Periodically dispersed reinforced nanomultilayer carbon-based film, preparation method and application thereof

Abstract

The application discloses a period dispersion reinforced nanometer multilayer carbon-based film, a preparation method and application thereof. The period dispersion reinforced nanometer multilayer carbon-based film comprises a bonding layer, a transition layer and a reinforcing layer; the bonding layer comprises a bonding metal; the transition layer comprises the bonding metal and amorphous carbon; the reinforcing layer comprises periodic first sublayer and second sublayer; the first sublayer comprises amorphous carbon; the second sublayer comprises amorphous carbon and a doped phase, the doped phase comprises carbide and / or nitride and is periodically dispersedly embedded in the second sublayer. The period dispersion reinforced nanometer multilayer carbon-based film effectively reduces the internal stress of the film and greatly improves the toughness and mechanical properties of the film, can effectively improve the thermal stability and high-temperature oxidation resistance of the carbon-based film, and the service temperature is increased to above 550 DEG C; the deposition process adopted in the preparation method is simple, easy to control and low in cost, and is favorable for industrial application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid lubricating coating, in particular to a periodic dispersion strengthening nanolayered carbon-based film, a preparation method and application thereof. BACKGROUND

[0002] Amorphous carbon-based (a-C) films are ideal surface friction protection functional materials in the fields of machinery, electronics, automobiles, aviation, medicine, optics, etc. due to their excellent hardness, low friction, high wear resistance, chemical inertness and corrosion resistance. However, high stress, low toughness, high brittleness and the fact that tribological behavior is greatly affected by the environment are still the main factors restricting the practical process of such composite films.

[0003] Studies have shown that the coherent, semi-coherent and non-coherent strain at the hetero-interface in the multilayer structure of nanolayered films can significantly reduce the stress in the film; at the same time, a large number of hetero-layer interfaces can effectively inhibit crack propagation, thereby improving the toughness, hardness, fracture toughness and wear resistance of the film. In addition, the incorporation of hetero-elements or compounds into amorphous carbon-based films can effectively improve the comprehensive performance of amorphous carbon-based films and enhance the tribological adaptability of amorphous carbon-based films under harsh service conditions. Through the design of doping components and multilayer structure, although the active control of the basic performance of carbon-based films and the certain extension of the service life have been realized, the amorphous carbon-based film still has a very narrow application temperature range under atmospheric conditions, which has become a serious obstacle to its application. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application aims to provide a periodic dispersion strengthening nanolayered carbon-based film, a preparation method and application thereof.

[0005] To achieve the foregoing application purposes, the technical solutions adopted by the present application comprise:

[0006] In a first aspect, the present application provides a periodic dispersion strengthening nanolayered carbon-based film, which is arranged on the surface of a substrate and comprises a bonding layer, a transition layer and a strengthening layer arranged in sequence along the thickness direction;

[0007] The bonding layer comprises a bonding metal, which is in contact with the substrate;

[0008] The transition layer comprises the bonding metal and amorphous carbon;

[0009] The strengthening layer comprises first sub-layers and second sub-layers arranged periodically along the thickness direction; the first sub-layers comprise amorphous carbon; the second sub-layers comprise amorphous carbon and a doped phase, the doped phase comprises any one or a combination of two or more of carbide, nitride and metal, and is periodically dispersed and embedded in the second sub-layers along the extension direction of the second sub-layers.

[0010] In a second aspect, the present application further provides a method for preparing a periodically dispersion-strengthened nanomultilayer carbon-based film, comprising:

[0011] 1) depositing an adhesive layer on the surface of the substrate, the adhesive layer comprising an adhesive metal;

[0012] 2) depositing a transition layer on the surface of the adhesive layer, the transition layer comprising the adhesive metal and amorphous carbon;

[0013] 3) periodically depositing amorphous carbon on the surface of the transition layer to form a first sublayer and co-depositing amorphous carbon and a doped phase to form a second sublayer, the first sublayer and the second sublayer together constituting a strengthening layer.

[0014] In a third aspect, the present application further provides a wear-resistant component, comprising a substrate and a wear-resistant layer coated on the surface of the substrate, the wear-resistant layer comprising the periodically dispersion-strengthened nanomultilayer carbon-based film described above.

