Superfine diamond ceramic bond tool bit and preparation method and application thereof

Abstract

The application provides a superfine diamond ceramic bond tool bit and a preparation method and application thereof, relates to the technical field of grinding tools, and comprises a base material and a functional additive; the base material comprises the following raw materials in parts by mass: 10-30 parts of a ceramic bond, 50-70 parts of diamond abrasive, 1-20 parts of a filler and 1-20 parts of a nano polishing agent; wherein the diamond abrasive is an irregularly shaped diamond aggregate; the functional additive comprises a temporary binder and a dispersing agent, the temporary binder accounts for 1-10% of the total mass of the base material, and the dispersing agent accounts for 1-10% of the total mass of the base material. The superfine diamond is not caused to agglomerate in the mixing process by changing the mixing mode of the diamond and introducing the diamond in the form of an irregularly shaped diamond aggregate, and the surface roughness of a workpiece is greatly improved by adding a spherical nano polishing agent, and the process is simple, controllable and stable.

Description

Technical Field

[0001] This invention relates to the field of abrasive technology, and in particular to an ultrafine diamond ceramic bonded cutting tool, its preparation method, and its application. Background Technology

[0002] Polycrystalline diamond (PCD) / polycrystalline cubic boron nitride (PcBN) is a composite material sintered under ultra-high pressure and high temperature conditions, using diamond or cBN micropowder as the framework and a binder as the bonding material. It overcomes the anisotropy of single crystal diamond or cBN, making it an ideal tool material widely used in automotive, aerospace, and other fields. As a high-performance tool for CNC equipment, due to its high hardness, high wear resistance, and difficulty in machining, grinding with metal or resin-bonded diamond wheels can easily lead to premature abrasive grain shedding and increased wear. Furthermore, the low porosity and insufficient sharpness of the grinding wheel result in reduced grinding force, further complicating machining. Ceramic-bonded diamond wheels, due to their outstanding machining performance, exhibit significant advantages in machining hard materials. Currently, domestically produced ceramic-bonded diamond grinding wheels can basically meet the rough grinding needs of PCD / PcBN tools, while high-end products such as fine-grit grinding wheels for fine grinding still rely heavily on imports, resulting in high prices and core technologies controlled by foreign countries. The processing quality of domestically produced fine-grit products is unstable, mainly due to uneven dispersion of ultrafine diamonds, thermal damage to the diamonds caused by high sintering temperatures of the binder, and dull grinding wheels. These factors lead to inconsistent surface quality and overall performance that fails to meet requirements, making it impossible to completely replace imports. Therefore, accelerating technological innovation in this product and replacing imports remains a pressing issue. Summary of the Invention

[0003] The purpose of this invention is to provide an ultrafine diamond ceramic bonded cutting tool, its preparation method, and its application. The introduction of ultrafine diamond differs from traditional methods, as it exists in the form of irregular aggregates with coarser particles. The mixing process does not cause the ultrafine diamond to agglomerate. Compared with the wet mixing method of fine materials, the process is simple, controllable, and has higher stability. This invention also incorporates spherical nano-polishing agents, which greatly improves the surface roughness of the workpiece being ground, resulting in a grinding wheel with good self-sharpening and sharpness, good surface quality of the processed workpiece, and high processing efficiency.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention provides an ultrafine diamond ceramic bonded cutting tip, comprising a base material and functional additives;

[0006] The base material, by mass parts, includes the following raw materials: 10-30 parts of ceramic binder, 50-70 parts of diamond abrasive, 1-20 parts of filler and 1-20 parts of nano polishing agent;

[0007] The diamond abrasive is an irregularly shaped diamond aggregate;

[0008] The functional additives include a temporary binder and a dispersant, wherein the temporary binder accounts for 1-10% of the total mass of the base material; and the dispersant accounts for 1-10% of the total mass of the base material.

[0009] Furthermore, based on the above technical solution, the diamond abrasive is an irregularly shaped diamond abrasive obtained by ball milling and crushing spherical ceramic diamond abrasive abrasives; preferably, the particle size of the diamond abrasive is 200-400 mesh.

[0010] And / or, in the diamond abrasive, the diamond content is 60-90%, and the diamond particle size is 1-10μm.

[0011] Furthermore, based on the above technical solution, the ceramic binder comprises the following components by mass percentage: SiO2 30-50wt%, Al2O3 5-20wt%, B2O3 10-20wt%, Na2O 10-20wt%, ZnO 3-10wt%.

[0012] And / or, the particle size of the ceramic binder is ≤200 mesh;

[0013] And / or, the filler comprises corundum and / or micro / nano-sized silicon carbide with a particle size of 0.1-5 μm;

[0014] And / or, the nanopolishing agent includes one or more of silicon oxide, aluminum oxide, and cerium oxide;

[0015] And / or, the particle size of the nanopolishing agent is 50-500 nm;

[0016] And / or, the temporary adhesive includes dextrin, water glass, or a polymeric adhesive;

[0017] Preferably, the polymeric adhesive includes one or more of phenolic resin, epoxy resin, polymethyl methacrylate, and polyvinyl acetal;

[0018] And / or, the dispersant comprises one or more of 4-(1,1,3,3-tetramethylbutyl)phenol polyethylene glycol ether, polyvinylpyrrolidone, sodium dodecylbenzenesulfonate, and polyvinyl alcohol.

[0019] Furthermore, based on the above technical solution, the porosity of the cutting head is 5-35%, and the pore diameter is 5-30μm.

[0020] The present invention also provides a method for preparing the above-mentioned ultrafine diamond ceramic bonded cutting tip, comprising the following steps:

[0021] S1: Weigh each raw material according to the design composition of the ceramic binder, mix and melt them, and then perform the first mechanical treatment to obtain the ceramic binder;

[0022] The ceramic binder was ball-milled with filler, nano polishing agent and dispersant. The resulting slurry was then subjected to a second mechanical treatment to obtain modified ceramic binder powder.

