High-energy beam welding method for thin-walled complex runner liquid cooling structure

Abstract

The present application relates to a kind of high-energy beam welding methods of thin-walled complex flow channel liquid cooling structure, belong to metal material and process field;Production assembly and shape clamps;Fixed base is horizontally placed, and thin-walled complex flow channel liquid cooling structure is horizontally placed on the upper surface of fixed base;Cover plate is horizontally placed on the upper surface of thin-walled complex flow channel liquid cooling structure;Pressing plate is horizontally placed on the upper surface of cover plate;And pressing plate is fixed with fixed base by tension screw;Cover plate is spot welded, after spot welding is completed, remove pressing plate;Cover plate is formally welded;After welding is completed, high pressure is added high temperature and stress relief annealing treatment is carried out, forming;The present application realizes that welding seam is formed after welding and is smooth and good, internal quality meets QJ20645-2016 requirement, laser weld seam is kept at 0.8MPa for 60min, is fatigued 1000 times at 0.8MPa, leakage rate is ≤1.0×10 ‑10 Pa·m 3 / s, laser welding joint strength coefficient is ≥0.9, flatness is ≤0.2mm.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of metal materials and processes, and relates to a high-energy beam welding method for a thin-wall complex flow channel liquid cooling structure. BACKGROUND

[0002] Flow channel and cavity type active cooling structures have a large number of applications in the field of industrial electronic equipment, such as waveguides, antennas, liquid cooling plates and the like. Active cooling is suitable for the case that the structure bears long-time and higher heat flux density aerodynamic heating. The active cooling structure generally adopts a double-layer jacket thin-wall structure, one layer of which is a base plate, and the other layer of which is a cover plate. The two layers of thin plates are connected to form a closed convex-concave cavity by welding, and the cooling liquid continuously flows in the continuous channel to reduce the wall temperature through convection and radiation heat exchange, so that the temperature of the structure itself is maintained within a lower range. The active cooling structure has the characteristics of small, dense and complex structure of the channel cross section. The structure requires high welding quality, high size precision of the channel inner cavity after welding and high welding success rate, which leads to great difficulty in welding. The commonly used welding methods include TIG welding, vacuum brazing and high-energy beam welding. The TIG welding has large heat input and large welding deformation, and the joint is seriously softened, so that the welding quality cannot be guaranteed. The conventional vacuum brazing is limited by factors such as assembly quality, large-area diffusion, solder spreading and inability to repair, and cannot meet the welding requirements. SUMMARY

[0003] The technical problem solved by the application is to overcome the shortcomings of the prior art, and to provide a high-energy beam welding method for a thin-wall complex flow channel liquid cooling structure, which realizes smooth and good weld forming after welding, internal quality meeting the requirements of QJ20645-2016, laser welds being able to withstand 0.8 MPa for 60 min, being able to withstand fatigue for 1000 cycles at 0.8 MPa, leakage rate being ≤1.0*10 -10 Pa·m 3 / s, laser welding joint strength coefficient being ≥0.9, and flatness being ≤0.2 mm.

[0004] The technical solution of the application is as follows:

[0005] A high-energy beam welding method for a thin-wall complex flow channel liquid cooling structure, comprising:

[0006] A manufacturing assembly and shape correcting clamp is prepared, which comprises a pressing plate and a fixed base;

[0007] The fixed base is placed horizontally, and the thin-wall complex flow channel liquid cooling structure is placed horizontally on the upper surface of the fixed base;

[0008] The cover plate is placed in the thin-wall complex flow channel liquid cooling structure;

[0009] Place the pressing plate horizontally on the upper surface of the cover plate and the thin-walled complex flow channel liquid cooling structure, and fix the pressing plate and the fixed base through the tensioning screw to press the thin-walled complex flow channel liquid cooling structure and the cover plate.

[0010] Spot weld the cover plate, and remove the pressing plate after the spot welding is completed.

[0011] Formally weld the cover plate.

