A method for manufacturing a 3D printed resin bond diamond tool

Abstract

The application provides a preparation method of a 3D printing resin binder diamond tool, which comprises the following steps: dispersion of diamond micro-powder, pre-solidification of resin, preparation of printing slurry, 3D printing forming and solidification. In addition, the printing blank of the application can have pores in the designed shape, and the porous diamond tool is obtained after solidification. The size of the pores is 0.4-1.2 mm, and the porosity is 40-70 vol.%. The advantages of the method of the application are as follows: firstly, the diamond micro-powder is ultrasonically dispersed by a dispersant, so that all the diamond micro-powder particles are dispersed into single particles, the grinding surface quality is uniform, and no large scratch appears; secondly, the pre-solidification step can improve the uniformity of the distribution of the diamond micro-powder particles and the content of the diamond micro-powder particles in the printing blank, so that the product quality is uniform, the grinding performance is improved, and the grinding efficiency is increased; finally, the pre-gel process is added to improve the viscoelasticity of the slurry, so that the printing blank will not be deformed, and the printing shape is accurately consistent with the designed shape.

Description

Technical Field

[0001] This invention relates to a method for preparing 3D printed resin-bonded diamond tools, belonging to the field of abrasive material technology. Background Technology

[0002] Diamond products refer to finished products with specific shapes, properties, and uses, made from diamond as the cutting and grinding material and with the aid of binders or other auxiliary materials. Diamond products are broadly categorized into tools (grinding wheels, sawing tools, drilling tools, cutting tools, wire drawing dies, etc.) and components (instrument elements and machine parts for special purposes). Diamond itself possesses advantages such as high hardness, high strength, and high machining precision; however, diamond materials are highly susceptible to graphitization during cutting, resulting in a significant reduction in mechanical strength. Enhancing the interfacial bonding strength between the diamond abrasive and the binder while preventing diamond carbonization, thereby maximizing the superior performance of diamond, has always been a focus of attention. Based on the type of binder, diamond tools can be classified into: metal-bonded diamond tools, electroplated diamond tools, resin-bonded diamond tools, and ceramic-bonded diamond tools, etc.

[0003] Metal-bonded abrasives offer high bonding strength and good wear resistance, but suffer from poor self-sharpening properties and low grinding efficiency. Improper use can lead to overheating and clogging. Ceramic-bonded abrasives are heat- and corrosion-resistant, and less prone to overheating and clogging, but their application range is limited and processing quality is poor. Electroplated metal-bonded abrasives exhibit strong bonding force, good surface finish, and high adaptability, but the resulting abrasive tools have short lifespans. Resin-bonded diamond abrasives possess advantages such as good elasticity, impact resistance, good self-sharpening properties, high grinding efficiency, and long service life. Furthermore, compared to pure diamond tools, resin-bonded diamond tools are easier to process and are commonly used in the machining industry. Among these, phenolic resin, polyimide resin, and epoxy resin are widely used resin abrasive binders due to their low price, superior overall performance, and simple production processes.

[0004] Diamond tools are difficult to machine once manufactured, therefore they must be designed and manufactured according to the shape of the workpiece. With industrial development, the shapes of diamond tools have become more complex, making the traditional method of using molds for manufacturing diamond tools time-consuming and costly. The emergence of 3D printing technology provides a convenient way to manufacture complex-shaped parts.

[0005] Currently available 3D printing methods for diamond tools include selective laser sintering (SLS), selective laser melting (SLM), and selective laser-bonded forming (SLA). Studies have shown that resin-bonded diamond tools prepared using SLS and SLM can effectively grind common hard and brittle materials with fast forming speeds and high strength. However, the high-speed irradiation of high-intensity lasers generates extremely high temperatures instantaneously, increasing the likelihood of thermal damage and graphitization of the diamond, reducing its strength and hardness, and thus degrading tool performance. SLA technology is commonly used in the forming of photosensitive resin-bonded diamond tools. This technology offers good surface finish and high printing precision, but the good stability and high chemical inertness of diamond powder limit its compatibility with polymers such as resins, thus affecting its stability during the photopolymerization process. Modified diamond powder can bond well with photosensitive resin, but the main problem is that photosensitive resin is not wear-resistant or heat-resistant, limiting the overall performance and lifespan of diamond tools when used as a resin binder. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides a novel 3D printing method based on slurry direct writing technology—3D gel printing. Its principle involves mixing powder with an organic system exhibiting a gel reaction to form a slurry. The organic system cross-links and binds the powder within it, forming a three-dimensional network structure. This process transforms the powder slurry from a liquid to a solid state. The high-solids-content, low-viscosity slurry is extruded from a nozzle of a specific size, rapidly solidifying and spreading layer by layer to form a blank. After debinding and sintering, a part with a certain strength is obtained. Compared to other technologies, 3D gel printing is applicable to a wide range of materials, including metals, ceramics, and their composites; the printing equipment is less expensive because it does not require a high-energy light beam or powder dispensing device; the printed parts are less expensive because they do not require a protective atmosphere or heating; and using slurry, it offers high printing efficiency, strong printing capability, and fast solidification speed.