[0023] S2: Mix diamond abrasive with the modified ceramic binder powder to obtain uniformly mixed powder gold; add temporary binder to the powder gold and mix to obtain a molding material;

[0024] S3: Place the molding material in a mold for cold pressing to obtain a ring-shaped diamond cutter head blank;

[0025] S4: The annular diamond cutter head green body is subjected to multi-stage sintering treatment to obtain an ultrafine diamond ceramic bond cutter head.

[0026] Furthermore, based on the above technical solution, in step S1, the mixing and melting includes: mixing each raw material of the ceramic binder in a mixer for 1-4 hours, then melting at a high temperature of 1300-1600℃ for 1-4 hours;

[0027] And / or, the first mechanical treatment includes: water quenching, mechanical crushing and sieving of the mixed molten ceramic binder;

[0028] Preferably, the mechanical crushing includes crushing with a crusher and ball milling with a ball mill;

[0029] Preferably, the ball mill crushing speed is 200-400 r / min, and the time is 1-4 h;

[0030] Preferably, the ball-milled powder is sieved through a 200-400 mesh screen.

[0031] Furthermore, based on the above technical solution, in step S1, the ball milling mixing includes: first placing the ceramic binder, filler and nano polishing agent into water, then adding a dispersant to obtain a mixed slurry, and mixing the mixed slurry on a high-energy ball mill;

[0032] And / or, the ball milling mixing conditions include: the weight ratio of the total weight of the balls and ceramic binder, filler, nano polishing agent and dispersant is 1:1-10:1, the weight ratio of the total weight of the ceramic binder, filler, nano polishing agent and dispersant to water is 1:1-1:5, the ball milling speed is 200-400 r / min, and the ball milling time is 1-10 h;

[0033] And / or, the second mechanical treatment includes: sequentially drying, crushing and sieving the mixed slurry obtained after ball milling.

[0034] Furthermore, based on the above technical solution, in step S2, the diamond abrasive is an irregularly shaped diamond abrasive obtained by ball milling and crushing spherical ceramic diamond abrasive abrasives;

[0035] Preferably, the conditions for ball milling the spherical ceramic diamond agglomerates are: rotation speed 50-100 r / min, time 20-60 min;

[0036] Preferably, the spherical ceramic diamond agglomerates are crushed by ball milling and then screened through a 200-400 mesh sieve to obtain irregularly shaped diamond agglomerates;

[0037] And / or, the powder gold is obtained by mixing diamond abrasive and modified ceramic binder in a three-dimensional mixer for 30-120 minutes, and then sieving it multiple times through a 60-mesh sieve.

[0038] Furthermore, based on the above technical solution, in step S3,

[0039] The cold pressing process includes: pouring the molding material into the mold, smoothing it with a scraper, and cold pressing it on a cold press. The molding pressure is 20-50MPa. No pressure holding is required, and the material is directly demolded.

[0040] And / or, in step S4, the multi-stage sintering process includes a primary process and a secondary process;

[0041] The primary treatment includes: a heating rate of 1-3℃ / min, and holding at 300-500℃ for 200-500min;

[0042] The secondary treatment includes: after the primary sintering treatment, the temperature is further increased at a rate of 2-4℃ / min, the final firing temperature is 600-700℃, and after holding at that temperature for 180-500min, the furnace is cooled.

[0043] The present invention also provides a diamond grinding wheel for precision machining of superhard cutting tools, including the ultrafine diamond ceramic bond cutting head as described above or the ultrafine diamond ceramic bond cutting head prepared by the preparation method of the ultrafine diamond ceramic bond cutting head as described above.

[0044] Preferably, the diamond grinding wheel for precision machining of superhard cutting tools further includes an aluminum matrix or a steel matrix.

[0045] The present invention provides an ultrafine diamond ceramic bonded cutting tip, its preparation method, and its application, with the following beneficial effects:

[0046] 1. In the ultrafine ceramic binder cutter head of the present invention, the introduction of ultrafine diamond is different from the traditional method. It exists in the form of irregular agglomerates with coarser particles. The mixing process will not cause the ultrafine diamond to agglomerate. Compared with the wet mixing method of fine materials, the process is simple, controllable and stable.

[0047] 2. The addition of the nano polishing agent of the present invention can play a role in grinding and polishing during the grinding process of the grinding wheel, removing deep scratches and greatly improving the surface roughness of the grinding workpiece; and the synergistic effect of the filler and the nano polishing agent can reduce the sintering temperature, thereby reducing the thermal damage of sintering to diamond and improving the sharpness of the grinding wheel.

[0048] 3. In the ultrafine-grained ceramic-bonded cutting tool of the present invention, the microstructure is uniform, and the pores are formed by the interconnected micropores in the agglomerates and the overlapping of agglomerated diamond bodies, without the need for additional pore-forming agents. The grinding wheel made from this ultrafine-grained ceramic-bonded cutting tool has good self-sharpening and sharpness, resulting in good workpiece surface quality and high processing efficiency. Attached Figure Description

[0049] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0050] Figure 1 The process flow diagram for preparing ultrafine diamond ceramic bonded cutting tools provided by this invention;

[0051] Figure 2 The overall structure diagram of the diamond grinding wheel for precision machining of superhard cutting tools provided by the present invention;

[0052] Figure 3 A schematic diagram of the internal structure of an ultrafine diamond ceramic bonded cutting tip;

[0053] Figure 4 SEM image of diamond abrasive;

[0054] Icons: 1. Ultra-fine diamond ceramic bonded cutting tip; 2. Aluminum substrate. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Process parameters not specifically specified in the following embodiments are generally performed under conventional conditions.

[0056] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0057] According to a first aspect of the present invention, an ultrafine diamond ceramic bonded cutting tip is provided, comprising a base material and functional additives;

[0058] The base material, by weight, includes the following raw materials: 10-30 parts of ceramic binder (e.g., 15 parts, 20 parts, 25 parts, etc.), 50-70 parts of diamond abrasive (e.g., 55 parts, 60 parts, 65 parts, etc.), 1-20 parts of filler (e.g., 5 parts, 10 parts, 15 parts, etc.), and 1-20 parts of nano polishing agent (e.g., 5 parts, 10 parts, 15 parts, etc.).

