A heterogeneous and shaped rotary friction extrusion welding structure and method

Abstract

The present invention provides a heterogeneous and special-shaped rotary friction extrusion welding structure and method, belonging to the field of material forming technology, comprising a first workpiece and a second workpiece, wherein a boss-shaped groove is provided at the axis of the pre-processed end face of the first workpiece, and a boss is provided at the axis of the pre-processed end face of the second workpiece. The present invention utilizes the characteristics of plastic deformation and flow of materials during the process of rotary friction welding of dissimilar metals, and while achieving effective connection of dissimilar metals, utilizes the fluidity of materials with relatively low yield strength to fill the gaps of the materials on the other side, thereby achieving integrated forming of dissimilar metals and special-shaped structures.

Description

Technical Field

[0001] The present disclosure relates to the technical field of material forming, and in particular to a heterogeneous and special-shaped rotary friction extrusion welding structure and method. Background Art

[0002] Rotary friction welding is a solid phase welding method that uses friction heat as a heat source and applies friction pressure during welding to make the welding material reach a plastic state and undergo plastic deformation and flow, thereby achieving effective material connection. Compared with traditional melting welding, the material does not melt during the rotary friction welding process, which avoids the formation of welding defects during the solidification of the material. At the same time, the flow of the material forms welding flash, which has a certain self-cleaning effect on impurities such as the oxide layer of the welded joint. Therefore, rotary friction welding can achieve high-quality connection of rotating structures of the same or different materials, and has been widely used in aerospace, petrochemical and other fields.

[0003] The rotary friction welding structure of the dissimilar metal rotating joint can achieve high-quality material connection and give full play to the advantages of the two materials. At present, the connection of dissimilar metals such as aluminum / steel, aluminum / copper, titanium / steel, etc. has been widely studied and applied. However, for the rotary friction welding of dissimilar materials, due to the difference in material properties, flash will be generated during welding. After welding, the welded joint needs to be processed secondary to remove the flash, resulting in material waste and increased processing costs, especially for precious metals such as copper and silver. Summary of the invention

[0004] In view of the defects or shortcomings in the prior art, the present invention provides a heterogeneous and shaped rotary friction extrusion welding structure and method, which can achieve integrated forming of complex structures while ensuring effective connection of dissimilar metals, avoid waste of precious metal materials and reduce processing costs.

[0005] In order to achieve the above objectives, the present disclosure adopts the following technical solutions:

[0006] In a first aspect, an embodiment of the present disclosure provides a heterogeneous and shaped rotary friction extrusion welding structure, comprising a first workpiece and a second workpiece, wherein a boss-shaped groove is provided at the axis of the pre-machined end face of the first workpiece, and a boss is provided at the axis of the pre-machined end face of the second workpiece.

[0007] Furthermore, the surface roughness of the boss-shaped groove is less than 1 μm.

[0008] Furthermore, the boss-shaped groove includes a first groove and a second groove, and the second groove is opened at the bottom of the first groove.

[0009] Furthermore, the first groove and the second groove are both circular grooves, the cross-sectional diameter of the second groove is smaller than the cross-sectional diameter of the first groove, and the axes of the first groove and the second groove coincide with the axis of the first workpiece.

[0010] Furthermore, a chamfer is provided on the peripheral side of the bottom surface of the first groove.

[0011] Further, the cross-sectional diameter of the second workpiece is the same as the cross-sectional diameter of the first groove, and the cross-sectional diameter of the boss is the same as the cross-sectional diameter of the second groove.

[0012] Further, the yield strength of the first workpiece is greater than the yield strength of the second workpiece.

[0013] In a second aspect, the present disclosure provides a heterogeneous and shaped rotational friction extrusion welding method, using a heterogeneous and shaped rotational friction extrusion welding structure as described above, comprising the following steps:

[0014] Step 1, machining the pre-welding end faces of the first workpiece and the second workpiece according to the actual structures of the workpieces;

[0015] Step 2, degreasing the first workpiece and the second workpiece;

[0016] Step 3, pre-assembling the processed first workpiece and the second workpiece and placing them on the rotating side and the feeding side of the rotary friction welding machine respectively, clamping them, and adjusting the welding parameters of the rotary friction welding machine;

[0017] Step 4, start the welding machine, and start welding when the welding machine reaches a preset speed. Control the friction pressure so that the second workpiece undergoes a certain amount of deformation, and fills the gap in the boss-shaped groove on the first workpiece under the action of pressure, thereby realizing the integrated molding of dissimilar metals.

[0018] Further, the second workpiece is placed on the rotating side of the rotary friction welding machine, and the first workpiece is placed on the feeding side of the rotary friction welding machine.

