Steady-state magnetic field coupling laser wire filling narrow groove repair device

Abstract

A steady-state magnetic field coupled laser wire-filling narrow groove repair device, the steady-state magnetic field coupled laser wire-filling narrow groove repair device comprises a laser, a wire feeder, a wire feed head and a clamp for fixing the wire feed head and adjusting the position of the wire feed head; the wire feed head is fixed on the laser by the clamp, an excitation coil is provided on the outside of the wire feed head, a direct current is passed through the excitation coil, so that a steady-state magnetic field is generated on the welding wire, and the steady-state magnetic field is accurately sent into the molten pool area through the welding wire; the wire feed head is made of non-ferromagnetic material, and the welding wire is made of ferromagnetic material. The present invention attaches the excitation coil to the wire feed head and uses the welding wire as an iron core, so that the steady-state magnetic field can accurately and stably act on the molten pool area, and can be applied to parts of different shapes such as shafts and curved surfaces.

Description

Technical Field

[0001] The invention relates to a steady-state magnetic field coupling laser wire filling narrow groove repairing device. Background Art

[0002] Laser remanufacturing technology is a general term for technologies that use high-energy laser beams as energy to remanufacture scrap parts. In order to avoid excessive damage to the matrix or repair internal cracks, milling grooves with a high depth-to-width ratio are required to meet the repair performance requirements, and finally the milling groove area is filled with metals of the same material or similar performance using laser remanufacturing technology. However, when metal powder is used as a filling material for repair, there will be defects such as difficulty in feeding the powder into the narrow groove, pores caused by hollow powder and other reasons, and poor melting. Laser wire welding has small thermal impact, small welding deformation, and a certain rigidity due to the use of welding wire. The filler metal can be directly fed into the bottom of the narrow groove, which can achieve the repair of extremely narrow grooves. However, laser wire welding also has some problems: for example, defects such as pores are easily left in the weld, affecting the performance after repair; the adjustment of laser process parameters alone cannot control the movement direction of the fluid inside the molten pool, thereby controlling the structure and performance of the solidified layer.

[0003] In response to the above problems, domestic and foreign scholars have used external magnetic fields to regulate laser welding. M. Bachmann and other scholars used the steady-state magnetic field provided by permanent magnets to regulate the full-depth fusion welding of aluminum alloys. Studies have shown that when the movement direction of the conductive fluid is not parallel to the direction of the magnetic field, the steady-state magnetic field will generate a Lorentz force opposite to the convection direction of the molten pool, inhibiting the flow of the molten pool, thereby improving the cross-section and surface morphology of the weld and inhibiting the spatter phenomenon during welding. Asai and other scholars found that the alternating magnetic field can reduce the size of equiaxed crystals and the relative volume of the columnar crystal region. Domestic scholars such as Liu Hongxi used alternating magnetic fields to refine the organization of the laser cladding layer. The devices disclosed in the above documents do not use steady-state magnetic fields for laser wire welding, and the magnetic field generated by the device acts on the entire substrate and cannot accurately act on the molten pool, and it is difficult to apply to complex morphology parts such as shafts and curved surfaces. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the present invention provides a steady-state magnetic field coupled laser wire feeding narrow groove repair device, which introduces a steady-state magnetic field into the molten pool through the excitation coil and the filling welding wire to achieve the purposes of regulating the solidification structure morphology, optimizing the repair performance, and improving the weld morphology.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A steady-state magnetic field coupling laser wire filling narrow groove repair device comprises a laser, a wire feeder, a wire feeding head and a clamp used for fixing the wire feeding head and capable of adjusting the position of the wire feeding head.

[0007] The wire feed head is fixed on the laser through a clamp, and an excitation coil is provided outside the wire feed head. A direct current is passed through the excitation coil to generate a steady-state magnetic field on the welding wire, and the steady-state magnetic field is accurately sent into the molten pool area through the welding wire. The wire feed head is made of non-ferromagnetic material, and the welding wire is made of ferromagnetic material.

[0008] The fixture comprises a bottom plate for fixing the fixture on the laser, a first adjustment plate along the X-axis direction, a second adjustment plate along the Y-axis direction, and a screw rod along the Z-axis direction.