[0007] Based on the above principles, this invention provides a method for preparing 3D printed resin-bonded diamond tools. The method includes the following steps: dispersion of diamond micropowder, pre-curing of resin, preparation of printing slurry, 3D printing, and curing. The specific preparation method of this invention includes the following steps:

[0008] (1) Dispersion of diamond micro powder: Add diamond micro powder to water and add dispersant for ultrasonic dispersion, then filter and dry;

[0009] (2) Pre-curing of resin: Add curing agent to liquid resin and stir evenly to obtain resin liquid;

[0010] (3) Preparation of printing slurry: The resin liquid obtained in step (2) is mixed with anhydrous ethanol, and a curing agent is added and stirred evenly to obtain a mixed solution. The diamond micro powder obtained in step (1) is mixed with the above mixed solution and stirred evenly to obtain printing slurry. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for pre-gelling.

[0011] (4) 3D printing: After setting the printing parameters, use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to extrude the printing slurry obtained in step (3) from the nozzle of the barrel and form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0012] (5) Curing: The printed blank from step (4) is dried and heated in air in sequence to obtain the resin-bonded diamond tool.

[0013] Further, in step (1), the mass ratio of diamond micro powder to water is 1:20-40, the amount of dispersant added is 0.5-2 wt.% of the mass of diamond micro powder, and the ultrasonic dispersion time is 40-60 min.

[0014] Furthermore, the diamond micron powder described in step (1) has a particle size of 1000 mesh or finer than 1000 mesh.

[0015] Furthermore, the dispersant mentioned in step (1) is one of the following: silane coupling agent KH550, KH450, polyacrylamide, ammonium citrate, sodium hexametaphosphate, and polyvinylpyrrolidone.

[0016] Furthermore, the amount of curing agent added in step (2) is 3-5 wt.% of the liquid resin mass, and the viscosity of the resin liquid is controlled to be 150-200 Pas after stirring evenly.

[0017] Furthermore, the resin mentioned in step (2) is one of phenolic resin and epoxy resin, the curing agent of phenolic resin is hydrochloric acid, and the curing agent of epoxy resin is polyamide 651.

[0018] Further, in step (3), the mass ratio of the resin liquid to anhydrous ethanol is 5:(3-5), the amount of curing agent added is 20-32 wt.% of the total mass of the liquid resin; the mass ratio of the diamond micro powder to the mixed solution in the printing slurry is (2.1-4.2):1, the viscosity of the printing slurry is 800-1000 Pas, and the standing time is 25-40 min.

[0019] Furthermore, the printing parameters in step (4) are: nozzle orifice diameter of 0.4 to 1.1 mm, printing layer height of 0.3 to 0.9 mm, and printing speed of 5 to 10 mm / s.

[0020] Furthermore, in step (4), the designed shape of the printed blank has pores, and the solidified blank is used to obtain a porous diamond tool.

[0021] Furthermore, the pore size is 0.4-1.2 mm, and the porosity is 40-70 vol.%.

[0022] Furthermore, the drying time in step (5) is 48 hours, and the heating and curing time is 24 hours.

[0023] The resin-based binder diamond tools prepared by the 3D gel printing technology of this invention have the following advantages: (1) Diamond micro powder and commonly used phenolic resin binder are directly used to print the shape at room temperature. After low-temperature curing, they can be directly put into application without a high-temperature process, thus maintaining the intrinsic properties of diamond micro powder; (2) 3D printing does not require mold forming or sintering, and high-performance products can be prepared at low cost; (3) The printing shape and size are not limited, and irregular diamond tools can be easily prepared; (4) Dense or porous diamond tools can be printed, and the grinding performance of diamond tools can be flexibly adjusted; (5) The use of dispersant promotes uniform dispersion of diamond micro powder particles on the one hand, and enhances the bonding force between diamond micro powder particles and resin on the other hand, improving the sharpness of diamond and improving grinding efficiency.

[0024] The advantages of the method of the present invention compared with the prior art are as follows:

[0025] (1) First, the diamond powder is ultrasonically dispersed with a dispersant to disperse all the diamond powder particles into single particles, so that the grinding surface quality is uniform and no large scratches occur, and to prevent the diamond powder particles from agglomerating into large particles, which would reduce the grinding surface quality.

[0026] (2) The pre-curing step can improve the uniformity of diamond powder particle distribution and increase the diamond powder particle content in the printed blank, so that the product quality is uniform, the grinding performance is improved, and the grinding efficiency is increased.

[0027] (3) The pregel process improves the viscoelasticity of the slurry, so that the printed blank will not be deformed and the printed shape is accurate and consistent with the design shape. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1The diamond tools prepared according to Examples 1, 2 and 3 of this invention, wherein Figure 1 (a) shows the diamond tool prepared in Example 1. Figure 1 (b) shows the diamond tool prepared in Example 2. Figure 1 (c) shows the diamond tool prepared in Example 3;

[0030] Figure 2 The diamond tools prepared in Examples 4 and 5 of this invention, wherein Figure 2 (a) shows the diamond tool prepared in Example 4. Figure 2 (b) shows the diamond tool prepared in Example 5;

[0031] Figure 3 The diamond tools prepared in Examples 6 and 7 of this invention, wherein Figure 3 (a) shows the diamond tool prepared in Example 6. Figure 3 (b) shows the diamond tool prepared in Example 7;

[0032] Figure 4 These are photographs of the porous diamond tools prepared in Examples 8 and 9 of the present invention, wherein... Figure 4 (a) shows the diamond tool prepared in Example 8 of this invention, with a porosity of 40 vol.%. Figure 4 (b) shows the diamond tool prepared in Example 9, with a porosity of 70 vol.%.

