A laser vibration-assisted milling device and method

Abstract

The application relates to a laser vibration auxiliary milling machining device and method, which is used for laser, vibration and milling machining on a workpiece to-be-machined area. The machining device comprises a vibration module, a milling module and a laser auxiliary module. The milling module comprises a milling cutter located above the workpiece to-be-machined area. The milling cutter comprises a cutter handle part connected with a main shaft of a machine tool and a cutting part arranged at the end of the cutter handle part. The cutting part comprises a plurality of peripheral teeth spirally distributed in a radial direction and end teeth arranged at the end of the peripheral teeth. The end teeth comprise a rake face, a main end edge, a first main relief face, a second main relief face and a secondary relief face. The rake face and the first main relief face intersect to form the main end edge. The included angle between the first main relief face and a cutting plane is an end edge first relief angle, which is 0 DEG. The second main relief face is an arc surface and is tangentially connected with the first main relief face. Compared with the prior art, the application can reduce residual tensile stress on the surface of the workpiece, improve the surface quality and enhance the fatigue strength of the part.

Description

Technical Field

[0001] This invention relates to the field of milling technology, and in particular to a laser vibration-assisted milling apparatus and method. Background Technology

[0002] In laser-assisted milling, the material surface temperature rises rapidly due to the localized heating effect of the laser beam, followed by rapid cooling after processing. This rapid heating and cooling process generates significant thermal stress on the material surface. Because of the large temperature gradient between the material's interior and surface, the surface cools faster than the interior, leading to uneven surface shrinkage and the formation of residual tensile stress. Processing parameters such as laser power, energy density, processing speed, and cooling effect all affect the magnitude and distribution of thermal stress. Excessively high laser power or energy density generates more tensile stress on the material surface, while excessively fast processing speed or uneven cooling exacerbates the concentration of thermal stress. The combined effect of these factors results in tensile stress on the material surface after laser processing, significantly reducing the material's fatigue strength.

[0003] Vibration-assisted machining (VAM) transforms surface stress into compressive stress, primarily because vibration alters the distribution of force and heat during the cutting process, thus affecting the surface stress state. In VAM, the cutting tool vibrates at high frequency along the cutting direction, changing the contact pattern between the tool and workpiece and the distribution of cutting forces. Specifically, tool vibration causes the cutting force to change periodically over short periods, subjecting the workpiece surface to repeated compression and tension. Due to the high frequency of vibration, this periodic force induces plastic deformation on the workpiece surface, forming a work-hardened layer. Simultaneously, tool vibration also makes the heat distribution during cutting more uniform, reducing localized overheating and thus mitigating the impact of thermal stress on the surface stress state. These factors combined result in compressive stress on the workpiece surface after machining, rather than the traditional tensile stress. This compressive stress improves the fatigue strength of the material because it can offset some of the working stress, thereby reducing the likelihood of fatigue crack initiation and propagation.

[0004] However, vibration-assisted machining may introduce additional machining defects. For example, in some cases, vibration may cause microstructural damage such as microcracks, particle breakage, or matrix deformation on the machined surface. Patent publication number CN108526912A discloses a laser-assisted horizontal three-dimensional ultrasonic elliptical vibration milling machine and its working method. This machine includes an air-floating platform, an XYZ moving assembly, a micro-motion unit, a workpiece fixture, a laser-assisted machining device, and an ultrasonic electric spindle assembly. During machining, the tool's flank face does not contact the machined surface, reducing surface damage and secondary wear. However, this design prevents the effective application of vibration-assisted machining's shot-peening-like strengthening effect during vibration, making it difficult to achieve the desired residual compressive stress strengthening effect on the workpiece surface. Furthermore, the large amount of heat generated by the laser cannot be dissipated quickly, significantly impacting the tool. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art by providing a laser vibration-assisted milling device and method, which can reduce residual tensile stress on the workpiece surface, improve surface quality, and enhance the fatigue strength of parts while improving the machinability of difficult-to-machine materials and the material removal efficiency.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] In one aspect, the present invention provides a laser vibration-assisted milling processing device for performing laser, vibration, and milling processing on the area to be processed of a workpiece, the processing device comprising:

[0008] A vibration module for placing and fixing the workpiece and vibrating in the Z-axis;

[0009] A milling module for milling a workpiece includes a milling cutter located above the area to be machined on the workpiece, and a machine tool for clamping the milling cutter and driving it to move and mill. The milling cutter has a milling cutter axis, a cutting plane, a base plane, and an orthogonal plane.

[0010] And a laser-assisted module disposed above the workpiece and used to laser heat and soften the area of ​​the workpiece to be processed;

[0011] The milling cutter includes a shank portion connected to the spindle of the machine tool and a cutting portion disposed at the end of the shank portion. The cutting portion includes a plurality of radially spirally distributed teeth and end teeth disposed at the end of the radially distributed teeth. The end teeth include a rake face, a main end cutting edge, a first main flank face, a second main flank face, and a secondary flank face. The rake face and the first main flank face intersect to form the main end cutting edge.

[0012] The angle between the first main relief face and the cutting plane is the first relief angle of the end edge, which is 0°. The second main relief face is an arc-shaped surface and is tangentially connected to the first main relief face.

[0013] Furthermore, the base plane is a plane that passes through a selected point on the main end edge, is perpendicular to the main motion direction, and passes through the axis of the milling cutter.

[0014] Furthermore, the cutting plane is a plane passing through a selected point on the main end edge, tangent to the main end edge, and perpendicular to the base plane; it is the plane formed by the main end edge and the cutting speed direction. In simpler terms, the cutting plane is the plane formed by the main end edge extending in a direction perpendicular to the base plane. That is to say, the cutting plane is the surface that needs to be machined with the milling cutter, and the base plane is the reference surface of the workpiece being machined.

