Solid sweating bionic cutter, dry type cutting cooling method and manufacturing process

Abstract

The invention relates to the technical field of cutting tools, in particular to a solid sweating bionic tool, a dry type cutting cooling method and a manufacturing process. The cutter body is provided with a cutting edge area and is made of a matrix phase material, a bag-shaped hair-fixing phase material is doped into the matrix phase material of the cutting edge area, the melting point of the hair-fixing phase material is lower than that of the matrix phase material, a part of the hair-fixing phase is exposed on the surface layer of the matrix phase, and a part of the hair-fixing phase is embedded into the surface layer of the matrix phase; the hair fixing phase can be heated to form an air film covering the surface of the cutter, and the air film can prevent cutting heat from being transmitted to the cutter and can form phase change heat dissipation when the air film is broken. The sweating structure is designed in the blade area of the cutter, a dynamic gas film is formed through gasification phase change heat absorption of a low-melting-point material, accurate cooling of the core cutting area is achieved, the service life of the cutter is prolonged, and meanwhile use of cutting fluid is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of cutting tools, and particularly to a solid sweating bionic tool, a dry cutting cooling method and a manufacturing process. Background Art

[0002] During the cutting process of a tool, the load-bearing environment in the cutting edge area has characteristics such as small area, large force and high temperature. The load gradient change in the cutting edge area of the tool is extremely large, and the thermal load is the primary factor accelerating tool failure and inhibiting tool speed increase and efficiency improvement. Therefore, the design and development of high-performance tools need to focus on cooling technology to achieve efficient cooling effects, improve tool life, and at the same time reduce the environmental pollution caused by traditional cutting fluids and the influence of cutting heat on machine tool errors.

[0003] Traditional cutting cooling methods mostly pour or spray liquid media such as cutting oil and emulsion into the cutting area, and use the liquid media to cool and lubricate the cutting area. Based on the concept of "green cutting", cooling technologies such as high-speed dry cutting, cryogenic cooling, minimum quantity lubrication and biodegradable cutting fluid have also emerged. Among them, high-speed dry cutting refers to a machining method that does not use cutting fluid or only uses a very small amount of cutting fluid during high-speed cutting; cryogenic cooling uses cryogenic media such as liquid nitrogen to cool the cutting area; minimum quantity lubrication sprays the lubricating oil atomized in a very small amount into the cutting area through compressed air; biodegradable cutting fluid uses biodegradable environmentally friendly cutting fluid to reduce the impact on the environment.

[0004] The prior art has the following technical problems: First, when the traditional cutting cooling method sprays cutting fluid into the cutting working area, due to the existence of cutting contact pressure, the coolant mostly forms a boundary lubricating film around the tool-chip and tool-workpiece contact areas, and it is difficult to enter the core high-temperature cutting area to effectively reduce the cutting temperature, and excessive cutting fluid will cause harm to the environment and the human body.

[0005] Second, cooling technologies such as high-speed dry cutting, cryogenic cooling, minimum quantity lubrication and biodegradable cutting fluid, although they can improve tool life to a certain extent, during high-efficiency cutting, the air turbulence generated by the high-speed rotating tool or workpiece will interfere with the flow of the coolant, and a large amount of coolant will disperse before reaching the cutting edge and cannot accurately reach the cutting core area, making it difficult to effectively wash and cool the tool face and unable to achieve the best cooling effect.

[0006] In addition, from the perspective of the cutting fluid supply method, the current cooling methods all supply the cutting fluid from the outside to the inside of the tool-workpiece and tool-chip contact areas (even for the internal cooling method, the coolant is supplied from the near-cutting area of the tool shank or blade), and the coolant cannot directly act on the core cutting heat generation area; from the perspective of heat absorption properties, except for the liquid nitrogen cryogenic cooling method, most of the current cooling methods use convective heat transfer of substances and are less able to form an efficient heat absorption effect of medium phase change. Summary of the Invention

[0007] In view of the deficiencies of the existing technology, the purpose of the embodiments of the present invention is to provide a solid sweating bionic tool. By designing a sweating structure in the cutting edge area of the tool and using the endothermic gasification phase change of a low melting point material to form a dynamic gas film, precise cooling of the core cutting area is achieved, the tool life is extended, and at the same time, the use of cutting fluid is avoided. The present invention can significantly improve the tool life and the machining surface quality, reduce the temperature in the cutting core area, and reduce the environmental pollution caused by the use of traditional emulsion and oily cutting fluids.

[0008] To achieve the above object, the embodiments of the present invention provide the following technical solutions: A solid sweating bionic tool, the tool body has a cutting edge area, the tool body is a matrix phase material, and a bag-shaped solid sweating phase material is incorporated into the matrix phase material in the cutting edge area. The melting point of the solid sweating phase material is lower than that of the matrix phase material. Part of the solid sweating phase is exposed on the surface layer of the matrix phase, and part is embedded in the surface layer of the matrix phase; the solid sweating phase can be heated to form a gas film covering the tool surface, and the gas film can block the transfer of cutting heat to the tool and can form phase change heat dissipation when the gas film ruptures.

