A dissimilar material additive friction stir welding method

Abstract

The application discloses a kind of heterogeneous material additive friction stir welding welding method, comprising the following steps: step one: the first plate and the second plate are processed into the required specification;Step two: a groove is processed on the surface of the first plate, and the first plate and the second plate are cleaned;Step three: the first plate and the second plate are overlapped on the welding table, and clamped with a clamp;Step four: a needleless stir head is used to weld the plate;Step five: a needleless consumable stir head is used to weld the plate for the second time, and the needleless consumable stir head is the same material as the first plate;By processing a groove on the surface of the metal plate, the carbon fiber interlacing phenomenon of the carbon fiber composite material during the first welding is effectively prevented from being damaged, and the needleless consumable stir head with the same material as the metal plate is used during the second welding, which can inhibit the overflow of the carbon fiber composite material in the stirring zone, avoid the problem of poor weld formation, and ensure the effective combination of the additive at the weld.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of additive manufacturing welding, in particular to a dissimilar material additive friction stir welding method. BACKGROUND

[0002] Light metals such as aluminum alloys, magnesium alloys, etc. are widely used in the manufacturing industry due to their low density, high strength and stiffness, etc. Carbon fiber composite materials are also applied in the fields of aerospace, automotive electronics, medical devices, etc. due to their excellent properties such as high temperature resistance, fatigue resistance and corrosion resistance.

[0003] With the continuous development of domestic and foreign manufacturing industry, the demand for carbon fiber-based composite material and light metal connection structure increases, but the difference between the two in physical and chemical properties and metallurgical incompatibility makes the connection between them difficult; in order to ensure the connection strength and stability, the joint form and structure need to be reasonably designed; the joint design needs to consider the properties of the materials, the connection process and the stress situation, etc. Therefore, the joint design is also a difficulty in the connection process. As a new solid-phase connection technology, friction stir welding can avoid the defects such as porosity and uneven stress distribution in the welding process, and can effectively improve the mechanical properties of the connected components. Therefore, this technology is more and more used in the connection of metal and composite materials.

[0004] In the prior art, the welding of light metal and carbon fiber composite material is realized by conventional friction stir welding technology such as design of stir head, selection of welding parameters and surface treatment. The design of stir head shape, size and material needs a long time and a large economic cost; the adjustment of welding parameters needs a lot of time and manpower; the surface treatment method needs to consider the compatibility, adhesive strength, heat resistance, corrosion resistance and other factors of the two materials; the traditional welding process using a needle-shaped stir head will change the structure of carbon fibers when connecting metal and composite materials, for example, long fibers become short fibers by stirring of the stir head, which finally affects the joint strength. In the prior art, a groove is opened on the surface of the metal, and powder is filled in the groove to realize the connection of dissimilar materials. In the actual welding process, the powder or particles filled in the groove will splash due to the large upsetting force of the stir head, which will cause the filling to be insufficient at the weld joint.

[0005] The prior art also realizes the connection of two materials by external auxiliary friction stir welding technology. The external auxiliary technology includes heat source, cold source and ultrasonic wave, etc. The main disadvantage of heat source auxiliary is inconvenient operation control. The cold pipe is difficult to closely match the weld in actual operation of cold source auxiliary, which is extremely low in efficiency. The efficiency of ultrasonic auxiliary is still low compared with other high-energy welding methods such as laser welding and electron beam welding, which may affect the production efficiency, and the application range of ultrasonic friction stir welding is relatively narrow. SUMMARY

[0006] In order to solve the problem of low production efficiency in the welding of metal plates and carbon fiber composite materials, the application provides a dissimilar material additive friction stir welding method.

[0007] The technical scheme adopted by the application to achieve the above-mentioned purpose is as follows: a dissimilar material additive friction stir welding method, comprising the following steps:

[0008] Step one: process the first plate 1 and the second plate 2 into the required specifications, the first plate 1 is a metal plate, and the second plate 2 is a polymer plate;

[0009] Step two: process a groove 6 on the surface of the first plate 1, and clean the first plate 1 and the second plate 2;

[0010] Step three: place the first plate 1 and the second plate 2 on the welding table in a top and bottom lap joint, and clamp them with a clamp;

[0011] Step four: use a needle-free stir head 3 to weld the plates at a specified welding speed, rotation speed, and down pressure amount of the shaft shoulder 5;

[0012] Step five: after the first welding is completed, use a needle-free consumable stir head 4 to perform a second welding on the plates at a specified welding speed, rotation speed, and down pressure amount, and adjust the down pressure amount according to the material loss of the needle-free consumable stir head 4 during the welding process, the needle-free consumable stir head 4 is the same material as the first plate 1.

[0013] Preferably, in the step two, the thickness of the first plate 1 is H, the length is D, the diameter of the shaft shoulder 5 is d, the height of the groove 6 is H1, the length is D1, and the width is L1, the values of H1, D1, and L1 are as follows:

[0014] H / 4≤H1≤3H / 4

[0015] D1<D

[0016] d≤L1≤2d

[0017] Preferably, in the step two, the shape of the groove 6 is rectangular, stepped, or sawtooth-shaped.

