A composite grinding wheel for post-processing of friction stir welds and its preparation and use method

Abstract

The present invention relates to a composite processing grinding wheel for post-processing of stir friction welds, comprising a grinding wheel base, a rough grinding wheel block, a micro-extrusion block and a polishing grinding wheel block fixed to the bottom of the grinding wheel base, wherein the rough grinding wheel block, the micro-extrusion block and the polishing grinding wheel block are located at different diameters, wherein the rough grinding wheel block is located at the outermost side, the polishing grinding wheel block is located at the innermost side, the micro-extrusion block is between the rough grinding wheel block and the polishing grinding wheel block, and the polishing grinding wheel block is flush with the micro-extrusion block and higher than the rough grinding wheel block. The composite processing grinding wheel of the present invention can sequentially complete the three processes of rough grinding, micro-extrusion and polishing in one clamping and one processing process. Compared with the traditional multi-equipment, multi-process processing method, the processing time is greatly shortened, the processing efficiency is improved, and the process error caused by multiple clamping and positioning is also reduced. In addition, the surface quality and mechanical properties of the stir friction welding weld are significantly improved as a whole.

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 friction stir welds and a preparation and use method thereof. Background Art

[0002] High-strength aluminum alloys, due to their high strength-to-weight ratio, are widely used in aerospace, automotive, and other fields. Friction stir welding, as an efficient and high-quality solid-state joining method, is increasingly being used in this application. However, friction stir welds often exhibit defects such as flash and fish scales, and the mechanical properties of the weld surface need to be further improved. Therefore, post-processing of the weld is necessary.

[0003] Traditional post-processing methods often require the coordination of multiple equipment and multiple processes. For example, first use cutting equipment to remove burrs, 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 it is impossible to achieve integrated and efficient processing. Therefore, it is of great practical significance to develop an integrated device or tool that can simultaneously achieve rough grinding of burrs 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 friction stir welds comprises a grinding wheel base, wherein 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, wherein 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 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 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, 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.

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

[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 friction stir welds comprises the following steps:

[0013] Production of grinding wheel base: Made of titanium alloy material, 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 grit range of 60-120 mesh are mixed evenly with a binder and prepared through a hot pressing process. During installation, 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: Use rubber or high molecular polymer materials mixed with evenly distributed cemented carbide particles, and prepare micro-extrusion blocks through a compression molding process. When installing, first embed the micro-extrusion blocks in the inserts, and then fix the inserts 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 blocks are prepared through an electroplating process. During installation, the polishing wheel blocks are 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 blocks is controlled at 5.5mm-6.5mm.

[0017] A method for using a composite grinding wheel for post-processing of friction stir welds, comprising 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 is running stably, the workbench drives the workpiece to slowly approach the composite processing grinding wheel. The workpiece first contacts the coarse grinding wheel block, which cuts the flash and obvious fish scale pattern of the weld.

[0021] As the worktable moves forward, the workpiece comes into contact with the micro-extrusion block. The micro-extrusion block uses its own elastic deformation to apply continuous and uniform extrusion force to the surface that has just been rough-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 forward, the workpiece comes into contact with the polishing wheel block, which finely grinds the micro-extruded surface, accurately removing the tiny marks produced during the micro-extrusion process and achieving high-precision surface finishing.

[0023] The present invention provides a composite grinding wheel for post-processing of friction stir welds 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 polishing 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 errors 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 grinding wheel block at the bottom of the grinding wheel base. The rough grinding wheel block is used to cut the burrs 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 grinding 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 structural schematic diagram of the composite processing grinding wheel of the present invention;

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

[0028] Figure 3 Schematic diagram of the connection between the rough grinding wheel block, the micro-extrusion block and the polishing grinding wheel block and the insert of the present invention;

[0029] Figure 4 It is a highly schematic diagram of the rough grinding wheel segment, micro extrusion segment and smooth grinding wheel segment 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. Polishing 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 following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts 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 to indicate directions or positional relationships based on the directions 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 device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said 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 an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0035] Example

[0036] Reference Figure 1-2A composite processing grinding wheel for post-processing of stir friction welds includes 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, 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 grinding wheel for post-processing of friction stir welds, comprising the following steps:

[0039] Production of the grinding wheel base 1: using titanium alloy material, and processing it into the required shape and size through mechanical processing;

[0040] Preparation and installation of the rough grinding wheel block 2: Silicon carbide or corundum abrasive particles with a grit range of 60-120 mesh are mixed evenly with a binder and prepared by a hot pressing process. During installation, 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 at 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 cemented carbide particles and prepared by a compression molding process. During installation, 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 5.5mm-6.5mm;

[0042] Preparation and installation of the polishing wheel segment 3: Diamond micropowder with a particle size range of 2000-5000 mesh is evenly mixed with a binder, and the polishing wheel segment 3 is prepared by an electroplating process. During installation, the polishing wheel segment 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 wheel segment 3 is controlled at 5.5mm-6.5mm.

