AU2018437433B2

AU2018437433B2 - Micro-textured cutter based on silicon brass structure and processing method and application thereof

Info

Publication number: AU2018437433B2
Application number: AU2018437433A
Authority: AU
Inventors: Yanfei DING; Liang Liang; Chao Yang; Yuchuan Yang
Original assignee: Guangdong Huayi Plumbing Fittings Industry Co Ltd; South China University of Technology SCUT
Current assignee: Guangdong Huayi Plumbing Fittings Industry Co Ltd; South China University of Technology SCUT
Priority date: 2018-08-22
Filing date: 2018-09-21
Publication date: 2022-01-06
Anticipated expiration: 2038-09-21
Also published as: WO2020037759A1; CN108856753A; CN108856753B; AU2018437433A1

Abstract

A micro-textured cutter based on a silicon brass structure. A composite micro-texture is provided in a certain area range of a cutting edge (4) of a cutter (1) and comprises a raised texture array and a longitudinal texture array, wherein the raised texture array is located between the cutting edge and the longitudinal texture array; the raised texture array comprises a plurality of raised textures (6) arranged in a rectangular array, and the raised texture (6) has a cube at the bottom and a trapezoidal table at an upper end; and the longitudinal texture array comprises a plurality of longitudinal textures (5) arranged in lines in a widthwise direction of the cutting edge, and the longitudinal texture (5) is a cuboid and has a lengthwise direction perpendicular to the width direction of the cutting edge.

