Electron beam welding forming method for die-casting aluminum alloy heating plate

Abstract

The invention provides an electron beam welding forming method of a die-casting aluminum alloy heating plate, which aims at welding an upper plate body and a lower plate body which are made of die-casting aluminum alloy, particularly aims at the condition that the die-casting aluminum alloy contains more alloy elements, and aims at reducing evaporation loss of low-melting-point elements such as Mg and Zn and the like. The electron beam focus of electron beam welding must be set as the deposited focus, molten pool disturbance is reduced, air hole formation is restrained, the aluminum oxide layer breakdown difficulty is reduced, the defects such as hot cracks and air holes are reduced, and the welding bonding strength is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of heating plates, and particularly relates to an electron beam welding forming method for a die-cast aluminum alloy heating plate. Background Art

[0002] In integrated circuit manufacturing, degassing equipment and annealing equipment are required to heat silicon wafers. The main function is to place the silicon wafers in a vacuum and high-temperature environment for a period of time to remove substances such as water vapor and organic matter adsorbed on the surface of the silicon wafers, and to reduce defects and doping redistribution, etc. Therefore, the heating plate is the core heating component in the degassing equipment and annealing equipment.

[0003] In recent years, with the rapid development of China's semiconductor industry, the demand for aluminum heating plates has been increasing, and high requirements and standards have been put forward for the disk body material and the overall temperature uniformity of the disk body. At present, the aluminum heating plates applied in the semiconductor industry often use casting / die-casting forming processes or forming methods such as electron beam welding / vacuum brazing. Die-casting / casting requires the use of die-cast aluminum alloys such as A380 and YL112, etc. However, there are often pores in the cross-section of the aluminum heating plate formed by this process, resulting in problems with the temperature uniformity of the disk body. Vacuum brazing / electron beam welding often uses deformed aluminum for welding, but the deformed aluminum cannot match the mechanical properties such as hardness of die-cast aluminum.

[0004] The structure of the aluminum heating plate is relatively complex and contains heating wires inside. In the aluminum heating plates currently obtained by die-casting / casting molding processes, the heating wires generally deform and are not on the same horizontal plane, which will cause the temperature uniformity and processing accuracy of the aluminum heating plate to be much worse. In response to this, relevant researchers considered dividing the die-cast aluminum alloy heating plate into three parts, specifically including a lower plate body, heating wires, and an upper plate body. Grooves are dug in the lower plate body to embed the heating wires, and finally the upper plate body and the lower plate body are welded to achieve molding, thereby improving the temperature uniformity and processing accuracy. CN 117862656A discloses a welding method for an aluminum heating plate, specifically providing an electron beam welding process for welding deformed aluminum such as A3003 / A1060. However, the electron beam welding forming process for deformed aluminum cannot be directly applied to the die-cast aluminum alloy forming process because die-cast aluminum alloys contain multiple alloy elements, and different alloy elements have different melting points, which are prone to cause discharge phenomena. For example, the Si content in A380 die-cast aluminum alloy is relatively high. During electron beam welding, Si is prone to segregate at grain boundaries, forming a brittle aluminum-silicon eutectic phase (such as Al-Si low-melting eutectic), significantly reducing the ductility of the weld and increasing the sensitivity to hot cracks. A380 die-cast aluminum alloy contains Fe (about 1.3%) and Cu (3-4%). During welding, brittle Al-Fe-Si or Al-Cu intermetallic compounds are easily formed. Especially under the condition of rapid solidification, these compounds are distributed along the grain boundaries, resulting in weld embrittlement. Elements such as Mg and Zn are prone to evaporation in the high-temperature environment of vacuum electron beams (such as the boiling point of Mg is only 1107°C), resulting in an imbalance in the alloy composition of the weld, affecting corrosion resistance and strength. In addition, there are micro-voids (casting defects) inside the A380 die-cast aluminum alloy. The high-energy input of the electron beam may cause the voids to expand in the molten pool, forming through-holes or causing the molten pool to collapse.

