Composite machining grinding wheel for post-treatment of friction stir welding seam and preparation and use method of composite machining grinding wheel

Abstract

The combined machining grinding wheel comprises a grinding wheel base body, a rough grinding wheel block, a micro-extrusion block and a smooth grinding wheel block are fixed to the bottom of the grinding wheel base body, the rough grinding wheel block, the micro-extrusion block and the smooth grinding wheel block are located on different diameters, the rough grinding wheel block is located on the outermost side, and the micro-extrusion block is located on the outermost side. The smooth grinding wheel block is located on the innermost side, the micro extrusion block is located between the rough grinding wheel block and the smooth grinding wheel block, and the smooth grinding wheel block is flush with the micro extrusion block and higher than the rough grinding wheel block. According to the combined machining grinding wheel, the three working procedures of rough grinding, micro extrusion and smooth grinding can be sequentially completed in the one-time clamping and one-time machining process, compared with a traditional multi-device and multi-working-procedure machining mode, the machining time is greatly shortened, the machining efficiency is improved, meanwhile, technological errors caused by multiple times of clamping and positioning are reduced, and the machining precision is improved. And the surface quality and the mechanical property of a friction stir welding seam are integrally and remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing, and in particular relates to a composite processing grinding wheel for post-processing of stir friction welds and a preparation and use method thereof. Background Art

[0002] High-strength aluminum alloys are widely used in aerospace, automobile manufacturing and other fields due to their high strength-to-weight ratio. As an efficient and high-quality solid-phase connection method, stir friction welding is increasingly used in high-strength aluminum alloy welding. However, the welds after stir friction welding usually have defects such as flash and fish scales, and the mechanical properties of the weld surface need to be further improved. Therefore, the weld needs to be post-processed.

[0003] Traditional post-processing methods often require the coordination of multiple equipment and multiple processes. For example, first use cutting equipment to remove flash, then use grinding equipment to process fish scales, and finally perform surface strengthening treatment. This post-processing method not only has low processing efficiency, but also easily leads to the accumulation of processing accuracy errors due to multiple clamping and positioning, affecting the quality of the final product. In addition, the existing surface strengthening methods are difficult to effectively combine with grinding, and integrated and efficient processing cannot be achieved. Therefore, it is of great practical significance to develop an integrated device or tool that can simultaneously achieve rough grinding of flash and partial fish scales, micro-extrusion surface strengthening, and polishing to complete the final quality finishing grinding. Summary of the invention

[0004] The main purpose of the present invention is to propose a composite processing grinding wheel for post-processing of stir friction welds and a preparation and use method thereof, which can effectively solve the problems in the background technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] A composite grinding wheel for post-processing of a friction stir weld comprises a grinding wheel base, a rough grinding wheel block, a micro-extrusion block and a smooth grinding wheel block are fixed to the bottom of the grinding wheel base, the rough grinding wheel block, the micro-extrusion block and the smooth grinding wheel block are located at different diameters, wherein the rough grinding wheel block is located at the outermost side, the smooth grinding wheel block is located at the innermost side, the micro-extrusion block is between the rough grinding wheel block and the smooth grinding wheel block, and the smooth grinding wheel block is flush with the micro-extrusion block and is higher than the rough grinding wheel block.

[0007] Preferably, the grinding wheel base has a cavity in the middle.

[0008] Preferably, the grinding wheel base includes a mounting plate and a mounting column, the mounting column is coaxially fixed to the bottom of the mounting plate, the mounting plate has a plurality of mounting holes, and the rough grinding wheel block, micro extrusion block and polishing grinding wheel block are fixed to the bottom of the mounting column.

[0009] Preferably, three first grooves are provided at the bottom of the grinding wheel base, inserts are detachably installed in the three first grooves, second grooves are provided at the bottoms of the three inserts, and the rough grinding wheel block, micro-extrusion block and polishing grinding wheel block are fixedly embedded in the second grooves of the three inserts.

[0010] Preferably, the rough grinding wheel block, the micro-extrusion block and the light grinding wheel block are in the shape of fan rings.