[0015] Furthermore, the orthogonal plane is a plane that passes through a selected point on the main peripheral cutting edge and is perpendicular to both the base plane and the cutting plane. The cutting plane, the base plane, and the orthogonal plane are all perpendicular to each other. The base plane is the center, and both the cutting plane and the orthogonal plane originate from the base plane; without the base plane, it is impossible to accurately construct the cutting plane and the orthogonal plane.

[0016] Furthermore, the intersection point of the main peripheral cutting edge and the main end cutting edge is the tool tip point; the selected point of the main end cutting edge through which the base plane passes is the tool tip point; and the selected point of the main end cutting edge through which the cutting plane passes is the tool tip point.

[0017] Furthermore, the angle between the second main relief face and the cutting plane is the second relief angle of the end edge, which is 0°~45°;

[0018] The second rear angle of the end edge at the point where the second main rear face is tangent to the first main rear face is 0°, and the second rear angle of the end edge gradually increases along the first main rear face away from the end tooth, with a maximum angle of 45°.

[0019] Furthermore, the second clearance angle of the end cutting edge is 0°~20°, the second clearance angle of the end cutting edge at the point where the second main clearance face is tangent to the first main clearance face is 0°, and the second clearance angle of the end cutting edge gradually increases along the distance from the first main clearance face of the end tooth, with a maximum angle of 20°.

[0020] Furthermore, the width of the first rear angle of the end blade is 1~2mm, and the width of the second rear angle of the end blade is 0.5~1.5mm.

[0021] Furthermore, within the orthogonal plane, the angle between the rake face and the base plane is the end-edge rake angle, which is 10°~50°, preferably 20°~40°, and more preferably 30°.

[0022] Furthermore, the angle between the main peripheral cutting edge of the rake face and the base surface is the end-edge rake angle.

[0023] Furthermore, adjacent rake faces and secondary flank faces are connected by grooves.

[0024] Furthermore, a groove angle is formed between adjacent end blades, and each groove angle has the same angle of 90°.

[0025] Furthermore, the main end blade is hook-shaped, allowing chips to flow out along the groove; the main peripheral blade is spiral-shaped.

[0026] Furthermore, the first main back face has an irregular shape with a hook-shaped tip;

[0027] The second main flank face is triangular, which is used to reduce stress concentration on the flank face during high-frequency vibration.

[0028] Furthermore, the angle between the first main back face and the base surface is the first cutting edge angle of the end edge, which is 90°;

[0029] The angle between the second main back face and the base surface is the second cutting edge angle of the end edge, which is 45°~90°, preferably 70°~90°;

[0030] The angle between the secondary flank face and the cutting plane is the secondary flank face angle, which is 60°~90°, preferably 60°~85°, and more preferably 75°.

[0031] Furthermore, the peripheral teeth include a rake face, a main peripheral cutting edge, a third main flank face, a fourth main flank face, and a secondary flank face, wherein the rake face and the third main flank face intersect to form the main peripheral cutting edge;

[0032] The angle between the third main back face and the orthogonal plane is the first back angle of the peripheral cutting edge, which is 10°~15°;

[0033] The angle between the fourth main back face and the orthogonal plane is the second back angle of the peripheral cutting edge, which is 20°~25°;

[0034] Located within the cutting plane, the angle between the rake face and the base plane is the circumferential rake angle, which is 30°~60°, preferably 45°.

[0035] Furthermore, the angle between the main end edge of the rake face and the base surface is the circumferential rake angle.

[0036] Furthermore, the width of the first clearance angle of the circumferential cutting edge is 0.4~0.8mm;

[0037] The width of the second rear angle of the circumferential blade is 0.2~0.8mm.

[0038] Furthermore, the laser-assisted module includes:

[0039] A laser emitter disposed on one side of the milling module and used to emit a laser beam toward the area to be processed of the workpiece.

[0040] An optical reflective assembly positioned along the laser beam path and used to diffuse the laser beam so that it illuminates the area to be processed on the workpiece.

[0041] Furthermore, the optical reflection assembly includes a laser reflector for receiving the laser beam emitted by the laser emitter, and a convex lens for receiving the laser beam from the laser reflector and focusing it on the processing area of ​​the workpiece.

[0042] Furthermore, the vibration module includes:

[0043] Work platform;

[0044] A clamping and positioning component disposed on the surface of the work platform and used to fix the workpiece;

[0045] And a vibration generator disposed at the lower part of the working platform and used to cause the working platform to vibrate in the Z direction.

[0046] Furthermore, the clamping and positioning element includes a bolt and nut combination structure.

[0047] Furthermore, the vibration generator employs conventional technology in the field, and its vibration generation methods include ultrasonic vibration, electromagnetic vibration, and mechanical vibration.

[0048] Furthermore, the vibration generator also has X-axis and Y-axis vibration.

[0049] Furthermore, the vibration module is mounted on the moving module, which includes X-axis, Y-axis, and Z-axis guide rails and corresponding drive devices, as well as sliders that can move along the X-axis, Y-axis, and Z-axis. It adopts conventional methods in the art and is only used to enable the workpiece to move in the X-axis, Y-axis, and Z-axis, so it will not be described in detail.

[0050] Furthermore, the machine tool spindle is provided with a spindle taper hole for clamping the tool holder.

[0051] Furthermore, the machine tool spindle is connected to a motor to provide rotation of the machine tool spindle.

[0052] Furthermore, the machine tool spindle can move in the X, Y, and Z directions, thereby driving the milling cutter to move in the X, Y, and Z directions, thus positioning the milling cutter on the workpiece surface.

[0053] Furthermore, the laser-assisted module is connected via a fixture, which is a universal table, enabling the laser-assisted module to be positioned and fixed at any processing point on the workpiece.

[0054] In another aspect, the present invention also provides a laser vibration-assisted milling method, which is implemented using the aforementioned processing device and includes the following steps:

[0055] S1. Install the workpiece on the vibration module and start the vibration module to make the workpiece vibrate along the Z direction;

[0056] S2. Activate the laser-assisted module to perform laser heating and softening on the workpiece's processing area;

[0057] S3. Milling is performed on the area softened by laser heating of the milling cutter in the milling module, so that the milling cutter intermittently contacts the area to be processed of the workpiece. When they contact each other, the first main flank face of the milling cutter is in complete contact with the area to be processed of the workpiece.

