A preparation method of a metal ceramic tool suitable for machining titanium alloy blades and a metal ceramic tool

Abstract

The present invention provides a preparation method and a metal ceramic tool suitable for titanium alloy blade disk processing, belonging to the field of metal ceramic technology, comprising: using a powder metallurgy process to prepare a metal ceramic tool sample with high saturated free carbon; in a vacuum environment, placing the metal ceramic tool sample in a high-frequency alternating electric field and rapidly heating it to 1000-1300°C, and then rapidly cooling it to 500±20°C in an inert atmosphere; rapidly heating the metal ceramic tool sample to 1000-1300°C under vacuum conditions, and then rapidly cooling it to 500°C±20°C in an inert atmosphere, repeating this process several times, and finally cooling it to room temperature to obtain a metal ceramic tool suitable for titanium alloy blade disk processing. The metal ceramic tool prepared by this method has the characteristics of high strength and high hardness, can improve the efficiency of blade disk processing, and reduce or eliminate processing wear.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal ceramics, and in particular relates to a preparation method of a metal ceramic tool suitable for machining titanium alloy blade disks and the metal ceramic tool. Background Art

[0002] Cermets are widely used in aviation cutting tools due to their excellent hardness, wear resistance, and corrosion resistance. However, when machining integral blade discs, because the primary component of the blade disc is titanium alloy, which has low thermal conductivity, high strength, and high chemical reactivity, high micro-cutting temperatures often result in increased adhesive and diffusion wear on the tool during machining, leading to low tool processing efficiency. Furthermore, because the blade structure is mostly thin-walled and has poor rigidity at the blade tip, excessive cutting forces and heat can easily exacerbate finishing vibrations, adversely affecting the blade surface integrity, roughness, and thickness tolerances. Summary of the Invention

[0003] In order to solve the problems of low processing efficiency and severe processing wear of metal ceramic tool blades, the present invention provides a method for preparing a metal ceramic tool suitable for titanium alloy blade processing. The metal ceramic tool prepared by this method has the characteristics of high strength and high hardness, can improve the processing efficiency of the blade, and reduce or eliminate processing wear.

[0004] The present invention also provides a metal ceramic tool suitable for machining titanium alloy blade disks.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention provides a method for preparing a metal ceramic tool suitable for machining titanium alloy blade disks, the preparation method comprising:

[0007] S1. Preparation of cermet cutting tool specimens with high saturated free carbon using powder metallurgy.

[0008] S2. In a vacuum environment, the metal ceramic tool sample is placed in a high-frequency alternating electric field and heated to 1000-1300°C at a rate of 100-120°C / s, and then rapidly cooled to 500±20°C in an inert atmosphere;

[0009] S3. After cooling in step S2, the metal-ceramic tool sample is rapidly heated to 1000-1300°C under vacuum conditions, and then rapidly cooled to 500°C ± 20°C under an inert atmosphere;

[0010] S4. Repeat step S3 several times, and finally cool to room temperature to obtain a metal ceramic tool suitable for titanium alloy blade disk processing.

[0011] Furthermore, the powder metallurgy process is used to prepare a metal ceramic tool sample with high saturated free carbon, specifically comprising:

[0012] MeC powder, Ni powder and nickel-coated activated carbon powder were mixed and pressed into green compacts, which were then sintered under an inert atmosphere to obtain metal-ceramic tool samples with high saturated free carbon.

[0013] Wherein, the MeC powder includes at least one of TiC, WC and TaC;

[0014] Alternatively, the MeC powder is a solid solution powder formed by at least two of TiC, WC and TaC;

[0015] In the green compact, the mass ratio of MeC powder, Ni powder and nickel-coated activated carbon powder is 85:10:5.

[0016] Furthermore, the mixing of MeC powder, Ni powder and nickel-coated activated carbon powder and pressing into a green compact, and sintering under an inert atmosphere to obtain a metal ceramic tool sample with high saturated free carbon specifically includes:

[0017] MeC powder, Ni powder and nickel-coated activated carbon powder were mixed and pressed into green compacts, which were sintered under inert atmosphere at a pressure of 5±0.5 MPa and a temperature of 1450±20°C. The mixture was kept at 1450°C for 1 hour to obtain metal ceramic tool samples with high saturated free carbon.

[0018] The particle sizes of the MeC powder, the Ni powder and the nickel-coated activated carbon powder are 1.2 μm, 1.5 μm and 1 μm respectively.