[0019] Furthermore, the welding parameters of the welding machine are as follows: initial rotation speed is 400-3000rpm, friction pressure is 10-300MPa, welding time is 1-10s; upsetting pressure is 20-400MPa; moment of inertia is 0-2kg·m 2 .

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. The present invention provides a boss-shaped groove at the axis of the pre-processed end face of the first workpiece and a boss at the axis of the pre-processed end face of the second workpiece, thereby effectively avoiding the generation of flash during welding, thereby avoiding the waste of precious metal materials in secondary processing and reducing processing costs.

[0022] 2. The present invention utilizes the characteristics of plastic deformation and flow of materials during the rotational friction welding of dissimilar metals to achieve effective connection of dissimilar metals (the sealing of the welding joint reaches more than 50atm, and the tensile strength reaches more than 3KN). At the same time, the fluidity of the material with relatively low yield strength is used to fill the gaps in the material on the other side, thereby realizing the integrated molding of dissimilar metals and special-shaped structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A diagram showing a connection structure between a first workpiece and a second workpiece;

[0024] Figure 2 This is a structural diagram of a first workpiece in an embodiment of the present disclosure;

[0025] Figure 3 This is a structural diagram of a second workpiece in an embodiment of the present disclosure;

[0026] Among them, 1. first workpiece; 2. second workpiece; 3. first groove; 4. second groove; 5. chamfer; 6. boss. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Embodiment 1

[0029] A typical implementation of the present disclosure is as follows: Figure 1-Figure 3 As shown, a heterogeneous and shaped rotary friction extrusion welding structure includes a first workpiece 1 and a second workpiece 2, wherein the first workpiece 1 and the second workpiece 2 are tubular structures or rod-shaped structures, and a boss-shaped groove is opened at the axis of the pre-machined end face of the first workpiece 1 by machining, and the surface roughness of the boss-shaped groove is less than 1 μm, and a boss 6 is machined at the axis of the pre-machined end face of the second workpiece 2.

[0030] Specifically, the boss-shaped groove includes a first groove 3 and a second groove 4, the second groove 4 is opened at the bottom of the first groove 3, the first groove 3 and the second groove 4 are both circular grooves, the cross-sectional diameter of the second groove 4 is smaller than the cross-sectional diameter of the first groove 3, the axes of the first groove 3 and the second groove 4 coincide with the axis of the first workpiece 1, and a chamfer 5 is opened on the peripheral side of the bottom surface of the first groove 3 to facilitate the matching between the first workpiece and the second workpiece.

[0031] In this embodiment, the first workpiece 1 is a tubular structure, such as Figure 2 As shown, the inner diameter of the first workpiece 1 is 7.8 mm, the outer diameter is 13 mm, a boss-shaped groove is provided at one end of the first workpiece 1, the first groove 3 is provided on the end face of the first workpiece 1, and its cross-sectional diameter is 6 mm, the second groove 4 is provided on the bottom face of the first groove 3, and its cross-sectional diameter is 4 mm, and a chamfer 5 with a diameter of 0.5 mm is provided on the peripheral side of the bottom face of the first groove 3.

[0032] The cross-sectional diameter of the second workpiece 2 is the same as that of the first groove 3, and the cross-sectional diameter of the boss 6 is the same as that of the second groove 4. In this embodiment, the second workpiece 2 is a rod-shaped structure. Figure 3 As shown, its cross-sectional diameter is 6 mm and its length is 40 mm. The boss 6 is arranged on one end surface of the second workpiece 2. The cross-sectional diameter of the boss 6 is 4 mm and its length is 2.8 mm.

[0033] The first workpiece 1 is made of a metal with a high yield strength and is not easily deformed, such as steel, titanium alloy, etc., and the second workpiece 2 is made of a metal with a low yield strength and is easily deformed, such as aluminum alloy, magnesium alloy, etc.

[0034] In this embodiment, the first workpiece 1 is made of copper with a relatively high yield strength of 70-90 MPa, and the second workpiece 2 is made of pure silver with a relatively low yield strength of 30-40 MPa. Compared with pure silver, copper has a higher yield strength and is not easily deformed during welding, while pure silver has a lower yield strength and is easily deformed and flows during welding to fill the mold.

[0035] During welding, Figure 1 As shown, the second workpiece 2 is inserted into the first groove 3 of the first workpiece 1, and the boss 6 at the end of the second workpiece 2 is inserted into the second groove 4 of the first workpiece 1. The boss can seal the second groove to avoid oxidation and increase the service life.

[0036] By using a friction welding machine, the second workpiece 2 is rubbed in the groove of the first workpiece 1 to produce a certain amount of deformation and flow, thereby filling the rounded corner of the first workpiece 1 without overflowing the groove of the first workpiece, thereby achieving a close combination of the two bars and avoiding the generation of flash.

