阅读说明：本技术 一种基于光固化3d打印成型的金刚石复合材料的制备方法及应用 (Preparation method and application of diamond composite material based on photocuring 3D printing molding ) 是由 杨温鑫 孟晓燕 邓欣 倪培燊 于 2021-06-30 设计创作，主要内容包括：本发明公开了一种基于光固化3D打印成型的金刚石复合材料的制备方法及应用,属于增材制造领域,具体包括以下步骤：将二氧化硅粉末和金刚石粉末加入光固化树脂中,经均质混合、脱泡处理后,得到光固化金刚石浆料,将所述浆料进行光固化3D打印成型,得到金刚石复合材料。本发明提供的制备方法实现了新型金刚石工具的开发以及高精度和高复杂形状金刚石复合材料零件的制备。(The invention discloses a preparation method and application of a diamond composite material based on photocuring 3D printing molding, belonging to the field of additive manufacturing and specifically comprising the following steps of: adding silicon dioxide powder and diamond powder into light-cured resin, carrying out homogeneous mixing and defoaming treatment to obtain light-cured diamond slurry, and carrying out light-cured 3D printing and forming on the slurry to obtain the diamond composite material. The preparation method provided by the invention realizes the development of a novel diamond tool and the preparation of a diamond composite material part with high precision and high complex shape.)

1. A preparation method of a diamond composite material based on photocuring 3D printing molding is characterized by comprising the following steps:

(1) adding silicon dioxide powder and diamond powder into light-cured resin, and carrying out homogeneous mixing and defoaming treatment to obtain light-cured diamond slurry;

(2) and (2) pouring the photocuring diamond slurry obtained in the step (1) into a forming cavity of a photocuring 3D printer, establishing a printing model file of the part, and adjusting printing parameters to obtain the 3D printing formed diamond composite material.

2. The preparation method of the diamond composite material based on photocuring 3D printing molding according to claim 1, wherein the photocuring resin in the step (1) comprises the following components in percentage by mass:

epoxy acrylate: 49% -59%;

urethane acrylate: 20 to 30 percent;

1.6-hexanediol diacrylate: 20 to 30 percent;

phenylbis (2,4, 6-trimethylbenzoyl) phosphine oxide: 1 to 3 percent.

3. The preparation method of the diamond composite material based on the photocuring 3D printing molding is characterized in that the mass percentages of the diamond powder, the silicon dioxide powder and the photocuring resin in the step (1) are respectively 15-50%: 1% -5%: 47 to 84 percent.

4. The method for preparing a diamond composite material based on photocuring 3D printing molding according to claim 3, wherein the particle diameter of the silica powder in the step (1) is 0.01-50 μm.

5. The method for preparing a diamond composite material based on photocuring 3D printing molding according to claim 3, wherein the silica powder in the step (1) is fumed silica powder, and the particle diameter is 0.01-1 μm.

6. The method for preparing a diamond composite material based on photocuring 3D printing molding according to claim 1, wherein the diamond powder in the step (1) is modified diamond powder, and the modified diamond powder can be prepared by the following steps:

(a) carrying out hydroxylation pretreatment on the diamond powder to obtain hydroxylated diamond powder; (b) adding the hydroxylated diamond powder obtained in the step (a) into a silane coupling agent alcohol water solution, reacting for 5-7 h at 60-80 ℃, and washing, filtering and drying to obtain modified diamond powder.

7. The method for preparing a diamond composite material based on photocuring 3D printing molding according to claim 6, wherein the hydroxylation pretreatment in the step (a) comprises the following steps: adding the diamond powder into an alkaline solution for pretreatment, washing, filtering and drying to obtain hydroxylated diamond powder.

8. The preparation method of the diamond composite material based on the photocuring 3D printing molding is characterized in that the particle size of the diamond powder is 2-50 μm, the alkaline solution is 0.05-1 g/mL of sodium hydroxide aqueous solution, and 1-10 g of diamond powder is added to each 100mL of the sodium hydroxide aqueous solution.