[0059] The diamond abrasive is an irregularly shaped diamond aggregate;

[0060] The functional additives include a temporary binder and a dispersant, wherein the temporary binder accounts for 1-10% (e.g., 2%, 4%, 6%, 8%, etc.) of the total mass of the base material; and the dispersant accounts for 1-10% (e.g., 2%, 4%, 6%, 8%, etc.) of the total mass of the base material.

[0061] As an optional embodiment of the present invention, the diamond abrasive is an irregularly shaped diamond abrasive obtained by ball milling and crushing spherical ceramic diamond abrasive abrasives; preferably, the particle size of the diamond abrasive is 200-400 mesh.

[0062] Specifically, the diamond abrasive in this invention is a sharp diamond agglomerate, obtained by secondary crushing and sieving of commercially available spherical ceramic diamond agglomerates, with a particle size of 200-400 mesh. For example... Figure 4 As shown, the broken particles are irregular in shape, and there are micropores in the aggregates. They have good sharpness and self-sharpening properties.

[0063] And / or, in the diamond abrasive, the diamond content is 60-90%, and the diamond particle size is 1-10μm.

[0064] Specifically, the purpose of limiting the diamond content in the diamond abrasive to 60-90% is to ensure the sharpness and wear resistance of the diamond abrasive; if the content is less than 60%, the diamond abrasive will not be sharp; if the content is more than 90%, the abrasive will not be durable and will have a short lifespan.

[0065] Furthermore, the ultrafine diamond ceramic bonded cutting tool prepared by this invention is mainly used to prepare diamond grinding wheels for precision machining of superhard cutting tools. These grinding wheels are mainly designed for the grinding and fine machining of PCD / PcBN tools. Therefore, this invention strictly limits the diamond particle size to 1-10μm to maximize the satisfaction of workpiece surface quality and efficiency requirements. If the diamond particle size is less than 1μm, the processing efficiency will be slowed down; if the diamond particle size is greater than 10μm, the surface finish of the grinding wheel will be too rough and will not meet the processing requirements.

[0066] As an optional embodiment of the present invention, the ceramic binder comprises the following components by mass percentage: SiO2 30-50wt%, Al2O3 5-20wt%, B2O3 10-20wt%, Na2O 10-20wt%, ZnO 3-10wt%.

[0067] And / or, the particle size of the ceramic binder is ≤200 mesh.

[0068] As an optional embodiment of the present invention, the filler comprises corundum and / or micro / nano-sized silicon carbide with a particle size of 0.1-5 μm.

[0069] As an optional embodiment of the present invention, the nano-polishing agent includes one or more of silicon oxide, aluminum oxide, and cerium oxide;

[0070] And / or, the particle size of the nanopolishing agent is 50-500 nm.

[0071] Specifically, the addition of nano-polishing agents can polish the surface during the grinding process, reducing deep scratches and significantly improving the surface roughness of the workpiece. However, excessive amounts of nano-polishing agents may affect the lifespan of the cutting tool.

[0072] As an optional embodiment of the present invention, the temporary adhesive includes dextrin, water glass, or a polymeric adhesive;

[0073] Preferably, the polymeric adhesive includes one or more of phenolic resin, epoxy resin, polymethyl methacrylate, and polyvinyl acetal;

[0074] And / or, the dispersant comprises one or more of 4-(1,1,3,3-tetramethylbutyl)phenol polyethylene glycol ether (Triton X-100), polyvinylpyrrolidone, sodium dodecylbenzenesulfonate, and polyvinyl alcohol.

[0075] Specifically, the purpose of adding a temporary binder is to fully and evenly wet the diamond abrasive.

[0076] As an optional embodiment of the present invention, the porosity of the cutter head is 5-35%, and the pore diameter is 5-30μm.

[0077] Specifically, the grinding wheel structure contains pores, including through micropores in the aggregates and pores formed by the overlapping of diamond aggregates, with a porosity of 5-35%, and no additional pore-forming agent is needed to form pores.

[0078] According to a second aspect of the invention, such as Figure 1 As shown, a method for preparing the above-mentioned ultrafine diamond ceramic bonded cutting tip is provided, comprising the following steps:

[0079] S1: Weigh each raw material according to the design composition of the ceramic binder, mix and melt them, and then perform the first mechanical treatment to obtain the ceramic binder;

[0080] The ceramic binder was ball-milled with filler, nano polishing agent and dispersant. The resulting slurry was then subjected to a second mechanical treatment to obtain modified ceramic binder powder.

[0081] S2: Mix diamond abrasive with the modified ceramic binder powder to obtain uniformly mixed powder gold; add temporary binder to the powder gold and mix to obtain a molding material;

[0082] S3: Place the molding material in a mold for cold pressing to obtain a ring-shaped diamond cutter head blank;

[0083] S4: The annular diamond cutter head green body is subjected to multi-stage sintering treatment to obtain an ultrafine diamond ceramic bond cutter head.

[0084] Specifically, the ultrafine diamond ceramic binder cutter head obtained after sintering still needs to undergo deburring, inspection, and finishing.

[0085] Specifically, traditional methods such as mechanical mixing cannot uniformly mix 1-10μm gold powder. Wet mixing, on the other hand, is complex, influenced by numerous factors, and difficult to control in terms of process stability, often resulting in uneven microstructure. This invention changes the way diamond is added. Diamond abrasive containing irregularly shaped diamond agglomerates is first mixed with modified ceramic binder powder, then with a temporary binder, and finally cold-pressed. In this invention, the diamond exists in the form of irregular agglomerates with coarser particles. Due to their irregular shape, pores can be generated during the mixing process, thus preventing the agglomeration of ultrafine diamonds. Compared to traditional methods, the process is simpler, more controllable, and more stable.

