CN116162900A - Titanium nitride-based self-release carbon lubricating composite coating and preparation method and application thereof - Google Patents

Abstract

The invention provides a titanium nitride-based self-release carbon lubricating composite coating, and a preparation method and application thereof, and relates to the technical field of friction and wear protection. Depositing a porous titanium nitride coating on a substrate; the deposition is multi-arc ion plating deposition, and the included angle between the normal line of the substrate and the normal line of the titanium metal target in the deposition process is 75-85 degrees; soaking the porous titanium nitride coating in a carbon source water solution for hydrothermal treatment, and carbonizing the obtained titanium nitride coating compounded with the carbon precursor in a protective atmosphere to obtain the titanium nitride-based self-release carbon lubricating composite coating. According to the invention, the titanium nitride-based self-release carbon lubricating composite coating is prepared by combining oblique angle deposition, a multi-arc ion plating technology and a hydrothermal carbon filling method, carbon in the titanium nitride nano-pores can be continuously supplied to a friction contact surface in sliding friction, and an antifriction lubricating effect is provided; the invention can also realize the control of the porosity of the coating, thereby realizing the control of the carbon filling amount and further realizing the control of the service life of the composite coating.

Description

A titanium nitride-based self-releasing carbon lubricating composite coating and its preparation method and application

technical field

The invention relates to the technical field of friction and wear protection, in particular to a titanium nitride-based self-releasing carbon lubricating composite coating and its preparation method and application.

Background technique

TiN (Titanium Nitride, titanium nitride) is a ceramic material with high hardness and high wear resistance. It is one of the most mature engineering materials today and has a wide range of technical applications. For a long time, it has been used as a protective and decorative coating in many fields such as mold manufacturing, automotive industry, and aerospace. However, titanium nitride coating lacks lubricity and has a high coefficient of friction, which limits its application in the field of lubrication and friction reduction.

Contents of the invention

In view of this, the object of the present invention is to provide a titanium nitride-based self-releasing carbon lubricating composite coating and its preparation method and application. The titanium nitride-based self-releasing carbon lubricating composite coating prepared by the invention has excellent lubricating, friction-reducing and wear-resisting effects.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

The invention provides a preparation method of a titanium nitride-based self-releasing carbon lubricating composite coating, comprising the following steps:

Deposit a porous titanium nitride coating on the substrate; the deposition is multi-arc ion plating deposition, with a titanium metal target as the target material, and nitrogen as the working gas. During the deposition process, the substrate normal and the titanium metal target method The included angle of the line is 75-85°;

Soaking the porous titanium nitride coating in an aqueous carbon source solution for hydrothermal treatment to obtain a titanium nitride coating composited with a carbon precursor;

The titanium nitride coating compounded with the carbon precursor is carbonized in a protective atmosphere to obtain the titanium nitride-based self-releasing carbon lubricating composite coating.

Preferably, the deposition conditions include: target-base distance of 40-60 mm, vacuum degree of 0.2-1.0 Pa, nitrogen flow rate of 100-800 sccm, arc current of 75-85A, and deposition time of 30-35 min.

Preferably, before depositing the porous titanium nitride coating, depositing a titanium layer on the substrate is also included.

Preferably, the thickness of the titanium layer is 400-500 nm.

Preferably, the carbon source in the carbon source aqueous solution is small molecule sugar; the concentration of the carbon source aqueous solution is 195-200 g/L.

Preferably, the temperature of the hydrothermal treatment is 150-200° C., and the time is 150-240 minutes.

Preferably, the protective atmosphere is argon or nitrogen; the gas flow of the protective atmosphere is 60-150 sccm.

Preferably, the temperature of the carbonization is 500-600° C., and the time is 120-240 minutes.

The invention provides a titanium nitride-based self-releasing carbon lubricating composite coating prepared by the preparation method described in the above technical scheme, including a porous titanium nitride coating deposited on a substrate and a porous titanium nitride coating filled in the porous titanium nitride coating. A carbon lubricating phase in the pores, the pores of the porous titanium nitride coating are nanoscale.

