A bionic integral ceramic end mill cutter and its application

Abstract

The present invention discloses a bionic integral ceramic end mill cutter and its application, belonging to the technical field of end mills. A bionic integral ceramic end mill cutter includes a shank portion and a cutting edge portion. The cutting edge portion includes a side cutting edge and a bottom cutting edge. The outer circular edge of the side cutting edge adopts a bionic structure of the barbs on the femur of a mantis. The angle between the side cutting edges is an unequal helix angle structure, and a micro-texture structure is arranged on the rake face of the side cutting edge. The bionic integral ceramic end mill cutter is applied in the milling of nickel-based superalloys. By using the bionic integral ceramic end mill cutter of the present invention, the problems of severe wear and short tool life of existing tools when cutting nickel-based superalloys can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of milling cutters, and in particular to a bionic integral ceramic end mill cutter and its application. Background Art

[0002] Nickel-based superalloys have Ni as the main matrix and contain alloying elements such as Cu, Cr, and Mo. Their strength remains very high at 650 - 1000 °C, and they have good oxidation resistance, corrosion resistance, and tissue stability. Nickel-based superalloys are the most widely used type of alloy, and components such as blades, disk shafts, and casings in the high-temperature working areas of aeroengines are made of nickel-based superalloys.

[0003] The machinability of nickel-based superalloys is relatively poor, and its poor machinability is mainly manifested in the following aspects: (1) Large cutting force: Nickel-based superalloys have high high-temperature strength, and under the same cutting conditions, the deformation resistance and friction force generated during cutting are greater than those of ordinary steel, and the cutting force fluctuates greatly, which is likely to cause cutting vibration. (2) High cutting temperature: During the cutting process, large plastic deformation occurs in nickel-based alloys, and intense friction occurs between the tool and the workpiece and between the tool and the chip. Deformation and friction generate a large amount of heat, and its thermal conductivity is poor, with the thermal conductivity coefficient being lower than 30% of that of 45 steel, and the cutting temperature can reach twice that of ordinary steel. (3) Large work hardening tendency: When nickel-based superalloys undergo plastic deformation during high-speed cutting, residual stress will be generated inside. In addition, the strengthening phases in the alloy precipitate from the solid solution, resulting in a dispersion strengthening effect, which causes the strength and microhardness of the machined surface to increase by 1.5 - 2 times, while the toughness is significantly reduced. Therefore, the cutting tools for nickel-based superalloys should have good wear resistance, high hardness, strength, fracture toughness, thermal shock resistance, and high-temperature chemical stability.

[0004] Due to the long-term exposure of organisms to complex working conditions or the interaction of energy and matter with the surrounding environment, various types of forms, configurations, materials, and structures have been optimized, providing new ideas for the research of structural problems faced in the artificial field. Therefore, structural bionics has been widely applied in research. The existing patent CN202311179175.9 discloses a coupled bionic end mill, which includes a shank part, a core part, and a cutting part. The front face of the peripheral cutting teeth consists of a first front face, a second front face, a third front face, and a first transition arc. The first front face is determined by arc A1 and chord length L1, the second front face is determined by straight line L2, the third front face is determined by arc A2 and chord length L3. The radial profile of the front face of the peripheral cutting teeth is a convex circle - straight line - concave circle structure, and the radial profile of its flank face is a straight line type. The cutting part is divided into three equal parts: the first part, the second part, and the third part. The helix angle of the first part is 44° - 42°, the helix angle of the second part is 42° - 39°, and the helix angle of the third part is 39° - 34°. The above-mentioned coupled bionic end mill has the characteristics of small cutting force, being easy to cut into the workpiece, reducing or even eliminating vibration to a certain extent, improving the transmission smoothness, increasing the chip pocket area and chip evacuation volume, and facilitating the discharge of chips. However, the above patent cannot meet the cutting requirements of nickel-based superalloys, and the chips cause serious wear to the cutting edges, affecting the service life of the tool. Summary of the Invention

[0005] The purpose of the present invention is to provide a bionic integral ceramic end mill tool and its application, aiming to solve the problems of severe wear and short tool service life when the existing tools cut nickel-based superalloys.

[0006] To achieve the above purpose, the present invention provides a bionic integral ceramic end mill tool, which includes a shank part and a cutting edge part. The cutting edge part includes a side cutting edge and a bottom cutting edge. The outer circular edge of the side cutting edge adopts a bionic structure of the barbs on the femur of a mantis. The angle between the side cutting edges is an unequal helix angle structure, and a micro-texture structure is arranged on the front face of the side cutting edge.