[0015] Based on the technical solution described above, the present application has at least the following advantages over the prior art:

[0016] The periodically dispersion-strengthened nanomultilayer carbon-based film provided by the present application has a brand-new nanomultilayer composite structure formed by overlapping the first sublayer of amorphous carbon and the second sublayer of periodically dispersed and doped phase, which realizes the integration of the advantages of nanomultilayer structure and periodic dispersion strengthening and doping, effectively reduces the internal stress of the film and greatly improves the toughness and mechanical properties of the film; the doped phase is periodically and dispersion-embedded in the amorphous carbon to form the second sublayer, which effectively improves the thermal stability and high-temperature oxidation resistance of the carbon-based film, effectively improves the deterioration of the tribological properties of the film in the medium temperature range (150-250℃), and further increases the service temperature of the carbon-based film and the component comprising the film to above 550℃.

[0017] In addition, the deposition process used in the preparation method provided by the present application is simple, easy to control and low in cost, which is conducive to industrial application.

[0018] The above description is only a summary of the technical solution of the present application. In order for those skilled in the art to more clearly understand the technical means of the present application and can implement it according to the content of the description, the following describes the preferred embodiments of the present application with reference to the detailed drawings as follows. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a cross-sectional structure schematic diagram of a periodically dispersion-strengthened nanomultilayer carbon-based film provided by a typical embodiment of the present application;

[0020] Figure 2a is a cross-sectional structure electron microscope photo of a nanodoped carbon-based film provided by a comparative embodiment of the present application;

[0021] Figure 2b is a cross-sectional structure electron microscope photo of a nanometer multilayer carbon-based film provided by another comparative embodiment of the present application;

[0022] Figure 2c is a cross-sectional structure electron microscope photo of a periodic dispersion strengthening nanometer multilayer carbon-based film provided by a typical embodiment of the present application;

[0023] Figure 3 is a mechanical performance comparison test chart of a nanometer doped carbon-based film provided by some typical comparative and embodiment cases of the present application;

[0024] Figure 4 is a high temperature tribological performance evaluation test chart of a nanometer doped carbon-based film provided by some typical comparative and embodiment cases of the present application. DETAILED DESCRIPTION

[0025] In view of the deficiencies in the prior art, the present inventors have made long-term research and a large number of practices, and thus have come up with the technical solution of the present application. The technical solution, its implementation process and principles will be further explained as follows.

[0026] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, however, the present application can also be implemented in other manners different from those described herein, and thus, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0027] Moreover, the relationship terms such as “first” and “second” are merely used to distinguish one from another of the components or method steps having the same name, and do not necessarily require or imply any such actual relationship or sequence between these components or method steps.

[0028] The carbide or nitride is mixed in the same crystal structure by ionic bond, covalent bond and metal bond, and thus they have many unique physicochemical properties, especially high hardness, high temperature oxidation resistance and wear resistance, and if they are embedded in the amorphous carbon-based network, the mechanical properties of the carbon-based film will be greatly enhanced, the thermal stability and oxidation resistance will be improved, and the application temperature range will be further widened.

[0029] The present inventors found that if transition metal carbide or nitride is uniformly dispersed in amorphous carbon matrix in ultrafine particles by regulating key deposition parameters to prepare a dispersion strengthened doped amorphous carbon matrix film, the mechanical properties and thermal stability of the film can be greatly enhanced, and the wide temperature range tribological properties can be improved. Furthermore, if a new composite nanolayer structure is formed by alternately arranging amorphous carbon nanolayers and periodic dispersion amorphous carbon nanolayers, the performance advantages of the two can be integrated, and the mechanical properties, thermal stability and wide temperature range tribological properties of the amorphous carbon matrix film can be greatly improved.

[0030] Thus, the technical scheme of the present application is proposed, and a new periodic dispersion strengthened nanolayer carbon matrix film and a preparation method thereof are provided. The present application realizes great improvement in the mechanical properties and tribological properties of the film by arranging undoped amorphous carbon nanolayers and periodic dispersion amorphous carbon nanolayers to form a new periodic dispersion strengthened nanolayer carbon matrix film. The technical scheme of the present application is described in more detail as follows.

[0031] Referring to Figure 1 The embodiment of the present application provides a periodic dispersion strengthened nanolayer carbon matrix film arranged on the surface of a substrate, which comprises a bonding layer, a transition layer and a strengthening layer arranged in sequence along the thickness direction; the bonding layer comprises a bonding metal in contact with the substrate; the transition layer comprises the bonding metal and amorphous carbon; the strengthening layer comprises first sublayers and second sublayers arranged in sequence along the thickness direction; the first sublayers comprise amorphous carbon; the second sublayers comprise amorphous carbon and a doped phase, the doped phase comprises any one or a combination of two or more of carbide, nitride and metal, and is periodically dispersed and embedded in the second sublayer along the extension direction of the second sublayer.