[0009] The bottom plate is provided with four through holes, which can be fixed to the laser by screws. A through hole is provided at one end of the first adjustment plate, which can be fixed to the bottom plate by screws. The first adjustment plate is provided with a through slot extending along the X-axis direction, and a first bolt is slidably provided in the through slot. The bottom end of the first bolt is connected to the second adjustment plate, and the top end is provided with a first nut which can tighten the first adjustment plate and the second adjustment plate together, so that the second adjustment plate can be moved or positioned on the first adjustment plate along the X-axis direction; a through slot extending along the Y-axis direction is provided in the middle of the second adjustment plate, a stud is passed through the slot, and second nuts are provided at the upper and lower ends of the stud. A double nut structure is adopted at the upper and lower ends, and the stud can be tightened with the second adjustment plate, so as to realize the movement and positioning of the stud in the through slot along the Y-axis direction and along the Z-axis direction; a wire feeding head is sandwiched between the two studs, and is tightened by the second bolt and the third nut, so that the wire feeding head can be rotated and positioned around the second bolt in the XZ plane.

[0010] The present invention mainly generates a steady-state magnetic field on the welding wire through an excitation coil, and introduces the steady-state magnetic field into the molten pool through the welding wire. The steady-state magnetic field generates a Lorentz force opposite to the convection direction of the molten pool when the movement direction of the conductive fluid is not parallel to the direction of the magnetic field, thereby inhibiting the flow of the molten pool, thereby achieving the purpose of regulating the solidification structure, improving the weld morphology, and reducing the number of defects.

[0011] The present invention has the following advantages:

[0012] (1) The present invention attaches an excitation coil to the wire feeder and uses the welding wire as an iron core, so that the steady-state magnetic field can accurately and stably act on the molten pool area, and is applicable to parts of different shapes such as shafts and curved surfaces.

[0013] (2) The magnetic field device used in the present invention is simple and low-cost, and only requires simple modification of the original wire feeding head without the need to purchase additional equipment.

[0014] (3) The present invention uses an external energy field to control the solidification structure and reduce the number of defects. There is no need to repeatedly conduct laser process research, thus simplifying the repair process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1It is a schematic diagram of a device for repairing narrow slots by steady-state magnetic field coupling laser wire feeding in the present invention.

[0016] Figure 2 It is a partial cross-sectional view of the excitation coil of the device for repairing narrow slots by steady-state magnetic field coupling laser wire feeding in the present invention.

[0017] Figure 3 This is a clamp diagram of the steady-state magnetic field coupled laser wire feeding narrow slot repair device in the present invention.

[0018] Figure 4 It is a stud diagram of the fixture of the steady-state magnetic field coupled laser wire feeding narrow slot repair device in the present invention. DETAILED DESCRIPTION

[0019] The following is a detailed description of the specific implementation of the present invention in conjunction with the accompanying drawings

[0020] A steady-state magnetic field coupled laser wire filling narrow groove repair device comprises a laser 2, a wire feeder 1, a wire feeder head 4 and a clamp 3 for fixing the wire feeder head and adjusting the position of the wire feeder head.

[0021] The wire feeding head 4 is fixed on the laser 2 by a clamp 3. An excitation coil 6 is provided outside the wire feeding head 4. A direct current is passed through the excitation coil 6 to generate a steady-state magnetic field on the welding wire, and the steady-state magnetic field is accurately sent into the molten pool area through the welding wire.

[0022] The fixture 3 includes a base plate 7 for fixing the fixture on the laser, a first adjustment plate 9 along the X-axis direction, a second adjustment plate 13 along the Y-axis direction, and a first screw 14 along the Z-axis direction.

[0023] The bottom plate 7 is provided with four through holes, which can be fixed to the laser by screws 8. A first adjustment plate 9 is connected to each of the two sides of the bottom plate 7; a through hole is provided at one end of the first adjustment plate 9 to be fixed to the bottom plate 7 by screws; a first through slot extending along the X-axis direction is provided on the first adjustment plate 9, a first bolt 11 is slidably provided in the first through slot, the bottom end of the first bolt 11 is connected to the second adjustment plate 13, and a first nut 12 is provided at the top end to tighten the first adjustment plate 9 and the second adjustment plate 13 together, so that the second adjustment plate 13 can be moved or positioned on the first adjustment plate 9 along the X-axis direction; a second adjustment plate 13 is provided in the middle with a second nut 12 extending along the Y-axis direction. Two through grooves, a first stud 14 is passed through the second through groove, and the first stud 14 has second nuts 10 on the upper and lower sides of the second through groove. A double nut structure is adopted on the upper and lower sides, and the first stud 14 and the second adjustment plate 13 can be tightened, so as to realize the movement and positioning of the first stud 14 in the through groove along the Y-axis direction and along the Z-axis direction; the lower ends of the two first studs 14 are connected with sleeves, and the two sleeves are passed through the second bolts 15 in the Y direction, with the earrings of the wire feeding head housing sandwiched in the middle, and the earrings of the wire feeding head housing are also passed through the second bolts 15, and are tightened by the second bolts 15 and the third nut 16, so that the wire feeding head 4 can be rotated and positioned around the second bolts 15 in the XZ plane.