[0011] Preferably, the bottom of the micro-extrusion block is arc-shaped, and the height increases from the inside to the outside.

[0012] A method for preparing a composite grinding wheel for post-processing of a friction stir weld comprises the following steps:

[0013] Production of grinding wheel matrix: titanium alloy material is used and processed into the required shape and size through mechanical processing;

[0014] Preparation and installation of rough grinding wheel block: Silicon carbide or corundum abrasive particles with a particle size range of 60-120 mesh are mixed evenly with a binder, and the rough grinding wheel block is prepared by hot pressing molding process. When installing, the rough grinding wheel block is first embedded in the insert, and then the insert is fixed to the bottom of the grinding wheel base. The height of the rough grinding wheel block is controlled at 4.5mm-5.5mm;

[0015] Preparation and installation of micro extrusion blocks: rubber or high molecular polymer materials are mixed with evenly distributed cemented carbide particles, and the micro extrusion blocks are prepared by compression molding. When installing, the micro extrusion blocks are first embedded in the inserts, and then the inserts are fixed to the bottom of the grinding wheel base. The height of the micro extrusion blocks is controlled at 5.5mm-6.5mm;

[0016] Preparation and installation of polishing wheel blocks: Diamond micropowder with a particle size range of 2000-5000 mesh is evenly mixed with a binder, and the polishing wheel block is prepared by electroplating process. During installation, the polishing wheel block is first embedded in the insert, and then the insert is fixed to the bottom of the grinding wheel base. The height of the polishing wheel block is controlled at 5.5mm-6.5mm.

[0017] A method for using a composite processing grinding wheel for post-processing of a friction stir weld comprises the following steps:

[0018] Install the composite machining grinding wheel on the spindle of the machining center;

[0019] Clamping the friction stir welding weld workpiece to be processed on the workbench of the machining center;

[0020] When the equipment runs stably, the worktable drives the workpiece to slowly approach the composite grinding wheel. The workpiece first contacts the rough grinding wheel block, which cuts the flash and obvious fish scale patterns of the weld.

[0021] As the worktable moves forward, the workpiece contacts the micro-extrusion block, which uses its own elastic deformation to apply continuous and uniform extrusion force to the surface that has just been roughly ground, so that the deformation of the metal on the weld surface is between plastic deformation and elastic deformation, effectively improving the surface hardness and residual compressive stress, and achieving surface strengthening;

[0022] As the workbench moves further forward, the workpiece comes into contact with the polishing wheel block, which finely grinds the micro-extruded surface, accurately removes the tiny marks produced during the micro-extrusion process, and achieves high-precision surface finishing.

[0023] The present invention provides a composite grinding wheel for post-processing of a friction stir weld and a preparation and use method thereof, which has the following beneficial effects:

[0024] 1. The composite grinding wheel of the present invention can complete the three processes of rough grinding, micro-extrusion and light grinding in sequence in one clamping and one processing process. Compared with the traditional multi-equipment and multi-process processing method, it greatly shortens the processing time and improves the processing efficiency. At the same time, it also reduces the process error caused by multiple clamping and positioning.

[0025] 2. The composite processing grinding wheel of the present invention fixes a rough grinding wheel block, a micro-extrusion block and a polishing wheel block at the bottom of the grinding wheel base. The rough grinding wheel block is used to cut the flash and obvious fish scale patterns of the weld, providing a good foundation for subsequent processing. The micro-extrusion block applies a continuous and uniform extrusion force to the rough-ground surface, thereby improving the surface hardness and residual compressive stress, and enhancing the wear resistance and fatigue resistance of the surface. The polishing wheel block is used to finely grind the micro-extruded surface to achieve high-precision surface finishing, thereby significantly improving the surface quality and mechanical properties of the stir friction welding weld as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the composite machining grinding wheel of the present invention;

[0027] Figure 2 It is a schematic diagram of the positions of the rough grinding wheel block, the micro extrusion block and the light grinding wheel block of the present invention;

[0028] Figure 3 It is a schematic diagram of the connection between the rough grinding wheel block, the micro extrusion block and the polishing wheel block and the insert of the present invention;

[0029] Figure 4 It is a highly schematic diagram of the rough grinding wheel block, the micro extrusion block and the light grinding wheel block of the present invention.