[0037] Embodiment 2

[0038] This embodiment discloses a heterogeneous and special-shaped rotational friction extrusion welding method, using a heterogeneous and special-shaped rotational friction extrusion welding structure as described in the first embodiment, comprising the following steps:

[0039] Step 1: machining the pre-welding end faces of the first workpiece 1 and the second workpiece 2 according to the actual structures of the workpieces.

[0040] A boss-shaped groove is opened at the axis of the pre-machined end face of the first workpiece 1 by machining, and the surface roughness of the boss-shaped groove is less than 1 μm. A boss 6 is machined at the axis of the pre-machined end face of the second workpiece 2 .

[0041] Step 2: Degreasing the first workpiece 1 and the second workpiece 2.

[0042] Step 3: pre-assemble the processed first workpiece 1 and the second workpiece 2 and place them on the rotating side and the feeding side of the rotary friction welding machine respectively, clamp them, and adjust the welding parameters of the rotary friction welding machine.

[0043] The rotary friction welding is a type of continuous drive friction welding machine or inertia friction welding. In this embodiment, a continuous drive friction welding machine is used to perform welding. The second workpiece 2 is placed on the rotating side of the friction welding machine, and the first workpiece 1 is placed on the feed side of the friction welding. After clamping both sides, the welding parameters are adjusted.

[0044] The welding parameters are as follows: initial rotation speed of 400-3000 rpm, friction pressure of 10-300 MPa, welding time of 1-10 s; upsetting pressure of 20-400 MPa; moment of inertia of 0-2 kg·m 2 .

[0045] Step 4, start the welding machine, and start welding when the welding machine reaches a preset speed. Control the friction pressure so that the second workpiece 2 undergoes a certain amount of deformation, and fills the gap in the boss-shaped groove on the first workpiece 1 under pressure, thereby achieving integrated molding of dissimilar metals and special-shaped structures.

[0046] In this embodiment, the initial speed is 800 rpm, the friction pressure is 40 MPa, the welding time is 5 s, and the upsetting pressure is 80 MPa. The welding machine is started, and when the speed reaches the preset 800 rpm, the friction pressure is started and the time is recorded. Under the action of the friction pressure, the silver side gradually heats up and reaches a plastic state. After 5 s, the upsetting pressure is applied to make the pure silver in the plastic state flow and fill the gap of the copper to achieve the integrated forming of the joint.

[0047] The present disclosure proposes to utilize the characteristics of plastic deformation and flow of materials during the process of rotary friction welding of dissimilar metals, and at the same time realize the effective connection of dissimilar metals, utilize the fluidity of materials with relatively low yield strength to fill the gaps of the materials on the other side, thereby realizing the integrated molding of dissimilar metals and special-shaped structures. The present disclosure realizes the integrated molding of complex structures while ensuring the effective connection of dissimilar metals (the sealing of the welding joint reaches more than 50atm, and the tensile strength reaches more than 3KN), avoiding the waste of precious metal materials and reducing the cost of secondary processing.

[0048] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A heterogeneous and shaped rotary friction extrusion welding structure, characterized in that: It comprises a first workpiece and a second workpiece, wherein a boss-shaped groove is provided at the axis of the pre-processed end surface of the first workpiece, and a boss is provided at the axis of the pre-processed end surface of the second workpiece; The boss-shaped groove includes a first groove and a second groove, the second groove is opened at the bottom of the first groove, the first groove and the second groove are both circular grooves, the cross-sectional diameter of the second groove is smaller than the cross-sectional diameter of the first groove, the axes of the first groove and the second groove coincide with the axis of the first workpiece, the cross-sectional diameter of the second workpiece is the same as the cross-sectional diameter of the first groove, and the cross-sectional diameter of the boss is the same as the cross-sectional diameter of the second groove; The bottom surface of the first groove is provided with a chamfered corner on its circumferential side; By providing a boss-shaped groove at the axis of the pre-processed end face of the first workpiece and providing a boss at the axis of the pre-processed end face of the second workpiece, the generation of flash is effectively avoided during welding; During welding, the second workpiece is inserted into the first groove of the first workpiece, and the boss at the end of the second workpiece is inserted into the second groove of the first workpiece. The boss can seal the second groove, thereby avoiding oxidation and improving the service life. By using a friction welding machine, the second workpiece is rubbed in the groove of the first workpiece to produce a certain amount of deformation and flow, thereby filling the chamfered part of the first workpiece without overflowing the groove of the first workpiece, thereby achieving a close combination of the two bars and avoiding the generation of flash.

2. A heterogeneous and shaped rotary friction extrusion welding structure as claimed in claim 1, characterized in that: The surface roughness of the boss-shaped groove is less than 1 μm.

3. The heterogeneous and shaped rotary friction extrusion welding structure according to claim 1, characterized in that: The yield strength of the first workpiece is greater than the yield strength of the second workpiece.

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