[0018] Preferably, in the step three, the clamp includes a pressing plate 8, a pressing stud 9, and a nut 10, the pressing plate 8 is arranged on both sides of the groove 6, and the pressing stud 9 penetrates through the pressing plate 8 and is connected with the nut 10.

[0019] Preferably, in the fourth step, the welding speed ranges from 10 to 80 mm / min, the rotation speed of the needleless stir head 3 ranges from 900 to 2000 r / min, the amount of pressing of the shaft shoulder 5 ranges from 0.1 to 0.5 mm, and the pressing duration of the needleless stir head 3 is 4 s.

[0020] Preferably, in the fourth step, when the thickness of the first plate 1 is 2 mm, the welding speed is 10 mm / min, the rotation speed of the needleless stir head 3 is 1600 r / min, and the amount of pressing of the shaft shoulder 5 is 0.2 mm.

[0021] Preferably, in the fifth step, the diameter of the needleless consumable stir head 4 is D2, and D2 ranges from L1 / 2 to L1.

[0022] L1 / 2≤D2≤L1

[0023] Preferably, in the fifth step, the welding speed ranges from 10 to 300 mm / min, the rotation speed of the needleless consumable stir head 4 ranges from 800 to 1600 r / min, the amount of pressing ranges from 0.1 to 0.3 mm, and the pressing duration of the needleless consumable stir head 4 is 4 s.

[0024] Preferably, in the fifth step, when the amount of pressing is 0.1 mm, the welding speed of the needleless consumable stir head 4 is 5 mm / min, and the rotation speed is 900 r / min.

[0025] Preferably, the first plate 1 is an aluminum alloy plate, and the second plate 2 is a carbon fiber composite material plate.

[0026] The welding method of the application can effectively prevent the carbon fiber interweaving phenomenon of the carbon fiber composite material from being damaged during welding, and can effectively prevent the carbon fiber composite material from overflowing the stirring area during welding. BRIEF DESCRIPTION OF DRAWINGS

[0027] Fig. 1 is a schematic diagram of the welding of the metal plate after the groove is processed.

[0028] Fig. 2 is a schematic diagram of the clamping of the clamp.

[0029] Fig. 3 is a schematic diagram of the needleless consumable stir head welding of the present application.

[0030] In the figure: 1, the first plate; 2, the second plate; 3, the needleless stir head; 4, the needleless consumable stir head; 5, the shoulder; 6, the groove; 7, the weld; 8, the pressing plate; 9, the pressing stud; 10, the nut; 11, the welding direction; 12, the rotation direction. DETAILED DESCRIPTION

[0031] A heterogeneous material additive friction stir welding method of the present application, as shown in the figure, comprises the following steps: Figs. 1 to 3

[0032] Step one: process the first plate 1 and the second plate 2 into the required specifications, the first plate 1 is an aluminum alloy plate, and the second plate 2 is a carbon fiber composite material plate;

[0033] Step two: process a groove 6 on the surface of the first plate 1, the groove 6 is rectangular, stepped or sawtooth-shaped, and clean the first plate 1 and the second plate 2 to remove oxides, dirt, etc. on the surface of the plate to ensure the welding quality; wherein the thickness of the first plate 1 is H, the length is D, the diameter of the shoulder 5 is d, the shoulder 5 is a smooth plane, d is 10-20mm, the height of the groove 6 is H1, the length is D1, and the width is L1, the values of H1, D1 and L1 are as follows:

[0034] H / 4≤H1≤3H / 4

[0035] D1<D

[0036] d≤L1≤2d

[0037] Such a structure ensures that the structure of the carbon fiber composite material plate is not easily damaged, promotes the flow of polymers in the carbon fiber composite material plate to the aluminum alloy plate, and forms a mechanical interlocking structure at the weld joint, avoiding the influence of the size of the slotted plate on the strength of the weld joint after welding.

[0038] Step three: place the first plate 1 and the second plate 2 on the welding table in an upper and lower lap joint, and clamp them with a clamp, the clamp includes a pressing plate 8, a pressing stud 9 and a nut 10, the pressing plate 8 is clamped on both sides of the groove 6, and the pressing stud 9 penetrates through the pressing plate 8 at both ends and is connected with the nut 10;

[0039] ​Step four: the plate is welded by using the needleless stirring 3, wherein the welding speed range is: 10-80mm / min, the rotation speed range of the needleless stirring head 3 is: 900-2000r / min, the down pressure range of the shaft shoulder 5 is 0.1-0.5mm, and the down pressure time of the needleless stirring head 3 is 4s.