9. The preparation method of the diamond composite material based on photocuring 3D printing molding according to claim 6, wherein the silane coupling agent alcohol aqueous solution in the step (b) comprises the following components in percentage by mass:

gamma- (2, 3-glycidoxy) propyltrimethoxysilane: 1% -5%;

anhydrous ethanol: 90% -94%;

deionized water: 5 to 7 percent.

10. The utility model provides an application of fashioned diamond composite material based on photocuring 3D prints which characterized in that: the diamond composite material obtained by the preparation method of the diamond composite material based on the photocuring 3D printing molding according to any one of claims 1 to 9 comprises a resin bonded diamond tool.

Technical Field

The application belongs to the field of additive manufacturing, and particularly relates to a preparation method of a diamond composite material based on photocuring 3D printing forming.

Background

The diamond is the substance with highest hardness in the nature, and has good thermal conductivity, stability, wear resistance and certain mechanical strength, so that the diamond can be widely applied to the precision machining fields of grinding, turning and milling, cutter cutting and the like. The current mainstream diamond material tools are metal bond, ceramic bond and resin bond diamond tools, and mainly adopt preparation methods such as hot pressing, electroplating and brazing; however, these methods not only have a long production cycle, but also require a certain pressure and temperature condition to rapidly increase the processing cost when preparing the metal bond and ceramic bond diamond tools, and are prone to degrade thermoplastic resin due to high temperature during the process of preparing the resin bond diamond tools to discharge harmful gases to pollute the environment, so that a new preparation process of diamond tool parts needs to be developed.

The additive manufacturing technology (3D printing) is concerned and valued by wide scholars since nearly half century, and photocuring molding is the additive manufacturing technology which is the earliest and the most mature in development stage, and the technology takes photosensitive resin as a liquid-phase component, adds corresponding solid-phase filler to mix to form photocuring slurry, irradiates a fixed area through an ultraviolet light source to realize curing, and forms the photocuring slurry by stacking layer by layer. The technology shortens the processing period of parts, reduces the processing cost, meets the preparation of special-shaped part tools, and has great development potential and advantages in the field of diamond material tools.

Among them, the performance of the photo-curing slurry is the most important factor in the photo-curing molding technology, and the diamond powder has good stability and high chemical inertness, so that the compatibility with high polymers such as resin and the like is limited, and the stability of the photo-curing molding preparation is influenced, so that the key for preparing the photo-curing diamond composite material is to modify the diamond powder and improve the performance of the photo-curing slurry.

Disclosure of Invention

The invention aims to overcome the defects of the traditional preparation process, improve the stability of preparing the diamond composite material by photocuring forming and provide a preparation method of the diamond composite material based on photocuring 3D printing forming.

In order to achieve the purpose, the invention provides a preparation method of a diamond composite material based on photocuring 3D printing forming, which comprises the following steps:

(1) adding silicon dioxide powder and diamond powder into light-cured resin, and carrying out homogeneous mixing and defoaming treatment to obtain light-cured diamond slurry;

(2) and (2) pouring the photocuring diamond slurry obtained in the step (1) into a forming cavity of a photocuring 3D printer, establishing a printing model file of the part, and adjusting printing parameters to obtain the 3D printing formed diamond composite material.

By adding the silicon dioxide powder, the rheological property of the system can be improved, 3D printing is easy, and the silicon dioxide powder can be used as reinforcing particles to improve the mechanical strength of the composite material.

The light-cured resin in the step (1) is preferably selected, and the light-cured resin in the step (1) comprises the following components in percentage by mass:

epoxy acrylate: 49% -59%;

urethane acrylate: 20 to 30 percent;

1.6-hexanediol diacrylate: 20 to 30 percent;

phenylbis (2,4, 6-trimethylbenzoyl) phosphine oxide: 1 to 3 percent.