The invention provides the application of the titanium nitride-based self-releasing carbon lubricating composite coating in the above technical solution in lubricating and reducing friction.

The invention provides a preparation method of a titanium nitride-based self-releasing carbon lubricating composite coating, comprising the following steps: depositing a porous titanium nitride coating on a substrate; the deposition is multi-arc ion plating deposition, and a titanium metal target is used as the target material, using nitrogen as the working gas, during the deposition process, the angle between the normal line of the substrate and the normal line of the titanium metal target is 75-85°; the porous titanium nitride coating is soaked in the carbon source aqueous solution Carrying out hydrothermal treatment to obtain a titanium nitride coating compounded with a carbon precursor; carbonizing the titanium nitride coating compounded with a carbon precursor under a protective atmosphere to obtain the titanium nitride-based self-releasing carbon lubricating composite coating. The present invention adopts oblique angle deposition (the included angle between the normal of the substrate and the normal of the titanium metal target is 75-85°), and by strengthening the influence of the self-shadowing effect during the coating deposition process, the growth direction of titanium nitride is made towards the titanium metal The incident direction of the target is inclined to obtain a porous (specifically porous columnar) titanium nitride hard wear-resistant coating; by filling the porous titanium nitride coating with hydrothermal carbon, the carbon precursor is filled to the nitriding In the nanoscale pores of the titanium coating; and then through carbonization, the carbon precursor is converted into a carbon lubricating phase to realize the storage of the carbon lubricating phase in the titanium nitride coating. The invention combines oblique angle deposition, multi-arc ion plating technology and hydrothermal carbon coating to prepare a titanium nitride-based self-releasing carbon lubricating composite coating, which can continuously supply carbon in titanium nitride nanopores during sliding friction To the friction contact surface, anti-friction lubrication effect is provided; and, the present invention adopts multi-arc ion plating deposition method to prepare titanium nitride-based hard coating, which has good bonding force and strong wear resistance, and can protect the carbon lubricating phase from different forms failure and improve the friction life of the composite coating. Further, the present invention can adjust the porosity of the titanium nitride coating by adjusting the deposition angle and the working pressure during deposition (i.e., the gas flow rate of nitrogen gas), so as to realize the controllable preparation of the carbon filling amount, and then realize the composite coating Layer lifetime control.

The present invention provides a titanium nitride-based self-releasing carbon lubricating composite coating prepared by the preparation method described in the above technical scheme. The titanium nitride-based self-releasing carbon lubricating composite coating provided by the present invention is nitrogen released from the friction-induced carbon lubricating phase. Titanium nitride-based coating, carbon filling greatly improves the anti-friction and wear-resistant lubrication performance of the coating. During sliding friction, the carbon in the titanium nitride nanopores can be continuously supplied to the friction contact surface, providing anti-friction and lubrication effects.

Description of drawings

Fig. 1 is the preparation flowchart of titanium nitride-based self-releasing carbon lubricating composite coating of the present invention;

Fig. 2 is the schematic diagram of the anti-friction lubrication mechanism of the titanium nitride-based self-releasing carbon lubricating composite coating in the embodiment of the present invention;

Fig. 3 is the scanning electron micrograph of porous titanium nitride coating and dense titanium nitride coating surface and section prepared in embodiment 3 and comparative example 1, among Fig. 3, (a) and (c) correspond to embodiment respectively 3 and the surface of Comparative Example 1, (b) and (d) correspond to the section of Embodiment 3 and Comparative Example 1 respectively;

Fig. 4 is the XRD spectrum of the titanium nitride coating obtained by multi-arc ion plating deposition under 80 ° of deposition angle in embodiment 3;

Fig. 5 is the friction coefficient curve of the titanium nitride-based self-releasing carbon lubricating composite coating prepared in Examples 1-3 and the titanium nitride dense coating composite carbon prepared in Comparative Example 1.