[0019] Furthermore, the size of the green body is 20×6.5×5.25 mm.

[0020] Furthermore, the nickel-coated activated carbon powder is prepared by the following method:

[0021] Evenly disperse the activated carbon powder in the SnCl2 solution, then heat it to 50-70°C and keep it warm for a certain period of time to obtain solution A;

[0022] Adding PaCl2 to the solution A to perform surface activation treatment on the activated carbon powder to obtain solution B;

[0023] Adding NiSO4, sodium citrate and anhydrous sodium carbonate hydrazine hydrate to the solution B to obtain solution C;

[0024] Adjusting the pH of the solution C to 10-13.2, and then reacting at 40-60° C. for 1-3 hours until the thickness of the Ni layer grown on the surface of the activated carbon powder exceeds 0.5 μm, thereby obtaining a solution D;

[0025] The solution D is filtered, washed and dried to obtain nickel-coated activated carbon powder.

[0026] Furthermore, the nickel-coated activated carbon powder is prepared by the following method:

[0027] Activated carbon powder with a particle size of 50nm-200nm is uniformly dispersed in a 2-20g / L SnCl2 solution, and then the temperature is raised to 50-70°C and kept warm for 1-1.5h. Ultrasonic oscillation is used during the holding period to obtain solution A;

[0028] Adding PaCl2 to the solution A to perform surface activation treatment on the activated carbon powder for 60-90 min to obtain solution B;

[0029] Adding NiSO4, sodium citrate and anhydrous sodium carbonate hydrazine hydrate (Na2CO3N2H4.H2O) to the solution B to obtain solution C;

[0030] Adjusting the pH of the solution C to 10-13.2, and then reacting at 40-60° C. for 1-3 hours until the thickness of the Ni layer grown on the surface of the activated carbon powder exceeds 0.5 μm, thereby obtaining a solution D;

[0031] The solution D is filtered, washed and dried to obtain nickel-coated activated carbon powder;

[0032] Wherein, the concentration of activated carbon powder in the solution A is 1 to 2.5 g / L;

[0033] The concentration of PaCl2 in the solution B is 0.1-0.3 g / L;

[0034] The concentrations of NiSO4, sodium citrate and anhydrous sodium carbonate hydrazine hydrate in the solution C are 0.1-0.3 g / L, 0.5-1 g / L and 0.8-1.4 g / L respectively.

[0035] Furthermore, the method of placing the metal ceramic tool sample in a high-frequency alternating electric field under a vacuum environment and heating it to 1000-1300° C. at a rate of 100-120° C. / s, and then rapidly cooling it to 500±20° C. under an inert atmosphere, specifically includes:

[0036] In a vacuum environment, the metal ceramic tool sample is placed in a high-frequency alternating electric field and heated to 1000-1300° C. at a rate of 100-120° C. / s, and then cooled to 500° C.±20° C. within 5-8 seconds under an inert atmosphere;

[0037] The vacuum degree of the vacuum environment is 2×10 -3 -6×10 -3 Pa;

[0038] The frequency of the high-frequency alternating electric field is 50-85 MHz, the current is 2-8 A, and the voltage is 380-500 V.

[0039] Furthermore, after the cooling in step S2 is completed, the metal ceramic tool sample is rapidly heated to 1000-1300° C. under vacuum conditions, and then rapidly cooled to 500° C.±20° C. under an inert atmosphere, specifically comprising:

[0040] After cooling in step S2 is completed, the temperature of the metal ceramic tool sample is raised to 1000-1300° C. within 5-8 seconds under vacuum conditions, and then cooled to 500° C.±20° C. within 5-8 seconds under an inert atmosphere.

[0041] Furthermore, in step S4, step S3 is repeated 10-50 times.

[0042] Based on the same inventive concept, the present invention provides a metal ceramic tool suitable for machining titanium alloy blade disks. The metal ceramic tool is manufactured by the above-mentioned method for preparing a metal ceramic tool suitable for machining titanium alloy blade disks.

