CN112553590B - Diamond film based on plasma vapor deposition and preparation method thereof - Google Patents

Abstract

The invention discloses a diamond film based on plasma vapor deposition and a preparation method thereof. The preparation method of the diamond film comprises the following steps; 1. taking the following raw materials in parts by weight; 75-80 parts of nano-diamond micro powder, 12-15 parts of methyl acrylate, 12-15 parts of dispersing agent and 1-3 parts of sodium stearate are subjected to step-by-step treatment to obtain nano-diamond mixed liquid; 2. preparing a nickel-silicon nitride substrate by adopting chemical plating, and then carrying out sodium alginate modification on the nickel-silicon nitride substrate; 3. placing the substrate obtained by the treatment in a nano-diamond mixed solution, and performing ultrasonic oscillation, adsorption and drying; 4. and (3) placing the obtained substrate in microwave plasma deposition equipment, and carrying out hydrogenation treatment to finally obtain the diamond film. The diamond film prepared by the method has strong adhesive force with the substrate and is not easy to fall off; the diamond film has good toughness and friction resistance.

Description

Diamond film based on plasma vapor deposition and preparation method thereof

Technical Field

The invention relates to the technical field of diamond film synthesis, in particular to a diamond film based on plasma vapor deposition and a preparation method thereof.

Background

The diamond film belongs to a cubic system, face-centered cubic unit cells, each unit cell contains 8C atoms, each C atom adopts sp3 hybridization to form covalent bonds with 4 surrounding C atoms, and the firm covalent bonds and the space network structure are reasons for high diamond hardness. High hardness, high chemical stability, high thermal conductivity and small thermal expansion coefficient, and is an excellent insulator. The diamond film is developed to the present, and has been widely applied to the industries of aerospace, semiconductors, water treatment, medical treatment, automobiles, mechanical manufacturing and the like; in the manufacturing industry, it is often used to machine cutting tools, special valve seats, molds, and the like.

For parts in high-temperature, high-pressure and high-speed erosion environments for a long time, such as spray drying nozzles, connecting pipe fittings in pipelines, valve seats and the like, the diamond film and the substrate are required to have strong adhesion performance, and good friction and abrasion resistance is required to be met.

In order to meet the requirement of diamond films used for parts and components in high-temperature, high-pressure and high-speed erosion environments, the invention provides a method for preparing a diamond film by using a plasma gas-phase chemical deposition method, the method is simple in operation steps and wide in raw material source, the prepared diamond film has strong adhesive force with a substrate, and meanwhile, the surface has strong friction and wear resistance, and the method can be used for processing raw materials of parts and components in high-temperature, high-pressure and high-speed erosion environments.

Disclosure of Invention

The invention aims to provide a diamond film based on plasma vapor deposition and a preparation method thereof, so as to solve the problems in the background technology.

In order to solve the technical problems, the invention provides the following technical scheme: a preparation method of a diamond film based on plasma vapor deposition comprises the following steps;

(1) preparing a nano-diamond mixed solution: dissolving a dispersing agent in water, and adjusting the pH value of the solution; adding the nano-diamond micro powder, and stirring at a high speed; adding methyl acrylate at 90-105 deg.C, adding initiator, reacting, filtering, and vacuum drying to balance weight; adding sodium stearate aqueous solution, and dispersing to obtain nano-diamond mixed solution;

(2) dissolving silicon nitride powder in SnCl₂And HNO₃Stirring in the solution at 50-55 deg.C to separate silicon nitride powder; adding AgNO₃Mixing with ammonia water, stirring, and separating silicon nitride powderTaking out, adding NiSO₄Stirring the solution, raising the temperature to 70-75 ℃, and dropwise adding NaH into the solution₂PO₂Stirring the solution, and reacting for 7-9h to obtain silicon nitride powder coated with a metal nickel layer; mixing the prepared silicon nitride powder coated with the metal nickel layer and nickel powder, dispersing the mixture in an ethanol solution, pressing and forming, sintering, and naturally cooling to obtain a nickel-silicon nitride substrate;

adding distilled water into sodium alginate powder at a mass ratio of 1: 50, stirring at room temperature to dissolve completely to obtain sodium alginate stock solution; immersing a nickel-silicon nitride substrate into the sodium alginate stock solution, stirring at a high speed, taking out, and naturally drying to obtain a pretreated substrate;