Detailed ways

The invention provides a preparation method of a titanium nitride-based self-releasing carbon lubricating composite coating, comprising the following steps:

Deposit a porous titanium nitride coating on the substrate; the deposition is multi-arc ion plating deposition, with a titanium metal target as the target material, and nitrogen as the working gas. During the deposition process, the substrate normal and the titanium metal target method The included angle of the line is 75-85°;

Soaking the porous titanium nitride coating in an aqueous carbon source solution for hydrothermal treatment to obtain a titanium nitride coating composited with a carbon precursor;

The titanium nitride coating compounded with the carbon precursor is carbonized in a protective atmosphere to obtain the titanium nitride-based self-releasing carbon lubricating composite coating.

Fig. 1 is a flow chart of the preparation of the titanium nitride-based self-releasing carbon lubricating composite coating of the present invention. The detailed description will be described below with reference to FIG. 1 .

The present invention deposits a porous titanium nitride coating on a substrate. The present invention has no special requirements on the substrate, and a substrate well known to those skilled in the art can be used, such as a metal substrate. In the present invention, the deposition is multi-arc ion plating deposition, with a titanium metal target (also referred to as a titanium metal deposition target) as the target material, and nitrogen as the working gas. During the deposition process, the substrate normal and The included angle of the normal line of the titanium metal target (the included angle is referred to as the deposition angle) is 75-85°, preferably 80°; the titanium metal target is preferably a circular titanium metal target with a purity of 99.7%. In the present invention, the deposition conditions preferably include: the target-base distance (the vertical distance between the center of the target and the center of the substrate) is 40-60mm, preferably 45-55mm; the degree of vacuum is 0.2-1.0Pa, preferably 0.25- 0.85Pa; nitrogen flow rate is 100-800sccm, preferably 150-500sccm; arc current is 75-85A, preferably 75-80A; deposition time is 30-35min, preferably 30-32min.

In the present invention, the device for multi-arc ion plating deposition (i.e. coating machine) includes a cavity and a turntable disk and a titanium metal target arranged in the cavity, and the turntable disk and the titanium metal target are unidirectionally vertical Placed directly inside the chamber; the turntable is provided with a base, and the turntable can be biased to achieve glow cleaning by reasonably controlling the bias during the coating process; the titanium metal target For bombardment cleaning of substrates and finishing coatings.

In the present invention, the specific operation of the multi-arc ion plating deposition preferably includes the following steps:

(a) placing the titanium metal target unidirectionally vertically inside the cavity of the device;

(b) putting the substrate into the cavity after ultrasonic cleaning, adjusting the target base distance to 40-60 mm and the deposition angle to 75-85°;

(c) extracting the air inside the cavity so that the inside of the cavity is in a vacuum state;

(d) In the vacuum state, heating the vacuum interior of the cavity, and passing high-purity argon gas into the first gas flow, and performing glow discharge cleaning on the substrate under the first negative bias voltage;

(e) reducing the flow rate of the high-purity argon gas to the second gas flow rate, opening the titanium metal target, and bombarding and cleaning the substrate under the second negative bias;

(f) blowing nitrogen gas into the vacuum cavity, maintaining the vacuum degree at 0.2-1.0 Pa, and depositing a porous titanium nitride coating.

In the present invention, the ultrasonic cleaning preferably includes the first ultrasonic cleaning and the second ultrasonic cleaning carried out in sequence; the first ultrasonic cleaning is preferably carried out in petroleum ether, and the cleaning time is preferably 10 to 15 minutes; the second ultrasonic cleaning The cleaning is preferably performed in absolute ethanol, and the cleaning time is preferably 10-15 minutes; after the ultrasonic cleaning, the obtained substrate is preferably dried. In the present invention, the vacuum degree of the vacuum state is preferably 4.0 to 5.0×10 ^-3 Pa, more preferably 4.5 to 5.0× ^{10 -3 Pa} ; the heating temperature is preferably 150 to 250°C, more preferably 200-250°C; the first gas flow is preferably 600-800 sccm, more preferably 700-800 sccm; the first negative bias voltage is preferably -1000--1200V, more preferably -1100--1200V, the The time for glow discharge cleaning is preferably 10-15 minutes, more preferably 12-15 minutes. In the present invention, the second air flow is preferably 150-200 sccm, more preferably 150-170 sccm; the second negative bias voltage is preferably -750-850V, more preferably -750-800V, the The bombardment cleaning time is preferably 3-5 minutes, more preferably 4-5 minutes.