[0033] Figure 5 The bending strength of the diamond tools prepared in Examples 4, 8 and 9 of this invention;

[0034] Figure 6 These are photographs of diamond tools prepared in Comparative Examples 1, 2, and 3 of this invention, wherein... Figure 6 (a) is a photograph of Comparative Example 1. Figure 6 Photo (b) is the comparative example 2. Figure 6 Photo (c) is Comparative Example 3. Detailed Implementation

[0035] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be described in detail below with reference to specific embodiments. It should be understood that the embodiments described in this specification are merely illustrative and not intended to limit the scope of the invention.

[0036] The most important characteristic of phenolic resins, epoxy resins, and polyimide resins is their high-temperature resistance; they can maintain structural integrity at very high temperatures and possess excellent dimensional stability. An important application of these resins is as binders. Properly designed resins, after cross-linking, can provide diamond tools with the necessary mechanical strength, wear resistance, and heat resistance. For these reasons, these resins are used in diamond tools as binders for diamond particles.

[0037] In current resin-based diamond tool manufacturing processes, whether using resin powder or resin liquid, molds are required to form the diamond tools. This results in high manufacturing costs for small-batch production and tools with complex shapes. Furthermore, in the existing manufacturing process of resin-based diamond tools, it is difficult to control the number and size of pores, which are crucial for chip removal during grinding. Compared to the chip removal function of the diamond tool's shape design, a properly designed pore structure can significantly improve the processing efficiency of diamond tools, reduce power consumption, and extend the overall lifespan of the machine, which is particularly important for diamond micron grinding tools.

[0038] Therefore, this invention provides a method for preparing 3D-printed resin-bonded diamond tools, applying 3D printing technology to the manufacture of resin-bonded diamond tools and solving the aforementioned problems. Specifically, this invention provides a 3D gel printing method for preparing resin-bonded diamond tools for grinding tools using 1000-mesh and finer diamond micropowder. The key to this invention is to prepare a slurry with high solid content, good fluidity, and good formability using resin and diamond micropowder. A preform is then printed using this slurry and cured to obtain the desired diamond tool. Since diamond powder coarser than 1000-mesh has large particles, it is prone to sedimentation and segregation, resulting in uneven distribution in the final product. Therefore, it is not within the scope of this invention's method, and other preparation methods will be used.

[0039] The method of this invention includes the following steps: dispersion of diamond micropowder, pre-curing of resin, preparation of printing slurry, 3D printing, and curing. The specific preparation method of this invention includes the following steps:

[0040] (1) Dispersion of diamond micro powder

[0041] Diamond micro powder is added to water at a mass ratio of 1:20-40, and 0.5-2 wt.% of a dispersant based on the weight of the diamond micro powder is added. The mixture is ultrasonically dispersed for 40-60 minutes, then filtered and dried. The diamond micro powder has a particle size of less than or equal to 1000 mesh, and the dispersant is one of the following: silane coupling agent KH550, KH450, polyacrylamide, ammonium citrate, sodium hexametaphosphate, and polyvinylpyrrolidone.

[0042] Diamond micropowder is highly prone to agglomeration, forming large clusters that increase the surface area of ​​the diamond and cause significant scratches during grinding. Therefore, the method of this invention first ultrasonically disperses the diamond micropowder using a dispersant, ensuring all particles are dispersed into individual particles. This results in a uniform grinding surface quality, preventing large scratches and thus avoiding the agglomeration of diamond micropowder particles that degrades the grinding surface quality. Due to the high inertness of diamond, water is chosen as the dispersion medium. The mass ratio of diamond micropowder to water is 1:20-40. Too little water leads to uneven diamond dispersion, while too much water reduces production efficiency and generates excessive wastewater. The dispersant is one of the following: silane coupling agent KH550, KH450, polyacrylamide, ammonium citrate, sodium hexametaphosphate, and polyvinylpyrrolidone. These dispersants are water-soluble, have good affinity with diamond, and exhibit high dispersing ability. The use of dispersants not only promotes the uniform dispersion of diamond micron powder particles, but also enhances the bonding force between diamond micron powder particles and resin, increases the diamond tip height, improves sharpness, and increases grinding efficiency.

[0043] (2) Pre-curing of resin

[0044] Add 3-5 wt.% of curing agent by weight of the liquid resin and stir until homogeneous to obtain a resin liquid, controlling the viscosity of the resin liquid to be 150-200 Pas; the resin is one of phenolic resin and epoxy resin. Hydrochloric acid is commonly used as a curing agent for phenolic resin, and polyamide curing agent 651 is commonly used as a curing agent for epoxy resin.

