CN104928639A - Super tough carbon-based surface protection coating and preparation method thereof - Google Patents

Abstract

The invention discloses a super strong and tough carbon-based surface protective coating. The coating is composed of carbon elements, carbide-forming metal elements and weak carbide-forming metal elements. In the coating, the carbon elements exist in an amorphous form. A carbon amorphous network is formed, carbide-forming metal elements combine with carbon to form carbide nanoparticles, weak carbide-forming metal elements exist as metallic nanoparticles, carbide nanoparticles and metal nanoparticles are embedded in the carbon amorphous network structure, Particles are separated by amorphous carbon; during preparation, by simultaneously introducing carbide metal elements and weak carbide metal elements into the carbon-based coating, the coating can be enhanced while increasing the hardness and reducing stress. The flexibility and adhesion of the coating improve the friction and wear resistance and thermal stability of the coating, making the coating more suitable for more harsh application environments and achieving better surface protection.

Description

A super-tough carbon-based surface protective coating and preparation method thereof

technical field

The invention relates to a carbon-based coating and a preparation method thereof, belonging to the technical field of surface protection technology and related coating materials.

Background technique

With the industrial field's requirements for energy saving, emission reduction, environmental protection, etc., as well as the high standard requirements for high precision, high reliability, and long life, a new generation of energy-saving, low-consumption, and low-carbon automotive engines, Nuclear power mechanical sealing systems, compressor oil-free lubrication systems, textile machinery systems, precision molds, precision transmission systems, bearing systems, machinery manufacturing and other industries all reflect the urgent need for new integrated surface protection technology that strengthens and lubricates.

Base coatings (e.g., diamond-like coatings, amorphous carbon coatings, graphite-like coatings) are a broadly defined class of amorphous carbon materials consisting mainly of graphitic clusters with sp ³ hybrid bonds and sp ² bonds in the diamond phase. The formation of a three-dimensional cross network structure of clusters has many excellent properties similar to diamond, such as high hardness, low friction coefficient, high wear resistance and corrosion resistance, wide light transmission range, excellent biocompatibility, etc., has always been a low-friction surface technology field One of the hotspots of research. However, carbon-based coatings have problems such as ① low toughness, strong brittleness, and poor thermal stability; ② high stress and weak film-base bonding; ③ tribological behavior is greatly affected by the environment, etc., which still restrict the life and reliability of this type of film. key bottleneck. How to give full play to the advantages of this kind of thin film materials under complex and changeable environmental conditions and special working conditions has become a key technical problem that needs to be solved urgently.

Contents of the invention

The purpose of the present invention is to provide a carbon-based protective coating with low stress, high strength and toughness, stable friction and strong film-base bonding, which can be applied to the surface of mechanical parts, cutting dies and other products.

Another object of the present invention is to provide a method for preparing the above-mentioned carbon-based protective coating.

The technical solution adopted in the present invention is: a super-hard carbon-based surface protective coating, which is composed of carbon elements, carbide-forming metal elements, and weak carbide-forming metal elements. In the coating, carbide-forming metal elements The atomic percentage content of carbon is 5~20%, the atomic percentage content of weak carbide-forming metal elements is 5~20%, and the balance is carbon element; in the coating, carbon element exists in the form of amorphous carbon, forming a carbon amorphous network , carbide-forming metal elements combine with carbon to form carbide nanoparticles with a particle size of 5-10nm, weak carbide-forming metal elements exist as metallic nanoparticles with a particle size of 5-10nm; carbide nanoparticles And metal nanoparticles are embedded in the carbon amorphous network structure, the particles are separated by amorphous carbon, and the average distance between the particles is 10~20nm.

The carbide metal element is titanium or chromium or tungsten.

The weak carbide forming element is copper or cobalt or nickel.