[0012] After the welding is completed, high-pressure and high-temperature stress relief annealing treatment is adopted to form.

[0013] In the high-energy beam welding method of the thin-walled complex flow channel liquid cooling structure, the pressing plate and the fixed base are both square plate structures; the upper surface of the pressing plate is provided with a square through hole; the square through hole is a subsequent spot welding position.

[0014] In the high-energy beam welding method of the thin-walled complex flow channel liquid cooling structure, the pressing plate and the fixed base are both copper materials; and the cover plate is a titanium alloy material.

[0015] In the high-energy beam welding method of the thin-walled complex flow channel liquid cooling structure, the thin-walled complex flow channel liquid cooling structure is a square plate structure; the upper surface of the thin-walled complex flow channel liquid cooling structure is provided with a flow channel-shaped groove; and the flow channel-shaped groove is a stepped groove structure.

[0016] In the high-energy beam welding method of the thin-walled complex flow channel liquid cooling structure, the cover plate is a flow channel plate structure; the shape of the cover plate corresponds to the shape of the flow channel-shaped groove; the cover plate covers in the flow channel-shaped groove to realize that the upper surface of the cover plate is coplanar with the upper surface of the thin-walled complex flow channel liquid cooling structure; and the lower surface of the cover plate and the remaining space of the flow channel-shaped groove form a flow channel.

[0017] In the high-energy beam welding method of the thin-walled complex flow channel liquid cooling structure, after being pressed, the cooperation gap between the upper surface of the fixed base and the lower flat surface of the thin-walled complex flow channel liquid cooling structure is not greater than 0.1 mm; the cooperation gap between the lower surface of the cover plate and the upper flat surface of the thin-walled complex flow channel liquid cooling structure is not greater than 0.1 mm; the misalignment gap between the cover plate and the thin-walled complex flow channel liquid cooling structure is not greater than 0.1 mm; and the distance between the spot welding position left by the square through hole of the pressing plate and the welding opening is 2-4 mm.

[0018] In the high-energy beam welding method of the thin-walled complex flow channel liquid cooling structure, the power of the spot welding is 400-800 W, the welding speed is 20-80 mm / s, the defocusing amount is-5~+5 mm, the front protective gas flow is 30-40 L / min, and the back protective gas flow is 5-10 L / min.

[0019] In the high-energy beam welding method of the thin-walled complex flow channel liquid cooling structure, the formal welding is divided into two sections of welding, and the welding directions are opposite.

[0020] In the thin-walled complex flow channel liquid cooling structure high-energy beam welding method, the peak welding power of the formal welding is 800W-1000W; the valley welding power is 100W-200W; the frequency is 25-50Hz; the welding speed is 20-80mm / s; the defocusing amount is-5~+5mm; the front protective gas flow is 30-40L / min; and the back protective gas flow is 5-10L / min.

[0021] In the thin-walled complex flow channel liquid cooling structure high-energy beam welding method, the stress annealing treatment parameters are as follows:

[0022] The pressure value is 0.5-5MPa, the temperature is 600-700 DEG C, and the holding time is 2-5h.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] (1) The present application adopts laser welding for the first time for the thin-walled complex flow channel liquid cooling structure, and solves the problems of high porosity sensitivity, easy collapse, poor sealing performance and the like during welding of the thin-walled complex flow channel.

[0025] (2) The welded joint has good appearance quality, no undercut, no inclusion and the like, and the internal quality meets the requirement QJ20645-2016, the joint strength coefficient is greater than or equal to 0.9, the laser welded joint is kept at 0.8MPa for 60min, is fatigued for 1000 cycles at 0.8MPa, and the helium mass spectrum detection leakage rate is less than or equal to 1.0*10 -10 Pa·m 3 / s.