[0007] Preferably, the side cutting edge includes a first spiral edge, a second spiral edge, a third spiral edge, and a fourth spiral edge arranged in sequence. The angle β1 of the first spiral edge is 25° - 30°, the angle β2 of the second spiral edge is 30° - 35°, the angle β3 of the third spiral edge is 25° - 30°, and the angle β4 of the fourth spiral edge is 30° - 35°.

[0008] Preferably, the four end teeth of the bottom cutting edge have an unequal tooth structure, a chip pocket is arranged between the bottom cutting edge and the outer circular edge, and a spiral chip evacuation groove is arranged between adjacent side cutting edges.

[0009] Preferably, the ratio of the core diameter to the outer diameter of the side cutting edge is 0.63 - 0.65:1, and the milling cutter diameter is 20 mm - 30 mm.

[0010] Preferably, the micro-texture structure is an X-shaped structure. The micro-texture structure is evenly distributed on the rake face. The width of the micro-texture is 20 μm, the length is 50 μm, and the micro-texture is filled with graphene powder.

[0011] Preferably, the tool is a (Zr,W)C-based solid solution ceramic tool material.

[0012] Preferably, the preparation method of the (Zr,W)C-based solid solution ceramic tool material includes the following steps:

[0013] S1. Weigh ZrO2, WO3 and carbon black according to the material ratio. The mass percentage of ZrO2 is 10% - 20%, the mass percentage of WO3 is 20% - 30%, and the mass percentage of carbon black is 50% - 70%.

[0014] S2. Perform high-energy ball milling on ZrO2, WO3 and carbon black to obtain a mixed material. The ball milling time is 12 hours.

[0015] S3. Sinter the mixed material at high temperature to obtain the (Zr,W)C-based solid solution ceramic tool material.

[0016] Preferably, the sintering temperature is 2000 °C, the heating rate is 100 °C / min, the holding time is 60 min, and the axial pressure is 60 MPa.

[0017] Preferably, the graphene powder is placed into the micro-texture. After ultrasonic vibration, it is placed in a sintering furnace for sintering. During sintering, first raise the temperature to 1200 °C at a heating rate of 40 °C / min and hold for 1 minute at 1200 °C; then raise the temperature to 1700 °C at a heating rate of 25 °C / min, the applied pressure is 35 Mpa, and hold and maintain pressure for 15 minutes at 1700 °C; finally, stop heating and pressurizing, and cool down to room temperature with the furnace.

[0018] The above bionic integral ceramic end mill is applied in the milling of nickel-based superalloys.

[0019] The advantages and positive effects of the bionic integral ceramic end mill tool and its application described in the present invention are:

[0020] 1. The tool of the present invention uses a (Zr,W)C-based solid solution ceramic tool material, which has high strength, high hardness and high fracture toughness, and can effectively improve the wear resistance, service life and high-temperature chemical stability of the tool.

[0021] 2. Design the included angle of the side cutting edge of the tool. The included angle β1 of the first helical edge is 25° - 30°, the included angle β2 of the second helical edge is 30° - 35°, the included angle β3 of the third helical edge is 25° - 30°, and the included angle β4 of the fourth helical edge is 30° - 35°. This can effectively reduce tool vibration and improve machining quality.

[0022] 3. Set a micro-texture structure on the rake face of the outer circle edge. The micro-texture is in an X shape, and graphene powder is filled in the micro-texture structure. The graphene powder precipitates under the action of cutting heat, reducing the friction between the rake face and the chip, reducing the wear of the rake face, and improving the service life of the tool.

[0023] Next, through the attached drawings and embodiments, the technical solution of the present invention will be further described in detail. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of the tool structure according to the embodiment of the present invention;

[0025] Figure 2 It is a schematic cross-sectional structure diagram of the tool according to the embodiment of the present invention;

[0026] Figure 3 It is a schematic diagram of the micro-texture structure according to the embodiment of the present invention.

[0027] Reference Signs

[0028] 1. Tool shank part; 2. Cutting edge part; 3. Side cutting edge; 4. Bottom cutting edge; 5. Outer circle edge; 6. Chip pocket; 7. First helical edge; 8. Second helical edge; 9. Third helical edge; 10. Fourth helical edge; 11. Core part; 12. Micro-texture structure; 13. Chip evacuation groove. Detailed Embodiment

[0029] The technical solution of the present invention will be further described below through the attached drawings and embodiments.