[0009] Optionally, the melting point of the solid sweating phase is lower than the temperature in the core area during tool cutting.

[0010] Optionally, the solid sweating phase is distributed in at least one of the rake face, flank face, chip breaker groove and table surface in the cutting edge area.

[0011] Optionally, the area of the part of the solid sweating phase exposed on the surface layer of the matrix phase is smaller than the area of the part embedded in the surface layer.

[0012] Optionally, the diameter range of the exposed part of the solid sweating phase is 0.1 - 1.0 mm, the maximum diameter range of the bag is 2.0 - 3.0 mm, and the depth range of the bag is 0.5 - 1.0 mm.

[0013] Optionally, the volume of the solid sweating phase accounts for 5% - 15% of the total volume of the entire tool material.

[0014] Optionally, the matrix phase is cemented carbide or ceramic, and the solid sweating phase is lead, zinc or copper.

[0015] Optionally, the shape of the tool is circular, triangular, square, diamond-shaped or irregular.

[0016] An embodiment of the present invention also provides a dry cutting cooling method using the solid sweating bionic tool as described above. During the cutting process, the solid phase in the cutting edge area of the tool is vaporized by the cutting heat to form an air film covering the surface of the tool; the air film is tightly attached to the tool surface through intermolecular forces, blocking the cutting heat from being transferred to the tool; when the air film ruptures, a phase change heat dissipation method of solid to gas is formed, and the solid phase in the sub-surface layer continues to vaporize to replenish the air film, forming a cyclic cooling process.

[0017] An embodiment of the present invention also provides a manufacturing process for a solid sweating bionic tool as described above: the tool is made by additive manufacturing; during the additive manufacturing process, the interface between the matrix phase and the solid phase is regulated by adjusting the laser power, scanning path, scanning rate and powder supply of the matrix phase and the solid phase deposition, while ensuring the area of the solid phase exposed on the outer surface and the capacity of the solid phase embedded in the sub-surface; the formed tool is sintered and densified to finally obtain a solid sweating bionic tool with a composite structure.

[0018] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages: 1. The solid sweating bionic tool of the present invention comprises a matrix phase and a solid phase, wherein the matrix phase is the main material of the tool, and the solid phase is a low melting point alloy. The solid phase is distributed in the surface and sub-surface of the cutting edge area in a sac-like structure. The sac-like structure allows the solid phase to have a larger area in the sub-surface to ensure sufficient sweating. The small area of the exposed part can reduce the impact on the overall mechanical properties of the tool. The two work synergistically to achieve efficient cooling while maintaining the hardness and strength of the tool as much as possible. When the cutting heat is conducted to the solid phase, it vaporizes to form an air film, covering the surface of the tool to block heat transfer; after the air film ruptures, phase change heat dissipation is formed, and the solid phase of the sub-surface continues to vaporize and supplement, forming dynamic cycle cooling. By designing a sweating bionic structure at the tool end, efficient heat insulation and heat dissipation effects are achieved, thereby achieving the cooling purpose in dry cutting. In addition, the toughness of the solid phase can be used to improve the ability of the tool matrix to resist fracture.

[0019] 2. After adopting the solid sweating bionic tool of the present invention, there is no need to use traditional oily cutting fluid or emulsified cutting fluid, and efficient cooling of dry cutting is achieved. The cooling effect is improved by 3 to 4 times, achieving the effect of traditional water cooling and oil cooling, and greatly realizing environmentally friendly processing.

[0020] 3. Since the low-melting-point phase of the solid sweating bionic tool is distributed in the surface layer and subsurface layer of a small area of the tool cutting edge, its volume content is small compared with the overall blade (sweating can achieve the cooling effect without a large amount of sweat), so it will not overly affect the mechanical properties of the matrix phase surface layer, which is significantly different from the use of sweating materials in aerospace (the sweating structure of the cutting tool needs to achieve efficient local cooling in a very small area while avoiding negative impacts on the overall mechanical properties of the tool, while aerospace sweating materials pay more attention to long-term stability in a large-scale high-temperature environment). At the same time, compared with the brittleness of traditional ceramic tools, the low-melting-point phase in the solid sweating tool has better toughness, which can improve the crack propagation resistance ability in the tool cutting edge area.

[0021] 4. The solid sweating phase of the solid sweating bionic tool is embedded in the surface and subsurface of the tool (the depth exceeds the depth of the crater wear of traditional tools), so it can provide a stable phase change source for the formation and gasification of the gas film, ensuring that there is still a cooling effect after the tool edge area is worn.

