Micro-textured cutting insert

Abstract

The application discloses a micro-texture cutting blade, and relates to the technical field of machining.The micro-texture cutting blade has a rake face and a relief face, the connecting part of the rake face and the relief face forms a cutting edge, the rake face is provided with a micro-texture, and the micro-texture at least comprises a spiral line groove.The spiral line groove has a first end and a second end, the spiral line groove extends in a spiral line type from the first end to the second end, and the first end is closer to the cutting edge than the second end.According to the micro-texture cutting blade, the cutting stress can be deflected, the crack propagation can be inhibited, the cutting edge is not easy to collapse, the service life is long, and the heat dissipation effect is good.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and more specifically, to a microtextured cutting insert. Background Technology

[0002] During the cutting process, the cutting edge of the cutting insert is subjected to extremely high mechanical and thermal stress. Micro-chipping is prone to occur in the rounded edge area, and fatigue cracks are prone to develop in the main cutting edge area. Crack propagation leads to premature failure of the insert.

[0003] Cutting inserts in related technologies attempt to reduce chip contact area and friction by machining microtextures on the rake face, but their structure is relatively simple and their effect on inhibiting crack propagation is limited. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a microtextured cutting insert, which can deflect cutting stress, inhibit crack propagation, and has advantages such as being less prone to chipping, having a long service life, and having good heat dissipation.

[0005] To achieve the above objectives, an embodiment of the present invention provides a microtextured cutting insert, the microtextured cutting insert having a rake face and a flank face, a cutting edge being formed at the junction of the rake face and the flank face, the rake face being provided with a microtexture, the microtexture including at least a helical groove, the helical groove having a first end and a second end, the helical groove extending in a helical shape from the first end to the second end, the first end being closer to the cutting edge relative to the second end.

[0006] The microtextured cutting inserts according to embodiments of the present invention can deflect cutting stress and suppress crack propagation, and have advantages such as being less prone to chipping, having a long service life, and having good heat dissipation.

[0007] In addition, the microtextured cutting blade according to the above embodiments of the present invention may also have the following additional technical features: According to an embodiment of the present invention, the helical profile of the helical groove satisfies the following equation in polar coordinates: r(θ) = a + b × θ, where r is the polar radius, θ is the polar angle, a > 0, and b is the pitch constant.

[0008] According to one embodiment of the present invention, the extreme diameter of the helical groove gradually increases from the first end to the second end.

[0009] According to one embodiment of the present invention, the depth and / or width of the spiral groove gradually increases from the first end to the second end.

[0010] According to one embodiment of the present invention, the cutting edge includes a rounded corner edge and a plurality of main cutting edges, the rounded corner edge being located between two adjacent main cutting edges, the rake face including a main cutting edge region and a rounded corner edge region, the main cutting edge region extending inward from the main cutting edges, the rounded corner edge region extending inward from the rounded corner edges, and the helical groove being disposed in the main cutting edge region.

[0011] According to one embodiment of the present invention, the microtexture further includes an arcuate groove, the middle portion of which protrudes toward the rounded corner edge from both ends.

[0012] According to one embodiment of the present invention, there are multiple arc grooves, and the spacing and / or arc radius and / or depth and / or width of the multiple arc grooves gradually increase from the outside to the inside.

[0013] According to one embodiment of the present invention, the two ends of the arc groove extend to the main cutting edge region.

[0014] According to one embodiment of the present invention, the first end is closer to the rounded corner blade region than the second end.

[0015] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of a microtextured cutting blade according to an embodiment of the present invention.

[0017] Figure 2 This is a partial structural schematic diagram of a microtextured cutting blade according to an embodiment of the present invention.

[0018] Figure 3 This is a partial structural schematic diagram of a microtextured cutting blade according to an embodiment of the present invention.

[0019] Figure 4 This is a partial structural schematic diagram of a microtextured cutting blade according to an embodiment of the present invention.

