Milling cutter for machining ceramic matrix composite

Abstract

The invention discloses a milling cutter for processing a ceramic matrix composite material, a cutting edge comprises a wave-shaped cutting edge and a tooth-shaped cutting edge, the wave-shaped cutting edge and the tooth-shaped cutting edge are positioned on different edge sections and are alternately arranged, the waveform of the wave-shaped cutting edge is a sine curve waveform, and the sine curve waveform is periodically arranged along the axial direction of the milling cutter; chip separating grooves are periodically formed in the tooth-shaped cutting edge in the axial direction of the milling cutter at intervals, and the chip separating grooves correspond to wave crests and wave troughs of the sine curve waveform. The wave-shaped cutting edge is in a sine curve wave shape, so that the length of the cutting edge is increased, the load in unit length is reduced, the machining cutting force is effectively reduced, heat dissipation is accelerated, vibration and deformation are reduced, the tooth-shaped cutting edge is divided by the chip dividing grooves of the tooth-shaped cutting edge, and chip removal and heat dissipation are facilitated while cutting force distribution is optimized; and in the machining process, discontinuous parts are cut through the tooth-shaped cutting edges, machining is conducted through the wave crests or the wave troughs of the wave-shaped cutting edges, and the cutting service life of the cutter is long.

Description

Technical Field

[0001] The present invention relates to the technical field of cutting and processing of composite materials, and particularly to a milling cutter for processing ceramic matrix composite materials. Background Art

[0002] Fiber-reinforced ceramic matrix composites are composed of a ceramic matrix and fibers. Although traditional ceramics have high temperature resistance, high strength and corrosion resistance, they are prone to fracture due to their large brittleness. The addition of fibers effectively compensates for this defect, can prevent crack propagation, and endows the material with good toughness. Such composite materials have high strength and modulus, can withstand large external forces; have low density, which is beneficial to the lightweight of products, and can reduce the structural weight and improve the energy utilization rate in aerospace and automotive manufacturing. At the same time, they have excellent high temperature resistance, can remain stable in high temperature environments above 1000°C, and are wear-resistant and corrosion-resistant, suitable for harsh working conditions.

[0003] Fiber-reinforced ceramic matrix composites are widely used in the fields of aerospace, automotive, energy, etc. With its low density characteristics, it can effectively achieve lightweight; at the same time, its excellent high temperature resistance and corrosion resistance can ensure the safe and reliable operation of equipment in high temperature and strong corrosion environments such as aviation, automotive engines, and energy and chemical industries; its good wear resistance is used in the manufacture of brake discs, which can effectively extend the service life of brake discs; in addition, its advantages of high strength and low density contribute to improving the wind capture efficiency of blades and the operating stability under complex weather conditions. With the maturity of technology, the performance of fiber-reinforced ceramic matrix composites will continue to be optimized, meet more extreme requirements and integrate multiple functions, so as to expand to more emerging fields such as biomedicine and intelligent transportation, and the market prospect is broad.

[0004] In terms of processing, there are significant difficulties in milling fiber-reinforced ceramic matrix composites. Due to the high hardness of the ceramic matrix and the uneven distribution of the fiber reinforcement phase, the tool is extremely prone to wear. Especially when processing high volume fraction fiber-reinforced materials, the tool life is greatly shortened, and frequent tool changes affect the processing efficiency and cost. In addition, a large cutting force is easily generated during the processing, resulting in workpiece deformation and it is difficult to ensure dimensional accuracy. For example, when milling thin-walled structural parts, the deformation problem is more prominent. At the same time, it is also difficult to control the machining surface quality, and defects such as high surface roughness, fiber pull-out, bulging, and matrix fracture are likely to occur, affecting the performance and service life of the product.