[0045] The pre-curing step improves the uniformity of diamond micron powder particle distribution and increases the diamond micron powder content in the printed preform, resulting in more uniform product quality, improved grinding performance, and increased grinding efficiency. Typically, liquid resins such as phenolic resin, epoxy resin, and polyimide resin have viscosities ranging from a few to tens of Pas. With the addition of appropriate curing agents, they gradually form a cross-linked gel until complete curing. However, the low initial viscosity results in weak adhesion to diamond micron powder particles. Although these are micronized particles, their density is much higher than that of the resin, making them prone to sedimentation and uneven particle dispersion. Furthermore, the diamond content in existing slurries is below 45 vol.%, but increasing the diamond content helps improve grinding performance and efficiency. However, due to the low initial viscosity of the resin liquid, when the diamond micron powder content exceeds 50 vol.%, resin separation from the diamond micron powder occurs during subsequent printing, leading to uneven particle distribution and defects such as porosity in the printed preform. The viscosity of the pre-cured resin solution is 150-200 Pas. If the viscosity is too low, the above effect will not be achieved. If the viscosity is too high, extrusion will be difficult during subsequent printing.

[0046] (3) Preparation of printing paste

[0047] The resin liquid treated in step (2) is mixed with anhydrous ethanol at a mass ratio of 5:(3~5), and 20-32 wt.% of curing agent of the total mass of liquid resin is added and stirred evenly to obtain a mixed solution. The diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of (2.1~4.2):1 and stirred evenly to obtain a printing slurry. The viscosity of the printing slurry is controlled, and the printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 25-40 minutes for pre-gelling.

[0048] This invention adjusts the viscosity of the printing slurry by changing the ratio of resin to anhydrous ethanol; this ratio must not be too low or too high. Too low anhydrous ethanol will result in excessively high slurry viscosity, making stable and continuous extrusion impossible, increasing defects in the diamond tool, and leading to a decrease in the mechanical properties of the product. Too high anhydrous ethanol will result in excessively low slurry viscosity, making it difficult to maintain the printed shape. This invention limits the slurry viscosity to 800-1000 Pas, achieved by coordinating the amounts of anhydrous ethanol and diamond powder added. The pre-gelling process of this invention improves the viscoelasticity of the slurry, ensuring that the printed blank shape accurately matches the designed shape and does not deform. This process is also crucial; without it, the printed blank shape will collapse, resulting in poor detail rendering and difficulty in obtaining an accurate shape. This settling process causes a certain gelation reaction in the organic resin, generating organic molecular chains or networks that lock in the diamond powder. This allows the slurry to immediately return to a high-viscosity state after being sheared and thinned by the printer nozzle, exhibiting excellent viscoelasticity and maintaining the printed shape. Too short a settling time will have no effect, while too long a settling time will result in excessively viscous slurry that cannot be extruded during printing. Therefore, the slurry viscosity and settling time must be matched to achieve the best results.

[0049] (4) 3D printing

[0050] Set the nozzle diameter to 0.4–1.1 mm, the layer height to 0.3–0.9 mm, and the printing speed to 5–10 mm / s. Use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to extrude the slurry from the nozzle and stably form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0051] These printing parameters are primarily determined based on the previously established slurry properties, and matching these properties is essential for achieving optimal printing results. When the nozzle orifice diameter is small, a lower viscosity slurry is suitable for printing, while a higher viscosity slurry is difficult to extrude. Similarly, when the nozzle orifice diameter is large, a higher viscosity slurry is suitable for printing, while a lower viscosity slurry is difficult to maintain the desired shape precisely after being extruded from the nozzle. Of course, the nozzle orifice diameter must also be selected considering the surface quality of the printed preform; a smaller orifice diameter yields a finer appearance. The slurry viscosity in this invention is 800-1000 Pas, and extrusion tests show that the suitable nozzle orifice diameter is in the range of 0.4–1.1 mm.

[0052] (5) Curing

[0053] The printed blank from step (4) is dried in air for 48 hours and then heated and cured for 24 hours to obtain the resin-bonded diamond tool with a bending strength in the range of 20-30 MPa.

[0054] The drying temperature is typically 60-80℃ to completely eliminate anhydrous ethanol, followed by the reaction between the resin and the curing agent to achieve final curing. The curing temperature varies depending on the type of resin and is generally known. The curing temperature for phenolic resins is typically 160℃, and for epoxy resins, it is typically 100℃, to obtain the final mechanical properties.

[0055] Furthermore, the printed blank of this invention can incorporate pores in its design shape, resulting in a porous diamond tool after curing. The pore size is 0.4-1.2 mm, and the porosity is 40-70 vol.%. Pores are the chip removal structure during grinding; a properly designed pore structure can significantly improve the processing efficiency of diamond tools. The 3D printing method of this invention can flexibly design and manufacture diamond tools with different pore sizes and porosities, thereby meeting the processing requirements of different workpieces. The porosity depends on the workpiece and its strength. The pore characteristics are designed during the creation of the 3D printing model and then realized through slicing software and the process of printing the blank using slurry. The size, number, and shape of the pores can all be designed during the creation of the printing model.

[0056] This invention utilizes 3D printing technology to fabricate diamond tools with complex shapes. These diamond tools possess high diamond content, appropriate porosity, and good mechanical properties, achieving excellent grinding performance. The resin-based bonded diamond tools fabricated using the 3D gel printing technology of this invention have the following advantages: (1) They can be directly formed by 3D printing diamond powder and resin at room temperature, and can be directly applied after low-temperature curing without a high-temperature process, thus preserving the intrinsic properties of the diamond powder; (2) They can be formed by 3D printing without mold forming or sintering, allowing for the low-cost production of high-performance products; (3) The printed shape and size are not limited, making it easy to fabricate irregularly shaped diamond tools; (4) Both dense and porous diamond tools can be printed, allowing for flexible adjustment of the grinding performance of the diamond tools.