[0086] As an optional embodiment of the present invention, in step S1, the mixing and melting includes: mixing each raw material of ceramic binder in a mixer for 1-4 hours, and then melting at a high temperature of 1300-1600℃ for 1-4 hours;

[0087] Specifically, the present invention limits the high-temperature melting temperature to 1300-1600℃ because the melting temperature is closely related to the composition and proportion of the raw materials. Too high a temperature will lead to overburning and energy waste, while too low a temperature will lead to underburning and insufficient melting between components.

[0088] And / or, the first mechanical treatment includes: water quenching, mechanical crushing and sieving of the mixed molten ceramic binder;

[0089] Preferably, the mechanical crushing includes crushing with a crusher and ball milling with a ball mill;

[0090] Preferably, the ball mill crushing speed is 200-400 r / min, and the time is 1-4 h;

[0091] Preferably, the ball-milled powder is sieved through a 200-400 mesh screen.

[0092] As an optional embodiment of the present invention, in step S1

[0093] The ball milling process includes: first placing the ceramic binder, filler, and nano-polishing agent into water, then adding a dispersant to obtain a mixed slurry, and then mixing the mixed slurry in a high-energy ball mill.

[0094] And / or, the ball milling conditions include: the weight ratio of the total weight of the balls and ceramic binder, filler, nano polishing agent and dispersant is 1:1-10:1, the weight ratio of the total weight of the ceramic binder, filler, nano polishing agent and dispersant to water is 1:1-1:5, the ball milling speed is 200-400 r / min, and the ball milling time is 1-10 h;

[0095] And / or, the second mechanical treatment includes: sequentially drying, crushing and sieving the mixed slurry obtained after ball milling.

[0096] As an optional embodiment of the present invention, in step S3, the diamond abrasive is an irregularly shaped diamond abrasive obtained by ball milling and crushing spherical ceramic diamond abrasive abrasives.

[0097] Preferably, the conditions for ball milling the spherical ceramic diamond agglomerates are a rotation speed of 50-100 r / min and a time of 20-60 min;

[0098] Preferably, the spherical ceramic diamond agglomerates are crushed by ball milling and then screened through a 200-400 mesh sieve to obtain irregularly shaped diamond agglomerates;

[0099] And / or, the powder gold is obtained by mixing diamond abrasive and modified ceramic binder in a three-dimensional mixer for 30-120 minutes, and then sieving it multiple times through a 60-mesh sieve.

[0100] As an optional embodiment of the present invention, in step S3...

[0101] The cold pressing process includes: pouring the molding material into the mold, smoothing it with a scraper, and cold pressing it on a cold press. The molding pressure is 20-50MPa. No pressure holding is required, and the material is directly demolded.

[0102] And / or, in step S4, the multi-stage sintering process includes a primary process and a secondary process;

[0103] The primary treatment includes: a heating rate of 1-3℃ / min, and holding at 300-500℃ for 200-500min;

[0104] The secondary treatment includes: after the primary sintering treatment, the temperature is further increased at a rate of 2-4℃ / min, the final firing temperature is 600-700℃, and after holding at that temperature for 180-500min, the furnace is cooled.

[0105] Specifically, the purpose of the first-stage treatment is to ensure that the moisture in the green body is fully removed, so as to avoid deformation and cracking of the green body;

[0106] The purpose of the secondary treatment is to ensure sufficient endothermic reaction between the components, so that the ceramic binder can better hold the diamond abrasive.

[0107] The firing temperature of the cutting head is controlled to be below 700℃ in order to protect the ultrafine diamond abrasive from heat damage during the sintering process.

[0108] According to a third aspect of the present invention, a diamond grinding wheel for precision machining of superhard cutting tools is provided, comprising an ultrafine diamond ceramic bond cutting head as described above or an ultrafine diamond ceramic bond cutting head prepared by the above-described method for preparing ultrafine diamond ceramic bond cutting heads.

[0109] Preferably, the diamond grinding wheel for precision machining of superhard cutting tools further includes an aluminum matrix or a steel matrix.

[0110] As an optional embodiment of the present invention, the preparation method of the diamond grinding wheel for precision machining of superhard cutting tools is as follows: the ultrafine diamond ceramic bonded cutting head and the aluminum matrix are bonded and fixed with epoxy resin adhesive, and a load of 2-5 kg ​​is applied to cure at room temperature for 24 hours. Then, the cutting edge is sharpened and re-grinded on an internal cylindrical grinding machine, an external cylindrical grinding machine and a surface grinding machine to obtain the diamond grinding wheel for precision machining of superhard cutting tools.

[0111] like Figure 2 The diagram shown is a schematic of the grinding wheel structure provided by the present invention. The ultrafine diamond ceramic bonded cutting head 1 and the aluminum substrate 2 are bonded and fixed by epoxy resin adhesive.

[0112] The present invention will be further described in detail below with reference to specific embodiments and comparative examples. It should be noted that the "parts" used in the following embodiments and comparative examples of the present invention when weighing each raw material are all parts by mass. For example, 25 parts of ceramic binder means that the mass of ceramic binder is 25 parts, 5 parts of SiC means that the mass of SiC is 5 parts, and so on.

[0113] Example 1

[0114] Weigh out the raw material components of the ceramic binder according to the following formula: SiO2 45 wt%, Al2O3 18 wt%, B2O3 14 wt%, Na2O 15 wt%, ZnO 8 wt%. Mix them in a three-dimensional mixer for 2 hours. After mixing, melt the mixture at 1500℃ and hold it for 2 hours. Then, quench it in water, crush it mechanically, and then ball mill it at 400 r / min for 1 hour. The ball-milled powder is then passed through a 200-mesh sieve. The material that passes through the sieve is the obtained ceramic binder.

[0115] Weigh out 25 parts of ceramic binder, 5 parts of SiC (average particle size 3μm), and 10 parts of nano-alumina (average particle size 100nm), and place them in deionized water. Then add 7 parts of dispersant 4-(1,1,3,3-tetramethylbutyl)phenol polyethylene glycol ether and mix in a high-energy ball mill. The weight ratio of balls to the total weight of ceramic binder, filler, nano-polishing agent, and dispersant is 4:1, and the weight ratio of the total weight of ceramic binder, filler, nano-polishing agent, and dispersant to water is 1:3. The ball milling speed is 300 r / min, and the milling time is 5 h. The mixed slurry obtained after ball milling is dried and crushed. Then it is sieved through a 200-mesh sieve, and the material passing through the sieve is the obtained modified ceramic binder powder.