[0005] If a milling cutter with a full front-wave edge is used, the structure of the wavy edge is relatively weak in a local area. When machining materials with higher hardness or hard particles, the edge is prone to chipping or wear, affecting the service life and machining quality of the tool. Especially in milling conditions with greater impact, the risk of edge damage is higher. The front-wave edge design can improve the cutting performance to a certain extent, but the wavy edge will cause chips to easily accumulate in the cutting area, thereby affecting the stability of the machining process and even possibly leading to increased tool wear and a decrease in the surface quality of the workpiece. If a milling cutter with a full tooth-shaped edge is used, the effective cutting part of the tool will be reduced, weakening the structural strength of the tool. When the cutting force is large, especially during rough machining or when machining materials with higher hardness, the tool is more likely to break or chip, affecting the service life of the tool and the continuity of machining. In addition, the edge of the chip-breaking groove may leave marks on the machined surface, affecting the surface finish. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a milling cutter for machining ceramic matrix composites with a more stable cutting process, a long cutting life, and good impact resistance.

[0007] To solve the above technical problems, the present invention adopts the following technical solutions: A milling cutter for machining ceramic matrix composites includes a tool shank and a cutting part. The cutting part includes a plurality of spiral grooves and blade segments arranged at intervals around the outer circumference of the cutting part. The spiral grooves are located between adjacent blade segments. A cutting edge is provided on the blade segment. The cutting edge includes a wavy cutting edge and a tooth-shaped cutting edge. The wavy cutting edge and the tooth-shaped cutting edge are located on different blade segments and are arranged alternately. The waveform of the wavy cutting edge is a sine curve waveform, and the sine curve waveform is periodically arranged along the axial direction of the milling cutter tool. The tooth-shaped cutting edge is periodically provided with chip-breaking grooves at intervals along the axial direction of the milling cutter tool, and the chip-breaking grooves are arranged corresponding to the peaks and valleys of the sine curve waveform.

[0008] As a further improvement of the above technical solution: The blade segment includes a rake face, a flank face, and a cutting edge located at the intersection of the rake face and the flank face. The chip-breaking groove is provided on the flank face and penetrates through the tooth-shaped cutting edge.

[0009] On a plane perpendicular to the central axis of the milling cutter, the projection points of the cutting edges on different blade segments are on the circumference of the same imaginary circle. The imaginary circle is a circle with the projection point O of the central axis of the milling cutter as the center and a diameter of d. Let the line connecting the projection point P1 of the waveform cutting edge and the projection point O be line OP1. The projection point of the adjacent tooth-shaped cutting edge on the side of the rake face close to the waveform cutting edge is P2, and the projection point of the adjacent tooth-shaped cutting edge on the side of the flank face close to the waveform cutting edge is P2'. The lines connecting the projection points P2 and P2' to the projection point O are line OP2 and line OP2' respectively. The angle between line OP1 and line OP2 is the groove angle β of the blade segment where the waveform cutting edge is located, and the angle between line OP1 and line OP2' is the groove angle γ of the blade segment where the tooth-shaped cutting edge is located. The helix angle of the helical groove is α, and it satisfies: 8mm ≤ d ≤ 20mm, α = 30° - 40°, β > γ.

[0010] The amplitude of the sine curve waveform is A, and the period along the axial direction of the milling cutter is T, and it satisfies: 0.05mm ≤ A ≤ 0.5mm, 0.04 ≤ A / T ≤ 0.4.

[0011] The wave depth of the sine curve waveform on the rake face is h, and it satisfies: h = 0.08d - 0.15d.

[0012] Let the stagger distance between the waveform cutting edges on the blade segments arranged relatively with respect to the central axis of the milling cutter be k1, and let the stagger distance between the tooth-shaped cutting edges on the blade segments arranged relatively with respect to the central axis of the milling cutter be k2, and it satisfies: k1 = k2 = T / 2.

[0013] The depth of the chip splitter groove is t, and the width along the axial direction of the milling cutter is w, and it satisfies: t = 0.2mm - 0.5mm, w = 0.15T - 0.25T.

[0014] The bottom and the wall of the chip splitter groove are connected by a first transition arc surface, the top of the chip splitter groove and the flank face are connected by a second transition arc surface. The radius of the first transition arc surface is R1, and the radius of the second transition arc surface is R2, and it satisfies: R1 = 0.05mm - 0.15mm, R2 = 0.05mm - 0.1mm.