[0030] Unless otherwise defined, the technical terms or scientific terms used in this invention shall have the ordinary meanings as understood by those of ordinary skill in the field to which this invention pertains. The "first", "second" and similar terms used in this invention do not denote any order, quantity or importance, but are only used to distinguish different components. Words such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0031] Embodiment

[0032] As Figure 1 、 Figure 2 shown. A bionic integral ceramic end mill cutter includes a tool shank portion 1 and a cutting edge portion 2, and the cutting edge portion 2 is provided at one end of the tool shank. In this embodiment, the end mill is a four-edge end mill. The end mill uses a (Zr,W)C-based solid solution ceramic tool material.

[0033] (The preparation method of the (Zr,W)C-based solid solution ceramic tool material includes the following steps:

[0034] S1. Weigh ZrO2, WO3 and carbon black according to the material ratio. The mass percentage of ZrO2 is 10%-20%, the mass percentage of WO3 is 20%-30%, and the mass percentage of carbon black is 50%-70%. In this embodiment, the mass percentage of ZrO2 is 15%, the mass percentage of WO3 is 25%, and the mass percentage of carbon black is 60%.

[0035] S2. Perform high-energy ball milling on ZrO2, WO3 and carbon black to obtain a mixed material, and the ball milling time is 12 hours.

[0036] S3. Sinter the mixed material at a high temperature to obtain the (Zr,W)C-based solid solution ceramic tool material.

[0037] The sintering temperature is 2000 °C, the heating rate is 100 °C / min, the holding time is 60 min, and the axial pressure is 60 MPa.

[0038] (Zr,W)C-based solid solution ceramic cutting tool materials have high strength, high hardness and high fracture toughness, which can effectively improve the wear resistance and service life of the cutting tools; at the same time, improve the high-temperature chemical stability of the milling cutters. However, it is difficult for the milling cutters formed with this material as the carrier to obtain a good machined surface on the surface of nickel-based superalloys, and there are still problems such as low tool life. Therefore, it is necessary to further improve its structure on the basis of this tool material.

[0039] The cutting edge part 2 includes a side cutting edge 3 and a bottom cutting edge 4. The outer circular edge 5 of the side cutting edge 3 adopts a bionic structure of the barbs on the mantis leg segment. The three-dimensional topography of the barbs is extracted by a three-dimensional non-contact white light interferometer, and the three-dimensional structure of the barbs is obtained by processing the scanned image with the three-dimensional analysis software SPIP of Boyue Instrument Co., Ltd., and the outer circular edge 5 of the cutting tool is machined based on the three-dimensional structure of the barbs. The outer circular edge 5 of the cutting tool is bionically designed with the barbs on the mantis leg segment, which effectively improves the integrity of the machined surface under the condition of meeting the machining efficiency. The rake face is connected to the core part 11 of the cutting edge through a transition arc, presenting a straight-concave circle-convex circle structure. The flank face is connected to the core part 11 of the cutting tool through a transition arc, presenting a straight-convex circle-convex circle structure.

[0040] Nickel-based superalloys are mainly used in the aerospace field, and frame parts are parts that are often machined in the aerospace field. In milling, as the material removal amount increases, its weak stiffness characteristics gradually appear, the sensitivity to cutting force increases significantly, and the change of force is extremely likely to cause tool chatter, resulting in an unstable cutting state, and finally causing machining deformation. The present invention designs the angle between the side cutting edges 3 to reduce the tool chatter caused during the machining process.

[0041] The angle between the side cutting edges 3 is an unequal helix angle structure, and the angle is the angle between the side cutting edge 3 and the tool axis. The side cutting edge 3 includes a first helical edge 7, a second helical edge 8, a third helical edge 9 and a fourth helical edge 10 arranged in sequence. The angle β1 of the first helical edge 7 is 25°-30°, the angle β2 of the second helical edge 8 is 30°-35°, the angle β3 of the third helical edge 9 is 25°-30°, and the angle β4 of the fourth helical edge 10 is 30°-35°. By designing the angle between the side cutting edges 3, the axial time-varying characteristics caused by the unequal helix angles of adjacent cutting edges change the time-domain periodicity of the milling force of the traditional end mill, effectively reducing the tool chatter during the machining process and improving the machining quality.

[0042] The four end-tooth cutting edges of the bottom cutting edge 4 are an unequal-tooth structure, a chip groove 6 is arranged between the bottom cutting edge 4 and the outer circular edge 5, and a spiral chip evacuation groove 13 is arranged between adjacent side cutting edges 3.

[0043] The ratio of the diameter of the core 11 to the outer diameter of the side cutting edge 3 is 0.63 - 0.65:1, and such a setting ensures sufficient chip space. The diameter of the milling cutter is 20 mm - 30 mm and it can be used for face milling.