[0020] Reference numerals: 1. Microtextured cutting insert; 10. Rake face; 11. Main cutting edge area; 12. Rounded corner edge area; 20. Flank face; 30. Cutting edge; 31. Main cutting edge; 32. Rounded corner edge; 40. Microtexture; 41. Helical groove; 42. Circular groove; 43. First end; 44. Second end. Detailed Implementation

[0021] This application is based on the findings and understanding of the following facts and issues: During the cutting process, the cutting edge of the cutting insert is subjected to extremely high mechanical and thermal stress. Micro-chipping is prone to occur in the rounded edge area, and fatigue cracks are prone to develop in the main cutting edge area. Crack propagation leads to premature failure of the insert.

[0022] Cutting inserts in related technologies attempt to reduce chip contact area and friction by machining microtextures on the rake face, but their structure is relatively simple and their effect on inhibiting crack propagation is limited.

[0023] Specifically, the microtexture of the cutting inserts in the relevant technology is a simple straight line or grid, which cannot effectively release cutting stress and has limited effect on inhibiting crack propagation.

[0024] During the cutting process, the cutting edge of the tool is subjected to extremely high mechanical and thermal stresses. Mechanical stress mainly originates from the cutting force generated by chip deformation and friction. The rounded edge region experiences a superposition of tangential, radial, and axial stresses, resulting in the most complex stress state. The peak tensile stress region is located 0.1-0.5 mm from the tool tip on the main cutting edge, which is the primary location for fatigue crack initiation. Thermal stress originates from the heat of chip deformation and frictional heat on the rake face. The temperature at the apex of the rounded edge can reach 900℃-1100℃, generating alternating thermal stress. The superposition of these two factors leads to micro-chipping and fatigue cracks, ultimately causing premature tool failure.

[0025] The mantis shrimp's claws possess excellent impact resistance, and their internal microstructure is a Brugon structure, a composite structure composed of multiple helically arranged fiber layers. Its core toughening effect originates from the minute torsion angles between adjacent fiber layers, effectively deflecting cracks and absorbing impact energy. This invention abstracts the core mechanism of this structure onto the two-dimensional plane of a cutting tool, allowing the microgroove to function as a "crack guide" or "stress deflector."

[0026] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0027] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and 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, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] The microtextured cutting blade 1 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0030] like Figures 1-4 As shown, the microtextured cutting insert 1 according to an embodiment of the present invention has a rake face 10 and a flank face 20. A cutting edge 30 is formed at the junction of the rake face 10 and the flank face 20. A microtexture 40 is provided on the rake face 10. The microtexture 40 includes at least a helical groove 41. The helical groove 41 has a first end 43 and a second end 44. The helical groove 41 extends in a helical shape L from the first end 43 to the second end 44. The first end 43 is closer to the cutting edge 30 than the second end 44.

[0031] Specifically, the first end 43 is disposed adjacent to the cutting edge 30. For example, the distance between the first end 43 and the cutting edge 30 is 0.1-0.3 mm.

[0032] The second end 44 faces the inside of the microtextured cutting insert 1. For example, the second end 44 may face the center of the microtextured cutting insert 1 or the chip groove.

[0033] like Figure 4As shown, let β be the deflection angle formed by the tangent at any point of the helical shape L of the helical groove 41 and the direction of the principal stress. β continuously changes along the extension direction of the helical groove 41. When a fatigue crack initiates and propagates from the cutting edge 30, the crack encounters the helical groove 41 at an angle β to the direction of the principal stress. The stress will deflect along the interface of the helical groove 41, with a deflection angle equal to β. Because the tangent angle α of the helical groove 41 continuously changes, the stress continuously encounters new deflection angle β values ​​during propagation, forcing the stress to continuously change direction and consume energy, thereby significantly improving the fracture toughness of the cutting edge 30. Moreover, as the extreme diameter r continuously increases, the path length for stress release is greatly increased, which can consume more fracture energy and prevent the crack from directly penetrating the cutting tool.