Description

MICRO-TEXTURED CUTTER BASED ON SILICON BRASS STRUCTURE AND PROCESSING METHOD AND APPLICATION THEREOF

FIELD OF THE INVENTION The present invention relates to the technical field of cutting high-performance alloy materials, in particular to a micro-textured cutter based on silicon brass structure, a processing method therefor and a use thereof. BACKGROUND OF THE INVENTION As a typical representative of copper alloy, lead brass is widely used in the manufacture of electronic and electrical parts, instrumentation parts, bathroom products, children's toys and other products due to its excellent strength, toughness, corrosion resistance, free cutting and high formability. However, lead is a heavy metal element. When lead brass products are not handled properly during the long-term use or after being discarded, they are easy to have a great impact on human health and natural environment. Therefore, the development of a new type of free-cutting environmentally friendly brass has become an issue of increasing concern. In view of this, the development and use of silicon brass has attracted more and more attention. Adding Si and Al to brass can greatly increase the zinc equivalent coefficient, thereby obtaining brass with higher phase content; even when the zinc equivalent exceeds a certain value, a hard and brittle phase will appear (see CN105274387A for Lead-free free-cutting high-strength corrosion-resistant silicon brass alloy, preparation method therefor and use thereof). Besides, ultrafine intermetallic compounds with high hardness will be distributed in the silicon brass grains and at the grain boundaries, thus forming an "uneven structure", and different constituent phases and intermetallic compounds can play a good role in chip breaking during cutting because of the significant differences in the elastic modulus, thermal expansion coefficient and microhardness thereof (see C. Yang, Z. Ding, Q.C. Tao, L. Liang, Y.F. Ding,WW. Zhang, Q.L. Zhu. High-strength andfree-cuttingsilicon brasses designed via the zinc equivalent rule. Materials Science & Engineering A, 723 (2018) 296-305). For silicon brass with a certain range of Si content, the cutting performance is much improved, with the optimal cutting performance reaching more than 80% to 90% of that of lead brass; however, from the aspects of alloy material composition and structure design as well as optimization of cutting parameters, the ability to improve the chip breaking or free cutting performance of alloy materials is limited. Therefore, how to improve the chip breaking or free cutting performance of silicon brass by improving cutters has become an urgent technical problem to be solved. Cutting processing refers to a machining method that uses cutting tools (including cutters, grinders and abrasives) to cut excess material layers on the blank or workpiece into chips, so that the workpiece can obtain the specified geometry, size and surface quality. Turning is the most important technological means of mechanical cutting. A cutter occupies a dominant position in this process. The cutter structure is critical to the chip breaking ability during the cutting process. Besides, phase composition, phase size and hardness, grain size and mechanical properties of microscopic regions determined by the grain size significantly affect the cutter wear and the chip breaking or free cutting performance of the alloy material being cut. Therefore, we put forward an academic idea of designing a composite micro-texture on the cutter based on the alloy material structure, so as to effectively improve the chip breaking or free cutting performance of the alloy materials. The micro-textured cutter is obtained by providing a micro-structure array with a certain size and uniform distribution on the surface of the cutter through a certain processing technology. The surface micro-texture processing technology mainly includes laser processing, micro-cutting processing, grinding processing, electrical discharge machining, reactive ion etching, photolithography technology, ultrasonic processing, surface embossing technology, etc. Among them, laser processing technology is considered to be one of the very successful processing methods in the field of surface texture, mainly because it has no pollution to the environment and has excellent shape and size control capabilities. At present, a lot of studies on bionic tribology have found that the high-performance surface micro-texture on the cutter can achieve good friction reduction and adhesion resistance, and promote the curling and breaking of chips, which has very broad application prospect, and also brings a new research direction and theoretical basis to the friction reduction between the cutter and the workpiece surface. Theoretically, in the cutting process, the contact between the cutter and the chip includes close contact and peak-point contact. In the close contact part, the friction force between the cutter and the chip is large, which makes the chip easy to get serious adhesion on the cutter; while for the peak-point contact, with the chips sliding out, the friction force gradually decreases, and there is also some adhesion. The friction force and adhesion between the cutter and the chip will reduce the flow speed of the cutting surface of the chips, which is not conducive to the deformation and fracture of the chips. Therefore, it is very important to improve the chip breaking or free cutting performance of alloy materials by designing the micro-texture of the cutter to change the contact form between the chip and the cutter. CONTENTS OF THE INVENTION In view of the technical problems existing in the prior art, the object of the present invention is to provide a micro-textured cutter based on silicon brass structure that can greatly improve the chip breaking or free cutting performance of silicon brass, as well as a processing method therefor and a use thereof. In order to achieve the above object, the present invention adopts the following technical solution: A micro-textured cutter based on silicon brass structure is provided; the cutter is provided within a certain area of the cutting edge with a composite micro-texture, which comprises a longitudinal texture array, and a convex texture array located between the longitudinal texture array and the cutting edge; the convex texture array comprises a plurality of convex textures arranged in a rectangular array, the convex texture being of a cube at the bottom and of a trapezoidal platform at the upper end; the longitudinal texture array comprises a plurality of longitudinal textures arranged in rows along the width direction of the cutting edge, the longitudinal texture being of a cuboid, the length direction thereof being perpendicular to the width direction of the cutting edge. Preferably, in the direction perpendicular to the cutting edge, the composite micro-texture is 10-30 pm away from the cutting edge, the length of the composite micro-texture is 3 mm, the length of the convex texture array is 110-150 pm, and the longitudinal texture array is 10-20 pm away from the convex texture array. Preferably, the cube at the bottom of the convex texture has a length of side of 40-50 pm; the convex texture is of a rectangle at the upper end face thereof, the length of the rectangle being identical to the length of side of the cube at the bottom of the convex texture in the direction perpendicular to the cutting edge, the width of the rectangle being 10-20 pm in the direction parallel to the cutting edge. Preferably, the spacing between the adjacent longitudinal textures is 20-100 pm, which can effectively reduce friction and adhesion of chips in close contact and peak-point contact zones, promote back flow of chips, and facilitate curling and breaking of chips. Preferably, the convex texture of the convex texture array functions as the cutting point of the cutting edge; in the longitudinal texture array, when the chips cross the longitudinal texture, a certain number of the longitudinal textures act on a range of grain size at the same time, which makes the grains deform more easily and promotes chip deformation and fracture. A method for processing the micro-textured cutter based on silicon brass structure is provided, comprising the following steps: (1) preparing a cutter; (2) designing a composite micro-texture; (3) processing the composite micro-texture of step (2) on the cutter of step (1) by laser processing; (4) preparing an alloy material; and (5) subjecting the cutter obtained in step (3) to a cutting test on the alloy material of step (4). Preferably, step (1): selecting a YG8 cemented carbide cutter and determining the position of a cutting edge to be processed, sanding and polishing the rake face of the cutter with 1500# metallographic sandpaper, and cleaning and blowing dry; step (2): placing the polished cutter in a laser processing machine, focusing to make the laser energy focused on the cutter, and then designing the composite micro-texture on the surface of the cutter; step (3): performing laser processing near the cutting edge of the rake face of the cutter, with the specific parameters as follows: processing number 80-150, processing speed 400-600 mm/s, processing power 5-10 W, and processing frequency 10-50 KHz; after processing the composite micro-texture, sanding and polishing the rake face of processed convex melt with metallographic sandpaper, and ultrasonically cleaning and blowing dry; and step (5): subjecting the designed micro-textured cutter and a non-textured cutter to a cutting test under the same conditions, with the cutting parameters as follows: cutting speed 80-100 m/min, feed rate 0.1-0.2 mm/r, and back-feeding amount 0.1-0.6 mm; after cutting, collecting the chips for analysis and comparison to evaluate the chip breaking performance of the micro-textured cutter. Preferably, in step (4), preparing pure metal materials according to the mass percentages of 58.5% to 60% of Cu, 37% to 39% of Zn, 0.7% to 1.11% of Si, 0.5% to 1% of Al, 0.01% to 0.1% of Ti, and 0 to 0.01% of B, and preparing silicon brass alloy by low-pressure casting process, with the low-pressure casting process parameters as follows: casting temperature 900°C to 1100°C, filling time