[0032] The main function of the bonding layer is to improve the bonding strength of the strengthening layer on the surface of the substrate, and a metal matching the material of the substrate is preferably used. For example, the bonding metal can comprise traditional Cr, Ti and other metals, and other metals such as Nb and Mo can also achieve the corresponding technical effects. Those skilled in the art can select appropriate materials by referring to the existing methods for constructing a bonding layer on a substrate, which are not limited to the examples shown in the embodiment of the present application, and can achieve the corresponding functions. In addition, the material of the substrate can also be appropriately adjusted, which is not limited to the examples shown in the present application.

[0033] The doped phase is preferably carbide and / or nitride, and metal doping can also have a similar effect.

[0034] In some embodiments, the thickness of the bonding layer can be 0.2-0.3 μm, the thickness of the transition layer can be 0.3-0.5 μm, and the thickness of the strengthening layer can be 2.0-4.0 μm.

[0035] In some embodiments, the modulation ratio of the first sub-layer to the second sub-layer can be 1:(0.75-1.25), and the modulation period can be 3-10 nm. The modulation ratio refers to the thickness ratio of the first sub-layer to the second sub-layer, and the modulation period refers to the total thickness of the first sub-layer and the second sub-layer in one cycle.

[0036] In some embodiments, the interface material of the substrate in contact with the bonding layer can be metal. The substrate can be all metal, or only the surface layer can be metal.

[0037] In some embodiments, the carbide can include any one or a combination of two or more of WC, TiC, SiC, and B4C.

[0038] In some embodiments, the nitride can include any one or a combination of two of TiN and Si3N4.

[0039] In some embodiments, in the transition layer, the content of the bonding metal gradually decreases and the content of amorphous carbon gradually increases in the thickness direction.

[0040] Embodiments of the present application also provide a preparation method of a periodically dispersion-strengthened nanomultilayer carbon-based film, including the following steps:

[0041] 1) Depositing a bonding layer on the surface of a substrate, wherein the bonding layer includes a bonding metal.

[0042] 2) Depositing a transition layer on the surface of the bonding layer, wherein the transition layer includes the bonding metal and amorphous carbon.

[0043] 3) Periodically depositing amorphous carbon on the surface of the transition layer to form a first sub-layer, and co-depositing amorphous carbon and a doped phase to form a second sub-layer, wherein the first sub-layer and the second sub-layer together constitute a strengthening layer.

[0044] As some typical application examples of the above technical solutions, the non-equilibrium magnetron sputtering technology can be used to sequentially deposit a metal bonding layer, a doped gradient transition layer, and a periodically dispersion-strengthened layer on the surface of a metal substrate, thereby preparing the novel periodically dispersion-strengthened nanomultilayer carbon-based film.

[0045] In some embodiments, step 2) can specifically include: using a non-equilibrium magnetron sputtering bonding metal target and a graphite target to form a transition layer; wherein the target current of the bonding metal target gradually decreases, and the target current of the graphite target gradually increases. Thus, a gradient transition layer is formed, in which the content of the bonding metal gradually decreases and the content of carbon gradually increases from the inside to the outside.

[0046] In some embodiments, the target current of the bonding metal target can be linearly decreased from 2.0-4.0 A to 0 A and the target current of the graphite can be linearly increased from 0 A to 3.0-3.5 A within a deposition time of 15-30 min.

[0047] In some embodiments, step 3) can specifically include: forming the periodically laminated first sub-layer and second sub-layer by using a non-equilibrium magnetron sputtering graphite target and periodically sputtering a doped target; wherein the substrate rotation speed during deposition of the second sub-layer is lower than that during formation of the first sub-layer.

[0048] In some embodiments, the substrate rotation speed during deposition of the first sub-layer can be 4-8 rpm and the substrate rotation speed during deposition of the second sub-layer can be 1-4 rpm.

[0049] In some embodiments, the target current of the graphite target can be 3.0-3.5 A and the target current of the doped target can be 0.3-0.8 A.

[0050] In some embodiments, the deposition time of the first sub-layer can be 0.5-2 min and the deposition time of the second sub-layer can be 0.5-2 min.

[0051] In some embodiments, the preparation method further includes the steps of cleaning and surface etching the substrate.

[0052] As some typical application examples of the above technical solutions, the preparation method can be specifically implemented by using the following steps:

[0053] Step S1, ultrasonic cleaning the substrate and activating the metal substrate surface with Ar+.

[0054] Step S2, depositing a metal bonding layer on the activated surface by using a non-equilibrium magnetron technique.

[0055] Step S3, simultaneously sputtering a metal target and a graphite target to deposit a doped gradient transition layer on the surface of the metal bonding layer.

[0056] Step S4, sputtering a graphite target to prepare an amorphous carbon nanolayer on the surface of the doped gradient transition layer as the first sub-layer.