[0043] The present invention also provides a method for using a composite 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 is running 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 scale pattern of the weld. Preferably, a larger feed rate is used during rough grinding. The rough grinding wheel block 2 can quickly remove a large amount of excess material in a short time by virtue of the large-grained silicon carbide or corundum abrasive particles and the high linear speed, thereby achieving the preliminary flatness of the weld surface. The rough grinding cutting speed is fast, and it is only for cutting the flash and obvious fish scale pattern 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 advances, the workpiece comes into contact with the micro-extrusion block 4. The micro-extrusion block 4 uses its own elastic deformation (and has uniformly distributed 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 increasing the surface hardness and residual compressive stress, thereby achieving surface strengthening. Preferably, a relatively small feed rate is used during micro-extrusion.

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

[0049] The composite grinding wheel of the present invention can complete the three processes of rough grinding, micro-extrusion and polishing 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 is fixed with a rough grinding wheel block 2, a micro-extrusion block 4 and a smooth grinding wheel block 3 at the bottom of the grinding wheel base 1. The rough grinding wheel block 2 is used to cut the burrs 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 middle portion of the grinding wheel base 1 has a cavity 101, which can form a laser transmission channel, allowing the laser to 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, the mounting column 12 is coaxially fixed to the bottom of the mounting plate 11, and the mounting plate 11 has a plurality of mounting holes 102, through which the grinding wheel base 1 can be conveniently connected to the spindle of the machining center, and the rough grinding wheel block 2, micro-extrusion block 4 and polishing grinding wheel block 3 are fixed to the bottom of the mounting column 12.

[0053] In a specific embodiment, a specific mounting structure for a rough grinding wheel block 2, a micro-extrusion block 4, and a smooth grinding wheel block 3 is provided. The bottom of the grinding wheel base 1 is provided with three first grooves, and inserts 6 are removably installed in each of the three first grooves. Specifically, the inserts 6 are connected to the grinding wheel base 1 via bolts 5. The bottoms of the three inserts 6 are respectively provided with second grooves, and the rough grinding wheel block 2, the micro-extrusion block 4, and the smooth grinding wheel block 3 are respectively fixedly embedded in the second grooves of the three inserts 6. The provision of the removable inserts 6 can improve 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, while facilitating their replacement.

[0054] In a specific embodiment, the rough grinding wheel block 2, the micro-extrusion block 4 and the polishing grinding wheel block 3 are fan-shaped.

[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 they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. 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 various embodiments of the present invention.

Claims

1. A composite grinding wheel for post-processing of friction stir welds, characterized by: The invention comprises a grinding wheel base, wherein 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, wherein 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.

2. The composite grinding wheel for post-processing of friction stir welds according to claim 1, characterized in that: The middle 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 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. The rough grinding wheel block, micro-extrusion block and polishing 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.

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 smooth grinding wheel block are in a fan ring shape.

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 its height increases from the inside to the outside.

7. A method for preparing a composite grinding wheel for post-processing of friction stir welds according to any one of claims 1 to 6, characterized in that: The following steps are involved: Production of grinding wheel base: Made of titanium alloy material, 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 grit range of 60-120 mesh are mixed evenly with a binder and prepared through a hot pressing process. During installation, 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: Use rubber or high molecular polymer materials mixed with evenly distributed cemented carbide particles, and prepare micro-extrusion blocks through a compression molding process. When installing, first embed the micro-extrusion blocks in the inserts, and then fix the inserts 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 blocks are prepared through an electroplating process. During installation, the polishing wheel blocks are 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 blocks is controlled at 5.5mm-6.5mm.

8. A method for using the composite grinding wheel for post-processing of friction stir welds according to any one of claims 1 to 6, 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 is running stably, the workbench drives the workpiece to slowly approach the composite processing grinding wheel. The workpiece first contacts the coarse grinding wheel block, which cuts the flash and obvious fish scale pattern of the weld. As the worktable moves forward, the workpiece comes into contact with the micro-extrusion block. The micro-extrusion block uses its own elastic deformation to apply continuous and uniform extrusion force to the surface that has just been rough-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 forward, the workpiece comes into contact with the polishing wheel block, which finely grinds the micro-extruded surface, accurately removing the tiny marks produced during the micro-extrusion process and achieving high-precision surface finishing.

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