[0024] The method of use of the present invention is as follows:

[0025] (1) According to the crack depth of the workpiece 5 to be repaired, a rectangular groove with a depth greater than or equal to the crack depth of 4 mm and a width of 2 mm to 4 mm is machined by a machining method to remove the crack area; the workpiece 5 to be repaired is initially polished, cleaned and dried, and then the workpiece 5 to be repaired is mounted on a workbench so that the opening of the rectangular groove faces upward; the length direction of the rectangular groove is defined as the X-axis direction.

[0026] (2) The laser 2 is placed directly above the rectangular groove, and the direction of the laser beam is assumed to be the Z axis. The wire feed head 4 is mounted on the laser 2 through the fixture 3. The wire feed head 4 and the laser 2 are located on the XZ plane, and the angle between the filler wire and the axis of the laser beam is 30° to 70°.

[0027] (3) The excitation coil 6 is wound on the wire feeder 4, and the welding wire is used as the magnetic core. The number of turns of the excitation coil is selected to be 100-400. A direct current of 10-20A is passed through, so that a steady-state magnetic field with a strength of 0.2-0.5T is generated on the welding wire inside the wire feeder;

[0028] (4) Turn on laser 2, and scan the laser beam in the rectangular groove area along the X-axis direction. At the same time, turn on wire feeder 1 to feed welding wire into the laser spot area. The distance between the tip of the filling wire and the center of the laser spot is 0~1mm; stop laser 2 and wire feeder 1 to complete the repair process.

[0029] The spot diameter is 2mm~4mm, the wire feeding speed is 10mm / s~25mm / s, the welding wire diameter is 0.8mm~2mm, the laser power is 1kw~3kw, and the scanning speed is 4mm / s~12mm / s.

[0030] The contents described in the embodiments of this specification are merely an enumeration of the implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms described in the embodiments. The protection scope of the present invention also extends to the equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. A steady-state magnetic field coupled laser wire filling narrow groove repair device, characterized in that: It comprises a laser (2), a wire feeder (1), a wire feed head (4), and a clamp (3) for fixing the wire feed head and capable of adjusting the position of the wire feed head; The wire feeding head (4) is fixed on the laser (2) by means of a clamp (3); an excitation coil (6) is provided outside the wire feeding head (4); a direct current is passed through the excitation coil (6) so that a steady-state magnetic field is generated on the welding wire, and the steady-state magnetic field is accurately fed into the molten pool area through the welding wire; the number of turns of the excitation coil (6) is 100 to 400; the direct current is a direct current of 10 to 20 A; the intensity of the steady-state magnetic field is 0.2 to 0.5 T; the wire feeding head (4) is made of non-ferromagnetic material, and the welding wire is made of ferromagnetic material.

2. A steady-state magnetic field coupled laser wire filling narrow groove repair device as claimed in claim 1, characterized in that: The fixture (3) comprises a base plate (7) for fixing the fixture on the laser, a first adjustment plate (9) along the X-axis direction, a second adjustment plate (13) along the Y-axis direction, and a first stud (14) along the Z-axis direction; The base plate (7) is fixed on the laser, and a first adjustment plate (9) is connected to each of the two sides of the base plate (7); one end of the first adjustment plate (9) is fixed to the base plate (7) by a screw, the first adjustment plate (9) is provided with a first through slot extending in the X-axis direction, a first bolt (11) is slidably arranged in the first through slot, the bottom end of the first bolt (11) is connected to the second adjustment plate (13), and the top end of the first bolt (11) is provided with a first nut (12) which can tighten the first adjustment plate (9) and the second adjustment plate (13) together, so that the second adjustment plate (13) can be moved or positioned on the first adjustment plate (9) in the X-axis direction; the middle part of the second adjustment plate (13) is provided with a second through slot extending in the Y-axis direction. A through slot is provided, and a first stud (14) is passed through the second through slot. The first stud (14) has a second nut (10) on the upper and lower sides of the second through slot. A double nut structure is adopted, and the stud (14) and the second adjustment plate (13) are tightened to achieve movement and positioning of the stud (14) in the through slot along the Y-axis direction and along the Z-axis direction. The lower ends of the two first studs (14) are connected to sleeves, and the two sleeves are passed through the second bolts (15) in the Y direction, with an earring of the wire feeding head shell sandwiched in between. The earring of the wire feeding head shell is also passed through the second bolt (15) and is tightened by the second bolt (15) and the third nut (16), so that the wire feeding head (4) can be rotated and positioned around the second bolt (15) in the XZ plane.

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