阅读说明：本技术 一种铝合金水冷接头真空电子束焊接方法 (Vacuum electron beam welding method for aluminum alloy water-cooled joint ) 是由 祝影 李生智 张维 韦宝权 张庆锋 谯永鹏 于 2019-07-25 设计创作，主要内容包括：本发明公开一种铝合金水冷接头真空电子束焊接方法；4xxx铝合金钎料,对6xxx铝合金水冷接头进行真空电子束自熔焊接。焊缝为对搭接结构,预置钎料。有效熔深为2-3mm。加工过程为：化学清洗,烘干,预置钎料,装夹,焊接,质量检验。焊接3次完成,预焊,熔焊,修饰焊。本发明的焊接方法功率密度高,能量集中,热输入低,热影响区小,焊接变形小。焊缝成型均匀,光滑,表面无气孔裂纹等缺欠产生。本发明提出的焊接方法功率密度高,能量集中,热输入低,热影响区小,焊接变形小。焊缝成型均匀,光滑,表面无气孔裂纹等缺欠产生。(the invention discloses a vacuum electron beam welding method for an aluminum alloy water-cooled joint; 4xxx aluminum alloy brazing filler metal, and carrying out vacuum electron beam self-fluxing welding on the 6xxx aluminum alloy water-cooling joint. The welding seam is a butt lap joint structure and is preset with brazing filler metal. The effective penetration is 2-3 mm. The processing process comprises the following steps: chemical cleaning, drying, presetting brazing filler metal, clamping, welding and quality inspection. And 3 times of welding, prewelding, fusion welding and decorative welding. The welding method has the advantages of high power density, concentrated energy, low heat input, small heat affected zone and small welding deformation. The weld joint is formed uniformly and smoothly, and no defects such as pore cracks and the like are generated on the surface. The welding method provided by the invention has the advantages of high power density, concentrated energy, low heat input, small heat affected zone and small welding deformation. The weld joint is formed uniformly and smoothly, and no defects such as pore cracks and the like are generated on the surface.)

1. A vacuum electron beam welding method for an aluminum alloy water-cooled joint is characterized by comprising the following steps:

The first step is as follows: chemically cleaning the workpiece and brazing filler metal, cleaning in 25% NaOH solution for 3min, and cleaning in 15% HNO solution₃cleaning with 0.5% HF mixed solution for 1min, and cleaning with clear water;

The second step is that: drying, and keeping the temperature in a drying box at 120 ℃ for 1 hour;

The third step: presetting brazing filler metal in an assembly gap of a part, wherein the assembly gap is 0.4-0.6 mm;

The fourth step: clamping the water-cooling joint and the workpiece by using a tool, and loading the workpiece into a vacuum electron beam welding chamber;

The fifth step: vacuumizing to reach vacuum degree of 10^-5pa；

And a sixth step: setting the parameters of the circumferential weld, wherein the beam current rises from 0 to a set value of 180 degrees, the set value is welded to 361 degrees, and the beam current falls from the set value to 0 to 180 degrees;

The seventh step: prewelding a workpiece with parameters of high voltage 120KV, beam current 5-7mA, focusing current 2200mA, welding speed 1500mm/min and no function waveform;

Eighth step: performing fusion welding on a workpiece, wherein the parameters are high voltage 120KV, beam current 15-20mA, focusing current 2200mA, welding speed 1200mm/min, function waveform is elliptical, X is equal to 0.3 and is the same as the welding direction, Y is equal to 0.5 and is vertical to the welding direction, and frequency is 2000 HZ;

the ninth step: performing modified welding on a workpiece, wherein the parameters are high voltage of 70KV, beam current of 8-12mA, focusing current of 2318mA, welding speed of 1000mm/min, waveform is circular, amplitude X is equal to Y and equal to 1mm, and frequency is 500 HZ;

The tenth step: cooling for 10min, and introducing nitrogen for protection;

The eleventh step: and inspecting the surface of the welding seam.

2. The vacuum electron beam welding method for the aluminum alloy water-cooled joint according to claim 1, characterized in that:

The water-cooled joint adopts 6xxx aluminum alloy, and is in a lap joint structure form.

3. The vacuum electron beam welding method for the aluminum alloy water-cooled joint according to claim 1, characterized in that:

4xxx aluminum alloy brazing filler metal is used as filling metal, and the filling metal is 0.2-1.2mm higher than the surface of the base metal.

Technical Field

the invention relates to the field of vacuum electron beam welding in IC equipment manufacturing, in particular to a vacuum electron beam welding method for an aluminum alloy water-cooling joint.

background

The aluminum alloy has low density and high specific strength, and has excellent performance, so that the aluminum alloy can be widely applied to the fields of automobiles, aerospace, machinery manufacturing and the like. Aluminum alloys are generally welded by welding methods such as TIG, MIG, FSW, LBW, EBW, and the like. For small-size welding seams, MIG, TIG, FSW and other welding processes cannot be realized. And the surface oxide film of the aluminum alloy is compact, the melting point is high, the heat conduction speed is high, and the welding difficulty is large. For aluminum alloy containing Mg, in the LBW welding process, the Mg element is volatilized, the surface tension is low, defects such as surface explosion points, surface depressions, internal air holes and the like are caused, and the absorption rate of the aluminum alloy to laser is low, so that the power required for welding the aluminum alloy is higher than that for welding steel.