[0015] The length of the first chip splitter groove on the blade segment from the end face of the milling cutter is L1, and it satisfies: L1 = T / 4 - w / 2.

[0016] The pitch between the central axes of adjacent chip splitter grooves on the same blade segment is p, and it satisfies: p = T / 2.

[0017] The cutting part includes a substrate, and the blade segments are located on the substrate. The blade segments are made of PCD material directly grown on the substrate by physical vapor deposition or chemical vapor deposition.

[0018] The rake angle of the cutting edge lobe is β1. The flank of the cutting edge lobe includes a first flank and a second flank. The first flank is located between the cutting edge and the second flank. The clearance angle of the first flank is α1, and the clearance angle of the second flank is α2, satisfying: 0° ≤ β1 ≤ 3°, 8° ≤ α1 ≤ 12°, 20° ≤ α2 ≤ 25°.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: For the milling cutter for machining ceramic matrix composites of the present invention, the cutting edge includes a waveform cutting edge and a tooth-shaped cutting edge. The waveform cutting edge and the tooth-shaped cutting edge are located on different cutting edge lobes and are arranged alternately. The waveform of the waveform cutting edge is a sine curve waveform, and the sine curve waveform is periodically arranged along the axial direction of the milling cutter tool. The tooth-shaped cutting edge is periodically provided with chip-breaking grooves at intervals along the axial direction of the milling cutter tool. The chip-breaking grooves correspond to the peaks and valleys of the sine curve waveform. The waveform cutting edge is a sine curve waveform, which increases the cutting edge length, reduces the load per unit length, effectively reduces the machining cutting force and accelerates heat dissipation, reduces vibration and deformation, thereby ensuring the accuracy and stability of the machining dimensions, helping to obtain higher machining accuracy, and during the machining process, the angle of the cutting edge inclination changes repeatedly (the angle of the cutting edge inclination refers to the angle between the tangential direction of the cutting edge being cut along the cutting edge and the surface of the workpiece being machined. Since the spiral groove is spirally arranged, the cutting edge lobe is also spirally arranged, and the cutting edge on the cutting edge lobe is also spirally arranged, so the angle of the cutting edge inclination also changes repeatedly), which is equivalent to adding a rotational motion, making the cutting more brisk. The segmented cutting method makes the cutting process more stable, reduces the fluctuation of the cutting force, and can effectively reduce the tool marks and roughness on the machined surface. The chip-breaking grooves of the tooth-shaped cutting edge divide the tooth-shaped cutting edge, optimize the distribution of the cutting force while facilitating chip evacuation and heat dissipation, avoid chip accumulation in the cutting area, can be machined with larger parameters, improve the efficiency of rough machining, and extend the tool life. The chip-breaking grooves on the tooth-shaped cutting edge correspond to the peaks and valleys of the waveform cutting edge respectively, so that after passing through the discontinuous part of the tooth-shaped cutting edge during the machining process, the peak or valley of the waveform cutting edge is used for machining. On the one hand, the traces left by the edge of the chip-breaking groove on the machined surface will be removed by the peak or valley of the waveform cutting edge, which does not affect the surface finish. On the other hand, the margin at the peak or valley of the waveform cutting edge is larger than that at other positions, and the impact resistance of the cutting edge is better, which is more conducive to improving the overall life of the tool. Description of the Drawings

[0020] Figure 1 is a schematic structural diagram of the first embodiment of the milling cutter for machining ceramic matrix composites of the present invention.

[0021] Figure 2 is Figure 1 a partial enlarged view of B in

[0022] Figure 3 is Figure 1 the front view in the A direction of

[0023] Figure 4 is Figure 3 the enlarged partial view at position C in

[0024] Figure 5 is the schematic diagram of the wave edge expansion of the waveform cutting edge of the first embodiment of the milling cutter for processing ceramic matrix composites according to the present invention.