In the present invention, before the deposition of the porous titanium nitride coating, it is also preferred to deposit a titanium layer on the substrate, especially after step (e), because the bias voltage (i.e. the second negative bias Under the influence of compression), a titanium layer with a dense structure is formed, and then the porous titanium nitride coating deposition in step (f) is carried out. In the present invention, the thickness of the titanium layer is preferably 400-500 nm, and the titanium layer is used as a transition layer, which is beneficial to improve the bonding force of the film base.

In the present invention, the substrate is subjected to multi-arc ion plating, and the oblique-angle deposition technique (the angle between the normal line of the substrate and the normal line of the titanium metal target is 75-85°) is used to deposit the titanium nitride hard wear-resistant coating with a porous structure on the surface of the substrate. layer. The oblique angle deposition technique is to change the direction of the substrate relative to the target, increase the influence of the self-shadowing effect during the deposition process, and obtain a specific porous coating with a freely separated nano-column structure while depositing the coating. The porous hard film obtained by the technology can not only play a load-bearing role, but also store solid lubricants as micro-reservoirs. On the one hand, it protects the solid lubricants from failure, and on the other hand, it can release the solid lubricants in time during the friction process. Frictional contact surfaces, reducing friction and wear during sliding, avoiding premature failure of coatings, and prolonging the service life of moving parts.

After the porous titanium nitride coating is obtained, the present invention soaks the porous titanium nitride coating in a carbon source aqueous solution for hydrothermal treatment to obtain a titanium nitride coating compounded with carbon precursors. In the present invention, the carbon source in the carbon source aqueous solution is preferably a small molecular sugar. The present invention has no special requirements for the small molecular sugar, and any small molecular sugar well known to those skilled in the art can be used, such as glucose, sucrose, fructose, etc.; the concentration of the carbon source aqueous solution is preferably 195-200 g/L, more preferably 198 g/L. In the present invention, the temperature of the hydrothermal treatment is preferably 150-200°C, more preferably 170-200°C, and the time is preferably 150-240min, more preferably 180-200min. In the process of the hydrothermal treatment, the small molecular sugar undergoes caramelization reaction, dehydrates to form caramel, and cracks to produce small molecular aldehydes and ketones, that is, the carbon precursor. The invention fills the carbon precursor into the nanopores of the porous titanium nitride coating through a hydrothermal method.

After obtaining the titanium nitride coating compounded with the carbon precursor, the present invention carbonizes the titanium nitride coating compounded with the carbon precursor under a protective atmosphere to obtain the titanium nitride-based self-releasing carbon lubricating composite coating layer. In the present invention, the protective atmosphere is preferably argon or nitrogen, and the argon or nitrogen is preferably high-purity argon or high-purity nitrogen; the gas flow rate of the protective atmosphere is preferably 60 to 150 sccm, more preferably 80 ~100 sccm. In the present invention, the carbonization temperature is preferably 500-600°C, more preferably 550°C, the time is preferably 120-240min, more preferably 180-200min, and the carbonization is preferably carried out in a tube furnace. In the invention, the carbonization may also be referred to as heat treatment. The present invention converts the carbon precursor into a carbon lubricating phase through the carbonization, and realizes the storage of the carbon lubricating phase in the titanium nitride coating.

