Tungsten steel composite friction stir welding

Abstract

The utility model relates to the technical field of friction welding, and discloses tungsten steel composite friction stir welding which comprises a clamping part. The transition part is arranged at the end part of the clamping part; the tungsten steel stirring head comprises a stirring base body and a stirring part, the end face of one side of the stirring base body is welded to the transition part, and a stirring concave part is arranged on the end face of the other side of the stirring base body; and the stirring part is arranged in the stirring concave part. The structural strength of the tungsten steel stirring head can be improved, the problems of abrasion, deformation and the like easily occurring in the long-time welding operation process are reduced, and the welding quality is improved.

Description

Technical Field

[0001] This utility model relates to the field of friction welding technology, and more specifically, to a tungsten carbide composite friction stir welding method. Background Technology

[0002] Friction stir welding (FSW) involves pressing a high-speed rotating stirring head into the workpiece, generating significant frictional and plastic deformation heat. This causes localized plasticization of the workpiece material, which then cools under the pressure of the shoulder to form a dense joint. FSW has wide applications in numerous industrial manufacturing sectors, such as aerospace, automotive, and shipbuilding. However, most existing FSW tools are machined from a single piece of mold steel, resulting in lower costs. During prolonged, high-intensity welding operations, the stirring head made of mold steel is prone to wear and deformation, which not only reduces weld quality but also increases production costs and reduces efficiency due to frequent head replacements. Summary of the Invention

[0003] The purpose of this invention is to address the technical problems existing in the prior art by providing a tungsten carbide composite friction stir welding method that can improve structural strength and welding quality.

[0004] To solve the problems mentioned above, the technical solution adopted by this utility model is as follows:

[0005] This utility model provides a tungsten carbide composite friction stir welding method, comprising:

[0006] Clamping part;

[0007] A transition portion is provided at the end of the clamping portion;

[0008] A tungsten carbide stirring head includes a stirring base and a stirring part. One end face of the stirring base is welded to a transition part, and the other end face of the stirring base is provided with a stirring recess. The stirring part is disposed in the stirring recess.

[0009] Furthermore, the cross-sectional area of ​​the transition portion perpendicular to the axis gradually decreases from the clamping portion toward the stirring substrate, and the outer surface of the transition portion is set as an arc-shaped surface.

[0010] Furthermore, the connection end between the transition portion and the clamping portion is provided with an arc segment, the radius of which is 5mm to 25mm.

[0011] Furthermore, the stirring part is a conical platform, and the cross-sectional area of ​​the stirring part perpendicular to the axis gradually decreases from the connection end with the stirring base to the other end. The stirring part is provided with multiple stirring grooves.

[0012] Furthermore, the surface of the stirring part is provided with a plurality of stirring inclined sections along the circumferential direction, each stirring inclined section being arranged along the axial direction of the stirring part, and the stirring groove being circumferentially divided.

[0013] Furthermore, the overall axial length of the friction stir welding is L, the axial length of the stirring head is L1, and the axial length of the stirring part is L2, where 1 / 5 ≤ L1 / L ≤ 1 / 3, and 1 / 10 ≤ L2 / L1 ≤ 4 / 5.

[0014] Furthermore, the width of the agitation groove is twice its depth.

[0015] Furthermore, the axial length of the stirring base is L3, and the depth of the stirring recess is l1, satisfying 1 / 11≤l1 / L3≤5 / 11.

[0016] Furthermore, the stirring recess is provided with a spiral groove along its circumferential direction.

[0017] Furthermore, each of the agitation grooves is an arc-shaped groove;

[0018] Alternatively, the multiple sets of agitation tanks are arranged in an alternating manner, each agitation tank has a V-shaped structure, and the included angle of the opening end of the agitation tank is 45° to 75°.

[0019] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0020] In this invention, the tungsten carbide stirring head and the clamping part are welded together. The tungsten carbide stirring head consists of a stirring base and a stirring part. The stirring base is provided with a stirring recess, which can improve the structural strength of the tungsten carbide stirring head, reduce wear and deformation problems that are prone to occur during long-term welding operations, and improve the welding quality. Attached Figure Description

[0021] To more clearly illustrate the solutions in this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0022] Figure 1 This is a schematic diagram of the tungsten carbide composite friction stir welding structure in this utility model.

[0023] Figure 2 This is a partial schematic diagram of the tungsten carbide composite friction stir welding in this utility model.