The preparation of the super strong and tough carbon-based coating of the present invention is carried out by using an ion beam composite magnetron sputtering coating machine. The ion beam composite magnetron sputtering coating machine consists of a vacuum chamber, two magnetron sputtering sources, An ion source and a workpiece support that can rotate simultaneously, the workpiece support is installed inside the vacuum chamber, and the two magnetron sputtering sources can be loaded with different metal targets. The specific steps for the preparation of the carbon-based coating are as follows:

(1) Ion beam etching: place the substrate on the workpiece support in the vacuum chamber, evacuate the vacuum chamber until the vacuum degree is below 5.0×10 ^-3 Pa, turn on the ion source, and inject 50~100 sccm argon gas into the ion source, Set the ion source power to 0.6~0.8KW, set the workpiece support bias voltage to 500~800V, and work for 30 minutes;

(2) Deposition of ultra-strong and tough carbon-based coatings: Simultaneously turn on the ion source and two magnetron sputtering sources, and the two magnetron sputtering sources are respectively loaded with different simple metal targets with a purity greater than 99.99%; The chamber is fed with gaseous hydrocarbon and argon, and the overall pressure of the vacuum chamber is controlled to 0.8~2Pa; the ion source power is set to 0.8~1KW, and the magnetron sputtering power is 1~2KW; at the same time, the bias voltage of the substrate is set to 100~300V, and the deposition time 2~3 hours;

(3) Turn off the power supply, wait until the temperature of the vacuum chamber drops to room temperature, open the vacuum chamber and take out the substrate, and the coating formed on the surface of the substrate is the super-tough carbon-based coating;

Wherein, the elemental metal target in step (2) is: elemental titanium target, elemental chromium target, elemental tungsten target, elemental copper target, elemental cobalt target, or elemental nickel target; the gaseous hydrocarbon is acetylene or methane gas.

In the preferred step (2), the two magnetron sputtering sources are respectively loaded with different elemental metal targets with a purity greater than 99.99%: one magnetron sputtering source is loaded with an elemental titanium target with a purity greater than 99.99% Or an elemental chromium target with a purity greater than 99.99% or an elemental tungsten target with a purity greater than 99.99%, and another magnetron sputtering source loaded with an elemental copper target with a purity greater than 99.99% or an elemental cobalt target with a purity greater than 99.99% or a Elemental nickel target.

Further preferably, the volume ratio of gaseous hydrocarbons to argon is 1-4:9-6, that is, gaseous hydrocarbons account for 10%-40% of the total volume of gas passed into the vacuum chamber.

The preparation method of the carbon-based coating of the present invention also includes the following pretreatment step: before the ion beam etching step, the substrate is ultrasonically cleaned with alcohol, then rinsed with deionized water, and dried with dry compressed air.

The substrate described in the technical solution of the present invention refers to the sample to be coated, that is, the method of the present invention is applicable but not limited to such as: the surface of metal mechanical parts, precision molds, precision transmission machinery equipment, bearings, electronic products, decorative products and materials protection.

Compared with the prior art, the present invention has the advantages of introducing carbide metal elements and weak carbide metal elements into the carbon-based coating at the same time, increasing the hardness of the coating and reducing the stress while enhancing the flexibility and adhesion of the coating. Focus on improving the friction and wear resistance and thermal stability of the coating, making the coating more suitable for more demanding application environments, such as the protection of the surface of mechanical parts, tool molds and other products.

Description of drawings

FIG. 1 is a schematic diagram of the coating structure of the present invention, wherein the pentagons represent metal nanoparticles 1 , the hexagons represent carbide nanoparticles 2 , and the rest are amorphous carbon structure regions 3 .

Fig. 2 is a nanoindentation test diagram of the carbon-based coating prepared in Example 1 of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and examples of implementation.

Embodiment 1 Realize the present invention according to the following steps:

1. Composite coating machine preparation: This implementation chooses to use ion beam composite magnetron sputtering coating machine, including a vacuum chamber, two magnetron sputtering sources, an ion source and a workpiece support that can rotate at the same time. The workpiece support is installed in a vacuum Inside the chamber; two magnetron sputtering sources are respectively loaded with a titanium target with a purity of 99.99% and a copper target with a purity of 99.99%;

2. Sample (substrate) pre-cleaning treatment: Use alcohol to ultrasonically clean the sample (substrate) to be coated, then rinse with deionized water, and dry with dry compressed air;

3. Use ion beam etching to clean the surface of the sample in the vacuum chamber: place the substrate on the workpiece support in the vacuum chamber, evacuate the vacuum chamber to below 5.0×10 ^-3 Pa, turn on the ion source, and feed 100 sccm into the ion source Argon gas, set the ion source power to 0.6KW, set the workpiece support bias to 800V, and work for 30 minutes;

4. Preparation of Cu and Ti metal-doped super-tough carbon-based coatings: Simultaneously turn on the ion source, magnetron sputtering equipped with a simple titanium target, and magnetron sputtering equipped with a simple copper target, and at the same time pass into the vacuum chamber Acetylene and argon (the volume ratio of acetylene to argon is 1:9), acetylene accounts for 10% of the total gas volume, and the overall air pressure is controlled at 1Pa; the ion source power is set to 1KW, and the magnetron sputtering power is 2KW; The voltage is set to 300V, and the deposition time is 2 hours;

5. Turn off the power, wait for the temperature of the vacuum chamber to drop to room temperature, open the vacuum chamber to take out the substrate, and a super tough carbon-based coating is formed on the surface of the substrate.