[0116] Spherical ceramic diamond agglomerates were weighed, crushed by ball milling at 100 r / min for 20 min, and then screened through a 200# sieve. The material discharged through the sieve is the irregularly shaped diamond agglomerates (i.e., diamond abrasive).

[0117] Diamond accounts for 70% of the composition; the average particle size of the diamond is 5 μm.

[0118] 60 parts of irregularly shaped diamond agglomerates and all the modified ceramic binder powder prepared above are mixed in a three-dimensional mixer for 30 minutes. Then, the mixture is sieved twice through a 60-mesh sieve. The material passing through the sieve is the uniformly mixed powder gold. Then, 5 parts of dextrin are added and mixed to ensure that the powder gold is uniformly wetted by the temporary binder to obtain the molding material.

[0119] The molding material is slowly and evenly poured into the mold and leveled with a scraper. It is then formed on a cold press at a molding pressure of 30 MPa. No pressure holding is required; the material is directly demolded to obtain a ring-shaped diamond cutting head green blank. The green blank is then placed in a muffle furnace for free multi-stage sintering treatment.

[0120] The first stage of treatment includes: heating at a rate of 1℃ / min and holding at 300℃ for 200min to ensure that the moisture in the green body is fully removed and to prevent the green body from deforming and cracking.

[0121] The secondary processing includes: after the primary sintering treatment, the temperature is further increased at a rate of 2℃ / min, with a final firing temperature of 680℃. After holding at this temperature for 180 min, the material is cooled in the furnace to obtain an ultrafine diamond ceramic bonded cutting tip. The sintered cutting tip is then deburred, inspected, and finished.

[0122] The cutting head and aluminum substrate of the aforementioned annular ceramic diamond grinding wheel are bonded together with epoxy resin and cured at room temperature for 24 hours with a 2kg load. Then, the wheel is re-grinded and sharpened on internal, external, and surface grinding machines to obtain a diamond grinding wheel for precision machining of superhard cutting tools.

[0123] like Figure 3 The image shown is a fracture surface diagram of the cutting head. Figure 3 It can be seen that the structure in the cutting head is uniform and has a high porosity without the addition of a pore-forming agent. It includes pores formed by the overlap between diamond agglomerates and pores existing in the diamond agglomerates, but there is no diamond agglomeration phenomenon.

[0124] Example 2

[0125] Weigh out the raw material components of the ceramic binder according to the following formula: SiO2 45 wt%, Al2O3 18 wt%, B2O3 14 wt%, Na2O 15 wt%, ZnO 8 wt%. Mix them in a three-dimensional mixer for 2 hours. After mixing, melt the mixture at 1600℃ and hold it for 2 hours. Then, quench it in water, crush it mechanically, and then ball mill it at 400 r / min for 1 hour. The ball-milled powder is then passed through a 200# sieve. The material that passes through the sieve is the obtained ceramic binder.

[0126] Weigh out 22.6 parts of ceramic binder, 4 parts of SiC (average particle size 3μm), and 11 parts of nano-alumina (average particle size 100nm), and place them in deionized water. Then, add 1 part of polyvinylpyrrolidone (PVP) dispersant and mix in a high-energy ball mill. The weight ratio of balls to the total weight of ceramic binder, filler, nano-polishing agent, and dispersant is 4:1, and the weight ratio of the total weight of ceramic binder, filler, nano-polishing agent, and dispersant to water is 1:3. The ball milling speed is 300 r / min, and the milling time is 5 h. The resulting slurry is dried and crushed. Then, it is sieved through a 200-mesh sieve, and the material passing through the sieve is the modified ceramic binder powder.

[0127] Spherical ceramic diamond agglomerates were weighed, crushed by ball milling at 100 r / min for 20 min, and then screened through a 200# sieve. The material discharged through the sieve is the irregularly shaped diamond agglomerates (i.e., diamond abrasive).

[0128] Diamonds account for 80% of the composition; the average diamond particle size is 7μm.

[0129] 62.4 parts of irregularly shaped diamond agglomerates were mixed with all the modified ceramic binder powder prepared above in a three-dimensional mixer for 30 minutes. Then, the mixture was sieved twice through a 60-mesh sieve. The sieve discharge was the uniformly mixed powder gold. Then, 5 parts of dextrin were added and mixed to ensure that the powder gold was uniformly wetted by the temporary binder to obtain the molding material.

[0130] The molding material is slowly and evenly poured into the mold and leveled with a scraper. It is then formed on a cold press at a molding pressure of 30 MPa. No pressure holding is required; the material is directly demolded to obtain a ring-shaped diamond cutting head green blank. The green blank is then placed in a muffle furnace for free multi-stage sintering treatment.

[0131] The first stage of treatment includes: heating at a rate of 1℃ / min and holding at 300℃ for 200min to ensure that the moisture in the green body is fully removed and to prevent the green body from deforming and cracking.

[0132] The secondary processing includes: after the primary sintering treatment, the temperature is further increased at a rate of 2℃ / min, with a final firing temperature of 680℃. After holding at this temperature for 180 min, the material is cooled in the furnace to obtain an ultrafine diamond ceramic bonded cutting tip. The sintered cutting tip is then deburred, inspected, and finished.

[0133] The cutting head and aluminum substrate of the aforementioned annular ceramic diamond grinding wheel are bonded together with epoxy resin and cured at room temperature for 24 hours under a certain load of 3 kg. Then, the wheel is re-grinded and sharpened on internal, external, and surface grinding machines to achieve the shape and dimensions required by the drawings.

[0134] Example 3

[0135] Weigh out the raw material components of the ceramic binder according to the following formula: SiO2 48wt%, Al2O3 15wt%, B2O3 12wt%, Na2O 17wt%, ZnO 8wt%. Mix them in a three-dimensional mixer for 2 hours. After mixing, melt the mixture at 1500℃ and hold it for 2 hours. Then, quench it in water, crush it mechanically, and then ball mill it at 400 r / min for 1 hour. The ball-milled powder is then passed through a 200-mesh sieve. The ceramic binder is obtained by passing the powder through the sieve.