By preparing proper light-cured resin, the compatibility of the diamond powder and the light-cured resin is good, the stability and the fluidity of the slurry can be improved, and 3D printing is easy to realize; on the basis of using proper light-cured resin, silicon dioxide powder is added, so that the rheological property of a light-cured diamond slurry system is further improved on the basis of good stability and fluidity of the light-cured diamond slurry, and the mechanical strength of the composite material can be improved by taking the silicon dioxide powder as reinforcing particles, so that the diamond composite material with high strength and high hardness is obtained.

Further preferably, in the step (1), the mass percentages of the diamond powder, the silicon dioxide powder and the light-cured resin are respectively 15% -50%: 1% -5%: 47 to 84 percent.

Preferably, the particle size of the silicon dioxide powder is 0.01-50 μm, and more preferably, the silicon dioxide powder in the step (1) is fumed silica powder, and the particle diameter is 0.01-1 μm; the gas phase silicon dioxide is added into the photo-cured diamond slurry, so that the sedimentation performance of the slurry can be improved, and the mechanical performance of a printed product is improved.

Preferably, the diamond powder in the step (1) is a modified diamond powder, and the modification method comprises the following steps:

(a) carrying out hydroxylation pretreatment on the diamond powder to obtain hydroxylated diamond powder; (b) adding the hydroxylated diamond powder obtained in the step (a) into a silane coupling agent alcohol water solution for full reaction, and washing, filtering and drying to obtain the modified diamond powder.

Preferably, in the step (b), the hydroxylated diamond powder obtained in the step (a) is added into a silane coupling agent alcohol water solution and reacts for 5-7 h at the temperature of 60-80 ℃.

The hydroxylation pretreatment in step (a) comprises: adding the diamond powder into an alkaline solution for pretreatment, washing, filtering and drying to obtain hydroxylated diamond powder.

Preferably, the diamond powder has a particle size of 2 to 50 μm, the alkaline solution is a 0.05 to 1g/mL sodium hydroxide aqueous solution, and 1 to 10g of diamond powder is added to 100mL of the sodium hydroxide aqueous solution.

More preferably, the diamond powder has a particle size of 2 to 20 μm, the alkaline solution is a 0.1g/mL sodium hydroxide aqueous solution, and 5g of the diamond powder is added to 100mL of the sodium hydroxide aqueous solution.

Adding the diamond powder into an alkaline solution, stirring for 5-7 h at the temperature of 60-80 ℃, washing with deionized water after pretreatment until the pH value of the suspension is 6-8, filtering, and drying to obtain hydroxylated diamond powder. Hydroxyl groups on the surfaces of the pretreated diamond powder particles can react with the hydrolyzed silane coupling agent, which is beneficial to the chemical modification of the diamond powder by the silane coupling agent.

Preferably, in the step (b), the hydroxylated diamond powder obtained in the step (a) is added into a silane coupling agent alcohol aqueous solution to react for 5-7 hours at the temperature of 60-80 ℃, wherein the silane coupling agent alcohol aqueous solution comprises the following components in percentage by mass:

gamma- (2, 3-glycidoxy) propyltrimethoxysilane: 1% -5%;

anhydrous ethanol: 90% -94%;

deionized water: 5% -7%;

further preferably, the pH value of the alcohol aqueous solution of the silane coupling agent is adjusted to 4 to 6.

Preferably, the preparation method of the diamond composite material based on photocuring 3D printing molding further comprises the steps of cleaning the uncured slurry remained on the surface of the diamond composite material subjected to 3D printing molding in the step (2) by using a solvent, and drying and preserving heat to obtain the final diamond composite material part. Preferably, the printed and molded diamond composite material part is repeatedly washed three times by adopting ethanol solution, and is dried for 5-8 hours in an oven at the temperature of 60-90 ℃. The curing degree of the printed part can be improved by drying and heat preservation treatment, and the comprehensive performance of the part can be improved.

The invention also comprises the application of the diamond composite material based on the photocuring 3D printing forming, wherein the diamond composite material obtained by the preparation method of the diamond composite material based on the photocuring 3D printing forming comprises a resin binder diamond tool; the resin bond diamond tool comprises a resin bond diamond grinding wheel.