[0057] Step S5, simultaneously sputtering a graphite target and a doped target to prepare a periodically dispersed amorphous carbon nanolayer on the surface of the amorphous carbon nanolayer as the second sub-layer.

[0058] Step S6, according to the requirement, the repeating steps S4 and S5 are sequentially and circularly executed, the total deposition time is 3.5h-6.5h, a new type of periodic dispersion nanostrengthening layer composed of amorphous carbon nanolayers and periodic dispersion amorphous carbon nanolayers is prepared, and then a new type of periodic dispersion strengthening nanomultilayer carbon-based film is prepared.

[0059] Specifically, in step S1, the metal substrate to be deposited can be sequentially ultrasonically cleaned with petroleum ether, acetone and anhydrous alcohol for 15 min, and then dried by blowing dry N2 gas and sent into the deposition cavity and placed on a sample holder which can rotate. After being introduced into the vacuum deposition cavity, the vacuum degree is extracted to 2x10 -4 -6x10 -5 Pa, then high-purity Ar gas with a gas flow of 15-20sccm is introduced, and the surface of the ultrasonic cleaning substrate is Ar + etched for more than 30 min to remove impurities on the surface of the sample and activate the surface of the substrate.

[0060] Specifically, in step S2, after the surface activation of the metal substrate is completed, high-purity Ar gas can be continuously introduced and the vacuum degree is maintained at 0.5-1.5 Pa, the negative bias is -50 to -100 V, the duty cycle is 50%, the metal target current is 2.0-4.0 A, and the deposition time is 5-15 min, and then a metal bonding layer is prepared on the surface of the metal substrate.

[0061] Specifically, in step S3, high-purity Ar gas can be continuously introduced and the vacuum degree is maintained at 0.5-1.5 Pa, the negative bias is -50 to -70 V, the metal target current is linearly reduced from 2.0-4.0 A to 0 A within 15-30 min, while the graphite target current is linearly increased from 0 A to 3.0-3.5 A, and the sample holder rotates at 5 rpm, and then a doped transition layer is prepared on the surface of the metal bonding layer.

[0062] Specifically, in step S4, high-purity argon gas can be continuously introduced, the negative bias is -50 to -70 V, the graphite target current is 3.0-3.5 A, the deposition time is 0.5-2 min, and the sample rotates at 4-8 rpm, and then an amorphous carbon nanolayer is prepared on the surface of the doped transition layer as a first sublayer.

[0063] Specifically, in step S5, high-purity argon gas can be continuously introduced, the negative bias is -50 to -70 V, the graphite target current is 3.0-3.5 A, the doped target current is 0.3-0.8 A, the deposition time is 0.5-2.0 min, and the sample holder rotates at 1-4 rpm, and then a periodic dispersion amorphous carbon nanolayer is prepared on the surface of the amorphous carbon nanolayer as a second sublayer.

[0064] The application also provides a wear-resistant component, comprising a substrate and a wear-resistant layer coated on the surface of the substrate, wherein the wear-resistant layer comprises the periodic dispersion strengthening nanomultilayer carbon-based film according to any one of the embodiments.

[0065] In some embodiments, the failure temperature of the wear-resistant component is above 550℃. The failure may be, for example, a sudden increase of the average friction coefficient by a factor of 1.5 or more in the range of 50℃ as the temperature rises, for example Figure 4 a sudden increase of 1.5 or more, and the like.

[0066] The technical solutions of the application are further described in detail below by means of several embodiments and in conjunction with the drawings. However, the selected embodiments are only used to illustrate the application and do not limit the scope of the application.

[0067] Embodiment 1

[0068] This embodiment illustrates a preparation process of a periodic dispersion strengthening nanomultilayer carbon-based film, and the process is as follows:

[0069] (1) Ultrasonic cleaning of the metal substrate and Ar+ etching activation

[0070] First, the high-speed steel substrate to be deposited is sequentially ultrasonically cleaned with petroleum ether, acetone and anhydrous alcohol for 15 minutes, and then dried with dry N2 gas and placed on the sample holder in the deposition chamber. After the vacuum deposition chamber is introduced, the vacuum degree is extracted to 2×10 -4 -6×10 -5 Pa (the vacuum degree may fluctuate up and down, the same below), high-purity Ar gas with a flow rate of 16 sccm is introduced, the negative bias is set to -500V, the duty cycle is 50%, and the metal substrate surface is plasma glow etched and activated for 30 minutes.