(3) placing the substrate pretreated in the step (2) in the nano-diamond mixed solution, performing ultrasonic oscillation, adsorbing for 3-4h, taking out the substrate, placing the substrate in deionized water and ethanol solution, washing, and drying for later use;

(4) and (4) placing the substrate obtained in the step (3) in microwave plasma deposition equipment, introducing hydrogen, and carrying out hydrogenation treatment to obtain the diamond film.

Further, a preparation method of the diamond film based on plasma vapor deposition is characterized by comprising the following steps: comprises the following steps;

(1) preparing a nano-diamond mixed solution: dissolving a dispersant in water, and adjusting the pH value of the solution to 7.5-10.0; adding the nano-diamond micro-powder, and stirring at a high speed of 1200-2000 r/min; under the protection of nitrogen, adding methyl acrylate at the temperature of 90-105 ℃, adding an initiator, reacting for 8-9h, filtering, and drying in vacuum to balance weight; adding sodium stearate aqueous solution, and dispersing to obtain nano-diamond mixed solution;

(2) pre-treating a substrate; dissolving silicon nitride powder in SnCl₂And HNO₃Stirring in the solution at 50-55 deg.C to separate silicon nitride powder; adding AgNO₃Mixing with ammonia water, stirring, separating silicon nitride powder, adding NiSO₄Adjusting pH to 10.5 with acetic acid-sodium acetate solution, stirring, increasing temperature to 70-75 deg.C, and adding NaH dropwise₂PO₂Stirring the solutionStirring and reacting for 7-9h to obtain silicon nitride powder coated with a metal nickel layer; mixing the prepared silicon nitride powder coated with the metal nickel layer and the nickel powder according to the mass ratio of 3:1, dispersing the mixture in an ethanol solution, pressing and forming, sintering at the temperature of 1500-;

adding distilled water into sodium alginate powder at a mass ratio of 1: 50, stirring at room temperature to dissolve completely to obtain sodium alginate stock solution; immersing a nickel-silicon nitride substrate into the sodium alginate stock solution, stirring at a high speed, taking out, and naturally drying to obtain a pretreated substrate;

(3) placing the pretreated substrate obtained in the step (2) in a nano-diamond mixed solution, performing ultrasonic oscillation, adsorbing for 3-4h, taking out the substrate, placing the substrate in deionized water and an ethanol solution, washing, and drying for later use;

(4) and (4) placing the substrate obtained in the step (3) in microwave plasma deposition equipment, introducing hydrogen, and carrying out hydrogenation treatment for 0.5-2h to obtain the diamond film.

Further, the nano-diamond solution comprises, by weight, 75-80 parts of nano-diamond micro powder, 12-15 parts of methyl acrylate, 12-15 parts of a dispersing agent and 1-3 parts of sodium stearate.

Further, the dispersing agent is methacryloyloxyethyl trimethyl ammonium chloride.

Further, any one of initiators of dimethyl azodiisobutyrate, azodiisobutyronitrile, azodiisoheptonitrile, benzoyl peroxide and di (2-ethyl) hexyl peroxydicarbonate in the nano-diamond mixed solution preparation in the step (1) is adopted.

Further, the working conditions of the microwave plasma deposition equipment are as follows:

the gas pressure is 2-5 KPa, the substrate temperature is 700-850 ℃, the hydrogen flow is 90-97 sccm, and the processing time is 45-60 min.

A plasma vapor deposition diamond film prepared by the above method.