The invention has the beneficial effects that:

1) the diamond powder has good compatibility with the light-cured resin by preparing the proper light-cured resin, and the stability and the fluidity of the slurry can be improved, and the light-cured slurry with the diamond content of 50 percent, which is obtained by the preparation method of the invention, can be shearedAt a rate of 100s^-1The viscosity of the ink is 7.09Pa · s, the fluidity is good, and 3D printing is easy to realize; on the basis of using proper light-cured resin, silicon dioxide powder is added, so that the rheological property of a light-cured diamond slurry system is further improved on the basis of good stability and fluidity of the light-cured diamond slurry, and the mechanical strength of the composite material can be improved by taking the silicon dioxide powder as reinforcing particles, so that the diamond composite material with high strength and high hardness is obtained.

2) Modifying the diamond to prepare a light-cured resin with good compatibility with the modified diamond, and uniformly mixing the modified diamond powder and the light-cured resin to obtain diamond light-cured resin slurry with good fluidity and good stability; on the basis of not adding a dispersing agent, silicon dioxide powder is added, so that the rheological property of the slurry is further improved, and the mechanical strength of the diamond composite material is improved.

3) The diamond composite material prepared by the method has good stability and rheological property, and can be used for manufacturing diamond composite material parts with high precision and high complex shapes.

4) The preparation method provided by the invention realizes the development of a novel diamond tool, and the diamond composite material obtained by the preparation method provided by the invention is combined with a 3D printing technology, so that the diamond composite material part with high precision and high complex shape can be manufactured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic flow chart of a preparation process according to an embodiment of the present invention;

FIG. 2 is a photograph showing a diamond composite molded article prepared in example 3 of the present invention.

Detailed Description

The following examples are intended to further illustrate the invention and are not to be construed as limiting the invention in any way.

Example 1

(1) Diamond pretreatment:

weighing 10g of diamond powder with the average particle size of 2 mu m, adding the diamond powder into 100ml of sodium hydroxide solution (0.1g/ml) for pretreatment, wherein the treatment temperature is 70 ℃, and the treatment time is 6 hours; and repeatedly washing the pretreated powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(2) Diamond modification treatment:

the weight percentage is 3%: 90%: stirring and mixing gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane, absolute ethyl alcohol and deionized water with the concentration of 7% to obtain a silane coupling agent alcohol-water solution, adjusting the pH value of the solution to 5, adding the dried pretreated diamond powder into the silane coupling agent alcohol-water solution for modification treatment, wherein the treatment temperature is 70 ℃, and the treatment time is 6 hours; and repeatedly washing the modified powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(3) Preparing photo-cured diamond slurry:

the weight percentage is 49%: 20%: 30%: 1 percent of epoxy acrylate, polyurethane acrylate, 1, 6-hexanediol diacrylate and phenyl bis (2,4, 6-trimethylbenzoyl) phosphine oxide are mixed to obtain the light-cured resin; fumed silica powder with the average particle size of 1 mu m and modified diamond powder are added into light-cured resin (the mass percentage of diamond, silica and light-cured resin is 15%: 1%: 84%), and light-cured diamond slurry is obtained after homogeneous mixing and defoaming treatment.

(4) Preparing the diamond composite material part by adopting photocuring 3D printing:

pouring the photocuring diamond slurry into a forming cavity of a photocuring 3D printer, establishing a printing model of the part, adjusting printing parameters, and preparing the diamond composite material part through rapid forming; and (3) cleaning the residual uncured slurry on the surface of the molded part with ethanol for three times, and drying the cleaned part in an oven at 80 ℃ for 6 hours to obtain the diamond composite part with high precision and high complex shape.