[0136] Weigh out 25 parts of ceramic binder, 5 parts of SiC (average particle size 3μm), and 10 parts of nano-silica (average particle size 100nm), and place them in deionized water. Then add 5 parts of sodium dodecylbenzenesulfonate dispersant and mix in a high-energy ball mill. The weight ratio of balls to the total weight of ceramic binder, filler, nano-polishing agent, and dispersant is 4:1, and the weight ratio of the total weight of ceramic binder, filler, nano-polishing agent, and dispersant to water is 1:3. The ball milling speed is 300 r / min, and the milling time is 5 h. The mixed slurry obtained after ball milling is dried and crushed. Then it is sieved through a 200-mesh sieve, and the material passing through the sieve is the obtained modified ceramic binder powder.

[0137] Spherical ceramic diamond agglomerates were weighed, crushed by ball milling at 100 r / min for 20 min, and then screened through a 200# sieve. The material discharged through the sieve is the irregularly shaped diamond agglomerates (i.e., diamond abrasive).

[0138] Of these, diamonds account for 65%; the average diamond particle size is 3μm.

[0139] 60 parts of irregularly shaped diamond agglomerates and all the modified ceramic binder powder prepared above are mixed in a three-dimensional mixer for 30 minutes. Then, the mixture is sieved twice through a 60-mesh sieve. The material passing through the sieve is the uniformly mixed powder gold. Then, 5 parts of dextrin are added and mixed to ensure that the powder gold is uniformly wetted by the temporary binder to obtain the molding material.

[0140] The molding material is slowly and evenly poured into the mold and leveled with a scraper. It is then formed on a cold press at a molding pressure of 30 MPa. No pressure holding is required; the material is directly demolded to obtain a ring-shaped diamond cutting head green blank. The green blank is then placed in a muffle furnace for free multi-stage sintering treatment.

[0141] The first stage of treatment includes: heating at a rate of 1℃ / min and holding at 300℃ for 200min to ensure that the moisture in the green body is fully removed and to prevent the green body from deforming and cracking.

[0142] The secondary processing includes: after the primary sintering treatment, the temperature is further increased at a rate of 2℃ / min, with a final firing temperature of 650℃. After holding at this temperature for 180 minutes, the material is cooled in the furnace to obtain an ultrafine diamond ceramic bonded cutting tip. The sintered cutting tip is then deburred, inspected, and finished.

[0143] The cutting head and aluminum substrate of the aforementioned annular ceramic diamond grinding wheel are bonded together with epoxy resin and cured at room temperature for 24 hours under a certain load of 2 kg. Then, the wheel is re-grinded and sharpened on internal, external, and surface grinding machines to achieve the shape and dimensions required by the drawings.

[0144] Example 4

[0145] Weigh out the raw material components of the ceramic binder according to the following formula: SiO2 50wt%, Al2O3 20wt%, B2O3 10wt%, Na2O 10wt%, ZnO 10wt%. Mix them in a three-dimensional mixer for 1 hour. After mixing, melt the mixture at 1300℃ for 2 hours. Then, quench it in water, crush it mechanically, and then ball mill it at 200 r / min for 4 hours. The ball-milled powder is then passed through a 300-mesh sieve. The material passing through the sieve is the obtained ceramic binder.

[0146] Weigh out 28 parts of ceramic binder, 5 parts of corundum (average particle size 5μm), and 10 parts of nano-alumina (average particle size 100nm), and place them in deionized water. Then add 3 parts of polyvinyl alcohol as a dispersant and mix in a high-energy ball mill. The weight ratio of balls to the total weight of ceramic binder, filler, nano-polishing agent, and dispersant is 10:1, and the weight ratio of the total weight of ceramic binder, filler, nano-polishing agent, and dispersant to water is 1:5. The ball mill speed is 200 r / min, and the milling time is 10 h. The mixed slurry obtained after ball milling is dried and crushed. Then it is sieved through a 200-mesh sieve, and the material passing through the sieve is the obtained modified ceramic binder powder.

[0147] Spherical ceramic diamond agglomerates were weighed, crushed by ball milling at 100 r / min for 60 min, and then screened through a 400# sieve. The material discharged through the sieve is the irregularly shaped diamond agglomerates (i.e., diamond abrasive).

[0148] Of these, diamonds account for 85%; the average diamond particle size is 8μm.

[0149] 57 parts of irregularly shaped diamond agglomerates were mixed with all the modified ceramic binder powder prepared above in a three-dimensional mixer for 120 minutes. Then, the mixture was sieved twice through a 60-mesh sieve. The sieve discharge was the uniformly mixed powder gold. Then, 3 parts of water glass were added and mixed to ensure that the powder gold was uniformly wetted by the temporary binder to obtain the molding material.

[0150] The molding material is slowly and evenly poured into the mold and leveled with a scraper. It is then formed on a cold press at a molding pressure of 50 MPa. No pressure holding is required; the material is directly demolded to obtain a ring-shaped diamond cutting head green blank. The green blank is then placed in a muffle furnace for free multi-stage sintering treatment.

[0151] The first-stage treatment includes: heating at a rate of 3℃ / min and holding at 500℃ for 300min to ensure that the moisture in the green body is fully removed and to prevent the green body from deforming and cracking.

[0152] The secondary processing includes: after the primary sintering treatment, the temperature is further increased at a rate of 4℃ / min, with a final firing temperature of 680℃. After holding at this temperature for 300min, the material is cooled in the furnace to obtain an ultrafine diamond ceramic bonded cutting tip. The sintered cutting tip is then deburred, inspected, and finished.

[0153] The cutting head and aluminum substrate of the aforementioned annular ceramic diamond grinding wheel are bonded together with epoxy resin and cured at room temperature for 24 hours under a certain load of 2 kg. Then, the wheel is re-grinded and sharpened on internal, external, and surface grinding machines to achieve the shape and dimensions required by the drawings.