[0058] S4. Close all modules, remove the workpiece, clean it, and obtain the finished product.

[0059] Compared with the prior art, the present invention has the following advantages:

[0060] (1) This invention utilizes the high energy density of a laser beam to locally heat the surface of the workpiece, softening the material in the workpiece's processing area and reducing its hardness and brittleness, thereby reducing the cutting force required during the cutting process. Simultaneously, the vibration module induces high-frequency vibration in the Z-direction of the workpiece through high-frequency micro-vibration, making the contact between the milling cutter and the workpiece intermittent, further reducing the cutting force and heat accumulation in the processing area, thus reducing milling cutter wear. Furthermore, this invention continuously applies high-frequency pressure to the processed surface and improves the material removal efficiency in the cutting area, thereby reducing surface roughness. The combined effect of laser heating and ultrasonic vibration optimizes the material's microstructure, reduces micro-defects, and improves the material's mechanical properties and corrosion resistance.

[0061] (2) In this invention, the first clearance angle of the end face of the milling cutter is designed to be 0 degrees so that the flank face of the milling cutter coincides with the cutting plane, allowing the flank face of the milling cutter to contact the machined surface and generate force, thereby reducing the residual tensile stress on the surface. The second clearance angle of the end face is 0°~20°. The flank face of the end tooth pair is an arc surface. The flank face of the end tooth pair is tangentially connected to the main flank face of the end tooth. At the tangent point, the second clearance angle of the end face is 0°, which can reduce the stress concentration on the flank face during high-frequency vibration and reduce the stress concentration caused by the relative vibration of the tool, thus reducing tool wear or breakage.

[0062] (3) During the machining process, the cutting tool of this invention undergoes axial high-frequency vibration relative to the workpiece surface due to the action of the ultrasonic vibration module, which generates shot peening on the machined surface and high-frequency pressure on the machined surface, transforming the residual stress on the material surface into residual compressive stress. The residual compressive stress will improve the fatigue strength of the part and extend its service life. Specifically, the milling cutter surface is regarded as a "shot," and the ultrasonic vibration causes the milling cutter surface to impact the workpiece area that has been softened by laser-assisted machining at an extremely high frequency. This impact is similar to the impact of the shot on the workpiece surface in traditional shot peening, which can introduce residual compressive stress on the workpiece surface. The residual compressive stress can effectively reduce the initiation and propagation of cracks, thereby significantly improving the fatigue strength and stress corrosion resistance of the workpiece surface.

[0063] (4) The present invention can improve the machinability and material removal efficiency of difficult-to-machine materials. The laser generates a uniform thermal field on the material being processed, which softens the material and reduces the cutting force during processing, thus reducing tool wear. Therefore, it is easier to process difficult-to-machine materials. At the same time, it can increase the cutting depth and feed rate of the tool. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the processing apparatus shown in Example 1;

[0065] Figure 2 This is a schematic diagram of the milling cutter shown in Example 1;

[0066] Figure 3 This is a schematic diagram showing the positions of the base plane, cutting plane, and orthogonal plane as shown in Example 1;

[0067] Figure 4 This is a schematic diagram of the cutting part of the milling cutter shown in Example 1;

[0068] Figure 5 This is a front view of the cutting part shown in Example 1;

[0069] Figure 6 This is a top view of the cutting section shown in Example 1;

[0070] Figure 7 This is a schematic diagram of the end tooth structure shown in Example 1;

[0071] Figure 8 This is a schematic diagram of the laser-assisted module shown in Example 1;

[0072] Figure 9 This is a schematic diagram of the vibration module shown in Example 1;

[0073] Figure 10 This is a schematic diagram of the milling module shown in Example 1;

[0074] Figure 11 The graph shows the test results of the cutting force as shown in Example 1 and Comparative Example 1;

[0075] Figure 12 The graph shows the test results of residual stress as shown in Example 1 and Comparative Example 1.

[0076] Explanation of markings in the diagram:

[0077] 1-Workpiece;

[0078] 2-Vibration module, 21-Working platform, 22-Vibration generator;

[0079] 3-Milling module, 31-Milling cutter, 311-Tool holder, 312-Cutting part, 3121-Main peripheral cutting edge, 3122-Main end cutting edge, 3123-Rake face, 3124-First main flank face, 3125-Second main flank face, 3126-Third main flank face, 3127-Fourth main flank face, 3128-Secondary flank face, 3129-Groove, 3130-Tool tip, 32-Machine tool, 321-Machine tool spindle, 3211-Spindle taper hole;

[0080] 4-Laser auxiliary module, 41-Laser emitter, 42-Optical reflection component, 421-Laser reflector, 422-Convex lens;

[0081] 5- Fixture;

[0082] 6-Moving module, 61-Slider;

[0083] a1 - First clearance angle of the end blade, a2 - Second clearance angle of the end blade, a3 - Front angle of the end blade, a4 - First cutting edge angle of the end blade, a6 - Angle between the secondary clearance face and the cutting edge, a7 - Groove angle;

[0084] b1 - First rear angle of the circumferential blade, b2 - Second rear angle of the circumferential blade, b3 - Front angle of the circumferential blade;

[0085] L1 - Width of the first rear angle of the end blade, L2 - Width of the second rear angle of the end blade;

[0086] l1 - width of the first rear corner of the circumferential blade, l2 - width of the second rear corner of the circumferential blade;

[0087] 0 - milling cutter axis, Ps - cutting plane, Pr - base plane, Po - orthogonal plane. Detailed Implementation

[0088] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments. In the following embodiments or examples, unless otherwise specified, the functional components or structures are conventional components or structures used in the art to achieve the corresponding functions.