[0022] 5. The cooling medium is directly sent into the heat generation area at the cutting core, and through the use of a small amount of cooling medium, an efficient cooling effect is achieved, reducing the heat generation of high-end equipment, reducing the influence of cutting heat on the thermal machine tool error, and improving the manufacturing efficiency and manufacturing accuracy of high-end equipment.

[0023] 6. After the low-melting-point solid sweating phase in the solid sweating bionic tool sweats, a gas film is first formed on the tool surface. This gas film has a certain stiffness (after the low-melting-point material gasifies, gas molecules form a dense layer on the tool surface. Due to the intermolecular force and dynamic air flow pressure, the gas film shows solid-like characteristics and is not easily blown away by the cutting force. Furthermore, the gas film resists external pressure during cutting, such as chip impact and cutting force), and is relatively thin. Due to the small contact distance with the tool surface, under the action of molecular van der Waals force, it closely adheres to the surface of the cutting edge area, isolating the heat propagation from the workpiece cutting area to the tool cutting edge, so that the cutting edge is not affected by high temperature. When the thickness of the gas film reaches a certain thickness, the gas film will rupture and gasify, thus forming a phase change process of solid gasification gas. This phase change process can absorb a large amount of cutting heat and reduce the temperature of the cutting area. This cooling method can increase the cutting life of the tool by 1.5 - 2 times, improve the surface quality of the processed surface by 1 / 3 - 1 / 2 times, and the temperature in the cutting core area can be stably controlled at 400 - 500 °C.

[0024] 7. Through additive manufacturing technology, the formation of complex-shaped structures is realized, providing a preparation method for the creation of the pore system framework structure of the high-melting-point matrix and the incorporation of the low-melting-point solid sweating phase in the sweating material; through additive manufacturing technology, a new type of solid sweating bionic tool is developed to achieve efficient cutting cooling, effectively solving the problem of large cutting heat control brought about by the increase in cutting speed.

[0025] Advantages of additional aspects of the present invention will be given in the following description, some of which will become apparent from the following description, or will be learned through the practice of the present invention. Brief Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. In addition, the distances or sizes between components are exaggerated for showing the positions of each component, and the schematic diagrams are only for illustration.

[0027] Figure 1 It is a schematic diagram of the tool structure and the solid-phase layout provided by an embodiment of the present invention, where the right side is a sectional view taken along the A-A position in the left figure; Figure 2 It is a schematic diagram of the distribution of the solid-phase in the matrix phase provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of the tool shape provided by an embodiment of the present invention, where Figure 3 (a) is a circular tool, Figure 3 (b) is a triangular tool, Figure 3 (c) is a square tool, Figure 3 (d) is a rhombic tool; Figure 4 It is a schematic diagram of the tool sweating cooling method provided by an embodiment of the present invention; Figure 5 It is a schematic diagram of the tool additive manufacturing method provided by an embodiment of the present invention; Detailed Description of the Embodiments It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. In addition, it should also be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0028] Term Explanation: Sweating cooling: It is proposed based on the principle that organisms control their body temperature by evaporating sweat. In engineering, by designing and manufacturing a sweating structure, the surface temperature of the material can be reduced by "sweating" in a high-temperature environment to achieve the purpose of the cooling condition. Among them, the sweating material is usually made of a porous matrix of high-melting-point metal, and then a low-melting-point metal is infiltrated into the porous matrix. At high temperatures, the low-melting-point metal evaporates and absorbs heat to cool the material surface. The application of this technology requires external conditions that can "sweat", that is, first, there must be a high external temperature condition to promote the gasification of the low-melting-point body, second, there must be a technology to realize the mutual doping of the high-melting-point matrix and the low-melting-point component, and third, the material itself must have certain mechanical properties before and after "sweating", and the mechanical properties cannot be reduced too much due to the "sweating" structure.

[0029] Example 1 As Figure 1 shown, this example proposes a solid sweating bionic tool, and further realizes the following effects: (1) Design a sweating bionic structure at the tool tip and realize this structure through additive manufacturing. The area of this structure should be small to avoid affecting the overall mechanical properties of the tool; (2) The solid low-melting-point material in the micro-region of the tool cutting edge is gasified by the cutting heat and becomes a gas film attached to the tool surface, forming an efficient heat insulation and heat isolation effect; (3) No cutting fluid is used during the cutting process to achieve cooling in dry cutting and realize low-carbon green manufacturing.

[0030] As Figure 1 、 Figure 2 shown, the solid sweating bionic tool includes a matrix phase and a solid sweating phase (solid sweating phase), and the melting point of the solid sweating phase is lower than that of the matrix phase; the solid sweating phase is a bag-like structure, and the solid sweating phase is distributed in the cutting edge area of the tool. The cutting edge area has a surface layer and a subsurface layer. Part of the solid sweating phase is exposed on the surface layer, and part is embedded in the subsurface layer; the solid sweating phase is heated to form a gas film covering the tool surface, and the gas film blocks the transfer of cutting heat to the tool, and phase change heat dissipation occurs when the gas film ruptures.