[0030] In the figure: 1, grinding wheel base; 11, mounting plate; 12, mounting column; 101, cavity; 102, mounting hole; 2, rough grinding wheel block; 4, micro extrusion block; 3, smooth grinding wheel block; 5, bolt; 6, insert. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention.

[0032] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than 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.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Example

[0036] Reference Figure 1-2A composite machining grinding wheel for post-processing of stir friction welds comprises a grinding wheel base 1, a rough grinding wheel block 2, a micro-extrusion block 4 and a smooth grinding wheel block 3 are fixed to the bottom of the grinding wheel base 1, the rough grinding wheel block 2, the micro-extrusion block 4 and the smooth grinding wheel block 3 are located at different diameters, wherein the rough grinding wheel block 2 is located at the outermost side, the smooth grinding wheel block 3 is located at the innermost side, the micro-extrusion block 4 is between the rough grinding wheel block 2 and the smooth grinding wheel block 3, the smooth grinding wheel block 3 is flush with the micro-extrusion block 4, and is higher than the rough grinding wheel block 2.

[0037] Preferably, the grinding wheel base 1 is made of a high-strength and high-toughness metal material, the coarse grinding wheel block 2 is made of a mixture of larger abrasive particles and a binder, the micro-extrusion block 4 is made of a material with elastic and plastic deformation capabilities, and tiny hard particles are evenly distributed therein, and the smooth grinding wheel block 3 is made of extremely fine abrasive particles and a binder.

[0038] The present invention also provides a method for preparing a composite machining grinding wheel for post-processing of a friction stir weld, comprising the following steps:

[0039] The grinding wheel substrate 1 is made of titanium alloy material and processed into the required shape and size by mechanical processing;

[0040] Preparation and installation of the rough grinding wheel block 2: Silicon carbide or corundum abrasive particles with a particle size range of 60-120 meshes are mixed evenly with a binder, and the rough grinding wheel block 2 is prepared by a hot pressing molding process. When installing, the rough grinding wheel block 2 is first embedded in the insert 6, and then the insert 6 is fixed to the bottom of the grinding wheel base 1. The height of the rough grinding wheel block 2 is controlled to be 4.5mm-5.5mm;

[0041] Preparation and installation of the micro-extrusion block 4: a rubber or high molecular polymer material is mixed with uniformly distributed hard alloy particles, and the micro-extrusion block 4 is prepared by a compression molding process. When installing, the micro-extrusion block 4 is first embedded in the insert 6, and then the insert 6 is fixed to the bottom of the grinding wheel base 1. The height of the micro-extrusion block 4 is controlled to be 5.5 mm-6.5 mm;

[0042] Preparation and installation of the polishing grinding wheel block 3: Diamond micropowder with a particle size range of 2000-5000 mesh is evenly mixed with a binder, and the polishing grinding wheel block 3 is prepared by an electroplating process. During installation, the polishing grinding wheel block 3 is first embedded in the insert 6, and then the insert 6 is fixed to the bottom of the grinding wheel base 1. The height of the polishing grinding wheel block 3 is controlled at 5.5mm-6.5mm.

[0043] The present invention also provides a method for using a composite processing grinding wheel for post-processing of a friction stir weld, comprising the following steps:

[0044] Install the composite machining grinding wheel on the spindle of the machining center;

[0045] Clamping the friction stir welding weld workpiece to be processed on the workbench of the machining center;

[0046] When the equipment runs stably, the worktable drives the workpiece to slowly approach the composite processing grinding wheel, and the workpiece first contacts the rough grinding wheel block 2, which cuts the flash and obvious fish scales of the weld. Preferably, during rough grinding, a larger feed rate is used. The rough grinding wheel block 2 can quickly remove a large amount of excess material in a short time by virtue of large-grained silicon carbide or corundum abrasive particles and a higher linear speed, so as to achieve the preliminary flattening of the weld surface. The rough grinding cutting speed is fast, and it is only for cutting the flash and obvious fish scales of the weld. Therefore, the height of the rough grinding wheel block 2 needs to be lower than that of the micro-extrusion block 4 and the light grinding wheel block 3 to avoid excessive cutting of the workpiece.

