阅读说明：本技术 一种斜向厚度复合涂层仿生刀具设计方法 (Design method of bionic cutter with oblique thickness composite coating ) 是由 范依航 王冰 郝兆朋 徐永硕 于 2021-10-12 设计创作，主要内容包括：发明名称一种斜向厚度复合涂层仿生刀具设计方法摘要本发明公开了一种斜向厚度复合涂层仿生刀具设计方法,刀具基体材料为硬质合金或高速钢,其具体特征为：在刀具与切屑接触表面设计一种仿生鲨鱼皮盾鳞微织构,在切削刃设计微凹槽的仿生微织构,在基体与微织构表面采用物理气相沉积PVD(Physical Vapor Deposition)与化学气相沉积CVD(Chemical Vapor Deposition)相结合的方法沉积斜向不同厚度的复合涂层,设计出全新的斜向厚度复合涂层微织构刀具；鲨鱼皮微织构设计可以起到减摩减阻和超疏水的效果,斜向厚度复合涂层可以有效阻止刀具裂纹的扩展；该设计可以使切削液进入刀屑接触区,减小切削过程中刀具与切屑之间的摩擦和粘结,可以提高刀具减摩润滑及耐摩擦磨损性能,能够显著提高涂层刀具的切削性能,减少裂纹扩展,提高刀具使用寿命。(The invention discloses a design method of a bionic cutter with an oblique thickness composite coating, which is characterized in that the base material of the cutter is hard alloy or high-speed steel: designing a bionic sharkskin shield scale micro-texture on the contact surface of a cutter and chips, designing a bionic micro-texture of a micro-groove on a cutting edge, depositing composite coatings with different oblique thicknesses on the surfaces of a substrate and the micro-texture by adopting a method combining Physical Vapor Deposition (PVD) and Chemical Vapor Deposition (CVD) (chemical Vapor deposition), and designing a brand new micro-texture cutter with the composite coatings with the oblique thicknesses; the shark skin micro-texture design can play a role in friction reduction, drag reduction and super-hydrophobic effect, and the oblique thickness composite coating can effectively prevent the crack of the cutter from expanding; the design can enable cutting fluid to enter the contact area of the cutting scraps, reduce friction and bonding between the cutter and the cutting scraps in the cutting process, improve the antifriction lubrication and friction and wear resistance of the cutter, remarkably improve the cutting performance of the coated cutter, reduce crack expansion and prolong the service life of the cutter.)

1. A design method of a bionic cutter with an oblique thickness composite coating is characterized in that a cutter substrate material is hard alloy or high-speed steel: the bionic sharkskin micro texture is processed on the contact area of the front and back tool faces and the cuttings, and composite coatings with different oblique thicknesses are deposited on the surfaces of the matrix and the micro texture by adopting a PVD and CVD combined method.

2. The micro texture machined on the front and back tool faces 20-100 microns away from a cutting edge according to claim 1 is structurally characterized by being divided into a main ridge and left and right auxiliary ridges, wherein the left and right auxiliary ridges are symmetrical relative to the main ridge, and the front section structure and the groove of the micro texture are both in a V-shaped circular arc structure.

3. The V-shaped grooves formed by the main ridge and the left and right auxiliary ridges of claim 2 are 25-125 degrees, the depth of the V-shaped grooves is 1-100 μm, and the micro-texture main body is arranged in an array with an area of 50 μm²-25mm²。

4. An oblique thickness composite coating according to claim 1, wherein the thickness of the same coating is obliquely changed under the condition of constant total thickness, and Al is used between each coating TiAlSiN/TiAlN/GrAlN and the substrate by adopting a method of combining PVD and CVD₂O₃As an intermediate layer.

5. The coating of TiAlSiN/TiAlN/GrAlN as claimed in claim 4, having a thickness of 1.5-4 μm, Al₂O₃The thickness of the intermediate layer is 0.5 μm to 2 μm.

Technical Field

The invention belongs to the technical field of cutting tools, and relates to a design method of a bionic tool with an oblique composite coating.

Background

In the cutting process of the difficult-to-machine material, the cutting performance is poor, and the phenomena of overlarge cutting force, higher cutting temperature and serious cutter abrasion can occur; in the machining process, severe friction is generated between a rear tool face of a tool and a machined surface and between a front tool face of the tool and chips, so that the temperature of a cutting edge is increased, the tool is abraded or is broken to cause the failure of the tool, and the abrasion of the tool can cause the quality change of the machined surface and the reduction of the surface machining quality; and as the damage of the cutter is accumulated, the cutter begins to crack, the crack gradually expands to cause the cutter to fail, and the cutter is the final factor influencing the cutting quality.