In the formed coating, the atomic percentage content of carbide forming metal element titanium is 20%, the atomic percentage content of weak carbide forming metal element copper is 20%, and the atomic percentage content of carbon element is 60%; in the coating, Carbon element exists in the form of amorphous carbon, forming carbon amorphous network, carbide forming metal elements combine with carbon to form carbide nanoparticles, the particle size is 5~10nm, weak carbide forming metal elements exist in metal state nanoparticles , the particle size is 5-10nm; carbide nanoparticles and metal nanoparticles are embedded in the carbon amorphous network structure, the particles are separated by amorphous carbon, and the average distance between particles is 10nm.

After residual stress, scratch test, and nanoindentation test (as shown in Figure 2), the residual stress of the prepared Ti and Cu-doped carbon-based coating is 0.3GPa, the coating has excellent adhesion, and the film/substrate critical The load reaches 10GPa and the hardness is 30GPa. At the same time, the coating exhibits excellent flexibility, with an elastic recovery capacity of 50%.

Embodiment 2 Realize the present invention according to the following steps:

1. Composite coating machine preparation: The ion beam composite magnetron sputtering coating machine selected for this implementation includes a vacuum chamber, two magnetron sputtering sources, an ion source and a workpiece support that can rotate at the same time. The workpiece support is installed on Inside the vacuum chamber; two magnetron sputtering sources are respectively loaded with a chromium target with a purity of 99.99% and a cobalt target with a purity of 99.99%;

2. Sample (substrate) pre-cleaning treatment: Use alcohol to ultrasonically clean the sample (substrate) to be coated, then rinse with deionized water, and dry with dry compressed air;

3. Use ion beam etching to clean the surface of the sample in the vacuum chamber: place the substrate on the workpiece support in the vacuum chamber, evacuate the vacuum chamber to 3.0×10 ^-3 Pa, turn on the ion source, and feed 80 sccm argon into the ion source Gas, set the ion source power to 0.6KW, set the workpiece support bias to 700V, and set the working time to 30 minutes;

4. Preparation of ultra-strong and tough carbon-based coating doped with chromium and cobalt metals: Simultaneously turn on the ion source, magnetron sputtering equipped with a simple chromium target, and magnetron sputtering equipped with a simple cobalt target, and at the same time feed into the vacuum chamber Methane and argon (the volume ratio of methane and argon is 1:9), methane accounts for 10% of the total gas volume, and the overall air pressure is controlled at 1.5Pa; the ion source power is set to 0.8KW, and the magnetron sputtering power is 1KW; the substrate The bias voltage is set to 300V, and the deposition time is 2.5 hours;

5. Turn off the power, wait for the temperature of the vacuum chamber to drop to room temperature, open the vacuum chamber to take out the substrate, and a super tough carbon-based coating is formed on the surface of the substrate.

In the formed coating, the atomic percentage content of carbide forming metal element chromium is 10%, the atomic percentage content of weak carbide forming metal element cobalt is 15%, and the atomic percentage content of carbon element is 75%; in the coating, Carbon element exists in the form of amorphous carbon, forming carbon amorphous network, carbide forming metal elements combine with carbon to form carbide nanoparticles, the particle size is 5~10nm, weak carbide forming metal elements exist in metal state nanoparticles , the particle size is 5-10nm; carbide nanoparticles and metal nanoparticles are embedded in the carbon amorphous network structure, the particles are separated by amorphous carbon, and the average distance between particles is 15nm.