[0154] Example 5

[0155] Weigh out the raw material components of the ceramic binder according to the following formula: SiO2 50wt%, Al2O3 5wt%, B2O3 20wt%, Na2O 20wt%, ZnO 5wt%. Mix them in a three-dimensional mixer for 4 hours. After mixing, melt the mixture at 1600℃ for 1 hour. Then, quench it in water, crush it mechanically, and then ball mill it at 300 r / min for 2 hours. The ball-milled powder is then passed through a 300-mesh sieve. The material passing through the sieve is the obtained ceramic binder.

[0156] Weigh out 20 parts of ceramic binder, 1 part of SiC (average particle size 3μm), and 15 parts of nano-cerium oxide (average particle size 200nm), and place them in deionized water. Then add 3 parts of dispersant 4-(1,1,3,3-tetramethylbutyl)phenol polyethylene glycol ether and mix in a high-energy ball mill. The weight ratio of balls to the total weight of ceramic binder, filler, nano-polishing agent, and dispersant is 7:1, and the weight ratio of the total weight of ceramic binder, filler, nano-polishing agent, and dispersant to water is 1:1. The ball milling speed is 400 r / min, and the milling time is 1 h. The mixed slurry obtained after ball milling is dried and crushed. Then it is sieved through a 200-mesh sieve, and the material passing through the sieve is the obtained modified ceramic binder powder.

[0157] Spherical ceramic diamond agglomerates were weighed, crushed by ball milling at 50 r / min for 40 min, and then screened through a 200# sieve. The material discharged through the sieve was the irregularly shaped diamond agglomerates (i.e., diamond abrasive).

[0158] Of these, diamonds account for 90%; the average diamond particle size is 1μm.

[0159] 64 parts of irregularly shaped diamond agglomerates and all the modified ceramic binder powder prepared above were put into a three-dimensional mixer and mixed for 100 minutes. Then, the mixture was sieved through a 60-mesh sieve three times. The material passing through the sieve was the uniformly mixed powder gold. Then, 1 part of epoxy resin was added and mixed to ensure that the powder gold was uniformly wetted by the temporary binder to obtain the molding material.

[0160] The molding material is slowly and evenly poured into the mold and leveled with a scraper. It is then formed on a cold press at a molding pressure of 20 MPa. No pressure holding is required; the material is directly demolded to obtain a ring-shaped diamond cutting head green blank. The green blank is then placed in a muffle furnace for free multi-stage sintering.

[0161] The first stage of treatment includes: heating at a rate of 2℃ / min and holding at 400℃ for 500min to ensure that the moisture in the green body is fully removed and to prevent the green body from deforming and cracking.

[0162] The secondary processing includes: after the primary sintering treatment, the temperature is further increased at a rate of 3℃ / min, with a final firing temperature of 690℃. After holding at this temperature for 500min, the material is cooled in the furnace to obtain an ultrafine diamond ceramic bonded cutting tip. The sintered cutting tip is then deburred, inspected, and finished.

[0163] The cutting head and aluminum substrate of the aforementioned annular ceramic diamond grinding wheel are bonded together with epoxy resin and cured at room temperature for 24 hours under a certain load of 2 kg. Then, the wheel is re-grinded and sharpened on internal, external, and surface grinding machines to achieve the shape and dimensions required by the drawings.

[0164] Comparative Example 1

[0165] The difference between this comparative example and Example 1 is that no nano-polishing agent is added; all other steps and technical parameters are the same as in Example 1.

[0166] Comparative Example 2

[0167] The difference between this comparative example and Example 1 is that it uses a traditional mechanical mixing method, as detailed below:

[0168] Traditional mechanical mixing methods involve mixing all raw materials, including ceramic binders, diamond abrasives, fillers, nano-polishing agents, temporary binders, and dispersants, simultaneously using mechanical mixing methods, such as a three-dimensional mixer, at a mixing speed of 100 rpm for 5 hours, to obtain the molded material.

[0169] The remaining steps and technical parameters are the same as in Example 1.

[0170] Performance testing

[0171] The ceramic-bonded diamond grinding wheels prepared in Examples 1-5 and Comparative Examples 1-2 of this invention were subjected to grinding performance tests. The grinding machine was a ZT-90 series PCD / PcBN tool grinding equipment, the grinding wheel speed was 2500 r / min, the feed rate was 1 mil, and the workpiece was a PCD tool. The specific test results are shown in Table 1.

[0172] The porosity of the cutting head was tested using the Archimedes water displacement method; the morphology of the fracture surface and the size of the pores were observed and measured using a scanning electron microscope.

[0173] The wear ratio was tested in accordance with JB / T 3235.

[0174] Table 1

[0175]

[0176]

[0177] As shown in Table 1, compared with Example 1, Comparative Example 1, due to the absence of nano-polishing agent, has an increased probability of deep scratches during the grinding process, resulting in chipping of the cutting edge and ripples on the surface.

[0178] As shown in Table 1, compared with Example 1, Comparative Example 2 uses a traditional mechanical mixing method, which causes the diamond powder to agglomerate during the mixing process, resulting in uneven mixing. This affects the cutting head, causing chipping on the cutting edge of the grinding wheel and surface contamination.