The invention obtains a porous structure while preparing a hard and wear-resistant titanium nitride coating, greatly improves the anti-friction and wear-resistant lubrication effect of the coating through carbon filling, and reduces the wear rate of the coating; and, The titanium nitride-based hard coating deposited by multi-arc ion plating has good bonding force and excellent wear resistance, which is more conducive to improving the bearing capacity of the composite coating; in addition, the present invention can also adjust the deposition angle and deposition time The working air pressure can be controlled to control the porosity of the coating, thereby realizing the controllable preparation of the carbon filling amount, and then realizing the control of the life of the composite coating.

The invention provides a titanium nitride-based self-releasing carbon lubricating composite coating prepared by the preparation method described in the above technical scheme, including a porous titanium nitride coating deposited on a substrate and a porous titanium nitride coating filled in the porous titanium nitride coating. A carbon lubricating phase in the pores, the pores of the porous titanium nitride coating are nanoscale. In the present invention, the porosity of the porous titanium nitride coating is preferably 7-14%. In the present invention, a titanium layer is preferably deposited between the substrate and the porous titanium nitride coating. The titanium nitride-based self-releasing carbon lubricating composite coating provided by the present invention is a titanium nitride-based coating that is released from the friction-induced carbon lubricating phase. The filling of carbon greatly improves the friction-reducing and wear-resistant lubrication performance of the coating. The carbon in the titanium nitride nanopores can be continuously supplied to the frictional contact surface to provide anti-friction lubrication effect. Figure 2 is a schematic diagram of the anti-friction lubrication mechanism of the titanium nitride-based self-releasing carbon lubricating composite coating in the embodiment of the present invention. The titanium nitride-based self-releasing carbon lubricating composite coating provided by the invention can be widely and effectively applied in lubricating and reducing friction.

The titanium nitride-based self-releasing carbon lubricating composite coating provided by the present invention and its preparation method and application will be described in detail below in conjunction with the examples, but they should not be understood as limiting the protection scope of the present invention.

Example 1

A circular Ti metal deposition target with a purity of 99.7% was used, placed vertically in one direction, and the arc current was 80A. 304 stainless steel was selected as the sample substrate for coating growth, and the 304 stainless steel substrate was a block of 20mm×20mm×2mm; the sample substrate was ultrasonically cleaned in petroleum ether and absolute ethanol for 15 minutes each, dried and put into the cavity. The deposition angle of the sample substrate (the angle between the normal of the sample substrate and the normal of the Ti metal deposition target) was adjusted to 80°, and the distance between the target and the substrate was adjusted to 45 mm.

Before the experiment, the vacuum degree of the cavity was pumped to 5.0×10 ^-3 Pa, preheated to 200°C, and 800 sccm of high-purity argon gas was introduced first. Under the bias voltage of -1200V, the substrate was cleaned by glow discharge for 15 minutes. Decrease to 150 sccm, turn on the Ti metal deposition target, and bombard the substrate for 5 minutes under the bias voltage of -800V. Pre-deposit a Ti layer (400-500nm in thickness) as a transition layer to improve the bonding force of the film base; pass nitrogen gas into the vacuum chamber to deposit a titanium nitride layer. The deposition time of the titanium nitride layer is 30min, and the deposition time of the nitrided For titanium, the flow rate of nitrogen gas is 150 sccm, and the degree of vacuum is 2.5-2.7×10 ^-1 Pa to form a titanium nitride hard coating with a porous structure (ie, a porous titanium nitride coating) prepared by multi-arc ion plating.

The titanium nitride-coated sample with a porous structure was transferred to an aqueous glucose solution for hydrothermal treatment. The concentration of glucose monohydrate in the aqueous glucose solution was 198g/L, the hydrothermal temperature was 200°C, and the hydrothermal time was 180min.

Transfer the hydrothermally treated sample to a tube furnace, and perform high-temperature heat treatment in a high-purity argon environment. The heat treatment temperature is 550°C, the heat treatment time is 180min, and the gas flow rate of the high-purity argon gas is 80 sccm. The titanium nitride-based self-releasing carbon lubricating composite coating with a porosity of 7.5% is denoted as M1.