[0034] According to an embodiment of the present invention, the microtextured cutting insert 1 has a helical groove 41 on the rake face 10. The helical groove 41 extends in a helical shape L from the first end 43 to the second end 44. The first end 43 is closer to the cutting edge 30 than the second end 44. The helical groove 41 with the helical shape L can simulate the Brugon spiral biomimetic structure of a mantis shrimp claw. Compared with the microtextured structures with simple structures in related technologies, the deflection angle β formed by the tangent of the helical shape L at any point of the helical groove 41 and the principal stress direction changes continuously, causing the stress to deflect continuously. This breaks the condition for linear crack propagation, forces the crack to change direction continuously, greatly increases the fracture energy required for crack propagation, and inhibits micro-chipping and main crack penetration from a mechanistic perspective. The helical groove 41 acts as a "crack guide" and a "stress deflector", thereby improving tool life.

[0035] Furthermore, by setting the microtexture 40, on the one hand, the actual contact area between the chip and the rake face 10 can be reduced, thereby reducing the cutting force and the coefficient of friction. On the other hand, the helical groove 41 helps guide the chip flow, facilitates the storage of lubricant and air, and forms a lubricating film or heat insulation layer on the rake face 10, reducing adhesion and diffusion wear. This is especially suitable for difficult-to-machine materials such as titanium alloys and high-temperature alloys. Moreover, the microtexture 40 can increase the heat dissipation area of ​​the rake face 10, which is conducive to the dissipation of heat through radiation or convection, cuts off the heat conduction path, promotes cooling, reduces the temperature of the cutting zone, slows down thermal fatigue, and inhibits the generation of thermal fatigue cracks.

[0036] Therefore, the microtextured cutting insert 1 according to the embodiments of the present invention can deflect cutting stress and suppress crack propagation, and has the advantages of being less prone to chipping, having a long service life, and having good heat dissipation.

[0037] The microtextured cutting blade 1 according to a specific embodiment of the present invention is described below with reference to the accompanying drawings.

[0038] Specifically, such as Figure 4 As shown, the helical shape L of the helical groove 41 satisfies the following equation in polar coordinates: r(θ) = a + b × θ, where r is the polar radius, θ is the polar angle, a > 0, and b is the pitch constant.

[0039] Specifically, such as Figure 4 As shown, the pole O is the fixed reference point of the helix L and the origin of the polar coordinate system. The polar axis x is a ray passing through the pole O, serving as the baseline for measuring the polar angle θ, with the polar axis direction being the direction where θ=0. The polar radius r is the distance from any point P on the helix L to the pole O. The polar radius r increases uniformly with the polar angle θ. The polar angle θ is the angle between the polar radius r at any point on the helix L and the polar axis x, expressed in radians (rad). a is the initial polar radius, i.e., the distance from the starting point of the helix to the center when θ=0. a>0 means that the helix does not start from the pole but begins its rotation from a position a distance a from the pole O. b is the pitch growth rate, i.e., the increase in polar radius r for every 1 rad increase in polar angle θ. The tangent direction angle α is the angle between the tangent at any point on the helix L and the polar axis x, which changes continuously with the polar angle θ. The β angle is the angle formed by the tangent at any point of the helical line L and the direction of the principal stress (i.e., the crack rotation angle), which changes continuously with the change of the α angle. The direction of the principal stress is perpendicular to the main cutting edge 31.

[0040] Since the polar diameter r increases linearly with the polar angle θ, the polar diameter r increases by 2πb for each revolution of the helix (θ increases by 2π radians). Therefore, the radial distance between two adjacent revolutions is constant and equal to 2πb. Due to the limited space of the rake face 10, the actual working range of the helical groove 41 is less than a quarter circumference (θ≤1.5rad<π / 2).

[0041] For example, the pitch growth rate b ranges from 2.0 to 3.5 mm / rad; the polar angle θ ranges from 0 to 1.5 rad (2π rad = 360 degrees); the second end polar diameter rmax = a + b 1.5 falls within the range of the rake face and points towards the chip removal groove at the center of the insert.

[0042] This facilitates the formation of the spiral groove 41, enabling the formation of a continuous, smooth, rotating spiral shape. This allows stress and cracks to be continuously deflected during transmission and propagation, preventing stress and crack concentration and effectively suppressing chipping and cracking.