3-6 s, pressure held 0.01-0.04 MPa, and pressure holding time 10-15 s. Preferably, the alloy material in step (4) is brass alloy, titanium alloy or iron alloy; when the brass alloy is used, the preparation process is low-pressure casting; when the titanium alloy is used, the preparation process is casting plus plastic deformation. The size of alloy materials can be adjusted according to the size of engineering parts. The micro-textured cutter based on silicon brass structure is used for cutting alloy materials in the aerospace, aviation, marine or medical fields, such as sanitary ware, hardware decoration, radiators, golf heads, medical equipment, machinery manufacturing, etc. The principle of the present invention is as follows: Based on the structure of a+p or p+y two-phase silicon brass, a composite micro-textured cutter that can greatly improve the chip breaking or free cutting performance of silicon brass is designed. As can be seen from the cutter-chip friction relationship in the cutting experiment, for the a+p or p+y two-phase silicon brass alloy with high plasticity, there is a certain scale of area of the close contact and peak-point contact between the cutter and the chip during cutting; this kind of cutter-chip contact surface will increase the friction force and adhesion while chips are produced, which is not conducive to chip breaking. In view of this, a composite micro-texture including a convex texture array of tens of microns and a longitudinal texture array of 100 microns is provided within a certain area of the cutting edge of the cutter. The composite micro-texture can change the close contact between the original cutter and chip into a peak-point contact, and reduce the area of the original peak-point contact surface, thus reducing the friction between the cutter and the chip. It is beneficial to increase the curling of chips and promote chip breaking, thereby improving the chip breaking or free cutting performance of alloy materials. The core of the design is to combine a convex texture array with a longitudinal texture array to form a composite micro-texture. Furthermore, the design is based on the following structure of a+p or p+y two-phase silicon brass: the a (or P) phase is uniformly distributed in the grain boundary or matrix of the P (or a) phase, and the grain size of the matrix phase is about 100-500 pm; alternatively, the y phase is uniformly distributed in the grain boundary or matrix of the P phase; at the same time, ultrafine intermetallic compound particles are distributed in the p-phase grain boundary. The mechanism of the interaction between the composite micro-texture and the brass structure is that the convex texture array in the composite micro-texture has a small convex surface, and thus functions as the cutting point of the cutting edge; the groove spacing of the longitudinal texture in the composite micro-texture is 20-100 pm, which is 1/5 to 1/4 of the average grain size of the silicon brass matrix phase; when the chips cross the longitudinal texture, a certain number of textures can act on a range of grain size at the same time, which makes the grains deform more easily and macroscopically promotes chip deformation and fracture. In short, by reducing the area of the close contact between the cutter and the chip, the composite micro-texture changes the close contact between the cutter and the chip into the peak-point contact, and reduces the area of the peak-point contact surface, thus greatly reducing the friction between the cutter and the chip; this makes the chip flow faster in the back direction, effectively reduces friction and adhesion between the chip and the cutter, and promotes curling and breaking of the chips, thereby improving the chip breaking or free cutting performance of the alloy materials. In the process of cutting metal alloys with traditional cutters or other micro-textured cutters, the cutter-chip contact surface is generally divided into a close friction zone and a peak-point friction zone. In the close friction zone, the cutter surface is prone to cold welding with metal materials; when the chip and the cutter slide relative to each other, the cold solder joint is sheared and the shear resistance exhibited becomes part of the friction force. In the peak-point friction zone, the friction force of the peak-point contact gradually decreases as the chips slide out. The two friction forces reduce the flow speed of chips when the chips flow off the rake face, which is not conducive to curling and breaking of the chips. Therefore, under the condition of general cutting parameters, a preliminary test for cutting silicon brass with cemented carbide cutters is conducted to analyze the area of the cutter-chip contact surface and the size of the two friction zones; on this basis, the composite micro-texture combining the convex texture array with the longitudinal texture array, not available in the existing micro-texture, is designed on the surface of the cutter. In order to reduce the area of the actual cutter-chip contact surface, the present invention uses a convex texture array