[0089] It should be noted that in the description of this invention, the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0090] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" 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 an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0091] In one aspect, the present invention provides a laser vibration-assisted milling processing device for performing laser, vibration, and milling processing on the area to be processed of a workpiece 1, the processing device comprising:

[0092] Vibration module 2 for placing and fixing the workpiece 1 and vibrating in the Z-direction;

[0093] The milling module 3 for milling workpiece 1 includes a milling cutter 31 located above the area to be processed of workpiece 1 and a machine tool 32 for clamping the milling cutter 31 and driving it to move and mill. The milling cutter 31 has a milling cutter axis O, a cutting plane Ps, a base plane Pr, and an orthogonal plane Po.

[0094] And a laser-assisted module 4 disposed above the workpiece 1 and used to laser heat and soften the area of ​​the workpiece 1 to be processed;

[0095] The milling cutter 31 includes a shank portion 311 connected to the spindle of the machine tool 32 and a cutting portion 312 disposed at the end of the shank portion 311. The cutting portion 312 includes a plurality of radially spirally distributed teeth and end teeth disposed at the end of the radial teeth. The end teeth include a rake face 3123, a main end cutting edge 3122, a first main flank face 3124, a second main flank face 3125 and a secondary flank face 3128. The rake face 3123 and the first main flank face 3124 intersect to form the main end cutting edge 3122.

[0096] The angle between the first main relief face 3124 and the cutting plane Ps is the first relief angle a1 of the end edge, which is 0°. The second main relief face 3125 is an arc-shaped surface and is tangentially connected to the first main relief face 3124.

[0097] In some specific embodiments, the base plane Pr is a plane that passes through a selected point on the main end cutting edge 3122, is perpendicular to the main motion direction, and passes through the milling cutter axis 0.

[0098] In some specific embodiments, the cutting plane Ps is a plane passing through a selected point on the main end cutting edge 3122, tangent to the main end cutting edge 3122, and perpendicular to the base surface Pr; it is the plane formed by the main end cutting edge 3122 and the cutting speed direction. In simpler terms, the cutting plane Ps is the plane formed by the main end cutting edge 3122 extending in a direction perpendicular to the base surface Pr. That is, the cutting plane Ps is the surface to be machined by the milling cutter 31, and the base surface Pr is the reference surface of the workpiece 1 being machined.

[0099] In some specific embodiments, the orthogonal plane Po is a plane that passes through a selected point on the main peripheral cutting edge 3121 and is perpendicular to both the base plane Pr and the cutting plane Ps. The cutting plane Ps, the base plane Pr, and the orthogonal plane Po are all perpendicular to each other. The base plane Pr is the center, and both the cutting plane Ps and the orthogonal plane Po originate from the base plane Pr. Without the base plane Pr, it would be impossible to accurately construct the cutting plane Ps and the orthogonal plane Po.

[0100] In some specific embodiments, the intersection point of the main peripheral cutting edge 3121 and the main end cutting edge 3122 is the tool tip point 3130, the selected point of the main end cutting edge 3122 through which the base plane Pr passes is the tool tip point 3130, and the selected point of the main end cutting edge 3122 through which the cutting plane Ps passes is the tool tip point 3130.

[0101] In some specific embodiments, the angle between the second main relief face 3125 and the cutting plane Ps is the second relief angle a2 of the end edge, which is 0°~45°;

[0102] The second rear angle a2 of the end edge at the point where the second main rear cutting face 3125 is tangent to the first main rear cutting face 3124 is 0°, and the second rear angle a2 of the end edge gradually increases as it moves away from the first main rear cutting face 3124, with a maximum angle of 45°.

[0103] In some specific embodiments, the second clearance angle a2 of the end cutting edge is 0°~20°, the second clearance angle a2 of the end cutting edge at the point where the second main clearance face 3125 is tangent to the first main clearance face 3124 is 0°, and the second clearance angle a2 of the end cutting edge gradually increases away from the first main clearance face 3124, with a maximum angle of 20°.

[0104] In some specific embodiments, the width of the first rear angle of the end blade L1 is 1~2mm, and the width of the second rear angle of the end blade L2 is 0.5~1.5mm.

[0105] In some specific embodiments, the angle between the rake face 3123 and the base plane Pr located in the orthogonal plane Po is the end-edge rake angle a3, which is 10°~50°, preferably 20°~40°, and more preferably 30°.

[0106] In some specific embodiments, the angle between the main peripheral cutting edge 3121 of the rake face 3123 and the base surface Pr is the end cutting edge rake angle a3.

[0107] In some specific embodiments, two adjacent rake faces 3123 and secondary flank faces 3128 are connected by a groove 3129.

[0108] In some specific embodiments, a groove angle a7 is formed between adjacent end blades, and each groove angle a7 has the same angle of 90°.

[0109] In some specific embodiments, the main end blade 3122 is hook-shaped, which allows chips to flow out along the groove 3129; the main peripheral blade 3121 is spiral-shaped.

[0110] In some specific embodiments, the first main flank face 3124 is an irregular shape with a hook-shaped tip;

[0111] The second main flank face 3125 is triangular, which is used to reduce stress concentration on the flank face during high-frequency vibration.

[0112] In some specific embodiments, the angle between the first main back face 3124 and the base plane Pr is the first cutting edge angle a4, which is 90°.

[0113] The angle between the second main back face 3125 and the base surface Pr is the second cutting edge angle of the end edge, which is 45°~90°, preferably 70°~90°;

[0114] The angle between the secondary flank face 3128 and the cutting plane Ps is the secondary flank face angle a6, which is 60°~90°, preferably 60°~85°, and more preferably 75°.

[0115] In some specific embodiments, the peripheral teeth include a front cutting face 3123, a main peripheral cutting edge 3121, a third main flank cutting face 3126, a fourth main flank cutting face 3127, and a secondary flank cutting face 3128, wherein the front cutting face 3123 and the third main flank cutting face 3126 intersect to form the main peripheral cutting edge 3121.