[0024] Figure 3 This is a schematic diagram of the tungsten carbide stirring head in this utility model.

[0025] Among them, 10-clamping part, 20-transition part, 21-arc segment, 30-tungsten steel stirring head, 31-stirring base, 32-stirring part, 33-stirring recess, 321-stirring groove, 322-stirring inclined part. Detailed Implementation

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. For example, terms such as “length,” “width,” “upper,” “lower,” “left,” “right,” “front,” “rear,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer” indicate orientations or positions based on the orientations or positions shown in the accompanying drawings and are merely for ease of description and should not be construed as limiting the invention.

[0027] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this utility model are intended to cover non-exclusive inclusion; the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish different objects, not to describe a particular order. In the specification, claims, and accompanying drawings of this utility model, when an element is referred to as "fixed to," "mounted to," "set on," or "connected to" another element, it can be directly or indirectly located on that other element. For example, when an element is referred to as "connected to" another element, it can be directly or indirectly connected to that other element.

[0028] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] See Figures 1 to 3 As shown, this utility model provides a tungsten carbide composite friction stir welding system, including: a clamping part 10;

[0030] The transition portion 20 is provided at the end of the clamping portion 10;

[0031] The tungsten carbide stirring head 30 includes a stirring base 31 and a stirring part 32. One end face of the stirring base 31 is welded to the transition part 20, and the other end face of the stirring base 31 is provided with a stirring recess 33. The stirring part 32 is disposed in the stirring recess 33.

[0032] Specifically, the clamping part 10, the transition part 20, and the tungsten carbide stirring head 30 are arranged coaxially in sequence. In order to facilitate the clamping part 10 to be clamped and cooperated with the external clamp, the clamping part 10 can be a multi-section cylinder. The length and diameter of each section cylinder can be set as needed. The outer surface of the clamping part 10 can be provided with a clamping surface, which can also facilitate the clamping operation.

[0033] Specifically, the clamping part 10 and the transition part 20 are usually made of mold steel. In this embodiment, the tungsten steel stirring head 30 is made of tungsten steel. The tungsten steel stirring head 30 and the transition part 20 are welded together, which can improve the structural strength of the tungsten steel stirring head 30 and reduce problems such as wear and deformation that are prone to occur during long-term welding operations.

[0034] Furthermore, the cross-sectional area of ​​the transition portion 20 perpendicular to the axis gradually decreases from the clamping portion 10 toward the stirring substrate 31, and the outer surface of the transition portion 20 is set as an arc-shaped surface.

[0035] Specifically, since friction stir welding involves high-speed rotation during operation and requires pressing the stirring part 32 into the material being welded, the cross-sectional area of ​​the end connecting the transition part 20 and the stirring base 31 is smaller than the cross-sectional area of ​​the opposite end. This allows for stress release and reduces stress concentration, thereby improving the overall structural rigidity of the friction stir welding.

[0036] In one embodiment, the connection end between the transition portion 20 and the clamping portion 10 is provided with an arc segment 21, the radius of which is 5mm to 25mm.

[0037] Understandably, the radius of the arc segment 21 can be 5mm, 10mm, 16mm, 25mm or any value within the range, which can better reduce stress concentration and further improve the structural rigidity of friction stir welding.

[0038] Furthermore, the stirring part 32 is a conical platform, and the cross-sectional area of ​​the stirring part 32 perpendicular to the axis gradually decreases from the connection end with the stirring base 31 to the other end. The stirring part 32 is provided with multiple sets of stirring grooves 321.

[0039] Specifically, during welding, the clamping part 10 is used for clamping, and the stirring part 32 generates heat through rotational friction, forming a forging force using the stirring recess 33 on the stirring base 31. The stirring part 32 adopts a conical truncated structure, that is, the diameter of the stirring part 32 near the stirring base 31 is large, and the diameter of the other end is small, which can improve the forging force of the overall structure of the stirring part 32.

[0040] Understandably, multiple stirring grooves 321 are arranged sequentially along the axial direction of the stirring part 32, and the axes of each stirring groove 321 are arranged parallel to each other. During the welding process, the surface of the stirring part 32 forms a multi-layer forging surface, and the resulting multi-layer forging pressure achieves more uniform stirring. The metal inside the weld flows more fully, thereby making the weld structure more uniform in the depth direction. It can also reduce the forging pressure of the stirring recess 33, thereby reducing the amount of downward pressure and reducing the thickness of the welding flash.