[0040] Step five: after the first welding, the plate is welded for the second time by using the needleless consumable stirring head 4, the needleless consumable stirring head 4 is the same material as the first plate 1, the down pressure is adjusted according to the loss of the material of the needleless consumable stirring head 4 during welding to ensure the overall filling of the weld and realize the close combination of the additive and the welded plate, the diameter of the needleless consumable stirring head 4 is D2, and the value range is:

[0041] L1 / 2≤D2≤L1

[0042] The welding speed range is: 10-300mm / min, the rotation speed range of the needleless consumable stirring head 4 is: 800-1600r / min, the down pressure range is: 0.1-0.3mm, and the down pressure time of the needleless consumable stirring head 4 is 4s. When the down pressure is 0.1mm, the welding speed of the needleless consumable stirring head 4 is: 5mm / min, and the rotation speed is: 900r / min.

[0043] The welding method of the present application is to process a groove on the surface of the metal plate, use a needleless stirring head in the first welding, promote the polymer in the underlying carbon fiber composite material to flow into the metal plate, form a mechanical bite at the welded joint, enhance the connection strength of the welded joint, effectively prevent the carbon fiber interweaving phenomenon of the carbon fiber composite material from being damaged during welding, combine the carbon fiber composite plate with the metal plate without being affected, ensure the strength of the welded joint, use a needleless consumable stirring head of the same material as the metal plate in the second welding, make the stirring head into a consumable, and the material on the stirring head is dissolved in the groove by high-speed rotation during welding, which inhibits the overflow of the carbon fiber composite material in the stirring area, avoids the problem of poor weld formation, ensures the effective fusion of the additive at the weld, and improves the production efficiency during the welding of dissimilar materials.

[0044] The present application is described by way of examples, and those skilled in the art will recognize that various changes and modifications of form and detail can be made therein without departing from the spirit and scope of the application. In addition, various features and embodiments of the present application can be applied to achieve specific situations and materials without departing from the spirit and scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application are intended to be within the scope of the present application.

Claims

1. A dissimilar material additive friction stir welding method, characterized by, The method comprises the following steps: Step 1: process the first plate (1) and the second plate (2) into the required specifications, wherein the first plate (1) is a metal plate, and the second plate (2) is a polymer plate; Step 2: process a groove (6) on the surface of the first plate (1), and clean the first plate (1) and the second plate (2); Step 3: place the first plate (1) and the second plate (2) on the welding table in a stacked manner, and clamp them with a clamp; Step 4: use a needleless stirring head (3) to weld the plates at a specified welding speed, rotation speed, and down pressure of the shaft shoulder (5); Step 5: after the first welding is completed, use a needleless consumable stirring head (4) to weld the plates for the second time at a specified welding speed, rotation speed, and down pressure, wherein the material on the stirring head is dissolved in the groove (6) through high-speed rotation during welding, the down pressure is adjusted according to the loss of the material of the needleless consumable stirring head (4) during the welding process, and the needleless consumable stirring head (4) is made of the same material as the first plate (1).

2. The dissimilar material additive friction stir welding method of claim 1, wherein, In step 2, the thickness of the first plate (1) is H, the length is D, the diameter of the shaft shoulder (5) is d, the height of the groove (6) is H1, the length is D1, and the width is L1, and the values of H1, D1, and L1 are in the following ranges: H / 4≤H1≤3H / 4 D1<D d≤L1≤2d.

3. The dissimilar material additive friction stir welding method of claim 1, wherein, In step 2, the shape of the groove (6) is rectangular, stepped, or zigzag.

4. The dissimilar material additive friction stir welding method of claim 1, wherein, In step 3, the clamp comprises a pressing plate (8), a pressing stud (9), and a nut (10), the pressing plate (8) is arranged on both sides of the groove (6), and the pressing stud (9) penetrates through the pressing plate (8) and is connected with the nut (10).

5. The dissimilar material additive friction stir welding method of claim 1, wherein, In step 4, the welding speed is 10-80 mm / min, the rotation speed of the needleless stirring head (3) is 900-2000 r / min, the down pressure of the shaft shoulder (5) is 0.1-0.5 mm, and the down pressure duration of the needleless stirring head (3) is 4 s.

6. The dissimilar material additive friction stir welding method of claim 1, wherein, In step 4, when the thickness of the first plate (1) is 2 mm, the welding speed is 10 mm / min, the rotation speed of the needleless stirring head (3) is 1600 r / min, and the down pressure of the shaft shoulder (5) is 0.2 mm.

7. The dissimilar material additive friction stir welding method of claim 2, wherein, In step 5, the diameter of the needleless consumable stirring head (4) is D2, and the value range of D2 is: L1 / 2≤D2≤L 1。 8. The dissimilar material additive friction stir welding method of claim 1, wherein, In step 5, the welding speed is 10-300 mm / min, the rotation speed of the needleless consumable stirring head (4) is 800-1600 r / min, the down pressure is 0.1-0.3 mm, and the down pressure duration of the needleless consumable stirring head (4) is 4 s.

9. The dissimilar material additive friction stir welding method of claim 1, wherein, In step 5, when the down pressure is 0.1 mm, the welding speed of the needleless consumable stirring head (4) is 5 mm / min, and the rotation speed is 900 r / min.

10. The dissimilar material additive friction stir welding method of claim 1, wherein, The first plate (1) is an aluminum alloy plate, and the second plate (2) is a carbon fiber composite material plate.

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