of equal thickness.

[0173] Comparative Example 2

[0174] The only difference from Example 1 is that the pure nickel intermediate layer is replaced by AlSi 12 Soldering piece.

[0175] Comparative Example 3

[0176] The only difference from Example 1 is that the first heat preservation is not performed.

[0177] Comparative Example 4

[0178] The only difference from Example 1 is that the second insulation step is not performed.

[0179] Comparative Example 5

[0180] The only difference from Example 1 is that no pressurization is performed, that is, no pressurization is performed during the heat preservation and pressure maintenance.

[0181] Example 5

[0182] The only difference from Example 1 is that the holding temperature of the first holding is 250°C.

[0183] Example 6

[0184] The only difference from Example 1 is that the holding temperature of the first holding is 550°C.

[0185] Example 7

[0186] The only difference from Example 1 is that the heating rate of the first heating is 8° C. / min.

[0187] Example 8

[0188] The only difference from Example 1 is that the pressure is controlled to 1t during the first insulation.

[0189] Example 9

[0190] The only difference from Example 1 is that the pressure is controlled to 6t during the first insulation.

[0191] Example 10

[0192] The only difference from Example 1 is that the holding temperature of the second holding is 400°C.

[0193] Example 11

[0194] The only difference from Example 1 is that the heating rate of the second heating is 8° C. / min.

[0195] The aluminum heating plates obtained by welding the above examples and comparative examples were subjected to creep performance testing according to GB / T 2039-2024 Metal Materials Uniaxial Tensile Creep Test Method, and the welding strength of the aluminum heating plates was tested according to GB / T 2651-2023. The results are detailed in Table 1 below.

[0196] Table 1

[0197]

[0198]

[0199] As can be seen from Table 1, the welding method provided by the present invention realizes efficient welding of the aluminum heating plate by adding a specific intermediate layer in combination with diffusion welding, so that the obtained aluminum heating plate has the advantages of high strength and not easy to deform, significantly reduces the creep of the aluminum heating plate in a high-temperature use environment, and is conducive to ensuring use.

[0200] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0201] It should be further noted that each of the various technical features described in the above embodiments can be combined with any other technical features in any suitable manner, and the present application shall be deemed to disclose all possible combinations thereof, without causing unnecessary repetition.

[0202] Furthermore, any combination of the various embodiments of the present application can be made, as long as it does not deviate from the spirit of the present application, and it shall be deemed to be disclosed by the present application.

Claims

1. A welding method for an aluminum heating plate, characterized in that: The welding method comprises: Assembling an aluminum upper plate, an aluminum lower plate, a heating wire and an intermediate layer to obtain an assembly; The resulting assembly is sequentially subjected to diffusion welding and electron beam welding to obtain an aluminum heating plate; The intermediate layer is provided between the aluminum upper plate and the aluminum lower plate; the hardness of the intermediate layer satisfies ≥ 4 times the hardness of the aluminum upper plate and / or 4 times the hardness of the aluminum lower plate; the tensile strength of the intermediate layer satisfies ≥ 4 times the tensile strength of the aluminum upper plate and / or 4 times the tensile strength of the aluminum lower plate; The diffusion welding comprises: first heating, first heat preservation, second heating, second heat preservation, pressurization, heat preservation and pressure preservation, and furnace cooling performed in sequence.

2. The welding method according to claim 1, wherein: The surface roughness of the welding surface of the aluminum upper plate is Ra < 0.6 μm; Preferably, the flatness of the welding surface of the aluminum upper plate is less than 0.1 mm; Preferably, the surface roughness of the welding surface of the intermediate layer Ra is less than 0.6 μm; Preferably, the flatness of the welding surface of the intermediate layer is less than 0.1 mm; Preferably, the surface roughness of the welding surface of the aluminum lower plate is Ra < 0.6 μm; Preferably, the flatness of the welding surface of the aluminum lower plate is less than 0.1 mm.

3. The welding method according to claim 1 or 2, wherein: At least one welding surface of the aluminum upper plate, the aluminum lower plate or the intermediate layer is provided with a thread; Preferably, the pitch of the thread is 0.3-0.8 mm; Preferably, the depth of the thread is 0.1-0.5 mm; Preferably, the thickness of the middle layer is 3-8 mm.

4. The welding method according to any one of claims 1 to 3, characterized in that: Before the assembly, the aluminum upper plate body, the aluminum lower plate body, the middle layer and the heating wire are cleaned.

5. The welding method according to any one of claims 1 to 4, characterized in that: During the diffusion welding, the absolute vacuum is controlled to be ≤0.001Pa; Preferably, the first heating rate is 2-5°C / min; Preferably, the pressure during the first heating process is controlled to be 2-5t; Preferably, the endpoint temperature of the first heating is the insulation temperature of the first insulation; Preferably, the first insulation temperature is 300-500°C; Preferably, the first insulation time is 1-3 hours.

6. The welding method according to any one of claims 1 to 5, characterized in that: The second heating rate is 2-5°C / min; Preferably, the endpoint temperature of the second heating is the insulation temperature of the second insulation; Preferably, the second insulation temperature is 500-600°C; Preferably, the second insulation time is 0.5-1h.

7. The welding method according to any one of claims 1 to 6, characterized in that: The terminal pressure of the pressurization is 2-15 MPa; Preferably, the pressurization is carried out for 0.4-0.6h; Preferably, the heat preservation and pressure preservation temperature is the heat preservation temperature of the second heat preservation; Preferably, the heat preservation and pressure maintaining pressure is the terminal pressure of pressurization; Preferably, the heat preservation and pressure preservation time is 1-5 hours.

8. The welding method according to any one of claims 1 to 7, characterized in that: The furnace cooling includes: cooling the furnace to below 100° C. while maintaining the pressure of heat preservation and pressure maintenance.

9. The welding method according to any one of claims 1 to 8, characterized in that: The electron beam welding comprises: welding along the circumferential weld seam of the disc body obtained by diffusion welding.

10. The welding method according to any one of claims 1 to 9, characterized in that: The beam current of the electron beam welding is 10-40mA; Preferably, the focus of the electron beam welding is -15 to 10 mm; Preferably, the welding speed of the electron beam welding is 10-30 mm / s.

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