[0026] (3) The body structure thickness of the present application is only 3mm, the cover plate thickness is only 1mm, the laser welded joint is more than 2800mm, and is single-sided welding, so the welding deformation is large, the present application designs a specific welding tool and a shaping tool, realizes high-precision assembly of the structure, ensures the assembly gap and the misalignment amount, eliminates the welding stress by combining high-temperature pressure annealing heat treatment, reduces the welding deformation, and the flatness of the thin-walled complex flow channel liquid cooling structure after welding is less than or equal to 0.2mm. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The present application is a thin-walled complex flow channel liquid cooling structure assembly schematic diagram.

[0028] Figure 2 The present application is a pressing plate structure schematic diagram.

[0029] Figure 3 The present application is a fixed base structure schematic diagram.

[0030] Figure 4A schematic diagram of the thin-walled complex flow channel liquid cooling structure of the present application is shown in the figure;

[0031] Figure 5 A schematic diagram of the cover plate of the present application is shown in the figure. DETAILED DESCRIPTION

[0032] The present application will be further described below in conjunction with examples.

[0033] The present application provides a high-energy beam welding method for a thin-walled complex flow channel liquid cooling structure, which is welded for the first time by laser welding. Through welding process research, the problems of high sensitivity to pores, easy collapse, poor sealing, etc. during welding of the thin-walled complex flow channel are solved, and the appearance quality of the weld after welding is well formed without defects such as undercut and inclusion.

[0034] The high-energy beam welding method for the thin-walled complex flow channel liquid cooling structure specifically includes the following steps:

[0035] A clamping jig for assembly and shape correction is made, including a pressing plate 1 and a fixed base 2. As shown in Figure 2 、 3 , the pressing plate 1 and the fixed base 2 are both square plate structures; the upper surface of the pressing plate 1 is provided with a square through hole; the square through hole is the subsequent spot welding position. The pressing plate 1 and the fixed base 2 are both made of copper material.

[0036] Place the fixed base 2 horizontally, and place the thin-walled complex flow channel liquid cooling structure horizontally on the upper surface of the fixed base 2. In the present application, the thin-walled complex flow channel liquid cooling structure is a square plate structure; the upper surface of the thin-walled complex flow channel liquid cooling structure is provided with a flow channel-shaped groove; the flow channel-shaped groove is a stepped groove structure, as shown in Figure 4 .

[0037] Place the cover plate in the thin-walled complex flow channel liquid cooling structure; the cover plate is made of titanium alloy material. The cover plate is a flow channel plate structure; the shape of the cover plate corresponds to the shape of the flow channel-shaped groove; the cover plate covers in the flow channel-shaped groove, so that the upper surface of the cover plate is coplanar with the upper surface of the thin-walled complex flow channel liquid cooling structure; the lower surface of the cover plate and the remaining space of the flow channel-shaped groove form a flow channel, as shown in Figure 5 .

[0038] Place the pressing plate 1 horizontally on the upper surface of the cover plate and the thin-walled complex flow channel liquid cooling structure; and fix the pressing plate 1 and the fixed base 2 by tightening the screws, so as to press the thin-walled complex flow channel liquid cooling structure and the cover plate, as shown in Figure 1 .

[0039] After pressing, the gap between the upper surface of the fixed base 2 and the lower plane of the thin-walled complex flow channel liquid cooling structure is not greater than 0.1mm; the gap between the lower surface of the cover plate and the upper plane of the thin-walled complex flow channel liquid cooling structure is not greater than 0.1mm; the gap between the cover plate and the thin-walled complex flow channel liquid cooling structure is not greater than 0.1mm; the distance between the spot welding position left by the square hole of the pressing plate 1 and the welding opening is 2-4mm.

[0040] The cover plate is spot welded, and after spot welding is completed, the pressing plate 1 is removed. The power of spot welding is 400-800W, the welding speed is 20-80mm / s, the defocusing amount is -5~+5mm, the front protective gas flow is 30-40L / min; the back protective gas flow is 5-10L / min.