Example 2

A circular Ti metal deposition target with a purity of 99.7% was used, placed vertically in one direction, and the arc current was 80A. 304 stainless steel was selected as the sample substrate for coating growth, and the 304 stainless steel substrate was a block of 20mm×20mm×2mm; the sample substrate was ultrasonically cleaned in petroleum ether and absolute ethanol for 15 minutes each, dried and put into the cavity. The deposition angle of the sample substrate (the angle between the normal of the sample substrate and the normal of the Ti metal deposition target) was adjusted to 80°, and the distance between the target and the substrate was adjusted to 45 mm.

Before the experiment, the vacuum degree of the cavity was pumped to 5.0×10 ^-3 Pa, preheated to 200°C, and 800 sccm of high-purity argon gas was introduced first. Under the bias voltage of -1200V, the substrate was cleaned by glow discharge for 15 minutes. Decrease to 150 sccm, turn on the Ti metal deposition target, and bombard the substrate for 5 minutes under the bias voltage of -800V. Pre-deposit a Ti layer (thickness is 400-500nm) as a transition layer to improve the bonding force of the film base; pass nitrogen gas into the vacuum chamber to deposit a titanium nitride layer, the deposition time of titanium nitride is 30min, and deposit titanium nitride At this time, the flow rate of nitrogen gas is 300 sccm, and the degree of vacuum is 5.0-5.2×10 ^-1 Pa to form a titanium nitride hard coating with a porous structure (ie, a porous titanium nitride coating) prepared by multi-arc ion plating.

The titanium nitride-coated sample with a porous structure was transferred to an aqueous glucose solution for hydrothermal treatment. The concentration of glucose monohydrate in the aqueous glucose solution was 198g/L, the hydrothermal temperature was 200°C, and the hydrothermal time was 180min.

Transfer the hydrothermally treated sample to a tube furnace, and perform high-temperature heat treatment in a high-purity argon environment. The heat treatment temperature is 550°C, the heat treatment time is 180min, and the high-purity argon gas flow rate is 80 sccm, forming on the substrate The titanium nitride-based self-releasing carbon lubricating composite coating with a porosity of 9.3% is denoted as M2.

Example 3

A circular Ti metal deposition target with a purity of 99.7% was used, placed vertically in one direction, and the arc current was 80A. 304 stainless steel was selected as the sample substrate for coating growth, and the 304 stainless steel substrate was a block of 20mm×20mm×2mm; the sample substrate was ultrasonically cleaned in petroleum ether and absolute ethanol for 15 minutes each, dried and put into the cavity. The deposition angle of the sample substrate (the angle between the normal of the sample substrate and the normal of the Ti metal deposition target) was adjusted to 80°, and the distance between the target and the substrate was adjusted to 45 mm.

Before the experiment, the vacuum degree of the cavity was pumped to 5.0×10 ^-3 Pa, preheated to 200°C, and 800 sccm of high-purity argon gas was introduced first. Under the bias voltage of -1200V, the substrate was cleaned by glow discharge for 15 minutes. Decrease to 150 sccm, turn on the Ti metal deposition target, and bombard the substrate for 5 minutes under the bias voltage of -800V. Pre-deposit a Ti layer (400-500nm in thickness) as a transition layer to improve the bonding force of the film base; pass nitrogen gas into the vacuum chamber to deposit a titanium nitride layer. The deposition time of the titanium nitride layer is 30min, and the deposition time of the nitrided For titanium, the flow rate of nitrogen gas is 500 sccm, and the degree of vacuum is 7.9-8.1×10 ^-1 Pa to form a titanium nitride hard coating with a porous structure (ie porous titanium nitride coating) prepared by multi-arc ion plating.

The titanium nitride-coated sample with a porous structure was transferred to an aqueous glucose solution for hydrothermal treatment. The concentration of glucose monohydrate in the aqueous glucose solution was 198g/L, the hydrothermal temperature was 200°C, and the hydrothermal time was 180min.