As organisms are subjected to complex working conditions for a long time or interact with the surrounding environment to generate energy and substances, various forms, configurations, materials and structures are optimized, and a brand-new thought is provided for the research of the friction problem in the artificial field, the bionic tribology is widely applied to the friction reduction and resistance reduction research of surface textures; for example, Chinese patent application number: 201810481164.9 discloses a bionic design method of a depth gradient change micro-texture turning tool, which adopts a non-contact laser scanner to obtain the point cloud data of the bamboo rat incisor, reconstructs a three-dimensional model of the incisor, extracts the appearance depth data of the incisor, utilizes the depth data value of the incisor to bionic design the depth gradient change micro-texture turning tool, reserves the characteristic that the texture reduces the cutting force of the tool, improves the structural strength of the tool, and has the advantages of prolonging the service life of the tool and improving the economic use value of the tool.

For example, Chinese patent application number: 201610508122.0 discloses a solid lubricated metal cutting tool and its processing method, wherein the tool processing surface has texture morphology, solid lubricant is filled in the texture morphology, convex dam is arranged on the tool surface on the chip flow direction side of the surface texture morphology, part of the solid lubricant is reflowed to the texture area, the utilization rate and the retentivity of the solid lubricant are improved, and the dual functions of solid lubrication antifriction and micro-convex debonding are exerted.

For example, the Chinese patent 'application No. 201910620319.7' discloses a preparation method of a super-hydrophobic bionic numerical control machining cutter, wherein a front cutter face and a rear cutter face of the cutter have two-section microscopic forms consisting of micro-protrusions and micro-grooves, a circular arc radius part of a cutter tip has a sawtooth nano-texture, and a solid lubricant coating is coated by supersonic flame spraying hard particles; a nanosecond laser processing technology is adopted to prepare two-section microscopic forms consisting of micro-protrusions and micro-grooves on the front tool face and the rear tool face of the tool, so that the contact area of the tool and chips is reduced, and the friction between the tool and the chips is reduced.

When a difficult-to-machine material is machined, a cutter-chip interface is mostly in a close contact state, external cutting fluid can only enter an edge area of a contact interface of a friction pair in a capillary permeation mode and the like, the lubricating effect cannot be exerted, the temperature rise is too high, the cutter abrasion is accelerated, micro-groove structures are orderly arranged on the skin of the surface of a shark along the flowing direction, and the special microstructure of the surface of the shark not only shows the function of drag reduction, but also shows other special functions of drainage, noise reduction, invisibility and the like.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the problems that cutting fluid is difficult to enter a cutting area in the processing process of the existing difficult-to-process material, and the friction wear and crack propagation phenomena of the cutting tool are caused by the fact that the material resists plastic deformation to generate overlarge pressure, the design method of the bionic tool with the oblique thickness composite coating is provided.

The design scheme of the invention is as follows: according to the microstructure of the sharkskin, a microtexture technology is introduced into the cutter design by utilizing bionics, the bionic microtexture of the sharkskin is designed, the protruding microtexture is processed on the front cutter face and the rear cutter face, and a micro groove is adopted as a cutting edge; depositing Al with the same thickness by CVD (chemical Vapor deposition)₂O₃And the intermediate layer is formed by depositing coatings with different thicknesses by a Physical Vapor Deposition (PVD) method.

Preferably, according to the contact state of the chips with the cutting edges and the front and rear cutter faces, the distribution of stress and temperature is combined with a friction theory, a shark skin bionic micro-texture is adopted in a front and rear cutter face contact area, and the cutting edges adopt a micro-groove treatment mode.

Preferably, according to the microstructure of the shield scale, a three-dimensional non-contact white light interference surface topographer is adopted to extract a three-dimensional scanning image of a shark skin prototype and a corresponding shark skin groove, a profile curve is extracted at the scanning image by utilizing three-dimensional topography analysis software SPIP of Bochang instruments, Inc., and three-dimensional reconstruction of the microtextured groove is carried out according to the profile curve of the cross section.

Preferably, according to the profile curve, fitting the curve of the collected data points by adopting a nonlinear least square method to obtain a curve equation, and performing three-dimensional modeling according to the fitted curve equation by utilizing CATIA software.