[0005] Therefore, it is necessary to develop an electron beam welding forming method for die-cast aluminum alloy heating plates. Summary of the Invention

[0006] In view of the problems existing in the prior art, the present invention provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. The electron beam welding forming method is aimed at welding the upper plate body and the lower plate body made of die-cast aluminum alloy, especially for the case where there are many alloy elements in the die-cast aluminum alloy. In order to reduce the evaporation loss of low-melting-point elements such as Mg and Zn, it is necessary to set the electron beam focus of the electron beam welding as a deep focus, reduce the disturbance of the molten pool, inhibit the formation of pores, reduce the difficulty of breaking through the alumina layer, reduce defects such as hot cracks and pores, and ensure the welding bonding strength.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] The purpose of the present invention is to provide an electron beam welding forming method for a die-cast aluminum alloy heating plate. The electron beam welding forming method includes the following steps:

[0009] Assemble the heating wire, the upper disc body and the lower disc body, and perform electron beam welding on the connection between the upper disc body and the lower disc body;

[0010] Among them, the materials of the upper disc body and the lower disc body are both die-cast aluminum alloy;

[0011] The electron beam focus of the electron beam welding is a defocused focus.

[0012] The electron beam welding forming method of the present invention is aimed at the welding of the upper disc body and the lower disc body made of die-cast aluminum alloy. Especially for the case where there are many alloy elements in the die-cast aluminum alloy, in order to reduce the evaporation loss of low-melting-point elements such as Mg and Zn, it is necessary to set the electron beam focus of the electron beam welding as a defocused focus, reduce the molten pool disturbance, inhibit the formation of pores, reduce the difficulty of breaking through the alumina layer, reduce defects such as hot cracks and pores, and ensure the welding joint strength.

[0013] As a preferred technical solution of the present invention, the materials of the upper disc body and the lower disc body are both A380 die-cast aluminum alloy or YL112 die-cast aluminum alloy.

[0014] As a preferred technical solution of the present invention, the electron beam current of the electron beam welding is 25 - 30 mA, such as 25 mA, 26 mA, 27 mA, 28 mA, 29 mA or 30 mA, etc., but not limited to the listed values, and other unlisted values within the above value range are equally applicable.

[0015] As a preferred technical solution of the present invention, the linear speed of the electron beam welding is 15 - 30 mm / s, such as 15 mm / s, 17 mm / s, 20 mm / s, 21 mm / s, 23 mm / s, 25 mm / s, 27 mm / s, 28 mm / s or 30 mm / s, etc., but not limited to the listed values, and other unlisted values within the above value range are equally applicable.

[0016] As a preferred technical solution of the present invention, the defocused focus of the electron beam welding is set to 15 - 20, such as 15, 16, 17, 18, 19 or 20, etc., but not limited to the listed values, and other unlisted values within the above value range are equally applicable.

[0017] As a preferred technical solution of the present invention, the depth of the molten pool formed by the electron beam welding is 3.0 - 5.5 mm, such as 3.0 mm, 3.3 mm, 3.5 mm, 3.8 mm, 4.0 mm, 4.2 mm, 4.5 mm, 4.7 mm, 5.0 mm, 5.2 mm or 5.5 mm, etc., but not limited to the listed values, and other unlisted values within the above value range are equally applicable.

[0018] As a preferred technical solution of the present invention, the width of the molten pool formed by electron beam welding is 5.0 - 7.5 mm, such as 5.0 mm, 5.3 mm, 5.5 mm, 5.8 mm, 6.0 mm, 6.3 mm, 6.5 mm, 6.7 mm, 7.0 mm, 7.3 mm or 7.5 mm, etc., but not limited to the listed values, and other unlisted values within the above numerical range are equally applicable.

[0019] As a preferred technical solution of the present invention, before the assembly, the upper disk body and the lower disk body are respectively subjected to surface cleaning.

[0020] As a preferred technical solution of the present invention, the surface cleaning includes: using sandpaper to polish and remove the oxide film, and then using a chemical reagent to wash and remove the oil stain, for example, the chemical reagent is acetone.

[0021] As a preferred technical solution of the present invention, the electron beam welding forming method includes the following steps:

[0022] Assemble the heating wire, the upper disk body and the lower disk body, and perform electron beam welding on the connection part between the upper disk body and the lower disk body;

[0023] Among them, the materials of the upper disk body and the lower disk body are both A380 die-casting aluminum alloy or YL112 die-casting aluminum alloy;

[0024] Before the assembly, the upper disk body and the lower disk body are respectively subjected to surface cleaning, and the surface cleaning includes: using sandpaper to polish and remove the oxide film, and then using a chemical reagent to wash and remove the oil stain;

[0025] The electron beam focus of the electron beam welding is a submerged focus and the submerged focus is set to 15 - 20, the electron beam current of the electron beam welding is 25 - 30 mA, the linear speed of the electron beam welding is 15 - 30 mm / s, the depth of the molten pool formed by the electron beam welding is 3.0 - 5.5 mm, and the width of the molten pool formed by the electron beam welding is 5.0 - 7.5 mm.