[0043] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0044] 1. The present invention provides a method for preparing a metal ceramic tool suitable for processing titanium alloy blade disks. The method adopts a powder metallurgy process to sinter a metal ceramic sample with high saturated free carbon, and then uses a high-frequency alternating electric field to assist rapid sintering to generate a temperature field with a gradient. Along the direction of the temperature field, the concentration of free carbon atoms in the sample will produce a gradient distribution. Due to the conjugation effect of carbon atoms and nickel atoms, the surface of the tool will show a high carbide distribution and the sub-surface will show a high metal phase distribution, so that the surface of the tool has high hardness and high wear resistance. The heat generated by cutting is quickly discharged along with the sub-surface metal, thereby preparing a metal ceramic tool with high strength, high hardness and high thermal conductivity, which can improve the processing efficiency of the blade disk and reduce or eliminate processing wear.

[0045] 2. The present invention provides a method for preparing a metal ceramic tool suitable for processing titanium alloy blade disks. The method utilizes a high-frequency alternating electric field to assist sintering to generate a high-speed dynamically changing temperature field, that is, during rapid heating and rapid cooling, the surface temperature of the metal ceramic sample is higher than the internal temperature, forming a temperature field from the surface downward to the internal area. Under the action of the temperature field, for carbon atoms with small mass and small radius, the atoms are easy to diffuse, there are more vacancies in the surface crystals with high temperature, and the crystals have larger lattice parameters. During the whole process, carbon atoms tend to migrate from the sub-surface area to the surface area. Therefore, a composition gradient corresponding to the temperature field gradient is generated, that is, the carbon atom concentration distribution is gradiently distributed along the direction of the temperature field, thereby preparing a metal ceramic with a hard surface and a tough core in which carbon atoms are gradiently distributed.

[0046] 3. The present invention provides a method for preparing a metal ceramic tool suitable for processing titanium alloy blade disks. Before performing the powder metallurgy process, activated carbon powder is wrapped with nickel, which can reduce the mutual diffusion between C atoms and carbides MeC before the nickel liquidus appears, and reduce the solid dissolution of C atoms by carbide unit cells during the sintering process. After the liquidus appears, most of the C atoms can be solid-dissolved in nickel. Nickel as a carrier has better fluidity, which is conducive to the formation of a gradient distribution of C atoms under the action of the temperature field. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1 This is the EDS element distribution map of the metal ceramic tool that was cyclically treated 30 times in a high-speed changing dynamic temperature field.

[0049] Figure 2 This is a graph showing the cutting force changes of a metal ceramic tool after 30 times of temperature field treatment and that of an ordinary metal ceramic tool when cutting titanium alloy under the same parameters.

[0050] Figure 3 This is the hardness distribution of the gradient metal ceramic after temperature field treatment. DETAILED DESCRIPTION

[0051] The present invention will be described in detail below in conjunction with specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly presented. It should be understood by those skilled in the art that these specific embodiments and examples are for illustrating the present invention, rather than for limiting the present invention.

[0052] Throughout this specification, unless otherwise specified, the terms used herein should be understood as having the same meaning as commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the event of any conflict, the present specification shall take precedence.

[0053] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0054] The technical principles of the present invention are as follows:

[0055] A method for preparing a metal ceramic tool suitable for machining titanium alloy blade disks, the method comprising:

[0056] S1. Preparation of cermet cutting tool specimens with high saturated free carbon using powder metallurgy.

[0057] S2. In a vacuum environment, the metal ceramic tool sample is placed in a high-frequency alternating electric field and heated to 1000-1300°C at a rate of 100-120°C / s, and then rapidly cooled to 500±20°C in an inert atmosphere;

[0058] S3. After cooling in step S2, the metal-ceramic tool sample is rapidly heated to 1000-1300°C under vacuum conditions, and then rapidly cooled to 500°C ± 20°C under an inert atmosphere;

[0059] S4. Repeat step S3 several times, and finally cool to room temperature to obtain a metal ceramic tool suitable for titanium alloy blade disk processing.

[0060] Step S1 specifically includes:

[0061] MeC powder, Ni powder and nickel-coated activated carbon powder were mixed and pressed into green compacts, which were then sintered under an inert atmosphere to obtain metal-ceramic tool samples with high saturated free carbon.

[0062] Wherein, the MeC powder includes at least one of TiC, WC and TaC;

[0063] Alternatively, the MeC powder is a solid solution powder formed by at least two of TiC, WC and TaC;

[0064] In the green compact, the mass ratio of MeC powder, Ni powder and nickel-coated activated carbon powder is 85:10:5.