[0043] Advantageously, such as Figures 1-4 As shown, the extreme diameter r of the helical shape L of the helical groove 41 gradually increases from the first end to the second end. This continuous increase in extreme diameter r significantly increases the stress release path length, facilitating the dissipation of more fracture energy.

[0044] More advantageously, such as Figures 1-3As shown, the depth and / or width of the helical groove 41 gradually increases from the first end 43 to the second end 44. Specifically, the cross-section of the helical groove 41 perpendicular to the extension direction can be trapezoidal or arched. The width of the helical groove 41 is 30-120 micrometers, and the depth is 30-100 micrometers. This simulates the gradient thickening structure of the fibrous layer inside the mantis shrimp claw, allowing the depth and / or width of the helical groove 41 to gradually increase from the high-stress area to the low-stress area. This disperses the stress concentrated near the cutting edge 30 along the path of the helical groove 41 to a larger area, avoiding stress concentration that could lead to direct chipping.

[0045] Figures 1-3 A microtextured cutting blade 1 according to some examples of the present invention is shown. For example... Figures 1-3 As shown, the cutting edge 30 includes a rounded edge 32 and multiple main cutting edges 31. The rounded edge 32 is located between two adjacent main cutting edges 31. The rake face 10 includes a main cutting edge region 11 and a rounded edge region 12. The main cutting edge region 11 extends inward from the main cutting edge 31, and the rounded edge region 12 extends inward from the rounded edge 32. A helical groove 41 is provided in the main cutting edge 31 region. In this way, the helical groove 41 can be used to guide and deflect the stress and cracks of the main cutting edge 31, and suppress chipping and cracking of the main cutting edge 31.

[0046] Advantageously, such as Figures 1-3 As shown, the microtexture 40 also includes an arc groove 42, the middle of which protrudes towards the rounded edge 32 from both ends. In this way, the arc groove 42 can intercept and dissipate the stress and crack energy at the rounded edge 32. After the stress enters the main cutting edge region 11, it is deflected and dissipated by the spiral groove 41, thus forming a complete tough defense from the rounded edge region 12 to the main cutting edge region 11.

[0047] Specifically, such as Figures 1-3 As shown, there are multiple arc grooves 42, and the spacing and / or radius and / or depth and / or width of the multiple arc grooves 42 gradually increase from the outside to the inside. For example, the radii of the multiple arc grooves 42 from the outside to the inside are R1, R2, and R3, where R1 < R2 < R3, and R1 = R0 + (0.1-0.3) mm, R0 is the radius of the rounded corner edge 32, and the radius difference ΔR between adjacent arc grooves 42 is 0.1-0.4 mm. The spacing between adjacent arc grooves 42 from the outside to the inside is L1, L2, and L3, and satisfies the relationship: L1 < L2 < L3. The distance between the rounded corner edges 32 of the innermost arc groove 42 is 0.1-0.5 mm. The width of the arc groove 42 is 20-80 micrometers, and the depth is 20-60 micrometers. Specifically, the multiple arc grooves 42 are arranged concentrically. This allows for the use of the outer circular arc groove 42 to intercept cracks and stress, and the dissipation of residual energy through the deep and wide groove of the inner circular arc groove 42.

[0048] More advantageously, such as Figures 1-3 As shown, the two ends of the arc groove 42 extend to the main cutting edge 31 region. Specifically, the spiral groove 41 and the arc groove 42 are spaced apart from each other. This facilitates the arc groove 42 to transfer the stress and cracks of the rounded edge 32 to the main cutting edge region 11, and facilitates the spiral groove 41 to guide and deflect the stress and cracks, and dissipate energy.

[0049] More specifically, such as Figures 1-4 As shown, the first end 43 is closer to the rounded edge region 12 than the second end 44. This facilitates the spiral groove 41 in guiding stress and cracks from the rounded edge region 12.

[0050] Furthermore, the spiral grooves 41 are multiple and spaced apart along the length of the main cutting edge 31. This allows the multiple spiral grooves 41 to disperse and guide stress and cracks, facilitating the coverage of the main cutting edge region 11 by the microtexture 40 and improving the uniformity of stress distribution in the main cutting edge region 11.