[0041] In other embodiments, multiple sets of stirring grooves 321 are staggered, each stirring groove 321 has a V-shaped structure, and the included angle of the opening end of the stirring groove 321 is 45° to 75°. Specifically, the included angle of the opening end of the stirring groove 321 can be 45°, 60°, 75° or any value within the range, which can further improve the working efficiency of the stirring part 32.

[0042] Furthermore, the surface of the stirring section 32 is provided with a plurality of stirring inclined sections 322 along the circumferential direction. Each stirring inclined section 322 is arranged along the axial direction of the stirring section 32, and the stirring groove 321 is circumferentially divided.

[0043] Specifically, three agitating inclined sections 322 are evenly arranged along the circumference of the stirring section 32, dividing the stirring groove 321 into three groups along the circumference. This further increases the forging pressure of the stirring section 32, thereby ensuring the overall working efficiency of friction stir welding. The angle between the agitating inclined section 322 and the axis of the stirring section 32 is 60° to 90°, specifically 60°, 70°, 75°, 80°, 85°, or any value within the range, all of which can ensure the overall working efficiency of friction stir welding.

[0044] Furthermore, the width l / depth h of the agitation groove 321 is 2, which enables more complete metal flow inside the weld and improves the working efficiency of the agitation section 32.

[0045] Furthermore, the overall axial length of the friction stir welding is L, the axial length of the stirring head 30 is L1, and the axial length of the stirring part 32 is L2. 1 / 5≤L1 / L≤1 / 3, 1 / 10≤L2 / L1≤4 / 5, which can improve the working efficiency of the stirring head 30.

[0046] Specifically, since the stirring head 30 plays a major role in the friction stir welding process, its length cannot be too small, otherwise the welding quality cannot be guaranteed. If the stirring head 30 is too long, the cost of the tool increases, and deformation is more likely to occur. L1 / L can be 1 / 5, 1 / 4, 2 / 5, 1 / 3, or any value within the range mentioned above, and L2 / L1 can be 1 / 10, 1 / 5, 3 / 10, 1 / 2, 2 / 5, 4 / 5, or any value within the range mentioned above, all of which can ensure the working efficiency of the stirring head 30.

[0047] In other embodiments, the stirring recess 33 is provided with a spiral groove, which can increase the contact area between the stirring recess 33 and the weld structure, and make the stirring head 30 rotate forward to rotate the weld structure to the center, so that the material does not overflow the weld, the weld is more compact, the weld quality is improved, and the stability of the high reliability weld is guaranteed.

[0048] Furthermore, the axial length of the stirring base 31 is L3, and the depth of the stirring recess 33 is l1, satisfying 1 / 11≤l1 / L3≤5 / 11.

[0049] Specifically, since the stirring recess 33 is provided on the stirring base 31, the forging pressure of the stirring head 30 can only be increased, thereby ensuring the welding quality, when the depth of the stirring recess 33 is within the appropriate range. Understandably, l1 / L3 can take values ​​of 1 / 11, 3 / 11, 5 / 11, or any value within the range, all of which can guarantee welding quality.

[0050] The tungsten carbide composite friction stir welder provided by this utility model includes the following specific steps in its preparation method:

[0051] Step S1: Select the first bar and the second bar respectively. The first bar is die steel and the second bar is tungsten steel.

[0052] Step S2: The first bar is machined by turning to obtain the clamping part 10 and the transition part 20 in sequence, and then heat-treated.

[0053] Step S3: Roughen the ends of the transition section 20 and the second bar to make the roughness Ra of the end faces of both the transition section 20 and the second bar ≤ 1.6 μm;

[0054] Step S4: Fit the second bar and the treated end face of the transition part 20 together, vacuum weld them into one piece and then cool them;

[0055] Specifically, the second bar and the transition part 20 are placed in a vacuum furnace with a pressure of 10MPa to 30MPa and held at 500℃ to 950℃ for 2 hours to complete the welding; after welding, the second bar and the transition part 20 are slowly cooled to 300℃ at a rate of 5℃ / min to 20℃ / min and then air-cooled.

[0056] Step S5: The second bar is processed using a CNC machine tool to obtain a stirring base 31 and a stirring part 32. The stirring base 31 has a stirring recess 33, and the stirring part 32 has a stirring groove 321 and a stirring inclined part 322.