[0026] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0027] The electron beam welding forming method of the present invention is aimed at the welding of the upper disk body and the lower disk body made of die-casting aluminum alloy, especially for the case where there are many alloy elements in the die-casting aluminum alloy. In order to reduce the evaporation loss of low-melting-point elements such as Mg and Zn, it is necessary to set the electron beam focus of the electron beam welding as a submerged focus, and further set the electron beam current of the electron beam welding to 25 - 30 mA and the linear speed to 15 - 30 mm / s. By combining the medium-high speed welding method with a low electron beam current, the disturbance of the molten pool is reduced, the formation of pores is inhibited, the difficulty of breaking through the alumina layer is reduced, and defects such as hot cracks and pores are reduced, ensuring the welding joint strength. Brief Description of the Drawings

[0028] Figure 1 is the weld appearance diagram corresponding to Embodiment 1 of the present invention;

[0029] Figure 2 is the weld appearance diagram corresponding to Embodiment 2 of the present invention;

[0030] Figure 3 is the weld appearance diagram corresponding to Embodiment 3 of the present invention;

[0031] Figure 4 is the weld appearance diagram corresponding to Embodiment 4 of the present invention;

[0032] Figure 5 is the weld appearance diagram corresponding to Embodiment 5 of the present invention;

[0033] Figure 6 is the weld appearance diagram corresponding to Embodiment 6 of the present invention;

[0034] Figure 7 is the weld appearance diagram corresponding to Embodiment 7 of the present invention;

[0035] Figure 8 is the weld appearance diagram corresponding to Embodiment 8 of the present invention;

[0036] Figure 9 is the molten pool size measurement diagram corresponding to Embodiment 1 of the present invention;

[0037] Figure 10 is the molten pool size measurement diagram corresponding to Embodiment 2 of the present invention;

[0038] Figure 11 is the molten pool size measurement diagram corresponding to Embodiment 3 of the present invention;

[0039] Figure 12 is the molten pool size measurement diagram corresponding to Embodiment 4 of the present invention;

[0040] Figure 13 is the molten pool size measurement diagram corresponding to Embodiment 5 of the present invention;

[0041] Figure 14 is the molten pool size measurement diagram corresponding to Embodiment 6 of the present invention;

[0042] Figure 15 is the molten pool size measurement diagram corresponding to Embodiment 7 of the present invention;

[0043] Figure 16 is the molten pool size measurement diagram corresponding to Embodiment 8 of the present invention. Detailed Description of the Invention

[0044] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and through specific embodiments.

[0045] To better illustrate the present invention and facilitate understanding of its technical solution, typical but non-limiting embodiments of the present invention are as follows:

[0046] In the specific embodiment of the present invention, an aluminum fixture is selected according to the size of the product to be welded for fixing the product during electron beam welding. Moreover, before electron beam welding, the welding material is pickled with acid solution to ensure that the surface of the welding material is free of stains, reducing the probability of abnormal electron beam welding.

[0047] Embodiment 1

[0048] This embodiment provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. The electron beam welding forming method includes the following steps:

[0049] Assemble the heating wire, the upper plate body and the lower plate body, and perform electron beam welding on the connection part between the upper plate body and the lower plate body;

[0050] Among them, the materials of the upper plate body and the lower plate body are both A380 die-cast aluminum alloy;

[0051] Before the assembly, the surfaces of the upper plate body and the lower plate body are respectively cleaned. The surface cleaning includes: using sandpaper to polish and remove the oxide film, and then using acetone to clean and remove the oil stain;

[0052] The electron beam focus of the electron beam welding is a defocused focus and the defocus is set to 20. The electron beam current of the electron beam welding is 25 mA, the linear speed of the electron beam welding is 15 mm / s, the depth of the molten pool formed by the electron beam welding is 4.6 mm, and the width of the molten pool formed by the electron beam welding is 7.1 mm.