[0065] In the present invention, the MeC powder uses at least one of TiC, WC, and TaC. The advantage is that all three types of powders exhibit excellent high-temperature creep resistance, while also possessing inherently high hardness, resulting in more wear-resistant tools. In the green body, a mass ratio of MeC powder, Ni powder, and nickel-coated activated carbon powder of 85:10:5 provides a tool matrix with excellent fracture toughness, reducing brittleness and preventing tool chipping. Furthermore, the use of Ni as a binder provides improved wettability, while solid solution strengthening also enhances wear resistance.

[0066] More specifically, step S1 includes:

[0067] MeC powder, Ni powder and nickel-coated activated carbon powder were mixed and pressed into green compacts, which were sintered under inert atmosphere at a pressure of 5±0.5 MPa and a temperature of 1450±20°C. The mixture was kept at 1450°C for 1 hour to obtain metal ceramic tool samples with high saturated free carbon.

[0068] The particle sizes of the MeC powder, the Ni powder and the nickel-coated activated carbon powder are 1.2 μm, 1.5 μm and 1 μm respectively.

[0069] The size of the green body is 20×6.5×5.25 mm.

[0070] In the present invention, the advantage of using a green body sintering temperature of 1450±20°C is that this sintering temperature is the main dissolution temperature of Ni, but not the dissolution temperature of MEC powder. In this condition, the metal is prone to solid solution, which can effectively enhance the basic mechanical properties of the liquid phase. At the same time, the hard phase can refine the grains through dissolution-precipitation, making the matrix grain size smaller. If the temperature is too low, the grain dissolution process is slow, the free energy obtained by the metal particles is low, resulting in incomplete solid solution reaction. There is a higher possibility that the Ni bonding phase will evaporate during the sintering process, reducing the bonding phase of the matrix and reducing the matrix strength. The advantages of using the above particle size range for the MeC powder, the Ni powder, and the nickel-coated activated carbon powder are good powder flowability. At the same time, the matrix hard phase and liquid phase produced by using a powder particle size of about 1μm are uniform and less prone to segregation. The green body size is 20×6.5×5.25mm, which is a common testing size for tool materials. It can be made to this size to perform tests such as transverse rupture strength, coating, hardness, density, and magnetic saturation.

[0071] In step S1, the nickel-coated activated carbon powder is prepared by the following method:

[0072] Evenly disperse the activated carbon powder in the SnCl2 solution, then heat it to 50-70°C and keep it warm for a certain period of time to obtain solution A;

[0073] Adding PaCl2 to the solution A to perform surface activation treatment on the activated carbon powder to obtain solution B;

[0074] Adding NiSO4, sodium citrate and anhydrous sodium carbonate hydrazine hydrate to the solution B to obtain solution C;

[0075] Adjusting the pH of the solution C to 10-13.2, and then reacting at 40-60° C. for 1-3 hours until the thickness of the Ni layer grown on the surface of the activated carbon powder exceeds 0.5 μm, thereby obtaining a solution D;

[0076] The solution D is filtered, washed and dried to obtain nickel-coated activated carbon powder.

[0077] In the present invention, the activated carbon powder is uniformly dispersed in the SnCl2 solution and then heated to 50-70°C in order to increase the kinetic energy of the liquid to facilitate sufficient reaction. The advantage of using PaCl2 to perform surface activation treatment on the activated carbon powder is that the solution only performs surface activation treatment on the object, does not participate in other reactions and is easy to remove. The purpose of adding sodium citrate and anhydrous sodium carbonate hydrazine hydrate to the solution B is to promote the coating of the powder.

[0078] In the present invention, the pH of the solution C is adjusted to 10-13.2 for the purpose of neutralizing the effects of the acidic reagent. The advantage of the Ni layer grown on the surface of the activated carbon powder being thicker than 0.5 μm is that it protects the Ni powder particle size to maintain its original shape during the ball milling process. If it is too thick, the C content will increase, and if it is too thin, it may not be able to protect the Ni powder well.

[0079] Step S2 specifically includes:

[0080] In a vacuum environment, the metal ceramic tool sample is placed in a high-frequency alternating electric field and heated to 1000-1300° C. at a rate of 100-120° C. / s, and then cooled to 500° C.±20° C. within 5-8 seconds under an inert atmosphere;

[0081] The vacuum degree of the vacuum environment is 2×10 -3 -6×10 -3 Pa;

[0082] The frequency of the high-frequency alternating electric field is 50-85 MHz, the current is 2-8 A, and the voltage is 380-500 V.