[0057] The preparation method provided by this utility model involves welding two materials, mold steel and tungsten steel. The stirring head is made of tungsten steel, which improves the strength and wear resistance of the stirring head compared to a one-piece mold steel structure, thereby improving the welding quality of the materials.

[0058] The following specific example illustrates the preparation process of the aforementioned tungsten carbide composite friction stir welding, which includes the following:

[0059] 1) Select the first bar made of SKD61 mold steel and the second bar made of YG15 tungsten steel respectively. The diameter of the first bar is 25mm and the diameter of the second bar is 9mm.

[0060] 2) The first bar is machined by turning to obtain the first clamping part, the second clamping part and the transition part in sequence. The diameter of the first clamping part is 20mm, the diameter of the second clamping part is 25mm, the radius of the transition section on the transition part is 16mm, and heat treatment is performed.

[0061] 3) Roughen the ends of the transition section and the second bar to make the roughness of the end faces of both 1.2um;

[0062] 4) Fit the second bar and the treated end face of the transition section together, vacuum weld them into one piece, and then cool them;

[0063] 5) The second bar is machined using a CNC machine tool to obtain the mixing matrix and the mixing section;

[0064] Specifically, the diameter of the mixing base is 9mm and the thickness is 2.2mm; the mixing section is a conical platform with a diameter that gradually decreases from 4.6mm to 2.8mm and a thickness of 3.8mm; the depth of the stirring groove on the mixing section is 0.4mm and the width is 0.8mm.

[0065] The friction stir welding method provided by this invention has a weld joint 30 with a tensile strength ≥850MPa. When applied to welding 6mm thick 6061 aluminum alloy, compared to welding 6mm thick 6061 aluminum alloy with traditional tools, its continuous working time is increased from 35H to 120H. When applied to welding 4mm thick TC4 titanium alloy, compared to welding with traditional tools, its continuous working time is increased from 0.5H to 50H, thus improving the efficiency of friction welding.

[0066] The above embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A tungsten steel hybrid friction stir weld, characterized by: The utility model relates to a friction stir welding head, including: Clamping part; Transition part, set up in the end of clamping part; Tungsten steel stirring head, including stirring base body and stirring part, one side end surface of stirring base body and transition part carry out welding, the other side end surface of stirring base body is equipped with stirring recess part;Stirring part sets up in stirring recess part.

2. The tungsten steel hybrid friction stir weld of claim 1, wherein: The cross section area of the transition part perpendicular to the axis gradually decreases from the clamping part to the stirring base body, and the outer surface of the transition part is provided with an arc surface.

3. The tungsten steel hybrid friction stir weld of claim 2, wherein: The connecting end of the transition part and the clamping part is provided with a circular arc segment, and the radius of the circular arc segment is 5mm-25mm.

4. The tungsten steel hybrid friction stir weld of any one of claims 1 to 3, wherein: The stirring part is a conical table, and the cross section area of the stirring part perpendicular to the axis gradually decreases from the connecting end to the other end of the stirring base body, and a plurality of stirring grooves are provided on the stirring part.

5. The tungsten steel hybrid friction stir weld of claim 4, wherein: The surface of the stirring part is provided with a plurality of stirring inclined parts along the circumference, each stirring inclined part is arranged along the axial direction of the stirring part and divides the stirring grooves circumferentially.

6. The tungsten steel hybrid friction stir weld of claim 4, wherein: The overall axial length of the friction stir welding is L, the axial length of the stirring head is L1, the axial length of the stirring part is L2, 1 / 5≤L1 / L≤1 / 3, and 1 / 10≤L2 / L1≤4 / 5.

7. The tungsten steel hybrid friction stir weld of claim 4, wherein: The width of the stirring groove is 2 times the depth.

8. The tungsten steel hybrid friction stir weld of claim 4, wherein: The axial length of the stirring base body is L3, the depth of the stirring recess part is l1, and 1 / 11≤l1 / L3≤5 / 11 is satisfied.

9. The tungsten steel hybrid friction stir weld of claim 4, wherein: The stirring recess part is provided with a spiral groove.

10. The tungsten steel hybrid friction stir weld of claim 7, wherein: Each stirring groove is an arc groove. Alternatively, the plurality of stirring grooves are arranged in a staggered manner, each stirring groove has a V-shaped structure, and the included angle of the opening end of the stirring groove is 45°-75°.

Images