Example 2

(1) Diamond pretreatment:

weighing 1g of diamond powder with the average particle size of 50 mu m, adding the diamond powder into 100ml of sodium hydroxide solution (0.05g/ml) for pretreatment, wherein the treatment temperature is 70 ℃, and the treatment time is 6 hours; and repeatedly washing the pretreated powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(2) Diamond modification treatment:

the weight percentage is 5%: 90%: stirring and mixing gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane, absolute ethyl alcohol and deionized water at the concentration of 5% to obtain a silane coupling agent alcohol-water solution, adjusting the pH value of the solution to 5, adding the dried pretreated diamond powder into the silane coupling agent alcohol-water solution for modification treatment, wherein the treatment temperature is 70 ℃, and the treatment time is 6 hours; and repeatedly washing the modified powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(3) Preparing photo-cured diamond slurry:

the weight percentage is 49%: 30%: 20%: 1 percent of epoxy acrylate, polyurethane acrylate, 1, 6-hexanediol diacrylate and phenyl bis (2,4, 6-trimethylbenzoyl) phosphine oxide are mixed to obtain the light-cured resin; adding silicon dioxide powder with the average grain diameter of 10 mu m and modified diamond powder into light-cured resin (the mass percentage of diamond, silicon dioxide and light-cured resin is 20%: 2%: 78%), and obtaining the light-cured diamond slurry after homogeneous mixing and defoaming treatment.

(4) Preparing the diamond composite material part by photocuring 3D printing:

pouring the photocuring diamond slurry into a forming cavity of a photocuring 3D printer, establishing a printing model of the part, adjusting printing parameters, and preparing the diamond composite material part through rapid forming; and (3) cleaning the residual uncured slurry on the surface of the molded part with ethanol for three times, and drying the cleaned part in an oven at 80 ℃ for 6 hours to obtain the diamond composite part with high precision and high complex shape.

Example 3

(1) Diamond pretreatment:

weighing 5g of diamond powder with the average particle size of 20 mu m, adding the diamond powder into 100ml of sodium hydroxide solution (0.3g/ml) for pretreatment, wherein the treatment temperature is 70 ℃, and the treatment time is 6 hours; and repeatedly washing the pretreated powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(2) Diamond modification treatment:

the weight percentage is 2%: 91%: stirring and mixing gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane, absolute ethyl alcohol and deionized water with the concentration of 7% to obtain a silane coupling agent alcohol-water solution, adjusting the pH value of the solution to 5, adding the dried pretreated diamond powder into the silane coupling agent alcohol-water solution for modification treatment, wherein the treatment temperature is 60 ℃, and the treatment time is 6 hours; and repeatedly washing the modified powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(3) Preparing photo-cured diamond slurry:

the weight percentage is 59%: 20%: 20%: 1 percent of epoxy acrylate, polyurethane acrylate, 1, 6-hexanediol diacrylate and phenyl bis (2,4, 6-trimethylbenzoyl) phosphine oxide are mixed to obtain the light-cured resin; fumed silica powder with the average grain diameter of 0.1 mu m and modified diamond powder are added into light-cured resin (the mass percentage of diamond, silica and light-cured resin is 15%: 2%: 83%), and light-cured diamond slurry is obtained after homogeneous mixing and defoaming treatment.

(4) Preparing the diamond composite material part by adopting photocuring 3D printing:

pouring the photocuring diamond slurry into a forming cavity of a photocuring 3D printer, establishing a printing model of the part, adjusting printing parameters, and preparing the diamond composite material part through rapid forming; and (3) cleaning the residual uncured slurry on the surface of the molded part with ethanol for three times, and drying the cleaned part in an oven at 80 ℃ for 6 hours to obtain the diamond composite part with high precision and high complex shape.

Example 4

(1) Diamond pretreatment:

weighing 5g of diamond powder with the average particle size of 10 mu m, adding the diamond powder into 100ml of sodium hydroxide solution (0.5g/ml) for pretreatment, wherein the treatment temperature is 70 ℃, and the treatment time is 6 hours; and repeatedly washing the pretreated powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(2) Diamond modification treatment:

1 percent by mass: 94%: stirring and mixing gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane, absolute ethyl alcohol and deionized water at the concentration of 5% to obtain a silane coupling agent alcohol-water solution, adjusting the pH value of the solution to 5, adding the dried pretreated diamond powder into the silane coupling agent alcohol-water solution for modification treatment, wherein the treatment temperature is 80 ℃, and the treatment time is 5 hours; and repeatedly washing the modified powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(3) Preparing photo-cured diamond slurry:

the weight percentage is 49%: 23%: 25%: 3 percent of epoxy acrylate, urethane acrylate, 1, 6-hexanediol diacrylate and phenyl bis (2,4, 6-trimethylbenzoyl) phosphine oxide are mixed to obtain the light-cured resin; fumed silica powder with the average particle size of 0.01 mu m and modified diamond powder are added into light-cured resin (the mass percentage of diamond, silica and light-cured resin is 35%: 3%: 62%), and light-cured diamond slurry is obtained after homogeneous mixing and defoaming treatment.

(4) Preparing the diamond composite material part by adopting photocuring 3D printing:

pouring the photocuring diamond slurry into a forming cavity of a photocuring 3D printer, establishing a printing model of the part, adjusting printing parameters, and preparing the diamond composite material part through rapid forming; and (3) cleaning the residual uncured slurry on the surface of the molded part with ethanol for three times, and drying the cleaned part in an oven at 80 ℃ for 6 hours to obtain the diamond composite part with high precision and high complex shape.

Example 5

(1) Diamond pretreatment:

weighing 5g of diamond powder with the average particle size of 20 mu m, adding the diamond powder into 100ml of sodium hydroxide solution (0.7g/ml) for pretreatment, wherein the treatment temperature is 70 ℃, and the treatment time is 6 hours; and repeatedly washing the pretreated powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(2) Diamond modification treatment:

the weight percentage is 3%: 90%: stirring and mixing gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane, absolute ethyl alcohol and deionized water with the concentration of 7% to obtain a silane coupling agent alcohol-water solution, adjusting the pH value of the solution to 5, adding the dried pretreated diamond powder into the silane coupling agent alcohol-water solution for modification treatment, wherein the treatment temperature is 80 ℃, and the treatment time is 5 hours; and repeatedly washing the modified powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(3) Preparing photo-cured diamond slurry:

the weight percentage is 50%: 22%: 25%: 3 percent of epoxy acrylate, urethane acrylate, 1, 6-hexanediol diacrylate and phenyl bis (2,4, 6-trimethylbenzoyl) phosphine oxide are mixed to obtain the light-cured resin; adding silicon dioxide powder with the average grain diameter of 50 mu m and modified diamond powder into light-cured resin (the mass percentage of diamond, silicon dioxide and light-cured resin is 40%: 3%: 57%), and obtaining the light-cured diamond slurry after homogeneous mixing and defoaming treatment.

(4) Preparing the diamond composite material part by adopting photocuring 3D printing:

pouring the photocuring diamond slurry into a forming cavity of a photocuring 3D printer, establishing a printing model of the part, adjusting printing parameters, and preparing the diamond composite material part through rapid forming; and (3) cleaning the residual uncured slurry on the surface of the molded part with ethanol for three times, and drying the cleaned part in an oven at 80 ℃ for 6 hours to obtain the diamond composite part with high precision and high complex shape.

Example 6

(1) Diamond pretreatment:

weighing 7g of diamond powder with the average particle size of 30 mu m, adding the diamond powder into 100ml of sodium hydroxide solution (1g/ml) for pretreatment, wherein the treatment temperature is 70 ℃, and the treatment time is 6 hours; and repeatedly washing the pretreated powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(2) Diamond modification treatment:

the weight percentage is 4%: 90%: stirring and mixing gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane, absolute ethyl alcohol and deionized water at 6 percent to obtain a silane coupling agent alcohol-water solution, adjusting the pH value of the solution to 5, adding the dried pretreated diamond powder into the silane coupling agent alcohol-water solution for modification treatment, wherein the treatment temperature is 80 ℃, and the treatment time is 5 hours; and repeatedly washing the modified powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(3) Preparing photo-cured diamond slurry:

the weight percentage is 50%: 22%: 25%: 3 percent of epoxy acrylate, urethane acrylate, 1, 6-hexanediol diacrylate and phenyl bis (2,4, 6-trimethylbenzoyl) phosphine oxide are mixed to obtain the light-cured resin; fumed silica powder with the average grain diameter of 0.1 mu m and modified diamond powder are added into light-cured resin (the mass percentage of diamond, silica and light-cured resin is 45%: 3%: 52%), and light-cured diamond slurry is obtained after homogeneous mixing and defoaming treatment.