[0071] (2) Preparation of Cr adhesive layer

[0072] After the activation of the metal substrate surface, high-purity Ar gas is continuously introduced and the vacuum degree is maintained between 0.5-1.5 Pa, the negative bias is -70V, the duty cycle is 50%, the Cr metal target current is 4.0 A, and the deposition time is 10 minutes, so as to prepare a metal Cr adhesive layer with a thickness of 0.2-0.3 μm on the metal substrate surface.

[0073] (3) Preparation of doped gradient transition layer

[0074] Continue to pass high-purity argon gas and maintain the vacuum degree in the range of 0.5-1.5 Pa, the negative bias is -70 V, within 20 min, the metal target current is linearly reduced from 4.0 A to 0 A, while the graphite target current is linearly increased to 3.5 A, the sample holder rotation speed is 5 rpm, and then a doped gradient transition layer with a thickness of 0.2-0.4 μm is prepared on the surface of the metal bonding layer.

[0075] (4) Amorphous carbon (a-C) sublayer preparation

[0076] Continue to pass high-purity argon gas, the negative bias is -70 V, the graphite target current is 3.5 A, the deposition time is 1 min, and the sample rotation speed is 5 rpm, and then an amorphous carbon (a-C) sublayer with a thickness of 2.0-3.0 nm is prepared on the surface of the doped gradient layer as a first sublayer.

[0077] (5) Periodic dispersion amorphous carbon (a-C:WC) nanosublayer preparation

[0078] Continue to pass high-purity argon gas, the negative bias is -70 V, and one graphite target and one WC doped target are sputtered, the graphite target current is maintained at 3.5 A, the WC doped target current is 0.3 A, the deposition time is 50 s, and the sample holder rotation speed is 1.1 rpm, and then a periodic dispersion amorphous carbon (a-C:WC) nanosublayer with a thickness of 2.0-2.5 nm is prepared on the surface of the amorphous carbon nanosublayer as a second sublayer.

[0079] (6) Periodic dispersion strengthening nanomultilayer preparation

[0080] The repeating step (4) and step (5) are sequentially cycled for a total of 6 h, and a nanocomposite multilayer strengthening layer composed of amorphous carbon (a-C) nanosublayers and periodic dispersion amorphous carbon (a-C:WC) nanosublayers is prepared, the thickness of the strengthening layer is 2.0-3.0 μm, and a novel periodic dispersion strengthening nanomultilayer carbon-based thin film is obtained, which is denoted as a-C / (a-C:WC).

[0081] It should be noted that due to the limitation of the plating process, the film layer naturally has a non-uniform thickness, which is a common phenomenon in plating, therefore, the thickness of each film layer obtained by testing is a narrow range value, rather than a specific single numerical value.

[0082] The cross-sectional morphology of the periodic dispersion strengthening nanomultilayer carbon-based thin film prepared in this embodiment is shown in FIG. 1. Figure 2c As can be clearly seen, it has a periodic layering structure in the thickness direction and a periodic inlaid doping structure in the extension direction, the combination of the periodic structures in the two different directions can provide excellent mechanical properties and wear resistance for the thin film, and also provides excellent wide-temperature-range adaptability, especially high-temperature adaptability.

[0083] Example 2

[0084] This embodiment illustrates a preparation process of a periodic dispersion strengthened nanomultilayer carbon-based film, which is specifically shown as follows:

[0085] (1) Ultrasonic cleaning of the metal substrate and Ar + Etching activation

[0086] The step (1) is the same as that in Example 1.

[0087] (2) Preparation of the Cr adhesive layer

[0088] The step (2) is the same as that in Example 1.

[0089] (3) Preparation of the doped gradient transition layer

[0090] The step (3) is the same as that in Example 1.

[0091] (4) Preparation of the amorphous carbon (a-C) nanolayer

[0092] Continue to introduce high-purity argon, the negative bias is -70 V, the graphite target current is 3.5 A, the deposition time is 1 min, and the sample rotation speed is 5 rpm, so as to prepare an amorphous carbon (a-C) nanolayer with a thickness of 2.0-3.0 nm on the surface of the doped gradient transition layer.

[0093] (5) Preparation of the periodic dispersion amorphous carbon (a-C:SiC) nanolayer

[0094] Continue to introduce high-purity argon, the negative bias is -70 V, and one graphite target and one SiC doped target are sputtered at the same time, the graphite target current is 3.5 A, the SiC doped target current is 0.5 A, the deposition time is 40 s, and the sample holder rotation speed is 1.5 rpm, so as to prepare a periodic dispersion amorphous carbon (a-C:SiC) nanolayer with a thickness of 2.5-3.5 nm on the surface of the amorphous carbon nanolayer.