[0047] As the worktable moves forward, the workpiece contacts the micro-extrusion block 4, which uses its own elastic deformation (and has uniformly distributed cemented carbide particles inside) to apply continuous and uniform extrusion force to the rough-ground surface, so that the deformation of the metal on the weld surface is between plastic deformation and elastic deformation, thereby improving the surface hardness and residual compressive stress and achieving surface strengthening; preferably, a relatively small feed rate is used during micro-extrusion;

[0048] As the workbench moves forward further, the workpiece contacts the polishing wheel block 3, and the polishing wheel block 3 finely grinds the micro-extruded surface, accurately removes the tiny traces produced during the micro-extrusion process, and achieves high-precision surface finishing; preferably, during polishing, an extremely fine feed amount is used.

[0049] The composite grinding wheel of the present invention can complete the three processes of rough grinding, micro-extrusion and light grinding in sequence during one clamping and one processing process. Compared with the traditional multi-equipment and multi-process processing method, it greatly shortens the processing time, improves the processing efficiency, and also reduces the process errors caused by multiple clamping and positioning.

[0050] The composite processing grinding wheel of the present invention fixes a rough grinding wheel block 2, a micro-extrusion block 4 and a smooth grinding wheel block 3 at the bottom of a grinding wheel base 1. The rough grinding wheel block 2 is used to cut the flash and obvious fish scale patterns of the weld, providing a good foundation for subsequent processing. The micro-extrusion block 4 applies a continuous and uniform extrusion force to the rough-ground surface, thereby improving the surface hardness and residual compressive stress, and enhancing the wear resistance and fatigue resistance of the surface. The smooth grinding wheel block 3 is used to finely grind the micro-extruded surface to achieve high-precision surface finishing, thereby significantly improving the surface quality and mechanical properties of the stir friction welding weld as a whole.

[0051] In a specific embodiment, the grinding wheel base 1 has a cavity 101 in the middle, which can form a laser transmission channel, so that the laser can act directly on the grinding area to meet the needs of specific processing scenarios.

[0052] In a specific embodiment, the grinding wheel base 1 includes a mounting plate 11 and a mounting column 12, and the mounting column 12 is coaxially fixed at the bottom of the mounting plate 11. The mounting plate 11 has a plurality of mounting holes 102, and the mounting holes 102 can be used to facilitate the connection between the grinding wheel base 1 and the spindle of the machining center. The rough grinding wheel block 2, the micro-extrusion block 4 and the polishing wheel block 3 are fixed at the bottom of the mounting column 12.

[0053] In a specific embodiment, a specific installation structure of a rough grinding wheel block 2, a micro extrusion block 4 and a smooth grinding wheel block 3 is provided, wherein three first grooves are provided at the bottom of the grinding wheel base 1, and inserts 6 are detachably installed in the three first grooves, and the inserts 6 can be connected to the grinding wheel base 1 by bolts 5, and second grooves are provided at the bottoms of the three inserts 6, respectively, and the rough grinding wheel block 2, the micro extrusion block 4 and the smooth grinding wheel block 3 are fixedly embedded in the second grooves of the three inserts 6. By setting the detachable installation inserts 6, the positioning accuracy and structural strength of the rough grinding wheel block 2, the micro extrusion block 4 and the smooth grinding wheel block 3 can be improved, and they can be easily replaced.

[0054] In a specific embodiment, the rough grinding wheel block 2, the micro extrusion block 4 and the light grinding wheel block 3 are in the shape of fan rings.

[0055] In a specific embodiment, the bottom of the micro-extrusion block 4 is arc-shaped, and the height increases from the inside to the outside, which helps to better contact the weld surface.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite grinding wheel for post-processing of friction stir welds, characterized in that: The invention comprises a grinding wheel base, a rough grinding wheel block, a micro-extrusion block and a light grinding wheel block are fixed at the bottom of the grinding wheel base, the rough grinding wheel block, the micro-extrusion block and the light grinding wheel block are located at different diameters, wherein the rough grinding wheel block is located at the outermost side, the light grinding wheel block is located at the innermost side, the micro-extrusion block is between the rough grinding wheel block and the light grinding wheel block, and the light grinding wheel block is flush with the micro-extrusion block and is higher than the rough grinding wheel block.