[0116] The angle between the third main back face 3126 and the orthogonal plane M3 is the first back angle b1 of the peripheral cutting edge, which is 10°~15°;

[0117] The angle between the fourth main back face 3127 and the orthogonal plane M3 is the second back angle b2 of the peripheral cutting edge, which is 20°~25°;

[0118] Located within the cutting plane Ps, the angle between the rake face 3123 and the base plane M2 is the peripheral rake angle b3, which is 30°~60°, preferably 45°.

[0119] Furthermore, the angle between the main cutting edge 3122 of the rake face 3123 and the base surface M2 is the circumferential rake angle b3.

[0120] In some specific embodiments, the width l1 of the first rear angle of the circumferential cutting edge is 0.4~0.8mm;

[0121] The width l2 of the second rear angle of the circumferential blade is 0.2~0.8mm.

[0122] Furthermore, the laser-assisted module 4 includes:

[0123] A laser emitter 41 is disposed on one side of the milling module 3 and is used to emit a laser beam toward the area to be processed of the workpiece 1;

[0124] An optical reflective assembly 42 is disposed on the laser beam path and used to diffuse the laser beam so that it illuminates the area to be processed on the workpiece.

[0125] In some specific embodiments, the optical reflection assembly 42 includes a laser reflector 421 for receiving the laser beam emitted by the laser emitter 41, and a convex lens 422 for receiving the laser beam from the laser reflector 421 and focusing it on the processing area of ​​the workpiece.

[0126] In some specific embodiments, the vibration module 2 includes:

[0127] Work platform 21;

[0128] A clamping and positioning component disposed on the surface of the work platform 21 and used to fix the workpiece 1;

[0129] And a vibration generator 22 disposed at the lower part of the working platform 21 and used to cause the working platform 21 to vibrate in the Z direction.

[0130] In some specific embodiments, the clamping and positioning element includes a bolt and nut combination structure.

[0131] In some specific embodiments, the vibration generator 22 employs conventional techniques in the art, and its vibration generation methods include ultrasonic vibration, electromagnetic vibration, and mechanical vibration.

[0132] In some specific embodiments, the vibration generator 22 also has X-axis and Y-axis vibrations.

[0133] In some specific embodiments, the vibration module 2 is mounted on the moving module 6. The moving module 6 includes X-axis, Y-axis, and Z-axis guide rails and corresponding driving devices, as well as a slider 61 that can move along the X-axis, Y-axis, and Z-axis. It adopts conventional means in the art and is only used to enable the workpiece 1 to move in the X-axis, Y-axis, and Z-axis, so it will not be described in detail.

[0134] In some specific embodiments, the machine tool spindle 321 is provided with a spindle taper hole 3211 for clamping the tool holder portion 311.

[0135] In some specific embodiments, the machine tool spindle 321 is connected to a motor to provide rotation of the machine tool spindle 321.

[0136] In some specific embodiments, the machine tool spindle 321 can move in the X, Y, and Z directions, thereby driving the milling cutter 31 to move in the X, Y, and Z directions, thereby positioning the milling cutter 31 on the surface of the workpiece 1.

[0137] In some specific embodiments, the laser-assisted module 4 is connected by a fixture 5, which is a universal table, enabling the laser-assisted module 4 to be positioned and fixed at any processing point of the workpiece 1.

[0138] A laser vibration-assisted milling method, implemented using the aforementioned processing device, includes the following steps:

[0139] S1. Install the workpiece 1 on the vibration module 2, and start the vibration module 2 to make the workpiece 1 vibrate along the Z direction;

[0140] S2. Activate the laser-assisted module 4 to perform laser heating and softening on the area to be processed of the workpiece 1;

[0141] S3. Milling is performed on the area softened by laser heating of the milling cutter 31 of the milling module 3, so that the milling cutter 31 is in intermittent contact with the area to be processed of the workpiece 1. When they are in contact, the first main flank face 3124 of the milling cutter 31 is in complete contact with the area to be processed of the workpiece 1.

[0142] S4. Close all modules, remove workpiece 1, clean it, and obtain the finished product.

[0143] Each of the above embodiments can be implemented individually or in any combination of two or more.

[0144] The following description uses specific examples to illustrate the point.

[0145] Example 1

[0146] like Figures 1-5 As shown, a laser vibration-assisted milling processing device is used to perform laser, vibration, and milling processing on the area to be processed of workpiece 1. The processing device includes:

[0147] Vibration module 2 for placing and fixing the workpiece 1 and vibrating in the Z-direction;

[0148] The milling module 3 for milling workpiece 1 includes a milling cutter 31 located above the area to be processed of workpiece 1 and a machine tool 32 for clamping the milling cutter 31 and driving it to move and mill. The milling cutter 31 has a milling cutter axis O, a cutting plane Ps, a base plane Pr, and an orthogonal plane Po.

[0149] And a laser-assisted module 4 disposed above the workpiece 1 and used to laser heat and soften the area of ​​the workpiece 1 to be processed;

[0150] The milling cutter 31 includes a shank portion 311 connected to the spindle of the machine tool 32 and a cutting portion 312 disposed at the end of the shank portion 311. The cutting portion 312 includes a plurality of radially spirally distributed teeth and end teeth disposed at the end of the radial teeth. The end teeth include a rake face 3123, a main end cutting edge 3122, a first main flank face 3124, a second main flank face 3125 and a secondary flank face 3128. The rake face 3123 and the first main flank face 3124 intersect to form the main end cutting edge 3122.

[0151] The angle between the first main relief face 3124 and the cutting plane Ps is the first relief angle a1 of the end edge, which is 0°. The second main relief face 3125 is an arc-shaped surface and is tangentially connected to the first main relief face 3124.

[0152] In this embodiment, as Figure 3 As shown, the base plane Pr is a plane that passes through a selected point on the main end cutting edge 3122, is perpendicular to the main motion direction, and passes through the milling cutter axis 0.