[0179] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-fine diamond ceramic bond tool tip, characterized by, Including base materials and functional additives; The base material, by mass parts, includes the following raw materials: 10-30 parts of ceramic binder, 50-70 parts of diamond abrasive, 1-20 parts of filler and 1-20 parts of nano polishing agent; The diamond abrasive is an irregularly shaped diamond aggregate; The functional additives include a temporary binder and a dispersant, wherein the temporary binder accounts for 1-10% of the total mass of the base material; and the dispersant accounts for 1-10% of the total mass of the base material. The diamond abrasive is an irregularly shaped diamond agglomerate obtained by ball milling and crushing spherical ceramic diamond agglomerates; the particle size of the diamond agglomerate is 200-400 mesh. In the diamond abrasive, the diamond content is 60-90%, and the diamond particle size is 1-10μm; The ceramic binder comprises the following components by mass percentage: SiO2 30-50wt%, Al2O3 5-20wt%, B2O3 10-20wt%, Na2O 10-20wt%, ZnO 3-10wt%; The particle size of the ceramic binder is ≤200 mesh; The filler comprises corundum and / or micro / nano-sized silicon carbide with a particle size of 0.1-5 μm; The nano-polishing agent includes one or more of silicon oxide, aluminum oxide, and cerium oxide; The particle size of the nanopolishing agent is 50-500 nm; The temporary adhesive includes dextrin, water glass, or a polymeric adhesive; The polymeric binder includes one or more of phenolic resin, epoxy resin, polymethyl methacrylate, and polyvinyl acetal. The dispersant includes one or more of 4-(1,1,3,3-tetramethylbutyl)phenol polyethylene glycol ether, polyvinylpyrrolidone, sodium dodecylbenzenesulfonate, and polyvinyl alcohol.

2. The ultra-fine diamond cermet bond tip according to claim 1, wherein The porosity of the cutter head is 5-35%, and the pore diameter is 5-30 μm.

3. A method of making a polycrystalline superabrasive compact according to any of claims 1-2, wherein the method comprises the steps of: providing a substrate; providing a plurality of diamond grains; providing a binder precursor; mixing the diamond grains and the binder precursor to form a mixture; and forming the mixture into a green compact on the substrate. Includes the following steps: S1: Weigh each raw material according to the design composition of the ceramic binder, mix and melt them, and then perform the first mechanical treatment to obtain the ceramic binder; The ceramic binder was ball-milled with filler, nano polishing agent and dispersant. The resulting slurry was then subjected to a second mechanical treatment to obtain modified ceramic binder powder. S2: Mix diamond abrasive with the modified ceramic binder powder to obtain uniformly mixed powder gold; add temporary binder to the powder gold and mix to obtain a molding material; S3: Place the molding material in a mold for cold pressing to obtain a ring-shaped diamond cutter head blank; S4: The annular diamond cutter head green body is subjected to multi-stage sintering treatment to obtain an ultrafine diamond ceramic bond cutter head.

4. The method for preparing the ultrafine diamond ceramic bonded cutting tip according to claim 3, characterized in that, In step S1, the mixing and melting includes: mixing the various raw materials of the ceramic binder in a mixer for 1-4 hours, then melting at a high temperature of 1300-1600℃ for 1-4 hours; The first mechanical treatment includes: water quenching, mechanical crushing and sieving of the mixed and molten ceramic binder.

5. The method for preparing the ultrafine diamond ceramic bonded cutting tip according to claim 4, characterized in that, The mechanical crushing includes crushing using a crusher and ball milling using a ball mill.

6. The method for preparing the ultrafine diamond ceramic bonded cutting tip according to claim 5, characterized in that, The ball mill crushing speed is 200-400 r / min, and the time is 1-4 h.

7. The method for preparing the ultrafine diamond ceramic bonded cutting tip according to claim 6, characterized in that, The crushed powder from the ball mill is then sieved through a 200-400 mesh screen.

8. The method for preparing the ultrafine diamond ceramic bonded cutting tip according to claim 3, characterized in that, In step S1, the ball milling mixing includes: first placing the ceramic binder, filler and nano polishing agent into water, then adding a dispersant to obtain a mixed slurry, and then mixing the mixed slurry in a high-energy ball mill; The ball milling mixing conditions include: the weight ratio of the total weight of the balls to the ceramic binder, filler, nano-polishing agent and dispersant is 1:1-10:1; the weight ratio of the total weight of the ceramic binder, filler, nano-polishing agent and dispersant to water is 1:1-1:5; the ball milling speed is 200-400 r / min; and the ball milling time is 1-10 h. The second mechanical treatment includes: the mixed slurry obtained after ball milling is successively dried, crushed and screened.

9. The method for preparing the ultrafine diamond ceramic bonded cutting tip according to claim 3, characterized in that, In step S2, the diamond abrasive is an irregularly shaped diamond abrasive obtained by ball milling and crushing spherical ceramic diamond abrasives; The powder gold is obtained by mixing diamond abrasive and modified ceramic binder in a three-dimensional mixer for 30-120 minutes, and then sieving it multiple times through a 60-mesh sieve.

10. The method for preparing the ultrafine diamond ceramic bonded cutting tip according to claim 9, characterized in that, The conditions for ball milling the spherical ceramic-based diamond agglomerates are: rotation speed 50-100 r / min, time 20-60 min.

11. The method for preparing ultrafine diamond ceramic bonded cutting tools according to claim 10, characterized in that, Spherical ceramic diamond agglomerates are crushed by ball milling and then sieved through a 200-400 mesh screen to obtain irregularly shaped diamond agglomerates.

12. The method for preparing the ultrafine diamond ceramic bonded cutting tip according to claim 3, characterized in that, In step S3, the cold pressing includes: pouring the molding material into the mold, smoothing it with a scraper, and cold pressing it on a cold press. The molding pressure is 20-50 MPa. No pressure holding is required, and the material is directly demolded. In step S4, the multi-stage sintering process includes a primary process and a secondary process; The primary treatment includes: a heating rate of 1-3℃ / min, and holding at 300-500℃ for 200-500min; The secondary treatment includes: after the primary sintering treatment, the temperature is further increased at a rate of 2-4℃ / min, the final firing temperature is 600-700℃, and after holding at that temperature for 180-500min, the furnace is cooled.

13. A diamond grinding wheel for precision machining of superhard cutting tools, characterized in that, The ultrafine diamond ceramic bonded cutting tip includes the ultrafine diamond ceramic bonded cutting tip as described in any one of claims 1-2 or the ultrafine diamond ceramic bonded cutting tip as described in any one of claims 3-12.

14. The diamond grinding wheel for precision machining of superhard cutting tools according to claim 13, characterized in that, The diamond grinding wheel for precision machining of superhard cutting tools also includes an aluminum matrix or a steel matrix.

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