Compared with the prior art, the invention has the following beneficial effects: the invention provides a method for preparing a diamond film by using a plasma vapor deposition method, wherein the diamond film takes nickel-silicon nitride as a substrate, and the diamond film is deposited on the surface of the substrate by using the plasma deposition method. Firstly, a nickel-silicon nitride substrate is obtained by adopting a chemical plating method, nickel is coated on the surface of silicon nitride by adopting chemical plating, and the nickel can be used as a metal transition layer to enhance the bonding force between the substrate and a diamond film; nickel is coated on the silicon nitride surface by chemical plating, and the nickel coating is more stable and stronger in binding force than the nickel coating directly sputtered on the silicon nitride substrate; the nickel-silicon nitride substrate is soaked and modified by sodium alginate, the surface of the nickel-silicon nitride substrate contains a large number of carboxyl groups and hydroxyl groups, the carboxyl groups have negative charges, and in addition, the carboxyl groups on the surface of the substrate modified by the sodium alginate are in bonding connection with amino groups on the molecular surfaces of the methacryloyloxyethyl trimethyl ammonium chloride and methyl acrylate copolymer, so that the binding force between the substrate and the diamond film is improved, and the diamond film is not easy to fall off.

In the process of preparing the nano-diamond mixed solution, firstly, methacryloyloxyethyl trimethyl ammonium chloride is used as a dispersing agent, and nano-diamond powder is uniformly dispersed in the liquid to prevent agglomeration; meanwhile, methacryloyloxyethyl trimethyl ammonium chloride and acrylate can perform polymerization reaction under the action of an initiator to obtain a copolymer; the copolymer has stronger polarity and strong affinity glue with anions; the generation of the polymer promotes the rice diamond mixed liquid system to present negative charges; the nano-diamond solution is used for dipping a substrate, the nano-diamond solution has positive charges, and the surface of the substrate has negative charges; the positive and negative charges are mutually attracted and combined, so that the adhesive force of the diamond film and the substrate is greatly enhanced. In addition, the copolymer of the methacryloyloxyethyl trimethyl ammonium chloride and the acrylate has a molecular weight and a straight-chain structure, so that the molecular flexibility is strong and the rigidity is weak; the flexible structure can improve the toughness and the friction resistance of the diamond film in a diamond film system. The diamond film prepared by the invention has good flexibility and friction resistance, strong adhesive force with a substrate and difficult shedding.

The diamond film prepared by the invention can be used for processing parts of cutting tools, dies, high-temperature high-pressure high-speed erosion environments and decorative films thereof.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Preparing raw materials: 75 parts of nano diamond micro powder, 14 parts of methyl acrylate, 14 parts of a dispersing agent and 1 part of sodium stearate.

The dispersant is methacryloyloxyethyl trimethyl ammonium chloride; the initiator is any one of dimethyl azodiisobutyrate, azodiisobutyronitrile, azodiisoheptonitrile, benzoyl peroxide and di (2-ethyl) hexyl peroxydicarbonate.

(1) Preparing a nano-diamond mixed solution: dissolving a dispersing agent in water, and adjusting the pH value of the solution to 8.0; adding the nano-diamond micro powder, and stirring at a high speed of 1200 r/min; under the protection of nitrogen, adding methyl acrylate, adding an initiator at the temperature of 90 ℃, reacting for 8 hours, filtering, and drying in vacuum to balance weight; adding sodium stearate aqueous solution, and dispersing to obtain nano-diamond mixed solution;

(2) pre-treating a substrate; dissolving silicon nitride powder in SnCl₂And HNO₃Stirring the solution at 50 ℃ to separate silicon nitride powder; adding AgNO₃Mixing with ammonia water, stirring, separating silicon nitride powder, adding NiSO₄Adjusting pH to 10.5 with acetic acid-sodium acetate solution, stirring, increasing temperature to 70 deg.C, and adding NaH dropwise₂PO₂Stirring the solution, and reacting for 7 hours to obtain silicon nitride powder coated with a metal nickel layer; mixing the prepared silicon nitride powder coated with the metal nickel layer and nickel powder according to the mass ratio of 3:1, dispersing the mixture in an ethanol solution, performing compression molding, sintering at 1500 ℃, and naturally cooling to obtain a nickel-silicon nitride substrate;

adding distilled water into sodium alginate powder at a mass ratio of 1: 50, stirring at room temperature to dissolve completely to obtain sodium alginate stock solution; immersing a nickel-silicon nitride substrate into the sodium alginate stock solution, stirring at a high speed, taking out, and naturally drying to obtain a pretreated substrate;

(3) placing the pretreated substrate obtained in the step (2) in a nano-diamond mixed solution, performing ultrasonic oscillation, adsorbing for 3 hours, taking out the substrate, placing the substrate in deionized water and an ethanol solution, washing, and drying for later use;

(4) placing the substrate obtained in the step (3) in microwave plasma deposition equipment, and introducing hydrogen, wherein the working conditions of the microwave plasma deposition equipment are that the gas pressure is 2KPa, the substrate temperature is 700 ℃, the hydrogen flow is 90sccm, and the processing time is 45 min; and carrying out hydrogenation treatment for 0.5h to obtain the diamond film.