[0031] The main function of the solid sweating phase is to gasify on the tool surface under the action of cutting heat to form an adiabatic gas film, and achieve the purpose of protecting the tool edge area through evaporation and adiabatic action. In addition, the toughness of the solid sweating phase can be used to improve the anti-fracture ability of the tool matrix phase.

[0032] By distributing the solid sweating phase in the cutting edge area, the cooling directly acts on the core heat generation area, realizing efficient cooling, improving the tool life, and without using traditional cutting fluid, reducing environmental pollution. In addition, the bag-like structure makes the solid sweating phase have a large area in the subsurface layer, ensuring sufficient sweating volume, and the small exposed area can reduce the impact on the overall mechanical properties of the tool. The two work together to maintain the hardness and strength of the tool as much as possible while realizing efficient cooling.

[0033] The melting point of the solid-phase coolant is lower than the temperature in the core area during tool cutting. Specifically, the melting point of the solid-phase coolant is below 500°C. This temperature range matches the core temperature (400 - 500°C) generated by common metal cutting. During the cutting process, the temperature in the cutting edge area of the tool usually rises. By setting the melting point of the solid-phase coolant below 500°C, it can be ensured that under the action of cutting heat, the solid-phase coolant can melt in time and form a gas film, thus achieving effective cooling.

[0034] The solid-phase coolant is distributed in at least one of the rake face, flank face, chip breaker groove, and table face in the cutting edge area. During the cutting process, the rake face mainly bears the cutting force and cutting heat, the flank face generates frictional heat when contacting the workpiece, and the chip breaker groove and table face play roles such as chip breaking and support during cutting. Distributing the solid-phase coolant in these key areas can make more effective use of the cooling function of the solid-phase coolant, cool the heat sources in different parts during the cutting process, and improve the cooling effect of the entire cutting area. For example, when the solid-phase coolant on the rake face is heated to form a gas film, it can reduce the impact of the cutting force on the tool and lower the cutting temperature; the gas film formed by the solid-phase coolant on the flank face can reduce the frictional heat transfer with the workpiece. Compared with the traditional cooling method, this targeted distribution method can more precisely solve the heat generation problem during cutting, and avoid introducing low-melting-point materials in non-critical areas to affect the tool strength, improving the cooling efficiency and service life of the tool.

[0035] The area of the exposed part of the solid-phase coolant on the surface layer of the matrix phase is smaller than the area of the part embedded in the subsurface layer. Such a design helps to ensure sufficient sweating while reducing the impact of the solid-phase coolant on the mechanical properties of the surface layer of the matrix phase. Because if the exposed area is too large, it will cause premature wear or shedding of the solid-phase coolant during the cutting process, affecting the service life and cooling effect of the tool; while the larger area of the embedded part in the subsurface layer can store more solid-phase coolant materials, ensuring the continuous supply of substances required for the gas film for a long time. The setting of this area relationship is adapted to the force and heat distribution of the tool during the cutting process, enabling the cooling function of the solid-phase coolant to be fully exerted while ensuring the structural strength of the tool. For example, during the cutting process, the surface layer of the matrix phase mainly bears the cutting force and cutting heat, while the subsurface layer is relatively less stressed. Therefore, distributing more solid-phase coolant in the subsurface layer can achieve efficient cooling without affecting the performance of the surface layer of the matrix phase.

[0036] The diameter range of the exposed part of the solid-phase coolant is 0.1 - 1.0 mm, the maximum diameter range of the pocket is 2.0 - 3.0 mm, and the depth does not exceed 5 - 10 times (≤2.0 mm) the depth of the crater wear of the tool. Preferably, the depth range of the pocket is 0.5 - 1.0 mm.

[0037] The diameter of the exposed part is relatively small, which is beneficial to form a uniform and stable gas film on the surface layer of the matrix phase, while reducing the direct loss of the solid-phase coolant during the cutting process; the setting of the maximum diameter and depth of the pocket ensures that there is sufficient storage space for the solid-phase coolant in the subsurface layer, so as to replenish the vaporized substances in time when the gas film breaks and maintain the continuity and stability of the gas film. While reducing stress concentration, it avoids cooling interruption caused by insufficient sweating. For tools of different sizes, those skilled in the art can adjust the diameter of the exposed part and the size of the pocket to adapt to different cutting conditions.

[0038] The volume of the solid-phase coolant accounts for 5%-15% of the total volume of the entire tool material. This volume ratio is set to ensure sufficient cooling effect while avoiding excessive solid-phase coolant affecting the overall performance of the tool. If the volume of the solid-phase coolant is too small, it cannot provide enough vaporized substances to form an effective gas film, resulting in poor cooling effect; while if the volume is too large, it may reduce the hardness and strength of the tool, affecting the cutting performance of the tool. By precisely controlling the volume ratio of the solid-phase coolant, a balance can be achieved between the cooling effect and the tool performance. In practical applications, according to factors such as the use of the tool, cutting parameters, and materials, an appropriate volume ratio of the solid-phase coolant can be selected to meet different cutting requirements.