Preferably, for a clearer representation of the model parameters, the following are illustrated (example parameters are within the scope of the claims): the pitch of each microtexture is 25 μm, the height of the main ridge is 30 μm, the left and right auxiliary ridges are 25 μm, the width of the groove is 25 μm, the distance from the cutting edge is 60 μm, and the angle of the V-shape is 60 °.

Preferably, the microtextured array area is 16mm along the chip flow direction²。

Preferably, the groove depth at the cutting edge is 25 μm and the groove angle is 60 °.

Preferably, Al is deposited on the tool base body by means of a CVD method₂O₃In the presence of Al by PVD method₂O₃Depositing a GrAlN coating on the surface, and using Al₂O₃As an intermediate layer between the cutter substrate and the GrAlN coating.

Preferably, Al is deposited on the surface of the coating GrAlN by means of a CVD method₂O₃In the presence of Al by PVD method₂O₃Depositing TiAlN coating on the surface, using Al₂O₃As an intermediate layer between the GrAlN coating and the TiAlN coating.

Preferably, Al is deposited on the TiAlN surface of the coating by a CVD method₂O₃In the presence of Al by PVD method₂O₃Depositing TiAlSiN coating on the surface, and using Al₂O₃As an intermediate layer of the TiAlN coating and the TiAlSiN coating.

As can be seen from the above description, the advantages of the present invention are:

in the cutting process, the material resists plastic deformation to generate shearing slippage, so that huge deformation resistance and frictional force are generated for the cutter, the cutting fluid is difficult to enter a cutting area, the cutter and the cutting fluid generate severe friction, and ultrahigh cutting heat is generated in the cutting area, so that the front cutter face is easy to generate adhesive wear; due to the existence of the micro-texture space structure, the contact of hard particles to the surface of the cutter can be reduced, so that the generation of abrasive wear is reduced, and the micro-texture can reduce the temperature rise of the cutter and reduce the friction wear.

The cutter can generate cracks at the position of the maximum tensile stress of the front cutter face of the cutter along with the continuous accumulation of damage in the cutting process, and the cracks can gradually expand towards the interior of the cutter along the direction of 45 degrees, so that a single-layer oblique composite coating with different thicknesses is deposited by adopting a method combining PVD and CVD, the toughness of the coating is gradually improved from the outer layer to the inner layer, and the crack expansion can be effectively reduced by the composite coating with oblique thickness along with the gradual increase of the coating thickness with better toughness in the crack expansion direction.

The coating with different thicknesses in the inclined direction is deposited on the surface of the cutter for processing the micro texture by adopting the method of combining the micro texture design with the design of the coating with different thicknesses in the inclined direction, so that the abrasion of the cutter can be reduced, the crack expansion of the cutter can be reduced, and the service life of the cutter can be prolonged.

Description of the drawings:

in order to be able to show the present embodiments or prior art designs in full, reference will now be made in brief to the accompanying drawings, which are used in the detailed description and in which the various parts are not necessarily drawn to true scale.

FIG. 1 is a front view of a microtexture.

Fig. 2 is a left view of microtexturing.

Fig. 3 is a top view of microtexturing.

FIG. 4 is a schematic view of the cutting fluid entering the cutting zone.

Fig. 5 is a partial enlarged view of the groove at the cutting edge.

Fig. 6 is a diagram of a tool with microtexturing.

Fig. 7 is a schematic view of a tool with oblique coatings of different thicknesses.

In fig. 7: 1 is coating TiAlSiN, 2 is intermediate layer Al₂O₃3 is coating TiAlN, 4 is intermediate layer Al₂O₃5 is coating GrAlN, 6 is intermediate layer Al₂O₃And 7 is a tool base body.

The specific implementation method comprises the following steps:

in order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, and the following detailed descriptions of the embodiments of the present invention provided in the drawings are not intended as bases for limiting the present invention.

As shown in fig. 1 to 7, the method for designing the bionic cutter with the oblique thickness composite coating provided by the invention comprises the following steps:

according to the microstructure of the shield scale, a three-dimensional non-contact white light interference surface topographer is adopted to extract a sharkskin prototype and a three-dimensional scanning image of a corresponding sharkskin groove, a software SPIP is utilized to extract a contour curve at the scanning image, and three-dimensional reconstruction of a micro-texture groove is carried out according to a cross section contour curve.