(4) Preparing the diamond composite material part by adopting photocuring 3D printing:

pouring the photocuring diamond slurry into a forming cavity of a photocuring 3D printer, establishing a printing model of the part, adjusting printing parameters, and preparing the diamond composite material part through rapid forming; and (3) cleaning the residual uncured slurry on the surface of the molded part with ethanol for three times, and drying the cleaned part in an oven at 80 ℃ for 6 hours to obtain the diamond composite part with high precision and high complex shape.

Example 7

(1) Diamond pretreatment:

weighing 3g of diamond powder with the average particle size of 20 mu m, adding the diamond powder into 100ml of sodium hydroxide solution (0.1g/ml) for pretreatment, wherein the treatment temperature is 70 ℃, and the treatment time is 6 hours; and repeatedly washing the pretreated powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(2) Diamond modification treatment:

the weight percentage is 5%: 90%: stirring and mixing gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane, absolute ethyl alcohol and deionized water at the concentration of 5% to obtain a silane coupling agent alcohol-water solution, adjusting the pH value of the solution to 5, adding the dried pretreated diamond powder into the silane coupling agent alcohol-water solution for modification treatment, wherein the treatment temperature is 70 ℃, and the treatment time is 6 hours; and repeatedly washing the modified powder by using deionized water until the pH value of the suspension is 7, filtering the powder and drying for later use.

(3) Preparing photo-cured diamond slurry:

the weight percentage is 50%: 22%: 25%: 3 percent of epoxy acrylate, urethane acrylate, 1, 6-hexanediol diacrylate and phenyl bis (2,4, 6-trimethylbenzoyl) phosphine oxide are mixed to obtain the light-cured resin; fumed silica powder with the average particle size of 1 mu m and modified diamond powder are added into light-cured resin (the mass percentage of diamond, silica and light-cured resin is 50%: 3%: 47%), and light-cured diamond slurry is obtained after homogeneous mixing and defoaming treatment.

(4) Preparing the diamond composite material part by adopting photocuring 3D printing:

pouring the photocuring diamond slurry into a forming cavity of a photocuring 3D printer, establishing a printing model of the part, adjusting printing parameters, and preparing the diamond composite material part through rapid forming; and (3) cleaning the residual uncured slurry on the surface of the molded part with ethanol for three times, and drying the cleaned part in an oven at 80 ℃ for 6 hours to obtain the diamond composite part with high precision and high complex shape.

And (3) performance testing:

photo-curing diamond is obtained by carrying out homogeneous mixing and defoaming treatment on the step (3) in the embodiments 3 and 7The stone slurry was subjected to a viscosity test. The viscosity test was carried out using a rotational rheometer (Physica MCR301) from austria apopa. The test mode is to control the rotation speed (shear rate 0.1-1000 s)^-1) And the system automatically obtains the torque (shear stress), and the viscosity of the slurry is calculated according to a viscosity formula (formula 1). The viscosity test was performed at room temperature. The results of the tests show that the photocurable diamond slurries of examples 3 and 7 had a shear rate of 100s^-1The viscosities at this time were 5.53 pas and 7.09 pas, respectively. The test result shows that the photocuring diamond slurry containing the modified diamond powder with different contents (15-50 wt%) has lower viscosity and is suitable for photocuring 3D printing.

(η -fluid viscosity, Pa · s,. tau. -shear stress, Pa;instantaneous shear rate, s^-1)

Example 8

As shown in FIG. 2, the diamond composite molded article prepared by the preparation method of example 3 has the characteristics of complex shape, high precision, good molding, high strength and high hardness.