[0083] In the present invention, the purpose of placing the metal ceramic tool sample in a high-frequency alternating electric field for rapid heating and cooling is that the sudden change in the electric field environment can effectively eliminate the defects generated during the crystallization process of the matrix. The high-frequency alternating electric field has a frequency of 50-85 MHZ, has a good treatment effect, and requires a short reaction time.

[0084] Step S3 specifically includes:

[0085] After cooling in step S2 is completed, the temperature of the metal ceramic tool sample is raised to 1000-1300° C. within 5-8 seconds under vacuum conditions, and then cooled to 500° C.±20° C. within 5-8 seconds under an inert atmosphere.

[0086] In the present invention, the purpose of heating the metal ceramic tool sample to 1000-1300°C within 5 to 8 seconds is to remove impurities (binders) inside the metal sample and activate the powder particle size. If the heating rate and target temperature are too high, the bonding phase will be liquefied, and if they are too low, the powder cannot be fully activated. The purpose of cooling the metal ceramic tool sample to 500°C±20°C within 5 to 8 seconds is to eliminate defects generated during the pressing process while maintaining partial activity of the powder. If the target cooling temperature is too high, the particles will shrink imperfectly, and if it is too low, the particles will lose their activity.

[0087] In the present invention, the heating process is carried out under vacuum conditions, and the cooling process is carried out under an inert atmosphere. The advantages are that the vacuum prevents the particles from oxidizing, and the pressure is less than the atmospheric pressure, which will make them denser. The inert gas is introduced during cooling to protect and reduce the temperature.

[0088] In step S4, step S3 is repeated 10-50 times.

[0089] In the present invention, the purpose of repeatedly rapidly heating and cooling the metal ceramic tool sample is to eliminate the residual stress inside the blank. The repetition number of 10-50 times is conducive to obtaining a fine and dense metal ceramic matrix.

[0090] The following will describe in detail a preparation method of a metal-ceramic tool suitable for machining titanium alloy blade disks and a metal-ceramic tool according to the present application in combination with examples and experimental data.

[0091] Example 1

[0092] This embodiment provides a method for preparing a metal ceramic tool suitable for machining a titanium alloy blisk, specifically comprising:

[0093] (1) Weigh 50 nm activated carbon powder and add it to a 10 g / L SnCl2 aqueous solution to obtain solution A (the final concentration of activated carbon powder is 1.8 g / L). Disperse solution A evenly and heat it to 70 °C for 1 h. Use ultrasonic oscillation during this period to ensure powder dispersibility.

[0094] (2) PaCl2 was added to the solution A, and the concentration of PaCl2 was ensured to be 0.1 g / L, to obtain solution B, so as to perform surface activity treatment on the dispersed activated carbon powder, the treatment time was 60 min, after the treatment was completed, NiSO4 (final concentration 0.2 g / L), sodium citrate (final concentration 0.5 g / L) and anhydrous sodium carbonate hydrazine hydrate (final concentration 1 g / L) were added to solution B to obtain solution C, which contained an effective Na ion concentration of 50 g / L, and NaOH solution was added to solution C to obtain solution D, the pH of which needed to be maintained at 10, and a Ni layer was grown on the powder surface. At this time, the temperature needed to be maintained at 40°C, and the treatment time was 1 h. At this time, the thickness of the Ni layer grown on the surface of the activated carbon powder exceeded 0.5 μm.

[0095] (3) Filtering, washing and drying the solution D to obtain nickel-coated activated carbon powder.

[0096] (4) Preparation of metal ceramic mixture. 5 wt.% of nickel-coated activated carbon powder was fully dried and weighed with 85 wt.% TiC powder and 10 wt.% Ni powder, totaling 300 g. This step is to obtain the maximum saturated free carbon atom content of the Ti-C-Ni three-phase. The powder was ball milled in a planetary ball mill with a powder to alloy ball ratio of 0.3:1. Deionized water was used as the ball milling medium. After ball milling for 6 hours, the powder slurry was sieved with a 200-mesh screen. After sieving, it was dried at 70°C. After drying, it was sieved with a 100-mesh screen. An industrial MW23 molding agent with a powder content of 10% was added to the powder.