[0095] (6) Preparation of the periodic dispersion strengthened nanomultilayer

[0096] The steps (4) and (5) are sequentially and repeatedly performed for a total of 5 h, so as to prepare a nanocomposite multilayer strengthened layer composed of the amorphous carbon (a-C) nanolayer and the periodic dispersion amorphous carbon (a-C:SiC) nanolayer alternately, and the thickness of the strengthened layer is 2.0-3.0 μm, that is, a new periodic dispersion strengthened nanomultilayer a-C / (a-C:SiC) carbon-based film.

[0097] Example 3

[0098] This embodiment illustrates a preparation process of a periodic dispersion strengthened nanomultilayer carbon-based film, which is basically the same as that in Example 1, and the only difference is that:

[0099] The WC doped target in step (5) is replaced by a B4C target.

[0100] The prepared periodic dispersion strengthened nanomultilayer carbon-based film has the same high-temperature wear resistance as that of Example 1.

[0101] Example 4

[0102] The preparation process of the periodic dispersion strengthened nanomultilayer carbon-based film in this example is basically the same as that of Example 1, with the only difference being that:

[0103] The high-speed steel substrate in step (1) is replaced by a titanium alloy substrate.

[0104] The Cr target in step (2) is replaced by a Ti metal target.

[0105] The prepared periodic dispersion strengthened nanomultilayer carbon-based film has the same high-temperature wear resistance as that of Example 1.

[0106] Example 5

[0107] The preparation process of the periodic dispersion strengthened nanomultilayer carbon-based film in this example is basically the same as that of Example 4, with the only difference being that:

[0108] The WC doped target in step (5) is replaced by a TiN target.

[0109] The prepared periodic dispersion strengthened nanomultilayer carbon-based film has the same high-temperature wear resistance as that of Example 1.

[0110] Comparative Example 1

[0111] The preparation process of the conventional nanodoped carbon-based film in this comparative example is specifically as follows:

[0112] (1) Ultrasonic cleaning of metal substrate and Ar+ etching activation

[0113] The same as step (1) in Example 1.

[0114] (2) Preparation of Cr adhesive layer

[0115] The same as step (2) in Example 1.

[0116] (3) Preparation of doped gradient transition layer

[0117] The same as step (3) in Example 1.

[0118] (4) Preparation of nanodoped a-C:WC film

[0119] Continue to pass high-purity argon gas, while sputtering a graphite target and a WC doping target, the negative bias is -70V, the graphite target current is 3.5A, the WC target current is 0.3A, the sample holder rotation speed is 5rmp, and the deposition time is 6h, thereby preparing a nanodoped film with a thickness of 2.0-3.5μm on the surface of the doping gradient transition layer, denoted as a-C:WC.

[0120] The cross-sectional morphology of the nanodoped film provided by the present comparative example is shown in Figure 2a It can be seen that it contains a periodic mosaic doping phase in the extension direction, but does not contain a periodic laminated structure in the thickness direction.

[0121] Comparative Example 2

[0122] The present comparative example illustrates the preparation process of a nanomultilayer carbon-based film, which is specifically as follows:

[0123] (1) Ultrasonic cleaning of metal substrate and Ar+ etching activation

[0124] The same as step (1) in Example 1.

[0125] (2) Preparation of Cr adhesive layer

[0126] The same as step (2) in Example 1.

[0127] (3) Preparation of doping gradient layer

[0128] The same as step (3) in Example 1.

[0129] (4) Preparation of nanomultilayer a-C / WC film

[0130] Continue to pass high-purity argon gas, while sputtering a graphite target and a WC doping target, the negative bias is -70V, the graphite target current is 3.5A, the WC target current is 0.75A, the sample holder rotation speed is 1.1rmp, and the deposition time is 6h, thereby preparing a nanomultilayer film with a thickness of 2.0-3.0μm on the surface of the doping gradient layer, denoted as a-C / WC.

[0131] Compared with Comparative Example 1, the main change of the present comparative example is the rotation speed of the sample holder, thereby forming a film layer structure different from that of Comparative Example 1; specifically: when the deposition rack rotates relatively fast, such as 5rmp in Comparative Example 1, the film layer structure will form the nanodoped structure shown in Comparative Example 1; when the deposition rack rotates relatively slowly, such as 1.1rmp in the present comparative example, because the placement positions of the two target materials are usually far apart, for example, the deposition targets are oppositely placed, the time interval corresponding to the two target materials at a specific position in the film layer will be prolonged, thereby forming a nanomultilayer structure.