[0057] Example 1:

[0058] (1) Dispersion of diamond micro powder: Add 1000 mesh diamond micro powder to water at a mass ratio of 1:20, and add 0.5 wt.% of the diamond micro powder mass of dispersant silane coupling agent KH550. Disperse ultrasonically for 40 min, and then filter and dry.

[0059] (2) Pre-curing of resin: Add 5 wt.% of curing agent hydrochloric acid to liquid phenolic resin, stir evenly, and control the viscosity of the resin liquid to 200 Pas.

[0060] (3) Preparation of printing slurry: The resin treated in step (2) is mixed with anhydrous ethanol at a mass ratio of 5:3. 20 wt.% of the total mass of the resin is added and stirred evenly to obtain a mixed solution. The diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of 2.1:1 and stirred evenly to obtain the printing slurry. The viscosity of the slurry is controlled at 800 Pas. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 40 min for pre-gelation.

[0061] (4) 3D printing: Set the nozzle diameter to 0.4mm, the layer height to 0.3mm, and the printing speed to 5mm / s. Use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to squeeze the slurry out of the nozzle and stably form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0062] (5) Curing: The printed blank from step (4) is dried in air for 48 hours and then heated to 160°C for 24 hours to obtain the resin-bonded diamond tool.

[0063] Example 2:

[0064] (1) Dispersion of diamond micro powder: Add 2000 mesh diamond micro powder to water at a mass ratio of 1:25, and add 0.8 wt.% of the diamond micro powder mass of dispersant silane coupling agent KH450. Disperse ultrasonically for 45 min, and then filter and dry.

[0065] (2) Pre-curing of resin: Add 4.5 wt.% of curing agent hydrochloric acid to liquid phenolic resin, stir evenly, and control the viscosity of the resin liquid to 190 Pas.

[0066] (3) Preparation of printing slurry: The resin treated in step (2) is mixed with anhydrous ethanol at a mass ratio of 5:3.5. 22.5 wt.% of the total resin mass of curing agent is added and stirred evenly to obtain a mixed solution. The diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of 2.6:1 and stirred evenly to obtain printing slurry. The viscosity of the slurry is controlled at 850 Pas. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 35 min for pre-gelation.

[0067] (4) 3D printing: Set the nozzle diameter to 0.5mm, the layer height to 0.4mm, and the printing speed to 6mm / s. Use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to squeeze the slurry out of the nozzle and stably form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0068] (5) Curing: The printed blank from step (4) is dried in air for 48 hours and then heated to 160°C for 24 hours to obtain the resin-bonded diamond tool.

[0069] Example 3:

[0070] (1) Dispersion of diamond micro powder: Add 4000 mesh diamond micro powder to water at a mass ratio of 1:30, and add 1.2 wt.% of the diamond micro powder mass of dispersant polyacrylamide. Disperse ultrasonically for 50 min, and then filter and dry.

[0071] (2) Pre-curing of resin: Add 4 wt.% of curing agent hydrochloric acid to liquid phenolic resin, stir evenly, and control the viscosity of the resin liquid to 180 Pas.

[0072] (3) Preparation of printing slurry: The resin treated in step (2) is mixed with anhydrous ethanol at a mass ratio of 5:4. 26 wt.% of the total mass of the resin is added and stirred evenly to obtain a mixed solution. The diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of 3.15:1 and stirred evenly to obtain the printing slurry. The viscosity of the slurry is controlled at 900 Pas. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 30 min for pre-gelation.

[0073] (4) 3D printing: Set the nozzle diameter to 0.6mm, the layer height to 0.5mm, and the printing speed to 7mm / s. Use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to squeeze the slurry out of the nozzle and stably form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0074] (5) Curing: The printed blank from step (4) is dried in air for 48 hours and then heated to 160°C for 24 hours to obtain the resin-bonded diamond tool.

[0075] Figure 1 (a) Figure 1 (b) and Figure 1 (c) The diamond tools prepared in Examples 1, 2, and 3 of this invention are shown respectively. It can be seen that the tools have good morphology and have not been deformed or collapsed.

[0076] Example 4:

[0077] (1) Dispersion of diamond micro powder: 6000 mesh diamond micro powder was added to water at a mass ratio of 1:35, and 1.6 wt.% of the diamond micro powder mass of ammonium citrate dispersant was added. The mixture was ultrasonically dispersed for 55 min, and then filtered and dried.

[0078] (2) Pre-curing of resin: Add 3.5 wt.% of curing agent hydrochloric acid to liquid phenolic resin, stir evenly, and control the viscosity of the resin liquid to 170 Pas.

[0079] (3) Preparation of printing slurry: The resin treated in step (2) is mixed with anhydrous ethanol at a mass ratio of 5:4.5. 28.5 wt.% of the total resin mass of curing agent is added and stirred evenly to obtain a mixed solution. The diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of 3.7:1 and stirred evenly to obtain printing slurry. The viscosity of the slurry is controlled at 950 Pas. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 25 min for pre-gelation.

[0080] (4) 3D printing: Set the nozzle diameter to 0.8mm, the layer height to 0.7mm, and the printing speed to 8mm / s. Use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to squeeze the slurry out of the nozzle and stably form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0081] (5) Curing: The printed blank from step (4) is dried in air for 48 hours and then heated to 160°C for 24 hours to obtain the resin-bonded diamond tool.