Transfer the hydrothermally treated sample to a tube furnace, and perform high-temperature heat treatment in a high-purity argon environment. The heat treatment temperature is 550°C, the heat treatment time is 180min, and the gas flow rate of the high-purity argon gas is 80 sccm. The titanium nitride-based self-releasing carbon lubricating composite coating with a porosity of 13.7%, is denoted as M3.

Comparative example 1

For comparison, a dense titanium nitride coating was prepared by multi-arc ion plating technology, using a circular Ti metal deposition target with a purity of 99.7%, placed vertically in one direction, and the arc current was 80A. 304 stainless steel was selected as the sample substrate for coating growth, and the 304 stainless steel substrate was a block of 20mm×20mm×2mm; the sample substrate was ultrasonically cleaned in petroleum ether and absolute ethanol for 15 minutes each, dried and put into the cavity. The deposition angle of the sample substrate (the angle between the normal of the sample substrate and the normal of the Ti metal deposition target) was adjusted to 0°, and the distance between the target and the substrate was adjusted to 45 mm.

Before the experiment, the vacuum degree of the cavity was pumped to 5.0×10 ^-3 Pa, preheated to 200°C, and 800 sccm of high-purity argon gas was introduced first. Under the bias voltage of -1200V, the substrate was cleaned by glow discharge for 15 minutes. Decrease to 150 sccm, turn on the Ti metal deposition target, and bombard the substrate for 5 minutes under the bias voltage of -800V. Pre-deposit a Ti layer (thickness is 400-500nm) as a transition layer to improve the bonding force of the film base; pass nitrogen gas into the vacuum chamber to deposit a titanium nitride layer, the deposition time of titanium nitride is 30min, and deposit titanium nitride At this time, the flow rate of nitrogen gas is 500 sccm, and the degree of vacuum is 7.9-8.1×10 ^-1 Pa to form a titanium nitride hard coating with a dense structure (ie, a dense titanium nitride coating) prepared by multi-arc ion plating.

The sample with dense titanium nitride coating was transferred to aqueous glucose solution for hydrothermal treatment. The concentration of glucose monohydrate in the aqueous glucose solution was 198g/L, the hydrothermal temperature was 200°C, and the hydrothermal time was 180min.

Transfer the hydrothermally treated sample to a tube furnace, and perform high-temperature heat treatment in a high-purity argon environment. The heat treatment temperature is 550°C, the heat treatment time is 180min, and the high-purity argon gas flow rate is 80 sccm, forming on the substrate Titanium nitride-based composite coating with dense structure (titanium nitride dense coating composite carbon), denoted as M4.

Fig. 3 is the scanning electron micrograph contrast figure of porous titanium nitride coating and dense titanium nitride coating surface and section prepared in embodiment 3 and comparative example 1, among Fig. 3, (a) and (c) correspond to respectively The surfaces of Example 3 and Comparative Example 1, (b) and (d) correspond to the cross-sections of Example 3 and Comparative Example 1, respectively. The results in Figure 3 show that with the introduction of the deposition angle, the surface of the titanium nitride coating changes from a dense structure to a porous structure, and the cross-section of the titanium nitride coating changes from a dense structure to a structure in which nanopillars are freely separated.

Fig. 4 is the XRD spectrum of the titanium nitride coating obtained by multi-arc ion plating deposition under 80 ° of deposition angles in embodiment 3, among Fig. 4, titanium nitride coating has polycrystalline structure, and has shown (220 ) preference orientation.