[0025] Figure 6 is the schematic diagram of the expansion of the tooth-shaped cutting edge on the rake face of the first embodiment of the milling cutter for processing ceramic matrix composites according to the present invention.

[0026] Figure 7 is the schematic diagram of the peripheral edge expansion of the first embodiment of the milling cutter for processing ceramic matrix composites according to the present invention.

[0027] Figure 8 is the schematic structural diagram of the second embodiment of the milling cutter for processing ceramic matrix composites according to the present invention.

[0028] Figure 9 is Figure 8 the enlarged partial view at position E in

[0029] Each label in the figure represents: 1. Tool shank; 2. Cutting part; 21. Substrate; 22. Helical groove; 23. Blade lobe; 231. Rake face; 232. Flank face; 233. Cutting edge; 2331. Waveform cutting edge; 2332. Tooth-shaped cutting edge; 7. Chip splitter groove; 9. First transitional arc surface; 10. Second transitional arc surface. Specific embodiments

[0030] The following will further elaborate on the present invention. Unless otherwise specified, the instruments or materials used in the present invention are commercially available.

[0031] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0033] In the present invention, unless otherwise clearly specified and defined, terms such as "connected", "connected to", "fixed" and the like should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between 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 specific circumstances.

[0034] Embodiment 1 As Figures 1 to 7 shown, the milling cutter for processing ceramic matrix composites in this embodiment includes a tool shank 1 and a cutting part 2. The cutting part 2 includes spiral grooves 22 and cutting edges 23 arranged at intervals along the outer circumference of the cutting part 2. The spiral grooves 22 are located between adjacent cutting edges 23. Cutting edges 233 are provided on the cutting edges 23. The cutting edges 233 include wave-shaped cutting edges 2331 and tooth-shaped cutting edges 2332. The wave-shaped cutting edges 2331 and the tooth-shaped cutting edges 2332 are located on different cutting edges 23 and are arranged alternately. The wave-shaped cutting edges 2331 and the tooth-shaped cutting edges 2332 cooperate to improve the cutting performance. The relatively small cutting force generated by the wave-shaped cutting edges 2331 can also correspondingly reduce the contact pressure between the tooth-shaped cutting edges 2332 and the workpiece surface. The effect of the tooth-shaped cutting edges 2332 in reducing friction is more significant. At the same time, the reduction of heat brought by the reduction of friction of the tooth-shaped cutting edges 2332 is beneficial to the wave-shaped cutting edges 2331 to cut at a more appropriate temperature. The waveform of the wave-shaped cutting edges 2331 is a sine curve waveform, and the sine curve waveform is periodically arranged along the axial direction of the milling cutter tool. Chip-breaking grooves 7 are periodically arranged at intervals along the axial direction of the milling cutter tool on the tooth-shaped cutting edges 2332. The chip-breaking grooves 7 and the peaks and valleys of the sine curve waveform are arranged correspondingly. The chip-breaking grooves 7 of the tooth-shaped cutting edges 2332 respectively correspond to the peaks and valleys of the wave-shaped cutting edges 2331. So that after the discontinuous part cut by the tooth-shaped cutting edges 2332 in the processing process, the peaks or valleys of the wave-shaped cutting edges 2331 are used for processing. On the one hand, the traces left by the edges of the chip-breaking grooves 7 on the machined surface will be removed by the wave-shaped cutting edges 2331, without affecting the surface finish. On the other hand, the allowance at the peaks or valleys of the wave-shaped cutting edges 2331 is larger than that at other positions, and the impact resistance of the cutting edges is better, which is more beneficial to improving the overall life of the tool.