Embodiment 3 Realize the present invention according to the following steps:

1. Composite coating machine preparation: The ion beam composite magnetron sputtering coating machine selected for this implementation includes a vacuum chamber, two magnetron sputtering sources, an ion source and a workpiece support that can rotate at the same time. The workpiece support is installed on Inside the vacuum chamber; a tungsten target with a purity of 99.99% and a nickel target with a purity of 99.99% are respectively loaded on two magnetron sputtering sources;

2. Sample (substrate) pre-cleaning treatment: Use alcohol to ultrasonically clean the sample (substrate) to be coated, then rinse with deionized water, and dry with dry compressed air;

3. Use ion beam etching to clean the surface of the sample in the vacuum chamber: place the substrate on the workpiece support in the vacuum chamber, evacuate the vacuum chamber to 4.0×10 ^-3 Pa, turn on the ion source, and inject 50 sccm argon into the ion source Gas, set the ion source power to 0.7KW, set the workpiece support bias voltage to 600V, and set the working time to 30 minutes;

4. Preparation of tungsten and nickel metal-doped super-tough carbon-based coatings: Simultaneously turn on the ion source, magnetron sputtering equipped with a simple tungsten target, and magnetron sputtering equipped with a simple nickel target, and at the same time feed into the vacuum chamber Acetylene and argon (the volume ratio of acetylene to argon is 4:6), acetylene accounts for 40% of the total gas volume, and the overall air pressure is controlled at 0.8Pa; the ion source power is set to 0.8KW, and the magnetron sputtering power is 1.5KW; The bias voltage of the substrate is set to 100V, and the deposition time is 3 hours;

5. Turn off the power, wait for the temperature of the vacuum chamber to drop to room temperature, open the vacuum chamber to take out the substrate, and a super tough carbon-based coating is formed on the surface of the substrate.

In the formed coating, the atomic percentage content of the carbide-forming metal element tungsten is 12%, the atomic percentage content of the weak carbide-forming metal element nickel is 5%, and the atomic percentage content of the carbon element is 83%; in the coating, Carbon element exists in the form of amorphous carbon, forming carbon amorphous network, carbide forming metal elements combine with carbon to form carbide nanoparticles, the particle size is 5~10nm, weak carbide forming metal elements exist in metal state nanoparticles , the particle size is 5-10nm; carbide nanoparticles and metal nanoparticles are embedded in the carbon amorphous network structure, the particles are separated by amorphous carbon, and the average distance between particles is 20nm.

Embodiment 4 Realize the present invention according to the following steps:

1. Composite coating machine preparation: The ion beam composite magnetron sputtering coating machine selected for this implementation includes a vacuum chamber, two magnetron sputtering sources, an ion source and a workpiece support that can rotate at the same time. The workpiece support is installed on Inside the vacuum chamber; two magnetron sputtering sources are respectively loaded with a tungsten target with a purity of 99.99% and a copper target with a purity of 99.99%;

2. Sample (substrate) pre-cleaning treatment: Use alcohol to ultrasonically clean the sample (substrate) to be coated, then rinse with deionized water, and dry with dry compressed air;

3. Use ion beam etching to clean the surface of the sample in the vacuum chamber: place the substrate on the workpiece support in the vacuum chamber, evacuate the vacuum chamber to 3.5×10 ^-3 Pa, turn on the ion source, and feed 90 sccm argon into the ion source Gas, set the power of the ion source to 0.8KW, set the bias voltage of the workpiece support to 500V, and set the working time to 30 minutes;

4. Preparation of tungsten and copper metal-doped super-tough carbon-based coatings: Simultaneously turn on the ion source, magnetron sputtering equipped with a simple tungsten target, and magnetron sputtering equipped with a simple copper target, and simultaneously feed into the vacuum chamber Methane and argon (the volume ratio of methane and argon is 2:8). Methane accounts for 20% of the total gas volume, and the overall pressure is controlled at 2Pa; the ion source power is set to 1KW, and the magnetron sputtering power is 2KW; the bias voltage of the substrate Set to 200V, deposition time is 2 hours;

5. Turn off the power, wait for the temperature of the vacuum chamber to drop to room temperature, open the vacuum chamber to take out the substrate, and a super tough carbon-based coating is formed on the surface of the substrate.