Example 2

Preparing raw materials: 77 parts of nano diamond micro powder, 13 parts of methyl acrylate, 12 parts of a dispersing agent and 2 parts of sodium stearate.

The dispersant is methacryloyloxyethyl trimethyl ammonium chloride; the initiator is any one of dimethyl azodiisobutyrate, azodiisobutyronitrile, azodiisoheptonitrile, benzoyl peroxide and di (2-ethyl) hexyl peroxydicarbonate.

(1) Preparing a nano-diamond mixed solution: dissolving a dispersing agent in water, and adjusting the pH value of the solution to 8.3; adding the nano-diamond micro powder, and stirring at a high speed of 1200 r/min; under the protection of nitrogen, adding methyl acrylate, adding an initiator at the temperature of 98 ℃, reacting for 9 hours, filtering, and drying in vacuum to balance weight; adding sodium stearate aqueous solution, and dispersing to obtain nano-diamond mixed solution;

(2) pre-treating a substrate; dissolving silicon nitride powder in SnCl₂And HNO₃Stirring the solution at the temperature of 52 ℃ to separate silicon nitride powder; adding AgNO₃Mixing with ammonia water, stirring, separating silicon nitride powder, adding NiSO₄The solution is adjusted to pH 10.5 with acetic acid-sodium acetate solution, stirred, the temperature is raised to 73 ℃ and N is added dropwise theretoaH₂PO₂Stirring the solution, and reacting for 7.5 hours to obtain silicon nitride powder coated with a metal nickel layer; mixing the prepared silicon nitride powder coated with the metallic nickel layer and nickel powder according to the mass ratio of 3:1, dispersing the mixture in an ethanol solution, pressing and forming, sintering at 1650 ℃, and naturally cooling to obtain a nickel-silicon nitride substrate;

adding distilled water into sodium alginate powder at a mass ratio of 1: 50, stirring at room temperature to dissolve completely to obtain sodium alginate stock solution; immersing a nickel-silicon nitride substrate into the sodium alginate stock solution, stirring at a high speed, taking out, and naturally drying to obtain a pretreated substrate;

(3) placing the pretreated substrate obtained in the step (2) in a nano-diamond mixed solution, performing ultrasonic oscillation, adsorbing for 3.5 hours, taking out the substrate, placing the substrate in deionized water and an ethanol solution, washing, and drying for later use;

(4) placing the substrate obtained in the step (3) in microwave plasma deposition equipment, and introducing hydrogen, wherein the working conditions of the microwave plasma deposition equipment are that the gas pressure is 3KPa, the substrate temperature is 780 ℃, the hydrogen flow is 95sccm, and the processing time is 50 min; and carrying out hydrogenation treatment for 1.5h to obtain the diamond film.

Example 3

Preparing raw materials: 80 parts of nano diamond micro powder, 12 parts of methyl acrylate, 12 parts of a dispersing agent and 3 parts of sodium stearate.

The dispersant is methacryloyloxyethyl trimethyl ammonium chloride; the initiator is any one of dimethyl azodiisobutyrate, azodiisobutyronitrile, azodiisoheptonitrile, benzoyl peroxide and di (2-ethyl) hexyl peroxydicarbonate.