(10-20 pm in width) in the original close friction zone of the cutter, so as to change the close friction of the alloy material with a grain size of 100-500 pm into the peak-point friction; meanwhile, a longitudinal texture array (groove texture) parallel to the chip flow direction is added to the original peak-point contact of the cutter to further reduce the friction force of the cutter-chip contact surface and reduce the curl radius of the produced chips, which will ultimately improve the chip breaking performance in cutting silicon brass. In addition, the scale of the micro-texture is designed according to the grain size of the silicon brass, so as to reduce blocking of the micro-texture during the cutting process while ensuring a certain strength, so that the rake face micro-texture continues to play its role. In summary, the present invention has the following advantages: The micro-textured cutter based on the structure of silicon brass material is a cutter design scheme, which can effectively improve the chip breaking or free cutting performance of the two-phase brass material, thereby improving the processing efficiency; it has the advantages such as improving product yield, and saving energy and time, and is suitable for industrial application. As can be seen from the examples by comparing the chips of the composite micro-textured cutter and the non-textured cutter obtained in the cutting test, the composite micro-textured cutter can obtain curlier and finer chips, and indeed greatly improve the chip breaking performance of the alloy materials. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of the design of the present invention. Fig. 2 is a partial enlarged view of the composite micro-texture in Fig. 1. Fig. 3 is a schematic diagram of the convex texture. Fig. 4 is a schematic diagram of the longitudinal texture. Fig. 5 shows the metallographic structure of silicon brass prepared by the low-pressure casting process. Fig. 6 shows the appearance of chips obtained by cutting silicon brass with a non-textured cutter. Fig. 7 shows the appearance of chips obtained by cutting silicon brass with a textured cutter under the same cutting parameters as those in Fig. 6. In the figures: 1. cutter; 2. rake face; 3. cutting point; 4. cutting edge; 5. longitudinal texture; 6. convex texture; 7. convex; and 8. groove. a. The length of the composite micro-texture in the direction perpendicular to the cutting edge; b. the distance from the composite micro-texture to the cutting point in the direction parallel to the cutting edge; c. the spacing between adjacent convex textures; d. the distance of the composite micro-texture from the cutting edge; e. the length of the convex texture array in the direction perpendicular to the cutting edge; f. the spacing between the longitudinal texture array and the convex texture array; g. the width of the longitudinal texture in the direction parallel to the cutting edge; h. the spacing between the adjacent longitudinal textures; i. the length of side of the cube at the bottom of the convex texture; j. the height of the convex texture; k. the width of the upper surface of the convex texture; and 1. the height of the longitudinal texture. DETAILED DESCRIPTION OF THE EMBODIMENTS The present invention will be further described below in detail in combination with specific embodiments. Example 1 A method for processing the micro-textured cutter based on silicon brass structure was provided, comprising the following steps: (1) Preparing a cutter: First selecting a YG8 cemented carbide cutter and determining the position of a cutting edge to be processed, sanding and polishing the rake face of the cutter with 1500# metallographic sandpaper, and then cleaning with alcohol and blowing dry. (2) Designing a composite micro-texture: Placing the polished cutter in a laser processing machine, focusing to make the laser energy focused on the cutter, and then designing a composite micro-texture of the convex texture and longitudinal texture at a distance of 20 pm from the cutting edge (Figs. 1 and 2). The convex texture array was within 140 pm from the cutting edge, comprising a cube at the bottom with the length of side of 50pm and a trapezoidal platform at the top; a single convex texture (Fig. 3) was of a rectangle at the upper end face thereof, the length of the rectangle being identical to the length of side of the cube, the width being 10 pm; a longitudinal texture (Fig. 4) perpendicular to the cutting edge was designed in the area of 20 pm from the convex texture array; the convex texture reached a size of tens of microns in the cutter-chip adhesion and wear region, and the longitudinal texture had a groove spacing of 20 pm, thereby effectively reducing friction and adhesion of chips in close contact and peak-point contact zones, promoting back flow of chips, and facilitating curling and breaking of chips. (3) Processing the composite micro-texture by laser: Performing laser processing near the cutting edge of the rake face of the cutter by an F-20 pulse fiber laser, with the specific parameters as follows: processing number 100, processing speed 500 mm/s, processing power 6 W, and processing frequency 20 KHz; after processing the composite micro-texture, sanding and polishing the rake face of processed convex melt with metallographic sandpaper, and ultrasonically cleaning in alcohol and taking out to blow dry. (4) Preparing alloy materials: Preparing alloy materials according to the mass percentages of 60% of Cu, 0.7% of Si, 0.5% of Al, 0.05% of Ti, 0.005% of B, and the balance of Zn, and preparing silicon brass by low-pressure casting process, with the low-pressure casting process parameters as follows: casting temperature 