[0051] The microtexture 40 reduces the actual contact area between the chip and the rake face 10 by 30%-50%.

[0052] Specifically, the core processing steps of the microtextured cutting insert 1 are as follows: metal powder mixture; loading into a mold and pressing to obtain a blank; loading into a degreasing furnace for high-temperature degreasing to remove the forming agent; loading into a sintering furnace for sintering to obtain the insert body; processing microgrooves using a picosecond / femtosecond laser processing system; and insert post-processing (grinding, sandblasting, coating).

[0053] The specific processing steps of microtexture 40 are as follows: The blade body is fixed on the five-axis linkage worktable of the picosecond / femtosecond laser processing equipment.

[0054] Import the executable model to generate machining paths for helical groove 41 and circular arc groove 42. The path for helical groove 41 is based on the polar coordinate equation r(θ)=a+b. θ is discrete into points spaced 0.02 mm apart.

[0055] Laser parameters are set as follows: shallow trenches use a single scan, while deep trenches use multiple scans, with each scan reducing the layer by 5-10 micrometers.

[0056] The process involves processing the spiral groove 41 and the circular arc groove 42 layer by layer, using high-energy laser pulses to directly ablate / vaporize the metal particles in the blade to form microgrooves. During the processing, a coaxial air blowing process is used to remove slag.

[0057] After processing, ultrasonic cleaning is used to remove surface deposits, and the tank shape and dimensions are inspected under a microscope.

[0058] According to the embodiments of the present invention, the microtextured cutting insert 1, as verified by experiments, under the same cutting parameters (Vc=200m / min, fz=0.15mm / z, ap=2mm, machining material 45 steel), compared with the insert without microtexturation 40, has the following characteristics: the main cutting force is reduced by about 12%; the tip temperature is reduced by about 80°C; and the insert life is increased by 2.5 times.

[0059] Other configurations and operations of the microtextured cutting blade 1 according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0060] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0061] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A microtextured cutting blade, characterized in that, The microtextured cutting insert has a rake face and a flank face, and a cutting edge is formed at the junction of the rake face and the flank face. The rake face is provided with a microtexture, which includes at least a helical groove. The helical groove has a first end and a second end. The helical groove extends in a helical shape from the first end to the second end, and the first end is closer to the cutting edge than the second end.

2. The microtextured cutting blade according to claim 1, characterized in that, The helical shape of the helical groove satisfies the following equation in polar coordinates: r(θ) = a + b × θ, where r is the polar radius, θ is the polar angle, a > 0, and b is the pitch constant.

3. The microtextured cutting blade according to claim 1, characterized in that, The extreme diameter of the helical groove gradually increases from the first end to the second end.

4. The microtextured cutting blade according to claim 1, characterized in that, The depth and / or width of the spiral groove gradually increase from the first end to the second end.

5. The microtextured cutting blade according to claim 1, characterized in that, The cutting edge includes a rounded edge and multiple main cutting edges. The rounded edge is located between two adjacent main cutting edges. The rake face includes a main cutting edge region and a rounded edge region. The main cutting edge region extends inward from the main cutting edge, and the rounded edge region extends inward from the rounded edge. The helical groove is provided in the main cutting edge region.

6. The microtextured cutting blade according to claim 5, characterized in that, The microtexture also includes an arc groove, the middle of which protrudes towards the rounded corner edge from both ends.

7. The microtextured cutting blade according to claim 6, characterized in that, There are multiple arc grooves, and the spacing and / or arc radius and / or depth and / or width of the multiple arc grooves gradually increase from the outside to the inside.

8. The microtextured cutting blade according to claim 6, characterized in that, The two ends of the arc groove extend to the main cutting edge region.

9. The microtextured cutting insert according to claim 5, characterized in that, The first end is closer to the rounded corner blade area than the second end.

10. The microtextured cutting blade according to claim 5, characterized in that, The spiral grooves are multiple and spaced apart along the length direction of the main cutting edge.

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