[0053] Embodiment 2

[0054] This embodiment provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. Compared with Embodiment 1, the difference is only that: the linear speed of the electron beam welding is set to 20 mm / s. Therefore, the depth of the molten pool formed by the electron beam welding is 3.0 mm, and the width of the molten pool formed by the electron beam welding is 7.1 mm.

[0055] Embodiment 3

[0056] This embodiment provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. Compared with Embodiment 1, the difference is only that: the linear speed of the electron beam welding is set to 25 mm / s. Therefore, the depth of the molten pool formed by the electron beam welding is 5.2 mm, and the width of the molten pool formed by the electron beam welding is 5.4 mm.

[0057] Example 4

[0058] This example provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. Compared with Example 1, the only difference is that the linear speed of the electron beam welding is set to 30 mm / s. Therefore, the depth of the molten pool formed by the electron beam welding is 5.4 mm, and the width of the molten pool formed by the electron beam welding is 5.4 mm.

[0059] Example 5

[0060] This example provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. The electron beam welding forming method includes the following steps:

[0061] Assemble the heating wire, the upper plate body and the lower plate body, and perform electron beam welding on the joint of the upper plate body and the lower plate body;

[0062] Among them, the materials of the upper plate body and the lower plate body are both A380 die-cast aluminum alloy;

[0063] Before the assembly, the surfaces of the upper plate body and the lower plate body are respectively cleaned. The surface cleaning includes: using sandpaper to polish and remove the oxide film, and then using acetone to clean and remove the oil stain;

[0064] The electron beam focus of the electron beam welding is a defocused focus and the defocus is set to 20. The electron beam current of the electron beam welding is 30 mA. The linear speed of the electron beam welding is 15 mm / s. The depth of the molten pool formed by the electron beam welding is 5.2 mm, and the width of the molten pool formed by the electron beam welding is 5.7 mm.

[0065] Example 6

[0066] This example provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. Compared with Example 5, the only difference is that the linear speed of the electron beam welding is set to 20 mm / s. Therefore, the depth of the molten pool formed by the electron beam welding is 5.2 mm, and the width of the molten pool formed by the electron beam welding is 6.9 mm.

[0067] Example 7

[0068] This example provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. Compared with Example 5, the only difference is that the linear speed of the electron beam welding is set to 25 mm / s. Therefore, the depth of the molten pool formed by the electron beam welding is 3.4 mm, and the width of the molten pool formed by the electron beam welding is 6.3 mm.

[0069] Example 8

[0070] This embodiment provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. Compared with Example 5, the only difference is that the linear speed of electron beam welding is set to 30 mm / s, so the depth of the molten pool formed by electron beam welding is 3.4 mm, and the width of the molten pool formed by the electron beam welding is 5.8 mm.

[0071] Comparative Example 1

[0072] This comparative example provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. Compared with Example 5, the only difference is that the line speed of electron beam welding is set to 12 mm / s, and individual pits will appear after welding, resulting in a molten pool depth of up to 6.6 mm at the pits, which can easily cause damage to the heating wire.

[0073] Comparative Example 2

[0074] This comparative example provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. Compared with Example 1, the only difference is that the electron beam current of the electron beam welding is set to 40mA, and the molten pool depth will be too deep after welding, causing the entire weldment located at the upper part to sink, resulting in welding failure.

[0075] Comparative Example 3

[0076] This comparative example provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. Compared with Example 1, the only difference is that the electron beam current of the electron beam welding is set to 15mA, and the molten pool depth is shallow after welding, which is only 2.7mm. Although the molten pool width is 5.3mm, it will also cause welding failure. This is because machining is required after the electron beam welding is completed. For example, the surface milling machine is machined off by about 1mm, and the thickness of the weld will become thinner after post-processing such as polishing. Therefore, the molten pool depth in this comparative example is shallow, which is only 2.7mm. After subsequent machining, the molten pool depth will be much less than 2mm, and the aluminum heating plate is prone to air leakage. In order to ensure the normal use of the product, this process parameter is judged to be unqualified.

[0077] Comparative Example 4

[0078] This comparative example provides an electron beam welding forming method for a die-cast aluminum alloy heating plate. Compared with Example 1, the only difference is that the electron beam focus of the electron beam welding is set to the surface focus and the surface focus is set to 20, which causes partial pores to appear in the molten pool. The molten pool is disturbed and eventually holes are generated at the weld, which does not meet the welding appearance requirements and requires repair welding.