[0035] The waveform cutting edge 2331 of the present invention is a sine curve waveform, and the peaks and valleys of the cutting edge change periodically. This cutting edge design increases the cutting edge length, reduces the load per unit length, effectively reduces the machining cutting force and accelerates heat dissipation, reduces vibration and deformation, thereby ensuring the accuracy and stability of the machining dimensions, contributing to obtaining higher machining accuracy, and during the machining process, the angle of the cutting edge inclination (the angle of the cutting edge inclination refers to the angle between the cutting edge being cut along the tangential direction of the cutting edge and the surface of the workpiece being machined. Since the spiral groove 22 is spirally arranged, the cutting blade 23 is also spirally arranged, and the cutting edge 233 on the cutting blade 23 is also spirally arranged, so the angle of the cutting edge inclination also changes repeatedly) changes repeatedly, which is equivalent to adding a rotational motion, making the cutting easier. The segmented cutting method makes the cutting process more stable, reduces the fluctuation of the cutting force, and can effectively reduce the tool marks and roughness on the machining surface. The chip-breaking groove 7 of the tooth-shaped cutting edge 2332 divides the tooth-shaped cutting edge 2332 into several serrated micro-edges, making the cutting edge arranged in the form of equidistant micro-edges. While optimizing the cutting force distribution, it is conducive to chip evacuation and heat dissipation, avoiding chip accumulation in the cutting area, and can be machined with larger parameters, improving the rough machining efficiency and extending the tool life. As Figure 3 shown, the cutting blade 23 includes a rake face 231, a flank face 232, and a cutting edge 233 located at the intersection of the rake face 231 and the flank face 232. The chip-breaking groove 7 is provided on the flank face 232 and passes through the tooth-shaped cutting edge 2332 (as Figure 2 shown).

[0036] As Figure 3As shown in the figure, on the plane perpendicular to the central axis of the milling cutter tool, the projection points of the cutting edges 233 on different blade lobes 23 are on the circumference of the same imaginary circle. The imaginary circle is a circle with the projection point O of the central axis of the milling cutter tool as the center and a diameter of d. Let the connection line between the projection point P1 of the waveform cutting edge 2331 and the projection point O be line OP1. The projection point of the adjacent tooth-shaped cutting edge 2332 on the side of the rake face 231 close to the waveform cutting edge 2331 is P2, and the projection point of the adjacent tooth-shaped cutting edge 2332 on the side of the flank face 232 close to the waveform cutting edge 2331 is P2'. The connection lines between the projection points P2, P2' and the projection point O are line OP2 and line OP2' respectively. The included angle between line OP1 and line OP2 is the groove included angle β of the blade lobe 23 where the waveform cutting edge 2331 is located, and the included angle between line OP1 and line OP2' is the groove included angle γ of the blade lobe 23 where the tooth-shaped cutting edge 2332 is located. The helix angle of the helical groove 22 is α. Considering the application and production of the tool and improving the sharpness of cutting and the smoothness of chip evacuation, it satisfies: 8mm ≤ d ≤ 20mm, α = 30° - 40°, β > γ, and the values of β and γ are different, indicating that the helical groove 22 of the present invention has an unequal pitch distribution. When the pitch is unevenly distributed, the cutting intervals of each cutting tooth are different, avoiding the periodic impact of each cutting tooth on the workpiece and thus generating resonance, making the cutting process stable, improving the surface machining quality, and reducing tool wear. In this embodiment, d = 10mm, α = 35°. To better ensure that the helical groove 22 has a certain chip space and at the same time has an effect of suppressing vibration, it satisfies: β = 97°, γ = 83°.

[0037] As Figure 5 shown, let the amplitude of the sine curve waveform be A, and the period along the axial direction of the milling cutter tool be T. To make the tool of the present invention have the characteristics of integrating rough machining and fine machining, and taking into account improving machining efficiency, surface quality and machining accuracy, it satisfies: 0.05mm ≤ A ≤ 0.5mm, 0.04 ≤ A / T ≤ 0.4. In this embodiment, A = 0.2mm, T = 5mm. When the sine curve period is smaller, the waveform cutting edge 2331 is equivalent to the tooth-shaped cutting edge 2332, and the tough fiber-reinforced material can be grabbed during the cutting process, avoiding the bulge defect on the surface of the part.