[0132] And by increasing the WC target current, the multilayer structure formed is also different from that of Example 1. Since the deposition rate of the WC target in the present comparative example is much faster than that of Example 1, the periodic dispersion nanolayer of amorphous carbon (a-C:WC) in Example 1 is not formed, but after the amorphous carbon layer is formed on the graphite target, the WC layer is directly formed on the amorphous carbon layer to form an a-C / WC layer structure with each layer having a single material.

[0133] Of course, if the equipment structure is limited in actual application, the two target materials are close to each other, and the above-mentioned layer structure cannot be generated by adjusting the rotation speed. The film layer with the same structure can also be formed by alternately switching the target current. This alternative embodiment can be changed by those skilled in the art with reference to the existing preparation technology of laminated film. The present comparative example mainly illustrates the performance difference caused by the different film layer structures, and is not limited to the specific structure preparation method.

[0134] The cross-sectional morphology of the nanodoped film provided by the present comparative example is shown in FIG. 4. Figure 2b As can be seen from FIG. 4, the film contains a periodic layer structure in the thickness direction, but does not contain a periodic inlaid doped phase in the extension direction.

[0135] Figure 3 The comparative test results of the hardness and elastic modulus of the films of Example 1, Comparative Example 1 and Comparative Example 2 are shown in FIG. 3. As can be seen from FIG. 3, the hardness and elastic modulus of the periodic dispersion strengthened nanomultilayer carbon-based film having a periodic structure in two directions of thickness and width are significantly higher than those of Comparative Example 1 and Comparative Example 2 having a periodic structure in only one direction.

[0136] Figure 4 The friction performance-temperature relationship curves of Example 1, Comparative Example 1 and Comparative Example 2 are shown in FIG. 5. As can be seen from FIG. 5, the temperature resistance performance of the conventional nanocomposite carbon-based film provided by Comparative Example 1 and Comparative Example 2 is poor, and the failure temperature is generally below 450°C. The failure temperature of the periodic dispersion strengthened nanomultilayer carbon-based film having a periodic structure in two directions of thickness and width is above 550°C, which is significantly higher than that of Comparative Example 1 and Comparative Example 2.

[0137] Comparative Example 3

[0138] (1) Ultrasonic cleaning of metal substrate and Ar + Etching activation

[0139] The step (1) is the same as that in Example 1.

[0140] (2) Preparation of Cr adhesive layer

[0141] The step (2) is basically the same as that in Example 2. The current of the Cr metal target is rapidly reduced from 4.0 A to 0 A within 10 s before the deposition is completed.

[0142] (3) The transition layer was prepared substantially the same as step (4) in Example 1, but the graphite target current was quickly increased from 0 A to 3.5 A within 10 s before the deposition started, instead of linearly increasing.

[0143] (4) Preparation of amorphous carbon nanometer (a-C) sublayer

[0144] The same as step (4) in Example 1.

[0145] (5) Preparation of nanometer doped amorphous carbon (a-C-WC) nanometer sublayer

[0146] The same as step (5) in Example 1.

[0147] (6) Preparation of a-C / (a-C:WC) nanometer multilayer

[0148] The repeating step (4) and step (5) were sequentially and cyclically performed for a total of 6 h to prepare a periodic dispersion strengthening nanometer multilayer carbon-based film without a gradient transition layer. The thermal stability and high-temperature tribological performance of the film layer will decrease to some extent due to the absence of the gradient transition layer. Of course, the bonding layer and the gradient transition layer are the conventional choices in the field when performing film plating, and the main technical means of the present application is still how to form a periodically dispersed strengthening layer structure, rather than being limited to how to prepare the gradient transition layer. Using other methods to prepare the bonding layer and the gradient transition layer with the same function still falls within the protection scope of the present application.

[0149] In addition, the present inventors also experimented with an embodiment in which the sample holder speed was not adjusted in step (5), but still maintained at 5 rpm in step (4) for film layer preparation. In this case, the periodicity in the width direction of the film layer is relatively poor, and the particle size distribution is also not very uniform, and the high-temperature friction performance is also not good. Therefore, it is not meaningful to very accurately characterize the specific friction performance, and thus specific comparative experimental cases and test results are not shown.

[0150] Based on the analysis and testing of the above examples and comparative examples, it can be clearly seen that the periodic dispersion strengthening nanometer multilayer carbon-based film provided by the examples of the present application realizes the integration of the advantages of the nanometer multilayer structure and the periodic dispersion strengthening doping by overlapping the first sublayer of amorphous carbon with the second sublayer of periodically dispersed composite doping, effectively reduces the internal stress of the film, and greatly improves the toughness and mechanical properties of the film. The doped phase is periodically dispersedly embedded in the amorphous carbon to form a periodically dispersed second sublayer, which can effectively improve the thermal stability and high-temperature oxidation resistance of the carbon-based film, effectively improve the deterioration of the tribological performance of the film in the medium temperature range (150℃-250℃), and further increase the service temperature of the carbon-based film and the member containing the film to 550℃.