In the formed coating, the atomic percentage content of the carbide-forming metal element tungsten is 5%, the atomic percentage content of the weak carbide-forming metal element copper is 10%, and the atomic percentage content of the carbon element is 85%; in the coating, Carbon element exists in the form of amorphous carbon, forming carbon amorphous network, carbide forming metal elements combine with carbon to form carbide nanoparticles, the particle size is 5~10nm, weak carbide forming metal elements exist in metal state nanoparticles , the particle size is 5-10nm; carbide nanoparticles and metal nanoparticles are embedded in the carbon amorphous network structure, and the particles are separated by amorphous carbon, and the average distance between particles is 18nm.

Claims (7)

1. a superpower tough carbon-base coating, it is characterized in that: this coating is elementary composition by carbon, carbide-forming metal element, weak carbide-forming metal, in coating, the atom percentage content of carbide-forming metal element is 5 ~ 20%, the atom percentage content of weak carbide-forming metal element is 5 ~ 20%, and surplus is carbon; In coating, carbon exists with decolorizing carbon form, forms the amorphous network of carbon, carbide-forming metal element is combined with carbon and forms carbide nanoparticles, its size is 5 ~ 10nm, and weak carbide-forming metal element exists with metallic state nano particle, and its size is 5 ~ 10nm; Carbide nanoparticles and metal nanoparticle are embedded in the amorphous network structure of carbon, are separated between particle with particle by decolorizing carbon, and between particle, average headway is 10 ~ 20nm.

2. superpower tough carbon-base coating according to claim 1, is characterized in that: described carbide metal element is titanium or chromium or tungsten.

3. superpower tough carbon-base coating according to claim 1, is characterized in that: described weak carbide forming element is copper or cobalt or nickel.

4. the preparation method of a superpower tough carbon-base coating according to claim 1, it is characterized in that: adopt ionic fluid combined magnetic-controlled sputter coating equipment to carry out, described ionic fluid combined magnetic-controlled sputter coating equipment is made up of a vacuum chamber, two controlled sputtering sources, ion sources and the work support that can rotate simultaneously, work support is arranged on internal vacuum chamber, described two controlled sputtering sources all can load different metal targets, and concrete steps prepared by described carbon-base coating are as follows:

(1) ion beam etching: be placed in by matrix on the work support of vacuum chamber, vacuum chamber is to vacuum tightness 5.0 × 10 ^-3below Pa, open ion source, pass into 50 ~ 100sccm argon gas to ion source, arrange ion source power 0.6 ~ 0.8KW, arrange work support bias voltage 500 ~ 800V, the working hour is 30 minutes;

(2) deposit superpower tough carbon-base coating: open ion source, two controlled sputtering sources, two controlled sputtering sources load different, that purity is greater than 99.99% elemental metals target respectively simultaneously; Pass into hydrocarbon gas and argon gas to vacuum chamber simultaneously, control the overall air pressure 0.8 ~ 2Pa of vacuum chamber; Arranging ion source power is 0.8 ~ 1KW, magnetron sputtering power 1 ~ 2KW; The bias voltage of matrix is set to 100 ~ 300V, and depositing time is 2 ~ 3 hours;

(3) powered-down, treats that vacuum chamber temperature is down to room temperature, and open vacuum chamber and take out matrix, the coating formed at matrix surface is described superpower tough carbon-base coating;

Wherein, the described elemental metals target of step (2) is: simple substance titanium target or simple substance chromium target or simple substance tungsten target or elemental copper target or simple substance cobalt target or elemental nickel target; Described hydrocarbon gas is acetylene or methane gas.

5. the preparation method of superpower tough carbon-base coating according to claim 4, it is characterized in that: in described step (2), two controlled sputtering sources load different, that purity is greater than the elemental metals target of 99.99% mode respectively: controlled sputtering source loads simple substance titanium target or the purity simple substance chromium target or the purity simple substance tungsten target that is greater than 99.99% that are greater than 99.99% that purity is greater than 99.99%, and another controlled sputtering source loads elemental copper target or the purity simple substance cobalt target or the purity elemental nickel target that is greater than 99.99% that are greater than 99.99% that purity is greater than 99.99%.

6. the preparation method of superpower tough carbon-base coating according to claim 4, is characterized in that: the volume ratio of described hydrocarbon gas and argon gas is 1 ~ 4:9 ~ 6.

7. the preparation method of superpower tough carbon-base coating according to claim 4, it is characterized in that: the method also comprises following pre-treatment step: before ion beam etching step, utilize alcohol ultrasonic cleaning matrix, then use rinsed with deionized water, then dry up by dried compressed air.