1000°C, filling time 4 s, pressure held 0.0395 MPa, and pressure holding time 13 s. Fig. 5 shows the metallographic structure of silicon brass prepared by the low-pressure casting process, where the bright white part was a P phase, and the black part was an a phase; the a phase was distributed in the p-phase matrix mainly in the form of needles and particles, and a small amount of intermetallic compounds were also distributed in the grains and at the grain boundaries; in the alloy structure, the content of the a phase was 12%, the content of the P phase was 88%, and the average grain size of the P phase was 400-500 pm. (5) Cutting test: Subjecting the designed composite micro-textured cutter and a non-textured cutter to a cutting test under the same conditions, with the cutting parameters as follows: cutting speed 90 m/min, feed rate 0.1 mm/r, and back-feeding amount 0.5 mm; after cutting, collecting the chips for analysis and comparison to evaluate the chip breaking performance of the composite micro-textured cutter. Figs. 6 and 7 show the appearance of chips obtained with the non-textured cutter and the composite micro-textured cutter under the same cutting parameters. The chips produced by the non-textured cutter were spiral chips with an average radius of curvature of 3 mm, while the chips produced by the textured cutter were C-shaped chips with an average radius of curvature of 2 mm. As can be seen by comparing the two kinds of chips, the composite micro-texture cutter produced chips with a smaller radius of curvature and curlier and finer appearance, greatly promoting the chip fracture, improving the chip breaking or free cutting performance of the alloy materials. Example 2 A method for processing the micro-textured cutter based on silicon brass structure was provided, comprising the following steps: (1) Preparing a cutter: First selecting a YG8 cemented carbide cutter and determining the position of a cutting edge to be processed, sanding and polishing a rake face of the cutter with 1500# metallographic sandpaper, and then cleaning with alcohol and blowing dry. (2) Designing a composite micro-texture: Placing the polished cutter in a laser processing machine, focusing to make the laser energy focused on the cutter, and then designing a composite micro-texture of the convex texture and longitudinal texture at a distance of 10 im from the cutting edge (Figs. 1 and 2). The convex texture array was within 110 pm from the cutting edge, comprising a cube at the bottom with the length of side of 40pm and a trapezoidal platform at the top; a single convex texture (Fig. 3) was of a rectangle at the upper end face thereof, the length of the rectangle being identical to the length of side of the cube, the width being 15 pm; a longitudinal texture perpendicular to the cutting edge was designed in the area of 15 pm from the convex texture array; the convex texture reached a size of tens of microns in the cutter-chip adhesion and wear region, and the longitudinal texture had a groove spacing of 60 pm, thereby effectively reducing friction and adhesion of chips in close contact and peak-point contact zones, promoting back flow of chips, and facilitating curling and breaking of chips. (3) Processing the composite micro-texture by laser: Performing laser processing near the cutting edge of the rake face of the cutter by an F-20 pulse fiber laser, with the specific parameters as follows: processing number 100, processing speed 500 mm/s, processing power 6 W, and processing frequency 20 KHz; after processing the composite micro-texture, sanding and polishing the rake face of processed convex melt with metallographic sandpaper, and ultrasonically cleaning in alcohol and taking out to blow dry. (4) Preparing alloy materials: Preparing alloy materials according to the mass percentages of 59.5% of Cu, 0.78% of Si, 0.7% of Al, 0.05% of Ti, 0.005% of B, and the balance of Zn, and preparing silicon brass by low-pressure casting process, with the low-pressure casting process parameters as follows: casting temperature 1000°C, filling time 4 s, pressure held 0.0395 MPa, and pressure holding time 13 s. In the obtained silicon brass alloy structure, the content of the a phase was 92%, and the content of the P phase was 8%, with the P phase distributed at the a-phase grain boundaries in the form of a net; besides, a small amount of intermetallic compounds were distributed in the grains and at the grain boundaries, and the average grain size of the a phase in the structure was 70-80 pm. (5) Cutting test: Subjecting the designed composite micro-textured cutter and a non-textured cutter to a cutting test under the same conditions, with the cutting parameters as follows: cutting speed 90 m/min, feed rate 0.1 mm/r, and back-feeding amount 0.5 mm; after cutting, collecting the chips for analysis and comparison to evaluate the chip breaking performance of the composite micro-textured cutter. The chips produced by the non-textured cutter were spiral chips with an average radius of curvature of 2.8 mm, while the chips produced by the composite micro-textured cutter were C-shaped chips with an average radius of curvature of 1.6 mm. The composite micro-texture cutter produced curlier and finer chips, greatly promoting the chip fracture, improving the chip breaking or free cutting performance of the alloy materials. Example 3 A method for processing the micro-textured cutter based on silicon brass structure was provided, comprising the following steps: (1) Preparing a cutter: First selecting a YG8 cemented carbide cutter and determining the position of a cutting edge to be processed, sanding and polishing a rake face of the cutter with 1500# metallographic sandpaper, and