(1) Preparing a nano-diamond mixed solution: dissolving a dispersing agent in water, and adjusting the pH value of the solution to 10.0; adding the nano diamond micro powder, and stirring at a high speed of 2000 r/min; under the protection of nitrogen, adding methyl acrylate, adding an initiator at the temperature of 05 ℃, reacting for 9 hours, filtering, and drying in vacuum to balance weight; adding sodium stearate aqueous solution, and dispersing to obtain nano-diamond mixed solution;

(2) pre-treating a substrate; dissolving silicon nitride powder in SnCl₂And HNO₃Stirring the solution at the temperature of 55 ℃ to separate silicon nitride powder; adding AgNO₃Mixing with ammonia water, stirring, separating silicon nitride powder, adding NiSO₄The solution is adjusted to pH 10.5 with acetic acid-sodium acetate solution, stirred, the temperature is raised to 75 ℃ and NaH is added dropwise thereto₂PO₂Stirring the solution, and reacting for 9 hours to obtain silicon nitride powder coated with a metal nickel layer; mixing the prepared silicon nitride powder coated with the metallic nickel layer and nickel powder according to the mass ratio of 3:1, dispersing the mixture in an ethanol solution, pressing and forming, sintering at 1800 ℃, and naturally cooling to obtain a nickel-silicon nitride substrate;

adding distilled water into sodium alginate powder at a mass ratio of 1: 50, stirring at room temperature to dissolve completely to obtain sodium alginate stock solution; immersing a nickel-silicon nitride substrate into the sodium alginate stock solution, stirring at a high speed, taking out, and naturally drying to obtain a pretreated substrate;

(3) placing the pretreated substrate obtained in the step (2) in a nano-diamond mixed solution, performing ultrasonic oscillation, adsorbing for 3-4h, taking out the substrate, placing the substrate in deionized water and an ethanol solution, washing, and drying for later use;

(4) placing the substrate obtained in the step (3) in microwave plasma deposition equipment, and introducing hydrogen, wherein the working conditions of the microwave plasma deposition equipment are that the gas pressure is 5KPa, the substrate temperature is 850 ℃, the hydrogen flow is 97sccm, and the processing time is 60 min; and carrying out hydrogenation treatment for 2h to obtain the diamond film.

Comparative example 1

Preparing raw materials: 80 parts of nano diamond micro powder, 12 parts of methyl acrylate, 12 parts of a dispersing agent and 3 parts of sodium stearate.

The dispersant is methacryloyloxyethyl trimethyl ammonium chloride; the initiator is any one of dimethyl azodiisobutyrate, azodiisobutyronitrile, azodiisoheptonitrile, benzoyl peroxide and di (2-ethyl) hexyl peroxydicarbonate.

Further, the working conditions of the microwave plasma deposition equipment are as follows:

the gas pressure is 4KPa, the substrate temperature is 800 ℃, the hydrogen flow is 97sccm, and the processing time is 60 min.

(1) Preparing a nano-diamond mixed solution: dissolving a dispersing agent in water, and adjusting the pH value of the solution to 10.0; adding the nano diamond micro powder, and stirring at a high speed of 2000 r/min; under the protection of nitrogen, adding methyl acrylate, adding an initiator at the temperature of 05 ℃, reacting for 9 hours, filtering, and drying in vacuum to balance weight; adding sodium stearate aqueous solution, and dispersing to obtain nano-diamond mixed solution;

(2) pre-treating a substrate; adding distilled water into sodium alginate powder at a mass ratio of 1: 50, stirring at room temperature to dissolve completely to obtain sodium alginate stock solution; immersing a silicon nitride substrate into sodium alginate stock solution, stirring at a high speed, taking out, and naturally drying to obtain a pretreated substrate;

(3) placing the pretreated substrate obtained in the step (2) in a nano-diamond mixed solution, performing ultrasonic oscillation, adsorbing for 3-4h, taking out the substrate, placing the substrate in deionized water and an ethanol solution, washing, and drying for later use;

(4) placing the substrate obtained in the step (3) in microwave plasma deposition equipment, and introducing hydrogen, wherein the working conditions of the microwave plasma deposition equipment are that the gas pressure is 5KPa, the substrate temperature is 850 ℃, the hydrogen flow is 97sccm, and the processing time is 60 min; and carrying out hydrogenation treatment for 2h to obtain the diamond film.

Compared with the embodiment 3, the substrate is a silicon nitride substrate, and the rest is the same as the embodiment 3.