[0082] Example 5:

[0083] (1) Dispersion of diamond powder: Add 8000 mesh diamond powder to water at a mass ratio of 1:40, and add 2 wt.% of the diamond powder mass of sodium hexametaphosphate as a dispersant. Disperse ultrasonically for 60 min, and then filter and dry.

[0084] (2) Pre-curing of resin: Add 3 wt.% of curing agent hydrochloric acid to liquid phenolic resin, stir evenly, and control the viscosity of the resin liquid to 150 Pas.

[0085] (3) Preparation of printing slurry: The resin treated in step (2) is mixed with anhydrous ethanol at a mass ratio of 5:5. 32wt.% of the total mass of the resin is added and stirred evenly to obtain a mixed solution. The diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of 4.2:1 and stirred evenly to obtain the printing slurry. The viscosity of the slurry is controlled at 1000Pas. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 25 minutes for pre-gelation.

[0086] (4) 3D printing: Set the nozzle diameter to 1.1mm, the layer height to 0.9mm, and the printing speed to 10mm / s. Use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to extrude the slurry from the nozzle and stably form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0087] (5) Curing: The printed blank from step (4) is dried in air for 48 hours and then heated to 160°C for 24 hours to obtain the resin-bonded diamond tool.

[0088] Figure 2 (a) and Figure 2 (b) Diamond tools prepared in Examples 4 and 5 of the present invention, respectively. It can be seen that the tools have good morphology and have not been deformed or collapsed.

[0089] Example 6:

[0090] (1) Dispersion of diamond micro powder: Add 6000 mesh diamond micro powder to water at a mass ratio of 1:33, and add 1.6 wt.% of the diamond micro powder mass of dispersant polyvinylpyrrolidone. Disperse ultrasonically for 50 min, and then filter and dry.

[0091] (2) Pre-curing of resin: Add 3.5 wt.% of curing agent polyamide curing agent 651 to liquid epoxy resin, stir evenly, and control the viscosity of resin liquid to 170 Pas.

[0092] (3) Preparation of printing slurry: The resin treated in step (2) is mixed with anhydrous ethanol at a mass ratio of 5:4. 26.5 wt.% of the total mass of the resin is added and stirred evenly to obtain a mixed solution. The diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of 3.15:1 and stirred evenly to obtain the printing slurry. The viscosity of the slurry is controlled at 900 Pas. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 30 min for pre-gelation.

[0093] (4) 3D printing: Set the nozzle diameter to 1.0mm, the layer height to 0.8mm, and the printing speed to 10mm / s. Use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to squeeze the slurry out of the nozzle and stably form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0094] (5) Curing: The printed blank from step (4) is dried in air for 48 hours and then heated to 100°C for 24 hours to obtain the resin-bonded diamond tool.

[0095] Example 7:

[0096] (1) Dispersion of diamond micro powder: Add 5000 mesh diamond micro powder to water at a mass ratio of 1:33, and add 1.0 wt.% of the diamond micro powder mass of dispersant polyvinylpyrrolidone. Disperse ultrasonically for 50 min, and then filter and dry.

[0097] (2) Pre-curing of resin: Add 3.5 wt.% of curing agent polyamide curing agent 651 to liquid epoxy resin, stir evenly, and control the viscosity of resin liquid to 170 Pas.

[0098] (3) Preparation of printing slurry: The resin treated in step (2) is mixed with anhydrous ethanol at a mass ratio of 5:4. 26.5 wt.% of the total mass of the resin is added and stirred evenly to obtain a mixed solution. The diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of 3.7:1 and stirred evenly to obtain the printing slurry. The viscosity of the slurry is controlled at 900 Pas. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 30 min for pre-gelation.

[0099] (4) 3D printing: Set the nozzle diameter to 1.0mm, the layer height to 0.8mm, and the printing speed to 10mm / s. Use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to squeeze the slurry out of the nozzle and stably form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0100] (5) Curing: The printed blank from step (4) is dried in air for 48 hours and then heated to 100°C for 24 hours to obtain the resin-bonded diamond tool.

[0101] Figure 3 (a) and Figure 3 (b) Diamond tools prepared in Examples 6 and 7 of the present invention, respectively. It can be seen that the tools have good morphology and have not been deformed or collapsed.

[0102] Example 8:

[0103] (1) Dispersion of diamond micro powder: 6000 mesh diamond micro powder was added to water at a mass ratio of 1:35, and 1.6 wt.% of the diamond micro powder mass of ammonium citrate dispersant was added. The mixture was ultrasonically dispersed for 55 min, and then filtered and dried.

[0104] (2) Pre-curing of resin: Add 3.5 wt.% of curing agent hydrochloric acid to liquid phenolic resin, stir evenly, and control the viscosity of the resin liquid to 170 Pas.

[0105] (3) Preparation of printing slurry: The resin treated in step (2) is mixed with anhydrous ethanol at a mass ratio of 5:4.5. 28.5 wt.% of the total resin mass of curing agent is added and stirred evenly to obtain a mixed solution. The diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of 3.7:1 and stirred evenly to obtain printing slurry. The viscosity of the slurry is controlled at 950 Pas. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 25 min for pre-gelation.