[0039] The matrix phase is cemented carbide (such as tungsten carbide) or ceramic (such as alumina, silicon nitride). Cemented carbide and ceramic are common tool materials with high hardness and good wear resistance, suitable for various cutting processes. The solid-phase coolant uses low-melting-point metal materials such as lead, zinc, and copper, which can melt in time under the action of cutting heat and form a gas film. The selection of this material combination is based on the material properties and the actual requirements of cutting processes. The cemented carbide or ceramic matrix phase provides the basic cutting performance of the tool, while the solid-phase coolant plays a cooling role during the cutting process.

[0040] As Figure 3 shown, the shape of the tool can be circular, triangular, square, diamond-shaped or irregular. Different tool shapes are suitable for different cutting process requirements. By designing tools with different shapes, the application scope of the present invention can be broadened, enabling it to play a role in cooling and improving tool life in various cutting processes.

[0041] Although sweating technology has applications in other fields, sweating cooling has not been applied to cutting machining for a long time because it is impossible to meet the dual requirements of "high-precision sweating structure" and "stable mechanical properties" simultaneously in the tool edge area. Specifically: ① Structural complexity: The sweating function requires a complex pore or pocket structure (such as micron-level channels) to be designed in the tool edge area. Traditional manufacturing methods (such as casting and machining) are difficult to precisely control the porous or composite structure of the matrix phase surface / sub-surface layer. ② Conflict in mechanical properties: The tool needs to have both high hardness and toughness. If low-melting-point materials (such as copper and zinc) are added to the edge area through traditional processes, interface cracks are likely to occur due to material incompatibility, reducing the tool strength. ③ Process limitations: Traditional sintering or coating technologies cannot achieve the gradient composite of low-melting-point materials and high-melting-point matrices (such as ceramics and cemented carbides).

[0042] Example 2 This example provides a dry cutting cooling method using the solid sweating bionic tool as described in Example 1: The present invention makes full use of the basic principle that a solid absorbs heat when it evaporates into a gas, forming a cyclic cooling method of gas film heat insulation and phase change heat dissipation in the cutting core area. As Figure 4 shown, during the cutting process, the solid phase of the tool cutting edge area is vaporized under the action of cutting heat, forming a gas film covering the tool surface. The gas film adheres tightly to the tool surface through intermolecular forces, and can effectively block the transfer of heat formed by cutting friction and chip deformation to the tool. If the gas film ruptures, a phase change heat dissipation method in which the solid turns into a gas is formed. At this time, the solid phase in the sub-surface layer continues to vaporize to replenish the gas film, thus forming a cyclic cooling process. This cooling method solves the problem of difficult effective cooling in traditional dry cutting, and realizes efficient cooling of the tool without cutting fluid.

[0043] Compared with traditional cooling methods, the cooling method of the present invention does not require external coolant, and uses the principle of heat absorption during the vaporization of the solid phase to directly form a cooling effect in the cutting core area, improving the cooling efficiency. At the same time, the formation and rupture process of the gas film can continuously remove cutting heat, ensure the temperature stability of the tool during the cutting process, extend the tool service life, and improve the machining quality and efficiency.

[0044] Example 3 This example proposes a manufacturing process for the solid sweating bionic tool as described in Example 1: The tool is made by additive manufacturing, such as Figure 5As shown in the figure, for the ceramic matrix, a composite process of photocuring and spray deposition (SLA+MJ) is selected; for the cemented carbide matrix, a directed energy deposition process (DED) is selected. During the additive manufacturing process, by adjusting parameters such as the laser power, scanning path, scanning rate, and powder supply amount of the matrix phase and the solid-phase deposition, the interface between the matrix phase and the solid-phase can be precisely controlled, while ensuring the area of the solid-phase exposed on the outer surface and the capacity of the solid-phase embedded in the subsurface. Subsequently, the formed tool is sintered and densified to finally obtain a solid-sweating bionic tool with a composite structure.

[0045] This manufacturing process overcomes the problem that traditional manufacturing methods are difficult to precisely control the distribution and structure of the solid-phase, providing the possibility for realizing solid-sweating bionic tools with complex structures. For example, the composite process of photocuring and spray deposition can precisely form the fine structure of ceramic matrix tools, while the directed energy deposition process is suitable for the manufacturing of cemented carbide matrix tools. By adjusting the manufacturing process parameters, the distribution of the solid-phase and its combination with the matrix phase can be optimized, improving the overall performance of the tool. The sintering densification treatment further increases the density and strength of the tool, ensuring the reliability and durability of the tool during the cutting process.