Comparative example 2

Preparing raw materials: 80 parts of nano diamond micro powder, 12 parts of methyl acrylate, 12 parts of a dispersing agent and 3 parts of sodium stearate.

The dispersant is methacryloyloxyethyl trimethyl ammonium chloride; the initiator is any one of dimethyl azodiisobutyrate, azodiisobutyronitrile, azodiisoheptonitrile, benzoyl peroxide and di (2-ethyl) hexyl peroxydicarbonate.

Further, the working conditions of the microwave plasma deposition equipment are as follows:

the gas pressure is 4KPa, the substrate temperature is 800 ℃, the hydrogen flow is 97sccm, and the processing time is 60 min.

(1) Preparing a nano-diamond mixed solution: dissolving a dispersing agent in water, and adjusting the pH value of the solution to 10.0; adding the nano diamond micro powder, and stirring at a high speed of 2000 r/min; under the protection of nitrogen, adding methyl acrylate, adding an initiator at the temperature of 05 ℃, reacting for 9 hours, filtering, and drying in vacuum to balance weight; adding sodium stearate aqueous solution, and dispersing to obtain nano-diamond mixed solution;

(2) pre-treating a substrate; dissolving silicon nitride powder in SnCl₂And HNO₃Stirring the solution at the temperature of 55 ℃ to separate silicon nitride powder; adding AgNO₃Mixing with ammonia water, stirring, separating silicon nitride powder, adding NiSO₄The solution is adjusted to pH 10.5 with acetic acid-sodium acetate solution, stirred, the temperature is raised to 75 ℃ and NaH is added dropwise thereto₂PO₂Stirring the solution, and reacting for 9 hours to obtain silicon nitride powder coated with a metal nickel layer; mixing the prepared silicon nitride powder coated with the metallic nickel layer and nickel powder according to the mass ratio of 3:1, dispersing the mixture in an ethanol solution, pressing and forming, sintering at 1800 ℃, and naturally cooling to obtain a nickel-silicon nitride substrate;

(3) placing the pretreated substrate obtained in the step (2) in a nano-diamond mixed solution, performing ultrasonic oscillation, adsorbing for 3-4h, taking out the substrate, placing the substrate in deionized water and an ethanol solution, washing, and drying for later use;

(4) placing the substrate obtained in the step (3) in microwave plasma deposition equipment, and introducing hydrogen, wherein the working conditions of the microwave plasma deposition equipment are that the gas pressure is 5KPa, the substrate temperature is 850 ℃, the hydrogen flow is 97sccm, and the processing time is 60 min; and carrying out hydrogenation treatment for 2h to obtain the diamond film.

Compared with the example 3, the substrate is a nickel-silicon nitride substrate, and the modification treatment of sodium alginate is not carried out, and the rest contents are the same as the example 3.

Comparative example 3

Preparing raw materials: 80 parts of nano diamond micro powder, 12 parts of methyl acrylate, 12 parts of a dispersing agent and 3 parts of sodium stearate.

The dispersant is methacryloyloxyethyl trimethyl ammonium chloride; the initiator is any one of dimethyl azodiisobutyrate, azodiisobutyronitrile, azodiisoheptonitrile, benzoyl peroxide and di (2-ethyl) hexyl peroxydicarbonate.

(1) Preparing a nano-diamond mixed solution: dissolving a dispersing agent in water, and adjusting the pH value of the solution to 10.0; adding the nano diamond micro powder, and stirring at a high speed of 2000 r/min; adding sodium stearate aqueous solution, and dispersing to obtain nano-diamond mixed solution;