[0097] (5) Sintering of metal ceramic tool sample. The mixture prepared in step (4) is pressed into a sample of 20×6.5×5.25 mm under a pressure of 300 MPa, or into a metal ceramic rod blank of the corresponding size of the required end mill. The pressed green blank size is D18*120L. The green blank is kept at 380°C for 6 hours, the forming agent is removed, and the solid phase is kept near the Ni liquidus line of 1310 degrees Celsius for 3 hours to make the sample initially reach a solid phase dense state. The temperature is then raised to 1450°C and kept for 1 hour. The sintering atmosphere is Ar and the sintering pressure is 5 MPa to obtain the metal ceramic tool sample.

[0098] (6) The metal ceramic tool sample was descaled on a grinding wheel, polished with sandpaper, and ultrasonically cleaned with ethanol. It was then placed in a high-frequency alternating current vacuum furnace (frequency 50-85 MHZ, current 2-8 A, voltage 380-500 V). The initial temperature was 25 °C, the heating rate was 100 °C / s, and the sample was rapidly heated to 1000 °C in about 10 s. The vacuum degree in the furnace was 2×10 - 3Pa. Heating was stopped and the sample was cooled to 500°C within 5 seconds in an Ar gas atmosphere at a flow rate of 100 L / h. The sample was then heated to 1000°C within 5 seconds with the Ar gas turned off. The sample was then cooled again to 500°C within 5 seconds with the Ar gas turned on. This step was repeated 30 times before finally cooling to room temperature (25°C) to obtain a metal ceramic tool.

[0099] The metal ceramic tool prepared in this embodiment was tested for transverse rupture strength using a universal fatigue testing machine, and its transverse rupture strength was 2470 MPa. The relative density of the matrix was measured by the drainage method and was 99.8%. The surface hardness of the tool was measured by a Vickers hardness tester and was 1810 HV. 30 , fracture toughness is 9.7MPam 1 / 2 The friction coefficient when grinding against titanium alloy is 0.15, and the main cutting force when cutting titanium alloy is less than 280N. It has excellent mechanical properties.

[0100] Example 2

[0101] This embodiment provides a method for preparing a metal ceramic tool suitable for machining a titanium alloy blisk, specifically comprising:

[0102] (1) Weigh 200 nm activated carbon powder and add it to a 20 g / L SnCl2 aqueous solution to obtain solution A (the final concentration of activated carbon powder is 2.2 g / L). Disperse solution A evenly and heat it to 70 °C for 90 min. Ultrasonic oscillation is used during this period to ensure powder dispersibility.

[0103] (2) PaCl2 was added to the solution A, and the concentration of PaCl2 was ensured to be 0.3 g / L, to obtain solution B, so as to perform surface activity treatment on the dispersed activated carbon powder, the treatment time was 60 min, after the treatment was completed, NiSO4 (0.2 g / L), sodium citrate (0.8 g / L) and anhydrous sodium carbonate hydrazine hydrate (1.2 g / L) were added to solution B to obtain solution C, which contained an effective Na ion concentration of 70 g / L, and NaOH solution was added to solution C to obtain solution D, the pH of which needed to be maintained at 13.2, and a Ni layer was grown on the powder surface. At this time, the temperature needed to be maintained at 60°C, and the treatment time was 3 h. At this time, the thickness of the Ni layer grown on the surface of the activated carbon powder exceeded 0.5 μm.

[0104] (3) Filtering, washing and drying the solution D to obtain nickel-coated activated carbon powder.

[0105] (4) Preparation of metal ceramic mixture. 5 wt.% of nickel-coated activated carbon powder was fully dried and weighed with 85 wt.% WC powder and 10 wt.% Ni powder, totaling 300 g. This step is to obtain the maximum saturated free carbon atom content of the WC-Ni three-phase. The powder was ball milled in a planetary ball mill with a powder to alloy ball ratio of 0.3:1. Deionized water was used as the ball milling medium. After ball milling for 4 hours, the powder slurry was sieved with a 200-mesh screen. After sieving, it was dried at 70°C. After drying, it was sieved with a 100-mesh screen. An industrial MW23 molding agent with a powder content of 10% was added to the powder.

[0106] (5) Sintering of metal ceramic tool sample. The mixture prepared in step (4) is pressed into a sample of 20×6.5×5.25 mm or a metal ceramic rod blank of the corresponding size of the required end mill under a pressure of 300 MPa. The pressed blank size is the same as that in Example 1. The blank is kept at 380°C for 6 hours, the forming agent is removed, and the solid phase is kept near the Ni liquidus line of 1310°C for 3 hours to make the sample initially reach a solid phase dense state. The temperature is then raised to 1450°C and kept for 1 hour. The sintering atmosphere is Ar and the sintering pressure is 5 MPa to obtain the metal ceramic tool sample.