[0041] The cover plate is formally welded. The formal welding is divided into two sections of welding, and the welding directions are opposite. The peak value of the welding power of the formal welding is 800W~1000W; the valley value of the welding power is 100W-200W; the frequency is 25-50Hz; the welding speed is 20-80mm / s; the defocusing amount is -5~+5mm; the front protective gas flow is 30-40L / min; the back protective gas flow is 5-10L / min.

[0042] After welding is completed, stress relief annealing treatment is carried out by high pressure and high temperature, and forming is carried out.

[0043] The parameters of the stress relief annealing treatment are:

[0044] The pressure value is 0.5-5MPa, the temperature is 600-700℃, and the holding time is 2-5h.

[0045] Embodiment

[0046] The application is suitable for high-energy beam welding of a high-strength aluminum-lithium alloy thin-walled rib structure.

[0047] The specific steps of welding are:

[0048] Step 1: A assembly clamp and a shape correcting clamp used for welding the above structure are designed, which are composed of a copper pressing plate and a copper fixed base, can realize pressing assembly and shape correction, and leave a laser spot welding position;

[0049] Step 2: The copper pressing plate is used to fix the thin-walled complex flow channel liquid cooling structure and the cover plate on the copper fixed base through the tensioning screw on the base plate, and the profile is required to be well fitted, the gap between the fixed base and the bottom plane is 0.1mm, the gap between the cover plate and the thin-walled rib structure is 0.1mm, the gap between the cover plate and the thin-walled rib structure is 0.1mm, and the distance between the spot welding position left by the pressing plate and the welding opening is 3mm.

[0050] Step 3: pickling the cover plate and thin-walled rib structure, the surface is free of stains, clean the surface of the welding part with anhydrous ethanol, and then dry naturally or dry with an electric hair dryer;

[0051] Step 4: open the argon to provide front and back gas protection, the front protection gas flow is 32 L / min, and the back protection gas flow is 5 L / min;

[0052] Step 5: spot weld the cover plate, the spot welding position is at the fixture hole position, the spot welding power is 600 W, the welding speed is 40 mm / s, and the defocusing amount is 0 mm;

[0053] Step 6: after spot welding, remove the spot welding fixture pressing plate, and then formally weld the ring cover plate, the formal welding is divided into two welding, the welding direction is opposite, the welding power peak value is 950 W, the welding power valley value is 200 W, the frequency is 30 Hz, the welding speed is 30 mm / s, the defocusing amount is 0 mm, the front protection gas flow is 33 L / min, and the back protection gas flow is 6 L / min;

[0054] Step 7: after laser welding, assemble the thin-walled complex flow channel liquid cooling structure on the shape correcting tool, and perform stress relief annealing treatment at high pressure and high temperature, the pressure value is 1 MPa, the temperature is 650 DEG C, and the holding time is 3 h.

[0055] After welding, the weld appearance is visually inspected, the weld appearance quality is good, there is no undercut, inclusion and other defects, the internal quality is detected by X-ray detection, meets the requirements of QJ20645-2016, the tensile strength of the fusion welded joint is 1080 MPa, the joint strength coefficient is greater than or equal to 0.9, the flatness of the bottom plate after welding is 0.2 mm, the laser weld does not leak under 0.8 MPa for 60 min, does not leak under 0.8 MPa for 1000 cycles, and the helium mass spectrum detection leakage rate is 7.7*10 -11 Pa·m 3 / s.

[0056] The present application adopts laser welding for the first time for the thin-walled complex flow channel liquid cooling structure, solves the problems of high porosity sensitivity, easy collapse and poor sealing during welding of the thin-walled complex flow channel, and the weld appearance quality is good after welding, there is no undercut, inclusion and other defects, the internal quality meets the requirements of QJ20645-2016, the joint strength coefficient is greater than or equal to 0.9, the laser weld does not leak under 0.8 MPa for 60 min, does not leak under 0.8 MPa for 1000 cycles, and the helium mass spectrum detection leakage rate is less than or equal to 1.0*10 -10 Pa·m 3 / s;

[0057] The body structure thickness of the application is only 3mm, the cover plate thickness is only 1mm, the laser welding seam is more than 2800mm, and is single-sided welding, the welding deformation is large, a specific welding tool and a shape correcting tool are designed, high-precision assembly of the structure is realized, assembly gap and misalignment are ensured, high-temperature pressure annealing heat treatment is combined, welding stress is eliminated, welding deformation is reduced, and the flatness of the thin-walled complex flow channel liquid cooling structure after welding is less than or equal to 0.2mm.