[0079] The key process parameters and molten pool related parameters of the above embodiments and comparative examples are summarized in Table 1. Figures 1 - 8 The weld appearance diagrams corresponding to Examples 1-8 are shown respectively, Figures 9 - 16The measured molten pool size diagrams corresponding to Embodiments 1-8 are respectively shown.

[0080] Table 1

[0081]

[0082] It can be seen from Table 1 as follows:

[0083] (1) For the electron beam welding forming method of the present invention for die-cast aluminum alloy, by precisely controlling the defocusing, beam current and linear velocity parameters, an ideal molten pool depth and molten pool width can be stably obtained, meeting the requirements of different welding structures, reducing the generation of welding defects such as hot cracks and pores, improving the stability and reliability of welding quality, reducing the rejection rate, improving production efficiency, and finally an aluminum heating plate with high hardness and no internal defects can be obtained;

[0084] (2) By comparing Embodiments 1-4, it can be seen that on the premise of defocusing of 20 and beam current of 25 mA, as the linear velocity increases, the molten pool width decreases from 7.1 mm to 5.4 mm, but the molten pool depth shows a trend of first becoming shallower and then deeper;

[0085] (3) By comparing Embodiments 5-8, it can be seen that on the premise of defocusing of 20 and beam current of 30 mA, as the linear velocity increases, the molten pool width shows a trend of first increasing and then decreasing, and the molten pool depth gradually decreases.

[0086] The present invention uses the above embodiments to illustrate the detailed structural features of the present invention, but 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 improvement to the present invention, the equivalent replacement of the components selected by the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0087] The preferred embodiments of the present invention have been 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 solutions of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0088] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any suitable way. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0089] In addition, any combination can be made between various different embodiments of the present invention, as long as it does not violate the idea of the present invention, it should also be regarded as the content disclosed by the present invention.

Claims

1. An electron beam welding method for a die-cast aluminum alloy heating plate, characterized in that: The electron beam welding forming method comprises the following steps: Assembling the heating wire, the upper plate body and the lower plate body, and performing electron beam welding on the connection between the upper plate body and the lower plate body; Wherein, the upper plate body and the lower plate body are made of die-cast aluminum alloy; The electron beam focus of the electron beam welding is deep focus.

2. The electron beam welding forming method according to claim 1, characterized in that: The upper plate body and the lower plate body are both made of A380 die-cast aluminum alloy or YL112 die-cast aluminum alloy.

3. The electron beam welding forming method according to claim 1, characterized in that: The electron beam current of the electron beam welding is 25-30 mA.

4. The electron beam welding forming method according to claim 1, characterized in that: The line speed of the electron beam welding is 15-30 mm / s.

5. The electron beam welding forming method according to claim 1, characterized in that: The electron beam welding focus is set to 15-20.

6. The electron beam welding forming method according to claim 1, characterized in that: The depth of the molten pool formed by the electron beam welding is 3.0-5.5 mm.

7. The electron beam welding forming method according to claim 1, characterized in that: The width of the molten pool formed by the electron beam welding is 5.0-7.5 mm.

8. The electron beam welding forming method according to claim 1, characterized in that: Before the assembling, the surfaces of the upper plate body and the lower plate body are cleaned respectively.

9. The electron beam welding forming method according to claim 8, characterized in that: The surface cleaning includes: using sandpaper to polish and remove the oxide film, and then using chemical reagents to clean and remove oil stains.

10. The electron beam welding forming method according to any one of claims 1 to 9, characterized in that: The electron beam welding forming method comprises the following steps: Assembling the heating wire, the upper plate body and the lower plate body, and performing electron beam welding on the connection between the upper plate body and the lower plate body; Wherein, the upper plate and the lower plate are made of A380 die-cast aluminum alloy or YL112 die-cast aluminum alloy; Before the assembly, the upper plate and the lower plate are cleaned respectively, and the surface cleaning includes: using sandpaper to polish and remove the oxide film, and then using chemical reagents to clean and remove oil stains; The electron beam focus of the electron beam welding is deep focus and the deep focus is set to 15-20, the electron beam current of the electron beam welding is 25-30mA, the linear speed of the electron beam welding is 15-30mm / s, the molten pool depth formed by the electron beam welding is 3.0-5.5mm, and the molten pool width formed by the electron beam welding is 5.0-7.5mm.

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