[0106] (4) 3D printing: The nozzle diameter is set to 0.8 mm, the layer height is 0.7 mm, and the printing speed is 8 mm / s. The design shape is sliced ​​using slicing software and the slice file is imported into the printer. Then, the slurry is extruded from the nozzle of the barrel by air pressure and stably formed into a uniform and continuous printing filament. The design shape is printed layer by layer to obtain the printed blank. The design shape of the printed blank has pores with a size of 0.4 mm and a porosity of 40 vol.%.

[0107] (5) Curing: The printed blank from step (4) is dried in air for 48 hours and then heated to 160°C for 24 hours to obtain a porous resin-bonded diamond tool.

[0108] Example 9:

[0109] (1) Dispersion of diamond micro powder: 6000 mesh diamond micro powder was added to water at a mass ratio of 1:35, and 1.6 wt.% of the diamond micro powder mass of ammonium citrate dispersant was added. The mixture was ultrasonically dispersed for 55 min, and then filtered and dried.

[0110] (2) Pre-curing of resin: Add 3.5 wt.% of curing agent hydrochloric acid to liquid phenolic resin, stir evenly, and control the viscosity of the resin liquid to 170 Pas.

[0111] (3) Preparation of printing slurry: The resin treated in step (2) is mixed with anhydrous ethanol at a mass ratio of 5:4.5. 28.5 wt.% of the total resin mass of curing agent is added and stirred evenly to obtain a mixed solution. The diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of 3.7:1 and stirred evenly to obtain printing slurry. The viscosity of the slurry is controlled at 950 Pas. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 25 min for pre-gelation.

[0112] (4) 3D printing: The nozzle diameter is set to 0.8 mm, the layer height is 0.7 mm, and the printing speed is 8 mm / s. The design shape is sliced ​​using slicing software and the slice file is imported into the printer. Then, the slurry is extruded from the nozzle of the barrel by air pressure and stably formed into a uniform and continuous printing filament. The design shape is printed layer by layer to obtain the printed blank. The design shape of the printed blank has pores with a pore size of 1.2 mm and a porosity of 70 vol.%.

[0113] (5) Curing: The printed blank from step (4) is dried in air for 48 hours and then heated to 160°C for 24 hours to obtain a porous resin-bonded diamond tool.

[0114] Figure 4 (a) A diamond tool prepared according to Example 8 of the present invention, with a porosity of 40 vol.%. Figure 4 (b) The diamond tool prepared in Example 9 has a porosity of 70 vol.%. This illustrates that the 3D printing method of the present invention can flexibly design and manufacture diamond tools with different pore sizes and porosities, thereby meeting the processing requirements of different processing objects.

[0115] Figure 5 The bending strength of the diamond tools prepared in Examples 4, 8 and 9 of this invention is shown. The bending strength of Example 4 is 27 MPa, the bending strength of Example 8 is 23.71 MPa and the bending strength of Example 9 is 21.65 MPa. Such strength levels can meet the requirements for tool processing and use.

[0116] Comparative Example 1:

[0117] (1) Pre-curing of resin: Add 3.5 wt.% of curing agent hydrochloric acid to liquid phenolic resin, stir evenly, and control the viscosity of the resin liquid to 170 Pas.

[0118] (2) Preparation of printing slurry: The resin treated in step (1) is mixed with anhydrous ethanol at a mass ratio of 5:4.5. 28.5 wt.% of the total resin mass of curing agent hydrochloric acid is added and stirred evenly to obtain a mixed solution. 6000 mesh diamond powder is mixed with the above solution at a mass ratio of 3.7:1 and stirred evenly to obtain printing slurry. The viscosity of the slurry is controlled at 950 Pas. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 25 min for pre-gelation.

[0119] (3) 3D printing: Set the nozzle diameter to 0.8mm, the layer height to 0.7mm, and the printing speed to 8mm / s. Use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to squeeze the slurry out of the nozzle and stably form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0120] (4) Curing: Dry the printed blank from step (3) in the air for 48 hours, and then heat it to 160°C for 24 hours to cure.

[0121] Figure 6 (a) is a photograph of the diamond tool obtained in Comparative Example 1. Since no dispersant was used to ultrasonically disperse the diamond powder, the diamond powder particles are prone to agglomeration, resulting in poor surface quality of the diamond tool and uneven printing filament.

[0122] Comparative Example 2:

[0123] (1) Dispersion of diamond micro powder: 6000 mesh diamond micro powder was added to water at a mass ratio of 1:35, and 1.6 wt.% of the diamond micro powder mass of ammonium citrate dispersant was added. The mixture was ultrasonically dispersed for 55 min, and then filtered and dried.

[0124] (2) Preparation of printing slurry: Liquid phenolic resin and anhydrous ethanol are mixed at a mass ratio of 5:4.5. 28.5 wt.% of the total resin mass of curing agent hydrochloric acid are added and stirred evenly to obtain a mixed solution. Diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of 1.9:1 and stirred evenly to obtain printing slurry. The viscosity of the slurry is controlled at 950 Pas. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for 25 min for pre-gelation.

[0125] (3) 3D printing: Set the nozzle diameter to 0.8mm, the layer height to 0.7mm, and the printing speed to 8mm / s. Use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to squeeze the slurry out of the nozzle and stably form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0126] (4) Curing: Dry the printed blank from step (3) in the air for 48 hours, and then heat it to 160°C for 24 hours to cure.