2. The composite grinding wheel for post-processing of friction stir welds according to claim 1, characterized in that: The middle part of the grinding wheel base body is provided with a cavity.

3. The composite grinding wheel for post-processing of friction stir welds according to claim 1, characterized in that: The grinding wheel base comprises a mounting plate and a mounting column, wherein the mounting column is coaxially fixed to the bottom of the mounting plate, the mounting plate has a plurality of mounting holes, and the rough grinding wheel block, the micro extrusion block and the smooth grinding wheel block are fixed to the bottom of the mounting column.

4. The composite grinding wheel for post-processing of friction stir welds according to claim 1, characterized in that: Three first grooves are provided at the bottom of the grinding wheel base, and inserts are detachably installed in the three first grooves. Second grooves are provided at the bottoms of the three inserts, and the rough grinding wheel block, micro-extrusion block and polishing grinding wheel block are fixedly embedded in the second grooves of the three inserts, respectively.

5. The composite grinding wheel for post-processing of friction stir welds according to claim 1, characterized in that: The rough grinding wheel block, the micro-extrusion block and the light grinding wheel block are in the shape of fan rings.

6. The composite grinding wheel for post-processing of friction stir welds according to claim 1, characterized in that: The bottom of the micro-extrusion block is arc-shaped, and the height increases from the inside to the outside.

7. A method for preparing a composite grinding wheel for post-processing of friction stir welds, characterized in that: The following steps are involved: Production of grinding wheel matrix: titanium alloy material is used and processed into the required shape and size through mechanical processing; Preparation and installation of rough grinding wheel block: Silicon carbide or corundum abrasive particles with a particle size range of 60-120 mesh are mixed evenly with a binder, and the rough grinding wheel block is prepared by hot pressing molding process. When installing, the rough grinding wheel block is first embedded in the insert, and then the insert is fixed to the bottom of the grinding wheel base. The height of the rough grinding wheel block is controlled at 4.5mm-5.5mm; Preparation and installation of micro extrusion blocks: rubber or high molecular polymer materials are mixed with evenly distributed cemented carbide particles, and the micro extrusion blocks are prepared by compression molding. When installing, the micro extrusion blocks are first embedded in the inserts, and then the inserts are fixed to the bottom of the grinding wheel base. The height of the micro extrusion blocks is controlled at 5.5mm-6.5mm; Preparation and installation of polishing wheel blocks: Diamond micropowder with a particle size range of 2000-5000 mesh is evenly mixed with a binder, and the polishing wheel block is prepared by electroplating process. During installation, the polishing wheel block is first embedded in the insert, and then the insert is fixed to the bottom of the grinding wheel base. The height of the polishing wheel block is controlled at 5.5mm-6.5mm.

8. A method for using a composite grinding wheel for post-processing of a friction stir weld, characterized in that: The following steps are involved: Install the composite machining grinding wheel on the spindle of the machining center; Clamping the friction stir welding weld workpiece to be processed on the workbench of the machining center; When the equipment runs stably, the worktable drives the workpiece to slowly approach the composite grinding wheel. The workpiece first contacts the rough grinding wheel block, which cuts the flash and obvious fish scale patterns of the weld. As the worktable moves forward, the workpiece contacts the micro-extrusion block, which uses its own elastic deformation to apply continuous and uniform extrusion force to the surface that has just been roughly ground, so that the deformation of the metal on the weld surface is between plastic deformation and elastic deformation, effectively improving the surface hardness and residual compressive stress, and achieving surface strengthening; As the workbench moves further forward, the workpiece comes into contact with the polishing wheel block, which finely grinds the micro-extruded surface, accurately removes the tiny marks produced during the micro-extrusion process, and achieves high-precision surface finishing.

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