[0058] Although the application has been disclosed with the above preferred embodiments, it is not intended to limit the application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the application by using the disclosed methods and technical contents without departing from the spirit and scope of the application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the application without departing from the technical solutions of the application shall fall within the protection scope of the technical solutions of the application.

Claims

1. A high-energy beam welding method for a thin-walled complex runner liquid cooling structure, characterized by: The utility model relates to a kind of thin-walled complex flow channel liquid cooling structure assembly and shaping fixture, including fixed base (2) and pressing plate (1);Thin-walled complex flow channel liquid cooling structure is placed on the upper surface of fixed base (2) by horizontal placement of fixed base (2). The thin-walled complex flow channel liquid cooling structure is a square plate structure, and the upper surface of the thin-walled complex flow channel liquid cooling structure is provided with a flow channel-shaped groove. The flow channel-shaped groove is a stepped groove structure. The cover plate is a flow channel plate structure, and the shape of the cover plate corresponds to the shape of the flow channel-shaped groove. The upper surface of the cover plate is coplanar with the upper surface of the thin-walled complex flow channel liquid cooling structure after the cover plate is covered in the flow channel-shaped groove. The pressing plate (1) is placed horizontally on the upper surface of the cover plate and the thin-walled complex flow channel liquid cooling structure, and the pressing plate (1) is fixedly connected with the fixed base (2) by tightening screws to press the thin-walled complex flow channel liquid cooling structure and the cover plate. The cover plate is spot-welded, and the pressing plate (1) is removed after spot welding is completed. The power of spot welding is 400-800W, the welding speed is 20-80mm / s, the defocusing amount is-5~+5mm, the front protective gas flow is 30-40L / min, and the back protective gas flow is 5-10L / min. The cover plate is formally welded. The formal welding is divided into two welding directions, and the welding power peak value of the formal welding is 800W-1000W, the welding power valley value is 100W-200W, the frequency is 25-50Hz, the welding speed is 20-80mm / s, the defocusing amount is-5~+5mm, the front protective gas flow is 30-40L / min, and the back protective gas flow is 5-10L / min. After welding is completed, stress relief annealing treatment is carried out by high pressure and high temperature to form. The pressing plate (1) and the fixed base (2) are both square plate structures, and the upper surface of the pressing plate (1) is provided with a square through hole.

2. The method of claim 1, wherein the method is a high-energy beam welding method for a thin-walled complex flow channel liquid cooling structure. The pressing plate (1) and the fixed base (2) are both copper materials, and the cover plate is a titanium alloy material.

3. The method of claim 1, wherein the method further comprises: After pressing, the cooperation gap between the upper surface of the fixed base (2) and the lower flat surface of the thin-walled complex flow channel liquid cooling structure is not more than 0.1mm, the cooperation gap between the lower surface of the cover plate and the upper flat surface of the thin-walled complex flow channel liquid cooling structure is not more than 0.1mm, the misalignment gap between the cover plate and the thin-walled complex flow channel liquid cooling structure is not more than 0.1mm, and the distance between the spot welding position left by the square through hole of the pressing plate (1) and the welding opening is 2-4mm.

4. The method of claim 2, wherein the method further comprises: The stress relief annealing treatment parameters are as follows:

5. The method of claim 1, wherein the method further comprises: The pressure value is 0.5-5MPa, the temperature is 600-700℃, and the holding time is 2-5h. ​

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