[0038] As Figure 4 shown, the wave depth h of the sine curve waveform on the rake face 231 is the distance from the cutting edge to the axis direction when grinding the sine wave-shaped rake face 231. The value of the wave depth h affects the size of the first transition arc surface 9 at the bottom of the split groove 7, thereby affecting the smoothness of chip evacuation. Therefore, the value should not be too large or too small, and it satisfies: h = 0.08d - 0.15d. In this embodiment, h = 1.2mm.

[0039] As Figure 7As shown in the figure, let the stagger distance between the waveform cutting edges 2331 on two cutting lips 23 arranged relatively with respect to the center axis of the milling cutter be k1, and let the stagger distance between the tooth-shaped cutting edges 2332 on two cutting lips 23 arranged relatively with respect to the center axis of the milling cutter be k2. To ensure the machining effect, further resist impact, and be conducive to improving the machining efficiency, it is satisfied that: k1 = k2 = T / 2. The setting of the stagger distances k1 and k2 means that when the wave crest of the waveform cutting edge 2331 on a certain cutting lip 23 corresponds to the wave trough of the waveform cutting edge 2331 on the opposite cutting lip 23, the intervals between the two cutting edges in contact with the workpiece are unequal tooth pitches. In this embodiment, k1 = k2 = 2.5 mm.

[0040] As Figure 6 shown, the depth of the chip splitter groove 7 is t, and the width in the axial direction of the milling cutter tool is w. According to the machining requirements, to balance the cutting edge strength and the chip splitting and heat dissipation functions, it is satisfied that: t = 0.2 mm to 0.5 mm, w = 0.15T to 0.25T. At this time, the width and depth of the chip splitter groove 7 are neither too large nor too small. In this embodiment, t = 0.4 mm and w = 1 mm.

[0041] As Figure 6 shown, the bottom and the wall of the chip splitter groove 7 are connected by a first transition arc surface 9, and the top of the chip splitter groove 7 and the flank 232 are connected by a second transition arc surface 10. The radius of the first transition arc surface 9 is R1, and the radius of the second transition arc surface 10 is R2. The first transition arc surface 9 promotes good chip evacuation, and the second transition arc surface 10 ensures the tip strength. It is satisfied that: R1 = 0.05 mm to 0.15 mm, R2 = 0.05 mm to 0.1 mm. In this embodiment, R1 = 0.1 mm and R2 = 0.05 mm. The first transition arc surface 9 and the second transition arc surface 10 can avoid the impact and chipping of the cutting edge and guide the chips into the spiral groove 22; As Figure 7As shown, the length of the first chip breaker groove 7 on the cutting blade 23 from the end face of the milling cutter is L1, satisfying L1 = T / 4 - w / 2. The stagger distance between the waveform cutting edges 2331 on two different cutting blades 23 is k1, and the stagger distance between the tooth-shaped cutting edges 2332 on two different cutting blades 23 is k2. The pitch between the central axes of adjacent chip breaker grooves 7 on the same cutting blade 23 (which is also the pitch of the tooth-shaped cutting edge 2332) is p. Since the chip breaker grooves 7 of the tooth-shaped cutting edge 2332 correspond to the wave crests and wave troughs of the waveform cutting edge 2331 respectively, after the discontinuous part is cut by the tooth-shaped cutting edge 2332 during the machining process, the wave crest or wave trough of the waveform cutting edge 2331 is used for machining. The allowance here is larger than that at other positions, and better impact resistance of the cutting edge is required. The wave crest or wave trough position of the waveform cutting edge 2331 just meets this characteristic. To achieve the best matching effect between the waveform cutting edge 2331 and the tooth-shaped cutting edge 2332, p = T / 2 is satisfied. In this embodiment, p = 2.5 mm and L1 = 0.75 mm. The pitch between the central axes of adjacent chip breaker grooves 7 in the present invention is the same as the half period of the sine curve waveform. Based on the uneven pitch distribution of the spiral groove 22, the adjacent tooth stagger distance is related to the period, making any axial section of the cutting edge an uneven tooth structure, which can effectively suppress vibration and improve cutting smoothness. The micro-edges of the tooth-shaped cutting edge 2332 in the present invention are closely distributed, enabling the machined part to obtain better surface quality.