[0153] In this embodiment, the cutting plane Ps is a plane passing through a selected point on the main end cutting edge 3122, tangent to the main end cutting edge 3122, and perpendicular to the base surface Pr. It is the plane formed by the main end cutting edge 3122 and the cutting speed direction. In simpler terms, the cutting plane Ps is the plane formed by the main end cutting edge 3122 extending in a direction perpendicular to the base surface Pr. That is, the cutting plane Ps is the surface to be machined by the milling cutter 31, and the base surface Pr is the reference surface of the workpiece 1 being machined.

[0154] In this embodiment, the orthogonal plane Po is a plane that passes through a selected point on the main peripheral cutting edge 3121 and is perpendicular to both the base plane Pr and the cutting plane Ps. The cutting plane Ps, the base plane Pr, and the orthogonal plane Po are all perpendicular to each other. The base plane Pr is the center, and both the cutting plane Ps and the orthogonal plane Po originate from the base plane Pr. Without the base plane Pr, it would be impossible to accurately construct the cutting plane Ps and the orthogonal plane Po.

[0155] In this embodiment, the intersection point of the main peripheral cutting edge 3121 and the main end cutting edge 3122 is the tool tip point 3130, the selected point of the main end cutting edge 3122 through which the base plane Pr passes is the tool tip point 3130, and the selected point of the main end cutting edge 3122 through which the cutting plane Ps passes is the tool tip point 3130.

[0156] In this embodiment, as Figure 5 As shown, the second clearance angle a2 of the end cutting edge is 0°~20°. The second clearance angle a2 of the end cutting edge at the point where the second main clearance face 3125 is tangent to the first main clearance face 3124 is 0°, and the second clearance angle a2 of the end cutting edge gradually increases as it moves away from the first main clearance face 3124, with a maximum angle of 20°.

[0157] In this embodiment, the width of the first rear angle of the end blade L1 is 1.5mm, and the width of the second rear angle of the end blade L2 is 1mm.

[0158] In this embodiment, located within the orthogonal plane Po, the angle between the rake face 3123 and the base plane Pr is the end-edge rake angle a3, which is 30°. Specifically, the angle between the main peripheral cutting edge 3121 of the rake face 3123 and the base plane Pr is the end-edge rake angle a3.

[0159] In this embodiment, two adjacent rake faces 3123 and secondary flank faces 3128 are connected by a groove 3129. A groove angle a7 is formed between adjacent end edges, and each groove angle a7 has the same angle of 90°.

[0160] In this embodiment, the main end blade 3122 is hook-shaped, which allows the chips to flow out along the groove 3129; the main peripheral blade 3121 is spiral-shaped.

[0161] In this embodiment, the first main back face 3124 is an irregular shape with a hook-shaped tip;

[0162] The second main flank face 3125 is triangular, which is used to reduce stress concentration on the flank face during high-frequency vibration.

[0163] In this embodiment, the angle between the first main back face 3124 and the base surface Pr is the first cutting edge angle a4, which is 90°.

[0164] The angle between the second main back face 3125 and the base face Pr is the second cutting edge angle of the end edge, which is 70°~90°;

[0165] The angle between the secondary flank face 3128 and the cutting plane Ps is the secondary flank face angle a6, which is 75°.

[0166] In this embodiment, as Figure 6 and 7 As shown, the peripheral teeth include a front cutting face 3123, a main peripheral cutting edge 3121, a third main flank cutting face 3126, a fourth main flank cutting face 3127, and a secondary flank cutting face 3128. The front cutting face 3123 and the third main flank cutting face 3126 intersect to form the main peripheral cutting edge 3121.

[0167] The angle between the third main back face 3126 and the orthogonal plane M3 is the first back angle b1 of the peripheral cutting edge, which is 13°;

[0168] The angle between the fourth main back face 3127 and the orthogonal plane M3 is the second back angle b2 of the peripheral cutting edge, which is 23°;

[0169] Located within the cutting plane Ps, the angle between the rake face 3123 and the base plane M2 is the circumferential rake angle b3, which is 60°, and the angle between the main end cutting edge 3122 of the rake face 3123 and the base plane M2 is the circumferential rake angle b3.

[0170] In this embodiment, the width l1 of the first rear angle of the circumferential blade is 0.6 mm;

[0171] The width l2 of the second rear angle of the circumferential blade is 0.5mm.

[0172] In this embodiment, as Figure 8 As shown, the laser-assisted module 4 includes:

[0173] A laser emitter 41 is disposed on one side of the milling module 3 and is used to emit a laser beam toward the area to be processed of the workpiece 1;

[0174] An optical reflective assembly 42 is disposed on the laser beam path and used to diffuse the laser beam so that it illuminates the area to be processed on the workpiece.

[0175] In this embodiment, the optical reflection assembly 42 includes a laser reflector 421 for receiving the laser beam emitted by the laser emitter 41, and a convex lens 422 for receiving the laser beam from the laser reflector 421 and focusing it on the processing area of ​​the workpiece.

[0176] In this embodiment, as Figure 9 As shown, the vibration module 2 includes:

[0177] Work platform 21;

[0178] A clamping and positioning component disposed on the surface of the work platform 21 and used to fix the workpiece 1;

[0179] And a vibration generator 22 disposed at the lower part of the working platform 21 and used to cause the working platform 21 to vibrate in the Z direction.

[0180] In this embodiment, the clamping and positioning component includes a bolt and nut combination structure.

[0181] In this embodiment, the vibration generator 22 employs conventional technology in the art, and its vibration generation methods include ultrasonic vibration, electromagnetic vibration, and mechanical vibration. In this embodiment, the vibration generator 22 is model HSD-2580-SP, manufactured by Suzhou Nason Ultrasonic Technology Co., Ltd. Within the vibration frequency range of this vibration generator 22, a higher vibration frequency results in a better reduction of residual tensile stress on the material surface.