[0107] (6) The metal ceramic tool sample was descaled on a grinding wheel, polished with sandpaper, and ultrasonically cleaned with ethanol. It was then placed in a homemade high-frequency alternating current vacuum furnace with an initial temperature of 25°C and a heating rate of 100°C / s. The sample was rapidly heated to 1300°C in about 13 seconds. The vacuum degree in the furnace was 2×10 -3 Pa. Heating was stopped and the sample was cooled to 500°C within 10 seconds in an Ar gas atmosphere at a flow rate of 100 L / h. The sample was then heated to 1300°C within 8 seconds with the Ar gas turned off. The sample was then cooled again to 500°C within 10 seconds with the Ar gas turned on. This step was repeated 50 times before finally cooling to room temperature (25°C) to obtain a metal ceramic cutting tool.

[0108] The test results show that the transverse fracture strength of the metal ceramic tool prepared in this embodiment is 3280 MPa, the relative density is 99.6%, and the surface hardness is 1720 HV. 30 , fracture toughness 11.2MPam 1 / 2 The friction coefficient when grinding against titanium alloy is 0.24, and the main cutting force when cutting titanium alloy is less than 300 N. It has excellent mechanical properties.

[0109] Figure 1 In order to observe the situation of Ni powder particles coating C powder using SEM at 8000 times the diameter, it can be seen that C powder forms a uniform coating layer around Ni powder.

[0110] Figure 2The above figure shows the cutting force during the actual machining process of the titanium alloy blade tool prepared in the manner of Example 1, tested using a Keister 9527B three-phase dynamometer. The cutting is smooth during the machining process, and the maximum cutting force is 194N.

[0111] Figure 2 The figure below shows the cutting force during the actual machining process of the titanium alloy blade rough machining tool prepared in the manner of Example 2, tested using a Keister9527B three-phase dynamometer. During the machining process, the cutting force decreases from high to low, and the maximum cutting force is 1426N.

[0112] Figure 3 The surface hardness of the rough machining tool substrate for titanium alloy blades prepared in Example 2 was tested using a scratch tester, and the maximum Vickers hardness of the test was 1820 Hv.

[0113] It is to be noted that the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0114] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0115] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for preparing a metal ceramic tool suitable for machining titanium alloy blade disks, characterized in that: The preparation method comprises: S1. Preparation of cermet cutting tool specimens with high saturated free carbon using powder metallurgy. S2. In a vacuum environment, the metal ceramic tool sample is placed in a high-frequency alternating electric field and heated to 1000-1300°C at a rate of 100-120°C / s, and then rapidly cooled to 500±20°C in an inert atmosphere; S3. After cooling in step S2, the metal-ceramic tool sample is rapidly heated to 1000-1300°C under vacuum conditions, and then rapidly cooled to 500°C ± 20°C under an inert atmosphere; S4 repeat step S3 several times, and finally cool to room temperature to obtain a metal ceramic tool suitable for titanium alloy blade processing; The method of preparing a metal ceramic tool sample having high saturated free carbon by using a powder metallurgy process specifically includes: MeC powder, Ni powder and nickel-coated activated carbon powder were mixed and pressed into green compacts, which were then sintered under an inert atmosphere to obtain metal-ceramic tool samples with high saturated free carbon. Wherein, the MeC powder includes at least one of TiC, WC and TaC; Alternatively, the MeC powder is a solid solution powder formed by at least two of TiC, WC and TaC; In the green compact, the mass ratio of MeC powder, Ni powder and nickel-coated activated carbon powder is 85:10:

5.

2. The method for preparing a metal ceramic tool suitable for machining titanium alloy blade disks according to claim 1, characterized in that: The method comprises the following steps: mixing MeC powder, Ni powder and nickel-coated activated carbon powder, pressing the mixture into a green compact, and sintering the mixture under an inert atmosphere to obtain a metal ceramic tool sample having high saturated free carbon. The method comprises: MeC powder, Ni powder and nickel-coated activated carbon powder were mixed and pressed into green compacts, which were sintered under inert atmosphere at a pressure of 5±0.5 MPa and a temperature of 1450±20°C. The mixture was kept at 1450°C for 1 hour to obtain metal ceramic tool samples with high saturated free carbon. The particle sizes of the MeC powder, the Ni powder and the nickel-coated activated carbon powder are 1.2 μm, 1.5 μm and 1 μm respectively.