(2) pre-treating a substrate; dissolving silicon nitride powder in SnCl₂And HNO₃Stirring the solution at the temperature of 55 ℃ to separate silicon nitride powder; adding AgNO₃Mixing with ammonia water, stirring, separating silicon nitride powder, adding NiSO₄The solution is adjusted to pH 10.5 with acetic acid-sodium acetate solution, stirred, the temperature is raised to 75 ℃ and NaH is added dropwise thereto₂PO₂Stirring the solution, and reacting for 9 hours to obtain silicon nitride powder coated with a metal nickel layer; mixing the prepared silicon nitride powder coated with the metallic nickel layer and nickel powder according to the mass ratio of 3:1, dispersing the mixture in an ethanol solution, pressing and forming, sintering at 1800 ℃, and naturally cooling to obtain a nickel-silicon nitride substrate;

adding distilled water into sodium alginate powder at a mass ratio of 1: 50, stirring at room temperature to dissolve completely to obtain sodium alginate stock solution; immersing a nickel-silicon nitride substrate into the sodium alginate stock solution, stirring at a high speed, taking out, and naturally drying to obtain a pretreated substrate;

(3) placing the pretreated substrate obtained in the step (2) in a nano-diamond mixed solution, performing ultrasonic oscillation, adsorbing for 3-4h, taking out the substrate, placing the substrate in deionized water and an ethanol solution, washing, and drying for later use;

(4) placing the substrate obtained in the step (3) in microwave plasma deposition equipment, and introducing hydrogen, wherein the working conditions of the microwave plasma deposition equipment are that the gas pressure is 5KPa, the substrate temperature is 850 ℃, the hydrogen flow is 97sccm, and the processing time is 60 min; and carrying out hydrogenation treatment for 2h to obtain the diamond film.

In comparison with example 3, the nano-diamond mixed solution was prepared by using only methacryloyloxyethyl trimethyl ammonium chloride as a dispersant, and the rest was the same as example 3.

Experimental data and analysis

Respectively carrying out performance detection on the diamond films prepared in the embodiments 1-3 and the comparative examples 1-3, wherein the detection results are shown in the following table 1;

	HV hardness, kg/mm2	Coefficient of friction	Friction force, N	Scratch method binding force, N
					Example 1	2355	0.08	887	37
Example 2	2370	0.08	880	37
					Example 3	2375	0.09	905	39
Comparative example 1	2360	0.07	779	35
					Comparative example 2	2330	0.07	785	32
Comparative example 3	2085	0.05	623	27

TABLE 1

As can be seen from the data in Table 1, the diamond films prepared in examples 1 to 3 have good HV hardness, friction coefficient, friction force and bonding force by a scratching method, and the diamond films have good toughness and wear resistance; compared with the embodiment 3, the substrate material of the comparative example 1 is silicon nitride instead of nickel-silicon nitride, and compared with the embodiment 3 of the comparative example 2, the nickel-silicon nitride is not modified by sodium alginate; the adhesive force between the substrate and the diamond film is directly reduced, so that the bonding force and hardness between the prepared diamond film and the substrate are reduced; compared with the embodiment 3, the methacryloyloxyethyl trimethyl ammonium chloride in the nano-diamond mixed solution is only used as a dispersing agent, does not copolymerize with methyl acrylate to generate a tough high molecular compound, and does not have a positive and negative charge bonding effect with a substrate, and finally the prepared diamond film has poorer bonding force, hardness and friction performance than the diamond film in the embodiment 3.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (7)

1. A method for preparing a diamond film based on plasma vapor deposition is characterized in that; comprises the following steps;

(1) preparing a nano-diamond mixed solution: dissolving a dispersing agent in water, and adjusting the pH value of the solution; adding the nano-diamond micro powder, and stirring at a high speed; adding methyl acrylate at 90-105 deg.C, adding initiator, reacting, filtering, and vacuum drying to balance weight; adding sodium stearate aqueous solution, and dispersing to obtain nano-diamond mixed solution;

(2) dissolving silicon nitride powder in SnCl₂And HNO₃Stirring in the solution at 50-55 deg.C to separate silicon nitride powder; adding AgNO₃Mixing with ammonia water, stirring, separating silicon nitride powder, adding NiSO₄Stirring the solution, raising the temperature to 70-75 ℃, and dropwise adding NaH into the solution₂PO₂Stirring the solution, and reacting for 7-9h to obtain silicon nitride powder coated with a metal nickel layer; mixing the prepared silicon nitride powder coated with the metal nickel layer and nickel powder, dispersing the mixture in an ethanol solution, pressing and forming, sintering, and naturally cooling to obtain a nickel-silicon nitride substrate;

adding distilled water into sodium alginate powder at a mass ratio of 1: 50, stirring at room temperature to dissolve completely to obtain sodium alginate stock solution; immersing a nickel-silicon nitride substrate into the sodium alginate stock solution, stirring at a high speed, taking out, and naturally drying to obtain a pretreated substrate;