[0182] In this embodiment, the vibration module 2 is mounted on the moving module 6. The moving module 6 includes X-axis, Y-axis, and Z-axis guide rails and corresponding driving devices, as well as a slider 61 that can move along the X-axis, Y-axis, and Z-axis. It adopts conventional means in the art and is only used to enable the workpiece 1 to move in the X-axis, Y-axis, and Z-axis, so it will not be described in detail.

[0183] In this embodiment, as Figure 10 As shown, the machine tool 32 is a VMC0850B CNC machining center, including a machine tool spindle 321, which is connected to the tool holder 311 of the milling cutter 31.

[0184] In this embodiment, the machine tool spindle 321 is provided with a spindle taper hole 3211 for clamping the tool holder portion 311.

[0185] In this embodiment, the machine tool spindle 321 is connected to a motor to provide rotation of the machine tool spindle 321.

[0186] In this embodiment, the machine tool spindle 321 can move in the X, Y, and Z directions, thereby driving the milling cutter 31 to move in the X, Y, and Z directions, thus positioning the milling cutter 31 on the surface of the workpiece 1.

[0187] In this embodiment, the laser-assisted module 4 is connected by a fixture 5, which is a universal table that can position and fix the laser-assisted module 4 at any processing point of the workpiece 1.

[0188] A laser vibration-assisted milling method, implemented using the aforementioned processing device, includes the following steps:

[0189] S1. The vibration module 2 is mounted on the moving module 6. The workpiece 1 is mounted on the vibration module 2, and the moving module 6 places the workpiece 1 in a suitable position.

[0190] S2. Move the milling cutter 31 using the machine tool 32 and place it above the workpiece 1, then activate the vibration module 2 to make the workpiece 1 vibrate along the Z direction;

[0191] S3. Activate the laser-assisted module 4 to perform laser heating and softening on the area to be processed of the workpiece 1;

[0192] S4. Milling is performed on the area softened by laser heating of the milling cutter 31 of the milling module 3, so that the milling cutter 31 is in intermittent contact with the area to be processed of the workpiece 1. When they are in contact, the first main flank face 3124 of the milling cutter 31 is in complete contact with the area to be processed of the workpiece 1.

[0193] S5. Move the laser-assisted module 4 and the milling cutter 31 to perform laser milling on the machining surface of the workpiece 1, so that the machining surface is laser-cut first and then milled. This process is carried out according to the actual situation and is a conventional technology in the field, so it will not be described in detail.

[0194] S6. Close all modules, remove workpiece 1, clean it to obtain the finished product.

[0195] Example 2

[0196] This embodiment is based on embodiment 1. In addition to Z-axis vibration, the vibrator 23 also has X-axis and Y-axis vibration.

[0197] Comparative Example 1

[0198] Compared with Example 1, most of them are the same, except that the milling cutter 31 is different. The different parameters are shown in Table 1.

[0199] Table 1 Comparison of milling cutter parameters between Example 1 and Comparative Example 1

[0200]

[0201] In Example 1 and Comparative Example 1, the relevant processing parameters of the processing device are shown in Table 2, and no vibration is applied. The workpiece being processed is a nickel-based superalloy (Inconel 718 alloy, Shanghai Xinrui Metal Materials Co., Ltd.).

[0202] Table 2 Relevant processing parameters of the processing device

[0203]

[0204] Under the machining parameters shown in Table 2, the cutting force and residual stress on the workpiece surface were tested.

[0205] The cutting force testing method involves using a force-measuring tool holder to measure the milling cutter torque during cutting. Since a four-flute milling cutter is used, the torque is converted into the cutting force per tooth using the torque formula. The torque formula is:

[0206] ,

[0207] Where Fz represents the single-tooth cutting force (N), Mt represents the total cutting torque (N·m), z represents the total number of cutting edges of the milling cutter, and r represents the tool radius (m).

[0208] The residual stress testing method involves addressing the issue that the interplanar spacing changes when residual stress is present in the sample. This leads to Bragg diffraction, causing the diffraction peaks to shift, with the shift distance depending on the stress magnitude. X-rays of wavelength λ are used to irradiate the sample several times at different incident angles. The corresponding diffraction angle 2θ is measured, and the slope M of 2θ relative to sin2ψ is calculated, allowing the determination of the stress σψ. The test was conducted using a DS-21L high-power X-ray stress analyzer and a DS-21P(L)1.016.2. Relevant test parameters are shown in Table 3.

[0209] Table 3 Relevant parameters for residual stress testing

[0210]

[0211] Test results are as follows Figure 11 and 12 As shown. A nickel-based superalloy was used as the experimental material for machining experiments. Due to the high hardness of the nickel-based superalloy, a cutting depth of 50 micrometers was selected. In Comparative Example 1, the cutting force was approximately 600 N, and the residual stress was 448.4 MPa; while in Example 1, the cutting force was approximately 400 N, and the residual stress was 185.2 MPa.

[0212] This is because the principles of the processing apparatus and processing method described in Example 1 and Comparative Example 1 are as follows:

[0213] A high-energy laser beam locally heats the surface of workpiece 1, raising the temperature and softening the material in the processing area, thereby reducing its hardness and strength. This laser pretreatment step effectively reduces cutting force and heat generation, creating more favorable conditions for subsequent processing. Subsequently, ultrasonic vibration machining technology is introduced. Through vibration module 2, the milling cutter 31 performs cutting under high-frequency vibration. This high-frequency vibration allows the milling cutter 31 to repeatedly enter and exit workpiece 1 in a very short time, further reducing the accumulation of cutting force and heat, while improving chip formation and removal. Ultrasonic vibration not only improves cutting efficiency but also significantly enhances the surface finish and quality of the machined surface.