[0042] As Figure 2 and Figure 3 shown, in this embodiment, the cutting part 2 includes a substrate 21, and the cutting blade 23 is located on the substrate 21. The cutting blade 23 is made of PCD material directly grown on the substrate 21 by physical vapor deposition or chemical vapor deposition. The PCD material has extremely high hardness, enabling the tool to have good wear resistance and thus a longer service life.

[0043] As Figure 4 shown, let the rake angle of the cutting blade 23 be β1. The flank face 232 of the cutting blade 23 includes a first flank face and a second flank face. The first flank face is located between the cutting edge 233 and the second flank face. The flank angle of the first flank face is α1, and the flank angle of the second flank face is α2. Considering the characteristics of the workpiece material (high hardness and brittleness, high hardness of the reinforcement and sharp edges), it satisfies: 0° ≤ β1 ≤ 3°, 8° ≤ α1 ≤ 12°, 20° ≤ α2 ≤ 25°.

[0044] In this embodiment, the substrate 21 is made of cemented carbide material. The cemented carbide has good toughness, enabling the tool to resist the impact during machining and giving play to its advantages in high-efficiency machining.

[0045] The number of the spiral grooves 22 of the present invention is 4, the spiral grooves 22 are distributed with unequal pitches, the number of the cutting edges 233 is 4, wherein the cutting edges 233 on one pair of the blade petals 23 are wave-shaped cutting edges 2331, and the cutting edges 233 on the other pair of the blade petals 23 are tooth-shaped cutting edges 2332.

[0046] Embodiment 2 Figure 8 and Figure 9 Fig. shows the second embodiment of the present invention. This embodiment is basically the same as the first embodiment, except that: in this embodiment, the period T is 2 mm. Correspondingly, the associated parameters also change accordingly. Specifically, in this embodiment, d = 10 mm, α = 35°, β = 97°, γ = 83°, A = 0.2 mm, T = 2 mm, h = 1.2 mm, t = 0.3 mm, w = 0.4 mm, R1 = 0.08 mm, R2 = 0.05 mm, p = 1 mm, L1 = 0.3 mm, β1 = 1°, α1 = 9°, α2 = 22°.

[0047] Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of the protection of the technical solution of the present invention.

Claims

1. A milling cutter for machining ceramic matrix composite materials, comprising a tool holder (1) and a cutting portion (2), the cutting portion (2) comprising a plurality of spiral grooves (22) and blade lobes (23) arranged at intervals around the outer circumference of the cutting portion (2), the spiral grooves (22) being located between adjacent blade lobes (23), the blade lobes (23) being provided with cutting edges (233), characterized in that: The cutting edge (233) comprises a corrugated cutting edge (2331) and a toothed cutting edge (2332); the corrugated cutting edge (2331) and the toothed cutting edge (2332) are located on different blade petals (23) and are arranged alternately; the waveform of the corrugated cutting edge (2331) is a sinusoidal waveform; the sinusoidal waveform is periodically arranged along the axial direction of the milling cutter; the toothed cutting edge (2332) is provided with chip dividing grooves (7) at periodic intervals along the axial direction of the milling cutter; the chip dividing grooves (7) are arranged correspondingly to the crests and troughs of the sinusoidal waveform.

2. The milling cutter for machining ceramic matrix composite materials according to claim 1, characterized in that: The blade flap (23) comprises a front cutting surface (231), a rear cutting surface (232), and a cutting edge (233) located at the intersection of the front cutting surface (231) and the rear cutting surface (232); the chip dividing groove (7) is arranged on the rear cutting surface (232) and passes through the toothed cutting edge (2332).