then cleaning with alcohol and blowing dry. (2) Designing a composite micro-texture: Placing the polished cutter in a laser processing machine, focusing to make the laser energy focused on the cutter, and then designing a composite micro-texture of the convex texture and longitudinal texture at a distance of 30 im from the cutting edge (Figs. 1 and 2). The convex texture array was within 150 pm from the cutting edge, comprising a cube at the bottom with the length of side of 45pm and a trapezoidal platform at the top; a single convex texture (Fig. 3) was of a rectangle at the upper end face thereof, the length of the rectangle being identical to the length of side of the cube, the width being 20 pm; a longitudinal texture perpendicular to the cutting edge was designed in the area of 10 pm from the convex texture array; the convex texture reached a size of tens of microns in the cutter-chip adhesion and wear region, and the longitudinal texture had a groove spacing of 100 pm, thereby effectively reducing friction and adhesion of chips in close contact and peak-point contact zones, promoting back flow of chips, and facilitating curling and breaking of chips. (3) Processing the composite micro-texture by laser: Performing laser processing near the cutting edge of the rake face of the cutter by an F-20 pulse fiber laser, with the specific parameters as follows: processing number 100, processing speed 500 mm/s, processing power 6 W, and processing frequency 20 KHz; after processing the composite micro-texture, sanding and polishing the rake face of processed convex melt with metallographic sandpaper, and ultrasonically cleaning in alcohol and taking out to blow dry. (4) Preparing alloy materials: Preparing alloy materials according to the mass percentages of 58.5% of Cu, 1.11% of Si, 1.0% of Al, 0.05% of Ti, 0.005% of B, and the balance of Zn, and preparing silicon brass by low-pressure casting process, with the low-pressure casting process parameters as follows: casting temperature 1000°C, filling time 4 s, pressure held 0.0395 MPa, and pressure holding time 13 s. In the obtained silicon brass alloy structure, the content of the P phase was 85%, and the content of the y phase was 15%, with the y phase distributed at the p-phase grain boundaries and matrix mainly in the form of particles; besides, a small amount of intermetallic compounds were distributed in the grains and at the grain boundaries, and the average grain size of the P phase in the structure was about 300-4000 pm. (5) Cutting test: Subjecting the designed composite micro-textured cutter and a non-textured cutter to a cutting test under the same conditions, with the cutting parameters as follows: cutting speed 90 m/min, feed rate 0.1 mm/r, and back-feeding amount 0.5 mm; after cutting, collecting the chips for analysis and comparison to evaluate the chip breaking performance of the composite micro-textured cutter. The chips produced by the non-textured cutter were long belt-shaped chips, while the chips produced by composite micro-textured cutters were C-shaped chips. The composite micro-texture cutter produced chips that looked obviously more conducive to chip breaking, effectively improving the chip breaking or free cutting performance of the alloy materials. Example 4 The alloy material of this example was a Ti-6Al-4V titanium alloy with two phases a+p, and its preparation method was casting + plastic deformation. What were not mentioned in this example were the same as those in Example 1. The preparation process of the Ti-6Al-4V titanium alloy of this example was as follows: Weighing the element bars of pure Ti (99.97%), Al (99.95%) and V (99.95%) according to the mass ratio, and placing them into a melting furnace for several times of vacuum melting until the components were homogenized, then casting to obtain an alloy ingot, and then subjecting the cast Ti-6Al-4V alloy ingot to plastic deformation to obtain a cylindrical titanium alloy bar. The test results of the Ti-6Al-4V titanium alloy prepared in this example were similar to those in Example 1, i.e., the composite micro-texture cutter produced chips that looked obviously more conducive to chip breaking, effectively improving the chip breaking or free cutting performance of the titanium alloy, which will not be repeated here. Example 5 The alloy material of this example was 45 steel, and what were not mentioned in this example were the same as those in Example 1. The test results of this example were similar to those in Example 1, i.e., the composite micro-texture cutter produced chips that looked obviously more conducive to chip breaking, effectively improving the chip breaking or free cutting performance of the 45 steel, which will not be repeated here. Example 6 A micro-textured cutter based on silicon brass structure was provided; the cutter was provided within a certain area of the cutting edge of the rake face with a composite micro-texture, which comprises a longitudinal texture array, and a convex texture array located between the longitudinal texture array and the cutting edge; the convex texture array comprises a plurality of convex textures arranged in a rectangular array, the convex texture being of a cube at the bottom and of a trapezoidal platform at the upper end; the longitudinal texture array comprises a plurality of longitudinal textures arranged in rows along the width direction of the cutting edge, the longitudinal texture being of a cuboid, the length direction thereof being perpendicular to the width direction of the cutting edge. Cutter 1 was a YG8 cemented carbide triangular blade, wherein a was 3 mm, b 5 mm, c 20 pm, d 20 pm, e 100 pm, f 20 pm, g 100 pm, h 20 pm, i 50 pm, j 80 pm, k 10 pm, and /80 pm.