[0046] Specifically: Scheme 1: Use DED laser-directed energy deposition of tungsten carbide (WC) as the matrix skeleton. When the material is stacked on the surface layer and subsurface layer of the tool body, select low-melting-point copper or zinc as the solid-phase for selective deposition according to the designed sweating structure. Adjust process parameters such as the laser power, scanning path, scanning rate, and powder supply amount of the matrix WC and the sweating copper or zinc phase deposition to control the interface between the matrix phase and the solid-phase, while ensuring the area of the solid-phase exposed on the outer surface and the capacity of the solid-phase buried in the subsurface.

[0047] Scheme 2: Use the SLA process in the composite process of photocuring and spray deposition (SLA+MJ) to additively manufacture a matrix skeleton of (Al2O3 or Si3N4). When the material is stacked on the surface layer and subsurface layer of the ceramic tool body, select additively manufactured copper or zinc as the solid-phase according to the designed sweating structure using the MJ process. Then, attempt to sinter the additively manufactured ceramic tool into a dense tool body using low-temperature co-sintering technologies such as microwave sintering, plasma sintering, and ultrasonic vibration sintering. Adjust composite process parameters such as the laser power, scanning path, scanning rate, and feeding rate of the matrix skeleton ceramic and the sweating copper or zinc phase deposition to control the interface between the matrix phase and the solid-phase.

[0048] To make the technical solution provided by the present invention clearer, the present invention is described by taking the ceramic-based solid self-sweating tool as an example. The results achieved by the present invention are as follows: 1) The structure design of the solid-sweating tool is completed; 2) The additive manufacturing process plan for the designed tool structure is designed, and a solid natural-sweating tool is prepared; 3) Cutting experiments are carried out, and the expected cutting effect is achieved.

[0049] (1) Structural design: ① First, use Thirdwave simulation software to calculate the heat generation in the cutting zone of ceramic tools with different geometric parameters, and obtain the cutting heat as the boundary condition for subsequent simulation calculations. The geometric parameters are set as follows: rake angle -20 to 20°, clearance angle 2 to 10°, main cutting edge angle 0 to 90°, negative cutting edge angle 0 to 70°, edge inclination angle -20 to 20°, edge rounding radius 0.1 to 1.0 mm, nose radius 0.1 to 1.0 mm, chip breaker groove (such as straight type and arc type, etc.); the cutting parameters are set as follows: cutting speed 100 to 500 m / min, feed rate 0.1 to 0.5 mm / r, and cutting depth 0.1 to 3.0 mm.

[0050] ② Take the cutting heat distribution obtained from the Thirdwave simulation calculation as the boundary condition and input it into the COMSOL phase change simulation software to calculate the amount of solidified sweating required to stably control the cutting temperature in the cutting deformation zone below 400 to 500 °C and the thickness of the gas film formed by this sweating amount. Then, calculate the content of the solid sweating agent required in the solid sweating tool according to the thermodynamic equation.

[0051] ③ Based on the cutting temperature distribution calculated by the Thirdwave simulation, focus on the tool heating area where the cutting temperature exceeds 500 °C. This area will be the area where the solid sweating agent is incorporated.

[0052] ④ According to the calculation results of steps ② and ③, draw the three-dimensional diagram of the solid sweating bionic tool in 3D modeling software such as AutoCAD, UG, and Solidwork. The solid sweating phase is mainly distributed around the cutting edge area of the tool (including the rake face, flank face, chip breaker groove / table surface), and there is no solid sweating phase distribution in the area outside the cutting edge area of the tool. The content of the solid sweating phase is controlled at 5 to 15 vol% (the volume of the solid sweating phase accounts for 5% - 15% of the total volume of the entire tool material), as Figure 1 shown. The solid sweating phase penetrates into the interior of the tool face matrix phase, and its state is a bag-like structure (as Figure 2 shown), that is, the exposed area of the tool face is small (the exposed part diameter range is 0.1 to 1.0 mm), while the embedded area of the subsurface layer is large (the maximum diameter range of the bag is 2.0 to 3.0 mm), and the depth range of the bag is 0.5 to 1.0 mm, so as to provide sufficient vaporized substances for the solid sweating phase to form a gas film on the tool face when sweating.

[0053] ⑤Properties of the solidifying phase and the matrix phase: The solidifying phase is a low-melting-point substance, i.e., a substance that can melt at the cutting temperature point (with a melting point below 500 °C), such as alloy materials like lead, zinc, or copper. The matrix phase is a ceramic such as alumina or silicon nitride. The main function of the solidifying phase is to vaporize under the action of cutting heat to form an insulating gas film on the tool surface, achieving the purpose of protecting the tool edge area through evaporation and insulation. Additionally, the toughness of the solidifying phase can be utilized to improve the fracture resistance of the tool matrix phase. The solidifying phase is mainly distributed in the surface layer and subsurface layer areas of the cutting edge zone, with a depth not exceeding 5 times the depth of the flank wear of the tool (≤1.0 mm). The solidifying phase in the subsurface layer should have a cavity capacity to maintain sufficient sweating volume during sweating. The overall content of the solidifying phase should not be excessive, provided that it can achieve the cutting temperature control ability without overly affecting the hardness of the tool.