3. The milling cutter for machining ceramic matrix composite materials according to claim 2, characterized in that: On a plane perpendicular to the center axis of the milling cutter, the projection points of the cutting edges (233) on different blade petals (23) are on the circumference of the same imaginary circle, the imaginary circle being a circle with a projection point O of the center axis of the milling cutter as the center and a diameter d, the line between the projection point P1 and the projection point O of the wavy cutting edge (2331) being the line OP1, the projection point of the toothed cutting edge (2332) adjacent to the front cutting edge (231) close to the wavy cutting edge (2331) being the projection point P2, and the projection point of the toothed cutting edge (2332) adjacent to the rear cutting edge (232) close to the wavy cutting edge (2331) being the projection point P3. ) on one side and adjacent to the toothed cutting edge (2332) is P2', the lines connecting the projection points P2 and P2' and the projection point O are line OP2 and line OP2', the angle between line OP1 and line OP2 is the groove angle β of the blade flap (23) where the wavy cutting edge (2331) is located, the angle between line OP1 and line OP2' is the groove angle γ of the blade flap (23) where the toothed cutting edge (2332) is located, the helix angle of the spiral groove (22) is α, satisfying: 8mm≤d≤20mm, α=30°~40°, β>γ.

4. The milling cutter for machining ceramic matrix composite materials according to claim 2 or 3, characterized in that: The amplitude of the sinusoidal waveform is A, and one period along the axial direction of the milling cutter is T, which satisfies: 0.05mm≤A≤0.5mm, 0.04≤A / T≤0.

4.

5. The milling cutter for machining ceramic matrix composite materials according to claim 3, characterized in that: The wave depth of the sinusoidal waveform on the front cutting edge (231) is h, which satisfies: h = 0.08d~0.15d.

6. The milling cutter for machining ceramic matrix composite materials according to claim 4, characterized in that: Assuming that the offset between the corrugated cutting edges (2331) on the blade flap (23) relatively arranged with respect to the center axis of the milling cutter is k1, and the offset between the toothed cutting edges (2332) on the blade flap (23) relatively arranged with respect to the center axis of the milling cutter is k2, it satisfies: k1=k2=T / 2.

7. The milling cutter for machining ceramic matrix composite materials according to claim 4, characterized in that: The chip dividing groove (7) has a depth of t and a width along the axial direction of the milling cutter tool of w, satisfying the following conditions: t=0.2 mm to 0.5 mm, w=0.15 T to 0.25 T.

8. The milling cutter for machining ceramic matrix composite materials according to claim 4, characterized in that: The bottom and the wall of the chip groove (7) are connected via a first transition arc surface (9), and the top and the back tool surface (232) of the chip groove (7) are connected via a second transition arc surface (10). The radius of the first transition arc surface (9) is R1, and the radius of the second transition arc surface (10) is R2, satisfying the following conditions: R1=0.05mm-0.15mm, and R2=0.05mm-0.1mm.

9. The milling cutter for machining ceramic matrix composite materials according to claim 7, characterized in that: The length of the first chip dividing groove (7) on the blade (23) from the end face of the milling cutter is L1, satisfying the condition that L1=T / 4-w / 2.

10. The milling cutter for machining ceramic matrix composite materials according to claim 4, characterized in that: The pitch between the central axes of adjacent chip dividing grooves (7) on the same blade (23) is p, satisfying p=T / 2.

11. The milling cutter for machining ceramic matrix composite materials according to any one of claims 1 to 3, characterized in that: The cutting portion (2) further comprises a substrate (21), the blade (23) being located on the substrate (21), and the blade (23) being made of PCD material grown directly on the substrate (21) by a physical vapor deposition method or a chemical vapor deposition method.

12. The milling cutter for machining ceramic matrix composite materials according to claim 2 or 3, characterized in that: The front angle of the blade flap (23) is β1, and the back tool surface (232) of the blade flap (23) includes a first back tool surface and a second back tool surface, the first back tool surface is located between the cutting edge (233) and the second back tool surface, the back angle of the first back tool surface is α1, and the back angle of the second back tool surface is α2, satisfying: 0°≤β1≤3°, 8°≤α1≤12°, and 20°≤α2≤25°.

Images