[0127] Figure 6 (b) is a photograph of the diamond tool obtained in Comparative Example 2. Due to the lack of resin pre-curing, the diamond microparticles are unevenly distributed, the solid content (diamond volume ratio) is low, and the diamond tool obtained has an overall collapse phenomenon.

[0128] Comparative Example 3:

[0129] (1) Dispersion of diamond micro powder: 6000 mesh diamond micro powder was added to water at a mass ratio of 1:35, and 1.6 wt.% of the diamond micro powder mass of ammonium citrate dispersant was added. The mixture was ultrasonically dispersed for 55 min, and then filtered and dried.

[0130] (2) Pre-curing of resin: Add 3.5 wt.% of curing agent to liquid phenolic resin, stir evenly, and control the viscosity of the resin liquid to 170 Pas.

[0131] (3) Preparation of printing slurry: The resin treated in step (2) is mixed with anhydrous ethanol at a mass ratio of 5:4.5. 28.5 wt.% of the total resin mass of curing agent is added and stirred evenly to obtain a mixed solution. The diamond micro powder treated in step (1) is mixed with the above solution at a mass ratio of 3.7:1 and stirred evenly to obtain printing slurry. The viscosity of the slurry is controlled at 950 Pas. The printing slurry is loaded into the barrel of the 3D printer and printed directly without pre-gelling.

[0132] (4) 3D printing: Set the nozzle diameter to 0.8mm, the layer height to 0.7mm, and the printing speed to 8mm / s. Use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to squeeze the slurry out of the nozzle and stably form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank.

[0133] (5) Curing: Dry the printed blank from step (4) in air for 48 hours, and then heat it to 160°C for 24 hours to cure.

[0134] Figure 6 (c) is a photograph of the diamond tool obtained in Comparative Example 3. Due to the lack of pre-gelling of the printing slurry, the viscoelasticity of the slurry decreased, and the resulting diamond tool was deformed near the bottom.

[0135] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this invention, and these modifications or substitutions should all be covered within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the scope defined in the claims.

Claims

1. A method for preparing a 3D printed resin-bonded diamond tool, characterized in that, Includes the following steps: (1) Dispersion of diamond micro powder: Add diamond micro powder to water and add dispersant for ultrasonic dispersion, then filter and dry; (2) Pre-curing of resin: Add curing agent to liquid resin and stir evenly to obtain resin liquid; (3) Preparation of printing slurry: The resin liquid obtained in step (2) is mixed with anhydrous ethanol, and a curing agent is added and stirred evenly to obtain a mixed solution. The diamond micro powder obtained in step (1) is mixed with the above mixed solution and stirred evenly to obtain printing slurry. The printing slurry is loaded into the barrel of the 3D printer and allowed to stand for pre-gelling. (4) 3D printing: After setting the printing parameters, use slicing software to slice the design shape and import the slice file into the printer. Then, use air pressure to extrude the printing slurry obtained in step (3) from the nozzle of the barrel and form a uniform and continuous printing filament. Print the design shape layer by layer to obtain the printed blank. (5) Curing: The printed blank from step (4) is dried and heated in air in sequence to obtain the resin-bonded diamond tool.

2. The method according to claim 1, characterized in that, In step (1), the mass ratio of diamond micro powder to water is 1:20-40, the amount of dispersant added is 0.5-2 wt.% of the mass of diamond micro powder, and the ultrasonic dispersion time is 40-60 min.

3. The method according to claim 1, characterized in that, The diamond micron powder mentioned in step (1) has a particle size of 1000 mesh or finer than 1000 mesh.

4. The method according to claim 1, characterized in that, The dispersant mentioned in step (1) is one of the following: silane coupling agent KH550, KH450, polyacrylamide, ammonium citrate, sodium hexametaphosphate, and polyvinylpyrrolidone.

5. The method according to claim 1, characterized in that, The amount of curing agent added in step (2) is 3-5 wt.% of the liquid resin mass. After stirring evenly, the viscosity of the resin liquid is controlled to be 150-200 Pas.

6. The method according to claim 1, characterized in that, The resin mentioned in step (2) is one of phenolic resin and epoxy resin. The curing agent of phenolic resin is hydrochloric acid, and the curing agent of epoxy resin is polyamide 651.

7. The method according to claim 1, characterized in that, In step (3), the mass ratio of the resin liquid to anhydrous ethanol is 5:(3-5), the amount of curing agent added is 20-32 wt.% of the total mass of the liquid resin; the mass ratio of the diamond micro powder to the mixed solution in the printing slurry is (2.1-4.2):1, the viscosity of the printing slurry is 800-1000 Pas, and the standing time is 25-40 min.

8. The method according to claim 1, characterized in that, The printing parameters in step (4) are: nozzle orifice diameter of 0.4 to 1.1 mm, printing layer height of 0.3 to 0.9 mm, and printing speed of 5 to 10 mm / s.

9. The method according to claim 1, characterized in that, Step (4) The designed shape of the printed blank has pores, the size of which is 0.4-1.2 mm and the porosity is 40-70 vol.%.

10. The method according to claim 1, characterized in that, The drying time in step (5) is 48 hours, and the heating and curing time is 24 hours.

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