Fig. 5 is the friction coefficient curve of the titanium nitride-based self-releasing carbon lubricating composite coating prepared in Examples 1 to 3 and the titanium nitride dense coating composite carbon prepared in Comparative Example 1, M1, M2, M3 and M4 corresponds to Example 1, Example 2, Example 3 and Comparative Example 1, respectively. The friction test conditions are: radius of rotation 4mm, load 2N, diameter of counter ball (material Al ₂ O ₃ ) 8mm, rotation speed 200r/min. The test results shown in Figure 5: In the friction and wear test, the initial friction coefficient of M1 is 0.2, and gradually increases with time, and the coating fails at about 6000s; The coefficient is stable at 0.4, and the coating fails around 7800s; the initial friction coefficient of M3 is 0.2, and the friction coefficient is stable at 0.4 in the range of 2000-9000s, and the coating fails around 9500s; the initial friction coefficient of M4 is 0.2, and then rises rapidly. As high as 0.85, the coating did not exhibit a good lubricating effect. According to the friction test results, it can be seen that the present invention can realize carbon filling in the titanium nitride nanopores, thereby reducing the friction coefficient of the titanium nitride-based composite coating.

It can be seen from the above examples that the present invention introduces the nanopore array into the titanium nitride coating through oblique angle deposition, which can effectively retain carbon in the hydrothermal treatment. The nanopore array of the coating is formed by the self-shadowing in the oblique angle deposition. Due to the effect, there is no need for later mechanical processing, and its convenience is better than that of the micro-texture manufacturing process; the porosity of the titanium nitride porous coating increases with the increase of the working pressure, and the carbon-filled titanium nitride porous coating It can effectively reduce the friction coefficient of titanium nitride. The invention combines oblique-angle deposition, multi-arc ion plating and hydrothermal carbon coating to prepare a porous titanium nitride-coated composite carbon lubricating coating, which can release supplementary lubricants to the frictional contact surface in time when the coating is worn. Carbon effectively reduces the friction coefficient of titanium nitride and increases the wear life of titanium nitride.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. A preparation method of titanium nitride-based self-releasing carbon lubricating composite coating, comprising the following steps: Deposit a porous titanium nitride coating on the substrate; the deposition is multi-arc ion plating deposition, with a titanium metal target as the target material, and nitrogen as the working gas. During the deposition process, the substrate normal and the titanium metal target method The included angle of the line is 75-85°; Soaking the porous titanium nitride coating in an aqueous carbon source solution for hydrothermal treatment to obtain a titanium nitride coating composited with a carbon precursor; The titanium nitride coating compounded with the carbon precursor is carbonized in a protective atmosphere to obtain the titanium nitride-based self-releasing carbon lubricating composite coating. 2. The preparation method according to claim 1, wherein the deposition conditions include: the distance between the target and the base is 40-60 mm, the degree of vacuum is 0.2-1.0 Pa, the flow rate of nitrogen is 100-800 sccm, the arc current It is 75~85A, and the deposition time is 30~35min. 3. The preparation method according to claim 1, characterized in that, before depositing the porous titanium nitride coating, further comprising depositing a titanium layer on the substrate. 4. The preparation method according to claim 3, characterized in that the thickness of the titanium layer is 400-500 nm. 5. The preparation method according to claim 1, characterized in that, the carbon source in the carbon source aqueous solution is a small molecular sugar; the concentration of the carbon source aqueous solution is 195-200 g/L. 6 . The preparation method according to claim 1 , characterized in that, the temperature of the hydrothermal treatment is 150-200° C. and the time is 150-240 min. 7 . The preparation method according to claim 1 , wherein the protective atmosphere is argon or nitrogen; the gas flow rate of the protective atmosphere is 60˜150 sccm. 8. The preparation method according to claim 1 or 5, characterized in that the temperature of the carbonization is 500-600° C. and the time is 120-240 min. 9. The titanium nitride-based self-releasing carbon lubricating composite coating prepared by the preparation method described in any one of claims 1 to 8, comprising a porous titanium nitride coating deposited on the substrate and filled in the porous titanium nitride The carbon lubricating phase in the pores of the coating, the pores of the porous titanium nitride coating are nanoscale. 10. The application of the titanium nitride-based self-releasing carbon lubricating composite coating in claim 9 in lubricating and reducing friction.

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