[0054] The tool structure designed according to the above process is as Figure 5 shown. The tool shapes include circular, triangular, square, diamond, and irregular shapes. The size of the circular tool is Φ12.5*2.5 mm, the size of the diamond insert is 12*12*6 mm, and the size of the square insert is 11*11*2.0 mm. The tool can have a chip breaker or not, and the solidifying phase is distributed near the rake face and flank face of the tool cutting edge zone.

[0055] (2) Theoretical analysis: Based on the above technical principles and parameters, a theoretical model of the gas film thickness, the content of the solidifying sweat agent, and the cutting parameters is established. Set the target gas film thickness as δ , and the following conditions need to be considered: ① Gas film adiabatic condition: The gas film needs to block the heat flux density q transmitted into the tool, satisfying: ; Among them: h c : Convective heat transfer coefficient of the gas film (W / m 2 ∙K), k g : Thermal conductivity of the gas (W / m∙K), T cut : Temperature of the cutting zone, T tool : Tool temperature, ∆ T : Temperature difference.

[0056] ② Requirement for the gasification amount of the sweat agent: The gas volume Vg required to form a gas film with a thickness of δ is: ; Among them, A is the area of the high-temperature zone of the tool (m2 ) and is related to the cutting depth a p and the principal cutting edge angle κ r related, A ∝ a p ∙l c ( lc : cutting edge contact length).

[0057] ③ Sweating agent consumption: The sweating agent completely vaporizes from the solid state (melting point < 500 °C), and its volume Vs satisfies: ; wherein, ρ s , ρ g : solid / gaseous density of the sweating agent (kg / m 3 ), V g : gas volume required for the gas film.

[0058] ④ Sweating agent content and tool structure constraint: Effective sweating volume V s is provided by the total volume of the sweating agent inside the tool: ; wherein, α : volume fraction of the sweating agent, V active : effective volume of the pocket in the high-temperature zone.

[0059] ; wherein, n is the number of pockets in the high-temperature zone, which is proportional to the area A proportional, d max is the maximum diameter of the pocket, h is the depth of the pocket.

[0060] Therefore, the expression for the gas film thickness is: ; wherein, k struct : pocket distribution density coefficient, determined by the number of pockets per unit area in the high-temperature zone, C: cutting geometry correction coefficient, positively correlated with the principal cutting edge angle.

[0061] (3)Manufacturing process: ①First, use 3D software such as UG and Solidwork to model the hair-fixing tool. The shape and structure of the tool are as shown in Figure 5 and save it as an STL format model. Then import the STL format file into the slicing software CeraMulti Slicer.

[0062] ②Slice the model in the CeraMulti Slicer software. Divide the entire tool model into upper, middle, and lower parts for cutting. The upper part includes the cutting edge area of the blade, which contains the tool matrix phase and the solid sweating phase, with a thickness of 1 / 5 of the overall blade thickness, ranging from 0.5 to 1.0 mm. The middle part only contains the tool matrix phase and does not contain the solid sweating phase, with a thickness of 3 / 5 of the overall blade thickness, ranging from 2.0 to 4.0 mm. The lower part has the same blade shape, structure, and material properties as the upper part, with a thickness of 1 / 5 of the overall blade thickness, ranging from 0.5 to 1.0 mm. High-density slicing is performed on the upper part and the upper part area. The single-layer slice thickness is 0.02 - 0.04 mm, and the total number of slice layers is 100 - 200 layers to ensure the printing accuracy of the blade shape and structure and the precise filling of the hair-fixing phase. Low-density slicing is performed on the middle part area. The single-layer slice thickness is 0.05 - 0.1 mm, and the total number of slice layers is 50 - 100 layers to ensure the printing accuracy of the blade shape and structure and the precise filling of the hair-fixing phase. ③Import the sliced tool model into the multi-material CeraMulti 3DPrinter. Set the printing parameters: the laser power is 50 - 150 mW, the laser scanning rate is 4.0 m / s, and the laser scanning spacing is 100 μm. The coating speed of the matrix phase ceramic paste is 1 - 4 mm / s, and the filling speed of the solid sweating incorporated phase is 20 - 30 mm / s.