(3) placing the substrate pretreated in the step (2) in the nano-diamond mixed solution, performing ultrasonic oscillation, adsorbing for 3-4h, taking out the substrate, placing the substrate in deionized water and ethanol solution, washing, and drying for later use;

(4) and (4) placing the substrate obtained in the step (3) in microwave plasma deposition equipment, introducing hydrogen, and carrying out hydrogenation treatment to obtain the diamond film.

2. The method for preparing a diamond film based on plasma vapor deposition according to claim 1, wherein the method comprises the following steps: comprises the following steps;

(1) preparing a nano-diamond mixed solution: dissolving a dispersant in water, and adjusting the pH value of the solution to 7.5-10.0; adding the nano-diamond micro-powder, and stirring at a high speed of 1200-2000 r/min; under the protection of nitrogen, adding methyl acrylate at the temperature of 90-105 ℃, adding an initiator, reacting for 8-9h, filtering, and drying in vacuum to balance weight; adding sodium stearate aqueous solution, and dispersing to obtain nano-diamond mixed solution;

(2) pre-treating a substrate; dissolving silicon nitride powder in SnCl₂And HNO₃Stirring in the solution at 50-55 deg.C to separate silicon nitride powder; adding AgNO₃Mixing with ammonia water, stirring, separating silicon nitride powder, adding NiSO₄Adjusting pH to 10.5 with acetic acid-sodium acetate solution, stirring, increasing temperature to 70-75 deg.C, and adding NaH dropwise₂PO₂Stirring the solution, and reacting for 7-9h to obtain silicon nitride powder coated with a metal nickel layer; mixing the prepared silicon nitride powder coated with the metal nickel layer and the nickel powder according to the mass ratio of 3:1, dispersing the mixture in an ethanol solution, pressing and forming, sintering at the temperature of 1500-;

adding distilled water into sodium alginate powder at a mass ratio of 1: 50, stirring at room temperature to dissolve completely to obtain sodium alginate stock solution; immersing a nickel-silicon nitride substrate into the sodium alginate stock solution, stirring at a high speed, taking out, and naturally drying to obtain a pretreated substrate;

(3) placing the pretreated substrate obtained in the step (2) in a nano-diamond mixed solution, performing ultrasonic oscillation, adsorbing for 3-4h, taking out the substrate, placing the substrate in deionized water and an ethanol solution, washing, and drying for later use;

(4) and (4) placing the substrate obtained in the step (3) in microwave plasma deposition equipment, introducing hydrogen, and carrying out hydrogenation treatment for 0.5-2h to obtain the diamond film.

3. The method for preparing a diamond film based on plasma vapor deposition according to claim 1, wherein the method comprises the following steps: in the step (1), 75-80 parts of nano diamond micro powder, 12-15 parts of methyl acrylate, 12-15 parts of a dispersing agent and 1-3 parts of sodium stearate by weight.

4. The method for preparing a diamond film based on plasma vapor deposition according to claim 3, wherein the method comprises the following steps: the dispersant is methacryloyloxyethyl trimethyl ammonium chloride.

5. The method for preparing a diamond film based on plasma vapor deposition according to claim 1, wherein the method comprises the following steps: the initiator in the nano-diamond mixed solution prepared in the step (1) is any one of dimethyl azodiisobutyrate, azodiisobutyronitrile, azodiisoheptonitrile, benzoyl peroxide and bis (2-ethyl) hexyl peroxydicarbonate.

6. The method for preparing a diamond film based on plasma vapor deposition according to claim 1, wherein the method comprises the following steps: the working conditions of the microwave plasma deposition equipment are as follows:

the gas pressure is 2-5 KPa, the substrate temperature is 700-850 ℃, the hydrogen flow is 90-97 sccm, and the processing time is 45-60 min.

7. A plasma vapor deposited diamond film made according to any of claims 1 to 6.