[0151] In addition, the deposition process adopted in the preparation method is simple, easy to control and low in cost, and is favorable for industrial application.

[0152] It should be understood that the above embodiments are only to illustrate the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made in accordance with the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A periodic dispersion strengthened nanomultilayer carbon-based film coated on a surface of a substrate, characterized in that, The wear-resistant layer comprises a bonding layer, a transition layer and a strengthening layer which are sequentially stacked along a thickness direction; The bonding layer comprises a bonding metal, and the bonding metal is in contact with the substrate; The transition layer comprises the bonding metal and amorphous carbon; The strengthening layer comprises first sub-layers and second sub-layers which are periodically stacked along the thickness direction, a modulation ratio of the first sub-layers to the second sub-layers is 1:(0.75-1.25), and a modulation period is 3-10 nm; the first sub-layers are amorphous carbon; the second sub-layers comprise amorphous carbon and a doped phase, the doped phase comprises any one or a combination of two or more of carbide, nitride and metal, and the doped phase is periodically and dispersedly embedded in the second sub-layers along an extension direction of the second sub-layers; the carbide comprises any one or a combination of two or more of WC, TiC, SiC and B4C; the nitride comprises any one or a combination of two of TiN and Si3N4.

2. The periodically dispersedly strengthened nanomultilayer carbon-based thin film according to claim 1, characterized in that, The thickness of the bonding layer is 0.2-0.3 μm, the thickness of the transition layer is 0.3-0.5 μm, and the thickness of the strengthening layer is 2.0-4.0 μm.

3. The periodically dispersedly strengthened nanomultilayer carbon-based thin film according to claim 1, characterized in that, An interface material of the substrate in contact with the bonding layer is metal.

4. The periodically dispersedly strengthened nanomultilayer carbon-based thin film according to claim 1, characterized in that, Along the thickness direction, the content of the bonding metal in the transition layer gradually decreases, and the content of the amorphous carbon gradually increases.

5. A method of producing the periodic dispersion-strengthened nanomultilayer carbon-based film according to any one of claims 1 to 4, characterized by, The method comprises the following steps: 1) depositing a bonding layer on a surface of a substrate, the bonding layer comprising a bonding metal; 2) depositing a transition layer on the bonding layer, the transition layer comprising the bonding metal and amorphous carbon; 3) periodically depositing the amorphous carbon to form first sub-layers and co-depositing the amorphous carbon and a doped phase to form second sub-layers, the first sub-layers and the second sub-layers together forming a strengthening layer.

6. The production method according to claim 5, wherein Step 2) specifically comprises: using a non-equilibrium magnetron sputtering bonding metal target and a graphite target to form the transition layer; wherein a target current of the bonding metal target gradually decreases, and a target current of the graphite target gradually increases.

7. The preparation method according to claim 6, characterized in that, In a deposition time of 15-30 min, the target current of the bonding metal target linearly decreases from 2.0-4.0 A to 0 A, and the target current of the graphite target linearly increases from 0 A to 3.0-3.5 A.

8. The preparation method according to claim 6, characterized in that, Step 3) specifically comprises: using a non-equilibrium magnetron sputtering graphite target and a periodic sputtering doped target to form the periodically stacked first sub-layers and second sub-layers; wherein a substrate rotation speed during deposition of the second sub-layers is lower than a substrate rotation speed during deposition of the first sub-layers.

9. The production method according to claim 8, characterized by, The substrate rotation speed during deposition of the first sub-layers is 4-8 rpm, and the substrate rotation speed during deposition of the second sub-layers is 1-4 rpm.

10. The preparation method according to claim 8, characterized in that, The target current of the graphite target is 3.0-3.5 A, and the target current of the doped target is 0.3-0.8 A.

11. The preparation method according to claim 8, characterized in that, The deposition time of the first sub-layers is 0.5-2 min, and the deposition time of the second sub-layers is 0.5-2 min.

12. The method of claim 6, wherein, The method further comprises: a step of cleaning and surface etching the substrate; the total deposition time of the first sub-layers and the second sub-layers is 3.5-6.5 h.

13. A wear member comprising a substrate and a wear resistant layer disposed on a surface of the substrate, characterized in that, The wear-resistant layer comprises the periodically dispersedly strengthened nanometer multilayer carbon-based film according to any one of claims 1-4.

14. The wear member of claim 13, wherein, The failure temperature of the wear-resistant member is above 550 ℃.

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