Extracting data points of the curve by utilizing getdata drag digitze data extraction software according to the contour curve, fitting the curve on the collected data points by utilizing a cftool box of matlab to obtain a curve equation, and performing three-dimensional modeling on the curve equation by utilizing CATIA software, wherein the parameters are as follows: the width of the micro-texture is 65 μm, the length is 75 μm, the grooves and the front end of the micro-texture are both in V-shaped circular arcs, and the angle of the V shape is 60 degrees, as shown in figure 1; the front end and the rear end of the microtexture form a rising angle of 30 degrees, as shown in fig. 2; the main ridge is 30 μm high, the left and right sub-ridges are 25 μm, the groove width is 25 μm, and the groove depth is 25 μm, as shown in FIG. 3.

When cutting is carried out by using the cutting fluid, the cutting fluid is rapidly and automatically gathered to a contact area of the cutting chip under the combined action of the micro grooves and the surface tension of the cutting fluid liquid drops, and the lubricating fluid can form hydrodynamic lubrication under the pressure between the cutting chip and the cutter, as shown in fig. 4.

The invention has no special limitation on the specific shape and material of the cutter substrate, and the cutter known by the technicians in the field can be used as the substrate; in the embodiment of the present invention, a cemented carbide YG8 cutter or a high-speed steel SKH6 cutter was used as the cutter base.

Firstly, carrying out surface polishing treatment on a cutter substrate, wherein a fiber laser with the model number of YLR-200-AC, which is produced by IPG company, is adopted, the rated power is 300W, and the wavelength is 1070 nm; laser is focused into a spot with the diameter of 20 mu m through a convex lens with the focal length of 100mm and is vertically irradiated on the surface of a material, the output power and the pulse width of the laser are mainly changed, linear scanning processing is carried out in the x direction, the frequency F =2000Hz and the speed V =150mm/s, laser processing is carried out on a cutter base body, microtexture is arranged in an array at the position 60 mu m away from a cutting edge, and the array area is about 16mm²Obtaining the pitch of each microtexture to be 35 mu m; the depth of the groove at the cutting edge is 35 μm, the groove angle is a 60 ° arc, as shown in fig. 5, and the whole tool is shown in fig. 6.

After the surface residues are cleaned by ultrasonic waves, the machined cutter needs to be polished to remove a surface oxidation film, the cutter is placed in an acetone solution and cleaned for 20 minutes by an ultrasonic cleaner, the cutter is taken out and dried, then the cutter is placed in an absolute ethyl alcohol solution again for ultrasonic cleaning, and Al is deposited on a blade substrate by adopting a Bernex BPXpro 530L full-automatic control hot-wall type chemical coating furnace of IHI Ionbond company₂O₃The intermediate layer thickness was about 1.5 μm, as shown at 6 in FIG. 7; adopting a JGP-450 type single-chamber magnetron sputtering system to prepare the coating, adopting industrial pure argon and pure nitrogen as working gas, opening the magnetron sputtering coating system to preheat for about one hour, loading the pretreated substrate sample into a furnace, and pumping to the limit vacuum (2 multiplied by 10)^-3Pa), introducing argon for pre-sputtering, cleaning impurities on the surface of the target material, introducing argon and nitrogen in a certain proportion to ensure that the impurities are not in contact with the target materialThe pressure in the empty chamber is stabilized at 4.5 multiplied by 10^-1Pa or so, opening the Gr target and the Al target for sputtering to obtain a GrAlN coating with the thickness of 1.8-3.5 μm, as shown in 5 in FIG. 7; al with the thickness of 1.5 mu m is prepared on the surface of the GrAlN coating by adopting the method₂O₃An intermediate layer, shown as 4 in fig. 7; by the sputtering method on Al₂O₃TiAlN coating with the thickness of 1.8-3 mu m is prepared on the surface, and is shown as 3 in figure 7; the method is adopted to prepare Al with the thickness of 1.5 mu m on the surface of the TiAlN coating₂O₃An intermediate layer, shown as 2 in fig. 7; by the sputtering method on Al₂O₃TiAlSiN coating with the thickness of 1.8-3 μm is prepared on the surface, as shown in 1 in figure 7.

It will be appreciated by those of ordinary skill in the art that the embodiments described herein are intended to assist the reader in understanding the principles of the invention and it is to be understood that the scope of the invention is not limited to such specific statements and embodiments, which, as a matter of language, might suggest themselves to those of ordinary skill in the art in light of the present disclosure, numerous other specific variations and combinations may be made without departing from the spirit of the invention, which scope is defined by the claims.