In this example, the upper ends of the convex texture and the longitudinal

texture were flush with the surface of the cutter, and the groove portion was

processed by laser. The composite micro-texture was distributed in the range of

about 3 mm X 5 mm between the cutting edge and the cutting point.

The above examples are the preferred embodiments of the present invention.

However, the embodiments of the present invention are not limited by the above

examples; any other alterations, modifications, substitutions, combinations and

simplifications made without departing from the spiritual essence and principle of

the present invention shall be equivalent replacements, and shall be included in

o the scope of protection of the present invention.

The reference to any prior art in this specification is not, and should not be

taken as, an acknowledgement or any form of suggestion that such prior art forms

part of the common general knowledge.

It will be understood that the terms "comprise" and "include" and any of

their derivatives (e.g. comprises, comprising, includes, including) as used in this

specification, and the claims that follow, is to be taken to be inclusive of features

to which the term refers, and is not meant to exclude the presence of any

additional features unless otherwise stated or implied.

Claims

1. A micro-textured cutter for use on silicon brass structure, comprising a rake surface, a cutting edge formed at the boundary of the rake surface, and a composite micro-texture located on the rake surface and adjacent to the cutting edge, the rake surface has a first direction parallel to the cutting edge and a second direction perpendicular to the cutting edge, characterized in that: the composite micro-texture comprises a first texture array and a second texture array spaced apart in the second direction, and the first texture array is closer to the cutting edge in the second direction than the second texture array; the first texture array comprises a plurality of first convex textures arranged in a rectangular array, each first convex texture being of a cube at the bottom and of a trapezoidal platform at the upper end; the second texture array comprises a plurality of second convex textures arranged in a row along the first direction, each second convex texture being of a cuboid extending along the second direction, and a groove extending along the second direction is defined between two adjacent second convex textures; the scale of the composite micro-texture is set based on a grain size of the silicon brass, the area of an upper end face of the first convex texture is smaller than the area of an upper end face of the second convex texture, the length of the grooves in the first direction is 1/5 to 1/4 of the grain size of the silicon brass, and the second texture array is configured to enable a certain number of the second convex textures to act on a range of grain size of the silicon brass at the same time.

2. The micro-textured cutter for use on silicon brass structure according to claim 1, characterized in that: in the direction perpendicular to the cutting edge, the composite micro-texture is 10-30 pm away from the cutting edge, the length of the composite micro-texture is 3 mm, the length of the convex texture array is 110-150 pm, and the longitudinal texture array is 10-20 pm away from the convex texture array.