[0214] The ultrasonic vibration cutting process cleverly utilizes the principle of shot peening. Specifically, the surface of the milling cutter 31 is considered as a "shot," and ultrasonic vibration causes the surface of the milling cutter 31 to impact the workpiece 1 area, which has been softened by laser-assisted machining, at an extremely high frequency. This impact is similar to the impact of a projectile on the surface of workpiece 1 in traditional shot peening, which can introduce residual compressive stress on the surface of workpiece 1. Residual compressive stress can effectively reduce the initiation and propagation of cracks, thereby significantly improving the fatigue strength and stress corrosion resistance of the workpiece 1 surface. By precisely controlling the frequency and amplitude of ultrasonic vibration, the distribution and magnitude of residual compressive stress can be optimized, further improving the surface properties of the workpiece.

[0215] In Embodiment 1, the first clearance angle a1 of the end face of the milling cutter 31 is designed to be 0°, so that the first primary clearance face 3124 of the milling cutter 31 coincides with the cutting plane Ps, allowing the first primary clearance face 3124 to contact the machined surface. During vibration-assisted milling, this generates a force on the machined surface, reducing residual tensile stress on the surface. The second clearance angle a2 of the end face is 0°~45°, and the second primary clearance face 3125 is an arc-shaped surface that is tangentially connected to the first primary clearance face 3124. At the tangent point, the second clearance angle of the end face is 0°, which can reduce stress concentration on the second primary clearance face 3125 during high-frequency vibration, and reduce tool wear or breakage caused by stress concentration during relative vibration of the milling cutter 31.

[0216] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A laser vibration-assisted milling processing device, characterized in that, The processing device is used for laser, vibration, and milling processing of the area to be processed of the workpiece (1), and includes: A vibration module (2) for placing and fixing the workpiece (1) and vibrating in the Z direction; A milling module (3) for milling a workpiece (1) includes a milling cutter (31) located above the area to be processed of the workpiece (1) and a machine tool (32) for clamping the milling cutter (31) and driving it to move and mill. The milling cutter (31) has a milling cutter axis (0), a cutting plane (Ps), a base plane (Pr), and an orthogonal plane (Po). And a laser-assisted module (4) disposed above the workpiece (1) and used to laser heat and soften the area to be processed of the workpiece (1); The milling cutter (31) includes a shank (311) connected to the spindle of the machine tool (32) and a cutting part (312) disposed at the end of the shank (311). The cutting part (312) includes a plurality of radially spirally distributed teeth and end teeth disposed at the end of the radial teeth. The end teeth include a rake face (3123), a main end cutting edge (3122), a first main flank face (3124), a second main flank face (3125), and a secondary flank face (3128). The rake face (3123) and the first main flank face (3124) intersect to form the main end cutting edge (3122). The angle between the first main relief face (3124) and the cutting plane (Ps) is the first relief angle (a1) of the end edge, which is 0°. The second main relief face (3125) is an arc-shaped surface and is tangentially connected to the first main relief face (3124). The angle between the second main relief face (3125) and the cutting plane (Ps) is the second relief angle (a2) of the end edge, which is 0°~45°; The second rear edge angle (a2) at the point where the second main rear edge (3125) is tangent to the first main rear edge (3124) is 0°, and the second rear edge angle (a2) gradually increases away from the first main rear edge (3124), with a maximum angle of 45°. Located within the orthogonal plane (Po), the angle between the rake face (3123) and the base plane (Pr) is the end-edge rake angle (a3), which is 10°~50°; The main end blade (3122) is hook-shaped; The two adjacent front face (3123) and secondary back face (3128) are connected by a groove (3129).

2. The laser vibration-assisted milling device according to claim 1, characterized in that, The angle between the first main back face (3124) and the base plane (Pr) is the first cutting edge angle (a4) of the end edge, which is 90°; The angle between the second main back face (3125) and the base face (Pr) is the second cutting edge angle of the end edge, which is 45°~90°; The angle between the secondary flank face (3128) and the cutting plane (Ps) is the secondary flank face angle (a6), which is 60°~90°.

3. The laser vibration-assisted milling apparatus according to claim 1, characterized in that, The peripheral teeth include a front cutting face (3123), a main peripheral cutting edge (3121), a third main flank cutting face (3126), a fourth main flank cutting face (3127), and a secondary flank cutting face (3128). The front cutting face (3123) and the third main flank cutting face (3126) intersect to form the main peripheral cutting edge (3121). The angle between the third main back face (3126) and the orthogonal plane (M3) is the first back angle (b1) of the peripheral cutting edge, which is 10°~15°; The angle between the fourth main back face (3127) and the orthogonal plane (M3) is the second back angle (b2) of the peripheral cutting edge, which is 20°~25°; Located within the cutting plane (Ps), the angle between the rake face (3123) and the base plane (M2) is the peripheral rake angle (b3), which is 30°~60°.

4. The laser vibration-assisted milling device according to claim 1, characterized in that, The laser-assisted module (4) includes: A laser emitter (41) is disposed on one side of the milling module (3) and is used to emit a laser beam toward the area to be processed of the workpiece (1). An optical reflective assembly (42) is disposed on the laser beam path and used to diffuse the laser beam so that it illuminates the area to be processed on the workpiece (1).

5. The laser vibration-assisted milling apparatus according to claim 1, characterized in that, The vibration module (2) includes: Work platform (21); A clamping and positioning element disposed on the surface of the work platform (21) and used to fix the workpiece (1); And a vibration generator (22) disposed at the lower part of the working platform (21) and used to generate Z-axis vibration of the working platform (21).

6. A laser vibration-assisted milling method, implemented using the processing apparatus described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Install the workpiece (1) on the vibration module (2) and start the vibration module (2) to make the workpiece (1) vibrate along the Z direction; S2. Activate the laser-assisted module (4) to perform laser heating and softening on the workpiece (1) to be processed area; S3. The area softened by laser heating is milled by the milling cutter (31) of the milling module (3), so that the milling cutter (31) and the area to be processed of the workpiece (1) are in intermittent contact. When they are in contact, the first main back face (3124) of the milling cutter (31) is in complete contact with the area to be processed of the workpiece (1). S4. Close all modules, remove the workpiece (1), and clean it to obtain the finished product.

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