3. The method for preparing a metal ceramic tool suitable for machining titanium alloy blade disks according to claim 1, characterized in that: The size of the green body is 20×6.5×5.25 mm.

4. The method for preparing a metal ceramic tool suitable for machining titanium alloy blade disks according to claim 1, characterized in that: The nickel-coated activated carbon powder is prepared by the following method: Evenly disperse the activated carbon powder in the SnCl2 solution, then heat it to 50-70°C and keep it warm for a certain period of time to obtain solution A; Adding PaCl2 to the solution A to perform surface activation treatment on the activated carbon powder to obtain solution B; Adding NiSO4, sodium citrate and anhydrous sodium carbonate hydrazine hydrate to the solution B to obtain solution C; Adjusting the pH of the solution C to 10-13.2, and then reacting at 40-60° C. for 1-3 hours until the thickness of the Ni layer grown on the surface of the activated carbon powder exceeds 0.5 μm, thereby obtaining a solution D; The solution D is filtered, washed and dried to obtain nickel-coated activated carbon powder.

5. The method for preparing a metal ceramic tool suitable for machining titanium alloy blade disks according to claim 4, characterized in that: The nickel-coated activated carbon powder is prepared by the following method: Activated carbon powder with a particle size of 50nm-200nm is uniformly dispersed in a 2-20g / L SnCl2 solution, and then the temperature is raised to 50-70°C and kept warm for 1-1.5h. Ultrasonic oscillation is used during the holding period to obtain solution A; Adding PaCl2 to the solution A to perform surface activation treatment on the activated carbon powder for 60-90 min to obtain solution B; Adding NiSO4, sodium citrate and anhydrous sodium carbonate hydrazine hydrate to the solution B to obtain solution C; Adjusting the pH of the solution C to 10-13.2, and then reacting at 40-60° C. for 1-3 hours until the thickness of the Ni layer grown on the surface of the activated carbon powder exceeds 0.5 μm, thereby obtaining a solution D; The solution D is filtered, washed and dried to obtain nickel-coated activated carbon powder; Wherein, the concentration of activated carbon powder in the solution A is 1 to 2.5 g / L; The concentration of PaCl2 in the solution B is 0.1-0.3 g / L; The concentrations of NiSO4, sodium citrate and anhydrous sodium carbonate hydrazine hydrate in the solution C are 0.1-0.3 g / L, 0.5-1 g / L and 0.8-1.4 g / L respectively.

6. The method for preparing a metal ceramic tool suitable for machining titanium alloy blade disks according to claim 1, characterized in that: The method of placing the metal ceramic tool sample in a high-frequency alternating electric field under a vacuum environment and heating it to 1000-1300° C. at a rate of 100-120° C. / s, and then rapidly cooling it to 500±20° C. under an inert atmosphere, specifically includes: In a vacuum environment, the metal ceramic tool sample is placed in a high-frequency alternating electric field and heated to 1000-1300° C. at a rate of 100-120° C. / s, and then cooled to 500° C.±20° C. within 5-8 seconds under an inert atmosphere; The vacuum degree of the vacuum environment is 2×10 -3 -6×10 -3 Pa; The frequency of the high-frequency alternating electric field is 50-85 MHz, the current is 2-8 A, and the voltage is 380-500 V.

7. The method for preparing a metal ceramic tool suitable for machining titanium alloy blade disks according to claim 1, characterized in that: After the cooling in step S2 is completed, the metal ceramic tool sample is rapidly heated to 1000-1300° C. under vacuum conditions, and then rapidly cooled to 500° C.±20° C. under an inert atmosphere, specifically comprising: After cooling in step S2 is completed, the temperature of the metal ceramic tool sample is raised to 1000-1300° C. within 5-8 seconds under vacuum conditions, and then cooled to 500° C.±20° C. within 5-8 seconds under an inert atmosphere.

8. The method for preparing a metal ceramic tool suitable for machining titanium alloy blade disks according to claim 1, characterized in that: In step S4, step S3 is repeated 10-50 times.

9. A metal ceramic tool suitable for machining titanium alloy blade disks, characterized in that: The metal ceramic tool is prepared by the preparation method of a metal ceramic tool suitable for machining titanium alloy blade disks according to any one of claims 1 to 8.

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