[0063] ④Start printing, and print in three parts: 1) Lower part printing: Feeding by the feeding platform: Select the matrix phase and inject it into the feeding trough, and use the feeding push plate to push the matrix phase upward and extrude it. Scraping and spreading: The scraper evenly spreads the matrix phase extruded from the feeding platform onto the printing platform, and at the same time scrapes the excess ceramic phase into the recycling bin. Laser system curing: Start the laser system and cure the matrix phase area according to the printing path. Nozzle grooving and spraying: Move the nozzle module above the matrix phase. First start the blowing nozzle and then start the spraying nozzle. In the preset hair-fixing phase filling area, the blowing nozzle is responsible for grooving, and the spraying nozzle supplies the hair-fixing phase material. After the hair-fixing phase spraying is completed, start the laser system again and cure the hair-fixing phase according to the preset path. Thus, the printing process of one layer is completed. After each layer is cured and formed, the printing platform descends by one layer thickness, and repeat the above steps until the lower part printing is completed.

[0064] 2) Middle part printing (no need to fill the hair-fixing phase, only print the matrix phase): Feeding platform feeding: Select the matrix phase and inject it into the feeding tank, and use the feeding push plate to push the matrix phase upward and extrude it; Scraper coating and spreading: The scraper evenly coats and spreads the matrix phase extruded from the feeding platform onto the printing platform, and at the same time scrapes the excess ceramic phase into the recovery bin; Laser system curing: Start the laser system and cure the matrix phase area according to the printing path. After each layer is cured and formed, the printing platform descends by one layer thickness, and the above steps are repeated.

[0065] 3) Upper part printing: The same as the upper part printing.

[0066] ⑤ After taking out the printing tool, clean the uncured paste around it with alcohol; ⑥ Place the cleaned multiple tool blanks into a ceramic sintering box, fill the surrounding with high-temperature resistant sealing refractory material clay, place it in a high-temperature sintering furnace, and sinter at a high temperature. Heat it up to 1450 - 1650 °C at a rate of 0.5 °C / min, then keep it warm for 120 min to make the sample gradually dense, and finally cool it down to room temperature at a rate of 1 °C / min. The sample sintering is completed to obtain the final solid self sweating tool.

[0067] Although the specific implementation manners of the present invention are described above in conjunction with the accompanying drawings, it is not a limitation to the protection scope of the present invention. Those skilled in the art should understand that based on the technical solutions of the present invention, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the protection scope of the present invention.

Claims

1. A solid sweating bionic tool, the tool body having a cutting edge area, characterized in that: The tool body is a matrix phase material, and a sac-like solid phase material is incorporated into the matrix phase material in the cutting edge area. The melting point of the solid phase material is lower than that of the matrix phase material. Part of the solid phase is exposed on the surface layer of the matrix phase, and part is embedded in the surface layer of the matrix phase; The solid phase can be heated to form a gas film covering the tool surface. The gas film can block the transfer of cutting heat to the tool and can form phase change heat dissipation when the gas film ruptures.

2. The solid sweating bionic tool according to claim 1, characterized in that, The melting point of the solid phase is lower than the temperature of the core area during tool cutting.

3. The solid sweating bionic tool according to claim 1, characterized in that The solid phase is distributed in at least one of the rake face, flank face, chip breaker groove and table surface in the cutting edge area.

4. The solid sweating bionic tool according to claim 1, wherein, The area of the solid phase exposed on the surface layer of the matrix phase is smaller than the area of the part embedded in the surface layer.

5. The solid sweating bionic tool according to claim 4, characterized in that, The diameter range of the exposed part of the solid phase is 0.1 - 1.0 mm, the maximum diameter range of the sac is 2.0 - 3.0 mm, and the depth range of the sac is 0.5 - 1.0 mm.

6. The solid sweating bionic tool according to claim 1, wherein The volume of the solid phase accounts for 5% - 15% of the total volume of the entire tool material.

7. The solid sweating bionic tool according to claim 1, wherein The matrix phase is cemented carbide or ceramic, and the solid phase is lead, zinc or copper.

8. The solid sweating bionic tool according to claim 1, characterized in that, The shape of the tool is circular, triangular, square, rhombic or irregular.

9. A dry cutting cooling method using the solid sweating bionic tool according to any one of claims 1 - 8, characterized in that: During the cutting process, the solid phase in the cutting edge area of the tool is vaporized by the cutting heat to form a gas film covering the tool surface; the gas film adheres tightly to the tool face through intermolecular forces, blocking the transfer of cutting heat to the tool; when the gas film ruptures, a phase change heat dissipation method of solid turning into gas is formed, and the solid phase in the subsurface continues to be vaporized to replenish the gas film, forming a cyclic cooling process.

10. A manufacturing process of the solid sweating bionic tool according to any one of claims 1 - 8, characterized in that: The tool is made by additive manufacturing. During the additive manufacturing process, by adjusting the laser power, scanning path, scanning rate and powder supply amount of the deposition of the matrix phase and the solid phase, the interface between the matrix phase and the solid phase is regulated, and at the same time, the area of the solid phase exposed on the outer surface and the capacity of the solid phase embedded in the subsurface are ensured; The formed tool is subjected to sintering densification treatment to finally obtain a solid sweating bionic tool with a composite structure.

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