3. The micro-textured cutter for use on silicon brass structure according to claim 2, characterized in that: the cube at the bottom of the convex texture has a length of side of 40-50 pm; the convex texture is of a rectangle at the upper end face thereof, the length of the rectangle being identical to the length of side of the cube at the bottom of the convex texture in the direction perpendicular to the cutting edge, the width of the rectangle being 10-20 pm in the direction parallel to the cutting edge.

4. The micro-textured cutter for use on silicon brass structure according to claim 2,

characterized in that: the spacing between the adjacent longitudinal textures is 20-100

pm.

5. A method for preparing and testing the micro-textured cutter for use on silicon

brass structure according to any one of claims 1 to 4, characterized in that: the

method comprises the following steps:

(1) preparing a cutter;

(2) designing a composite micro-texture;

(3) processing the composite micro-texture of step (2) on the cutter of step (1) by

laser processing;

wherein the cutter comprises a rake surface and a cutting edge formed at the

boundary of the rake surface, the composite micro-texture is located on the rake

surface and adjacent to the cutting edge, the rake surface has a first direction parallel

to the cutting edge and a second direction perpendicular to the cutting edge,

characterized in that: the composite micro-texture comprises a first texture array and

a second texture array spaced apart in the second direction, and the first texture array

is closer to the cutting edge in the second direction than the second texture array; the

first texture array comprises a plurality of first convex textures arranged in a

rectangular array, each first convex texture being of a cube at the bottom and of a

trapezoidal platform at the upper end; the second texture array comprises a plurality

of second convex textures arranged in a row along the first direction, each second

convex texture being of a cuboid extending along the second direction, and a groove

extending along the second direction is defined between two adjacent second convex textures; the scale of the composite micro-texture is set based on a grain size of the silicon brass, the area of an upper end face of the first convex texture is smaller than the area of an upper end face of the second convex texture, the length of the grooves in the first direction is 1/5 to 1/4 of the grain size of the silicon brass, and the second texture array is configured to enable a certain number of the second convex textures to act on a range of grain size of the silicon brass at the same time;

(4) preparing an alloy material; and

(5) subjecting the cutter obtained in step (3) to a cutting test on the alloy material of

step (4).

6. The method for preparing and testing the micro-textured cutter for use on silicon

brass structure according to claim 5, characterized in that:

the step (1) comprises: selecting a YG8 cemented carbide cutter and determining the

position of a cutting edge to be processed, sanding and polishing a rake face of the

cutter with 1500# metallographic sandpaper, and cleaning and blowing dry;

the step (2) comprises: placing the polished cutter in a laser processing machine,

focusing to make the laser energy focused on the cutter, and then designing the

composite micro-texture on the surface of the cutter;

the step (3) comprises: performing laser processing near the cutting edge of the rake

face of the cutter, with the specific parameters as follows: processing number 80-150,

processing speed 400-600 mm/s, processing power 5-10 W, and processing frequency

10-50 KHz; after processing the composite micro-texture, sanding and polishing the

rake face of processed convex melt with metallographic sandpaper, and ultrasonically

cleaning and blowing dry; and

the step (5) comprises: subjecting the designed micro-textured cutter and a

non-textured cutter to a cutting test under the same conditions, with the cutting

parameters as follows: cutting speed 80-100 m/min, feed rate 0.1-0.2 mm/r, and

back-feeding amount 0.1-0.6 mm; after cutting, collecting the chips for analysis and comparison to evaluate the chip breaking performance of the micro-textured cutter.

7. The method for preparing and testing the micro-textured cutter for use on silicon brass structure according to claim 5, characterized in that: in step (4), providing pure metals for an alloy having mass percentages of 58.5% to 60% of Cu, 37% to 39% of Zn, 0.7% to 1.11% of Si, 0.5% to 1% of Al, 0.01% to 0.1% of Ti, and 0 to 0.01% of B, and preparing silicon brass alloy by low-pressure casting process, with the low-pressure casting process parameters as follows: casting temperature 900°C to

1100°C, filling time 3-6 s, pressure held 0.01-0.04 MPa, and pressure holding time

10-15 s.

8. The method for preparing and testing the micro-textured cutter for use on silicon brass structure according to claim 5, characterized in that: the alloy material in step (4) is brass alloy; when the brass alloy is used, the preparation process is low-pressure casting; when the titanium alloy is used, the preparation process is casting plus plastic deformation.

9. A use of the micro-textured cutter for use on silicon brass structure according to any one of claims 1 to 4, characterized in that: the micro-textured cutter based on silicon brass structure is used for cutting alloy materials in aerospace, aviation, marine, medical or sanitary field.