The electron beam welding is to bombard the surface of a workpiece by utilizing electron beam flow moving at high speed to generate heat energy so as to fuse the welded workpieces together. The welding environment of the vacuum electron beam welding is vacuum, protective gas is not needed, the metal purity of a welding seam formed after welding is high, and no foreign impurities enter. The welding parameters of the electron beam can be accurately adjusted through an electric control system and the like, and the welding repeatability is good. The electron beam can control the focus position of the beam and the deflection direction of the beam through the two magnetic lenses, so that waveforms with different shapes can be generated, and the stirring effect is generated on a molten pool by matching with the welding direction, which is beneficial to the overflow of air holes of the molten pool. The electron beam is used as a high-energy beam welding method, the energy density is higher, the welding effect on the aluminum alloy with high heat conduction speed is ideal, the welding process is stable, and defects such as explosion points, depressions and the like are not easy to generate.

Disclosure of Invention

The invention aims to provide a vacuum electron beam welding method for an aluminum alloy water-cooled joint, which has the advantages of uniform weld forming, brightness, attractive appearance, small deformation, no air holes, no cracks and the like.

in order to achieve the purpose, the invention adopts the technical scheme that:

a vacuum electron beam welding method for an aluminum alloy water-cooled joint comprises the following steps:

the first step is as follows: chemically cleaning the workpiece and brazing filler metal, cleaning in 25% NaOH solution for 3min, and cleaning in 15% HNO solution₃Cleaning with 0.5% HF mixed solution for 1min, and cleaning with clear water;

The second step is that: drying, and keeping the temperature in a drying box at 120 ℃ for 1 hour;

The third step: presetting brazing filler metal in an assembly gap of a part, wherein the assembly gap is 0.4-0.6 mm;

The fourth step: clamping the water-cooling joint and the workpiece by using a tool, and loading the workpiece into a vacuum electron beam welding chamber;

the fifth step: vacuumizing to reach vacuum degree of 10^-5pa；

And a sixth step: setting the parameters of the circumferential weld, wherein the beam current rises from 0 to a set value of 180 degrees, the set value is welded to 361 degrees, and the beam current falls from the set value to 0 to 180 degrees;

The seventh step: prewelding a workpiece with parameters of high voltage 120KV, beam current 5-7mA, focusing current 2200mA, welding speed 1500mm/min and no function waveform;

eighth step: performing fusion welding on a workpiece, wherein the parameters are high voltage 120KV, beam current 15-20mA, focusing current 2200mA, welding speed 1200mm/min, function waveform is elliptical, X is equal to 0.3 and is the same as the welding direction, Y is equal to 0.5 and is vertical to the welding direction, and frequency is 2000 HZ;

The ninth step: performing modified welding on a workpiece, wherein the parameters are high voltage of 70KV, beam current of 8-12mA, focusing current of 2318mA, welding speed of 1000mm/min, waveform is circular, amplitude X is equal to Y and equal to 1mm, and frequency is 500 HZ;

the tenth step: cooling for 10min, and introducing nitrogen for protection;

the eleventh step: and inspecting the surface of the welding seam.

The invention has the beneficial effects that:

The welding method provided by the invention has the advantages of high power density, concentrated energy, low heat input, small heat affected zone and small welding deformation. The weld joint is formed uniformly and smoothly, and no defects such as pore cracks and the like are generated on the surface.

Drawings

FIG. 1 is a schematic representation of an aluminum alloy water-cooled joint.

FIG. 2 is a schematic cross-sectional view of an aluminum alloy water-cooled joint.

fig. 3 is a welding power curve.

Detailed Description

The invention is described in further detail with reference to the accompanying figures 1-3.

a vacuum electron beam welding method for an aluminum alloy water-cooled joint comprises the following steps:

The first step is as follows: chemically cleaning the workpiece and the brazing filler metal, cleaning in 25% NaOH for 3min, and then cleaning in 15% HNO₃And + 0.5% HF mixed solution for 1min, and finally washing with clear water.

The second step is that: drying, and keeping the temperature in a drying box at 120 ℃ for 1 hour.

the third step: and (3) presetting the brazing filler metal into an assembly gap of the part, wherein the assembly gap is 0.4-0.6mm, the thickness of the brazing filler metal is 0.4mm, and the brazing filler metal is 0.3mm higher than the surface of the part.

The fourth step: and clamping the water-cooling joint and the workpiece by using a tool, and loading the workpiece into a vacuum electron beam welding chamber.

the fifth step: vacuumizing to reach vacuum degree of 10^-5pa。

And a sixth step: setting parameters of a circumferential weld, welding half circle from 0mA to a set value when the beam current rises, then welding 1 circle according to the set value, and welding half circle from the set value to 0mA in the beam current descending stage. The beam current curve is shown in the figure.

The seventh step: prewelding a workpiece with parameters of high voltage 120KV, beam current 5-7mA, focusing current 2200mA, welding speed 1500mm/min and no function waveform.

eighth step: and performing fusion welding on the workpiece, wherein the parameters are high voltage 120KV, beam current 15-20mA, focusing current 2200mA, welding speed 1200mm/min, function waveform is elliptical, X is equal to 0.3 and is the same as the welding direction, Y is equal to 0.5 and is vertical to the welding direction, and frequency is 2000 HZ.

the ninth step: and (3) performing modified welding on the workpiece, wherein the parameters are high voltage of 70KV, beam current of 8-12mA, focusing current of 2318mA, welding speed is 1000mm/min, the waveform is circular, the amplitude X is equal to Y and is equal to 1mm, and the frequency is 500 HZ.

the tenth step: cooling for 10min, and introducing nitrogen.

The eleventh step: and inspecting the surface of the welding seam.

the water-cooled joint adopts 6xxx aluminum alloy, and is in a lap joint structure form.

4xxx aluminum alloy brazing filler metal is used as filling metal, and the filling metal is 0.2-1.2mm higher than the surface of the base metal.