[0044] As Figure 3 shown. When milling nickel-based superalloys, the wear of the rake face is relatively serious, which affects the service life of the tool. A micro-texture structure 12 is provided on the rake face of the side cutting edge 3. The micro-texture structure 12 is an X-shaped structure and is evenly distributed on the rake face. The width of the micro-texture is 20 μm, the length is 50 μm, and the distance between adjacent micro-textures is 10 μm - 30 μm. The micro-texture is filled with graphene powder.

[0045] Put the graphene powder into the micro-texture, and through ultrasonic vibration, the air between the graphene powders is discharged to make the graphene powders dense. Put the tool filled with graphene powder into a sintering furnace for sintering to achieve the effect of solidification. During sintering, first raise the temperature to 1200 °C at a heating rate of 40 °C / min and keep it at 1200 °C for 1 minute. Then raise the temperature to 1700 °C at a heating rate of 25 °C / min, and apply uniform and slow pressure during the heating process. When the temperature rises to 1700 °C, the applied pressure is 35 Mpa. Keep the temperature and pressure at 1700 °C for 15 minutes. Finally, stop heating and pressurizing, and cool down to room temperature with the furnace.

[0046] During the cutting process of the tool on nickel-based superalloys, the cutting heat generated during the processing causes graphene to precipitate, reducing the friction between the rake face and the chip, reducing the wear of the rake face, and improving the service life of the tool.

[0047] Therefore, by using the bionic integral ceramic end mill tool of the present invention, the problems of serious wear and short tool service life of existing tools when cutting nickel-based superalloys can be solved.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A bionic integral ceramic end mill cutter, characterized in that: It includes a tool shank part and a cutting edge part. The cutting edge part includes a side cutting edge and a bottom cutting edge. The outer circular edge of the side cutting edge adopts a bionic structure of barbs on the femur of a praying mantis. The angle between the side cutting edges is an unequal helix angle structure, and a micro-texture structure is arranged on the rake face of the side cutting edge. The side cutting edge includes a first spiral edge, a second spiral edge, a third spiral edge, and a fourth spiral edge arranged in sequence. The angle β1 of the first spiral edge is 25°-30°, the angle β2 of the second spiral edge is 30°-35°, the angle β3 of the third spiral edge is 25°-30°, and the angle β4 of the fourth spiral edge is 30°-35°. The micro-texture structure is an X-shaped structure. The micro-texture structure is evenly distributed on the rake face. The width of the micro-texture is 20μm, the length is 50μm, the distance from the micro-texture to the cutting edge is 500μm, and the micro-texture is filled with graphene powder. The graphene powder is put into the micro-texture, and after ultrasonic vibration, it is put into a sintering furnace for sintering. When sintering, first raise the temperature to 1200℃ at a heating rate of 40℃ / min and keep it at 1200℃ for 1 minute; then raise the temperature to 1700℃ at a heating rate of 25℃ / min, the applied pressure is 35Mpa, and keep it at 1700℃ for heat preservation and pressure holding for 15 minutes; finally, stop heating and pressurizing, and cool it to room temperature with the furnace. The tool material is a (Zr, W)C-based solid solution ceramic tool material. The bionic integral ceramic end mill is applied in the milling of nickel-based superalloys.

2. The bionic integral ceramic end mill cutter according to claim 1, characterized in that: The four end-tooth cutting edges of the bottom cutting edge have an unequal tooth structure. A chip pocket is arranged between the bottom cutting edge and the outer circular edge, and a spiral chip groove is arranged between adjacent side cutting edges.

3. The bionic integral ceramic end mill cutter according to claim 1, characterized in that: The rake face is connected to the core of the cutting edge through a transition arc. The ratio of the core diameter to the outer diameter of the side cutting edge is 0.63-0.65:1, and the diameter of the end mill is 20mm-30mm.

4. A bionic integral ceramic end mill cutter according to claim 1, characterized in that, The preparation method of the (Zr, W)C-based solid solution ceramic tool material includes the following steps: S1. Weigh ZrO2, WO3, and carbon black according to the material ratio. The mass percentage of ZrO2 is 10%-20%, the mass percentage of WO3 is 20%-30%, and the mass percentage of carbon black is 50%-70%. S2. Perform high-energy ball milling on ZrO2, WO3, and carbon black to obtain a mixture. The ball milling time is 12 hours. S3. Perform high-temperature sintering on the mixture to obtain a (Zr, W)C-based solid solution ceramic tool material.

5. The bionic integral ceramic end mill cutter according to claim 4, characterized in that: The sintering temperature is 2000℃, the heating rate is 100℃ / min, the heat preservation time is 60min, and the axial pressure is 60MPa.

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