A method for constructing a high-bonding and high-load-bearing carbon-based lubricating film interface on a rubber surface

Abstract

This invention discloses a method for constructing a high-bonding, high-load-bearing carbon-based lubricating film interface on a rubber surface. The method involves pre-constructing micron-sized pores on the rubber surface using laser etching, followed by in-situ co-implantation of metal and carbon elements to form a reinforcing layer, and finally depositing a carbon film on the reinforced rubber surface. This invention employs in-situ ion co-implantation to texture the surface. This co-implanted layer serves as both a reinforcing layer and an in-situ load-bearing layer, avoiding the risk of interlayer peeling present in load-bearing layers deposited on rubber surfaces. Furthermore, the reinforced textured surface achieves a near-mechanical interlocking effect with the carbon film, significantly improving the film's bonding strength and preventing lateral peeling under high tangential forces. This invention effectively overcomes the technical defects of lateral peeling between the bonding and load-bearing layers deposited on soft rubber surfaces. The process is easy to control and highly operable, resulting in a high-bonding, high-load-bearing carbon-based lubricating film on the rubber surface, making it suitable for large-scale industrial applications.

Description

Technical Field

[0001] This invention relates to a method for constructing a high-bonding, high-load-bearing carbon-based lubricating film interface on a rubber surface, and more particularly to a method for constructing an interface with high bonding and high load-bearing properties of a carbon-based solid lubricating film on a rubber surface through surface texturing and in-situ ion co-injection, which is used for the preparation of dynamic sealing components and belongs to the fields of solid lubricating materials and tribology. Background Technology

[0002] Modern industrial equipment contains numerous sealing devices to prevent leakage of working media and the intrusion of external dust and foreign objects. Leakage of the sealed media can lead to material loss and equipment damage, or even fire and explosion. Most dynamic seal leakage accidents are related to the failure of the seal itself. Rubber, with its excellent elasticity and compressive strength, is the most commonly used sealing material. However, after being installed in the sealing groove, rubber dynamic seals are deformed by the high-pressure medium and experience extremely high friction (µ>1) due to the frictional heat generated by the frictional contact with the steel groove wall and sealing rod under cyclic stress. This high friction easily softens the rubber seal and causes rapid wear and failure, allowing the high-pressure sealing medium to leak from the damaged area, affecting the safe and reliable operation of the equipment. Therefore, solving the problem of rubber seal wear and failure must start with reducing friction.

[0003] Carbon thin films possess excellent properties such as low adhesion to steel, low deposition temperature (≤100℃, preventing fatal damage to the nitrile rubber matrix), controllable composition and mechanical strength, diverse structures (e.g., multi-micro / nano structures, multi-element doping), and low friction and wear, making them ideal coatings for achieving low friction on rubber surfaces. However, rubber is a soft substrate, while carbon thin films are hard films. Ensuring that the hard film on the soft surface does not mechanically fracture under ultra-high loads (high load-bearing capacity) and does not peel off tangentially (high bonding properties) is crucial for achieving low friction on rubber surfaces. Traditional methods to improve load-bearing capacity and bonding involve depositing a bonding layer and a hard intermediate load-bearing layer on the rubber surface. However, each intermediate layer deposited changes the bonding interface from the rubber substrate-carbon film interface to two interfaces: the intermediate layer-rubber substrate interface and the intermediate layer-carbon film interface. This inherently increases the risk of tangential peeling under ultra-high loads. Therefore, constructing a high-bonding, high-load-bearing interface is paramount to ensuring the high reliability and long service life of carbon-based lubricating films on rubber surfaces.

[0004] To address this, Chinese invention patent CN202110538498.7 discloses a method for constructing a high-load-bearing, low-friction rubber surface through in-situ ion co-implantation. This method uses metal and carbon targets as ion co-implantation materials, employs a vacuum arc ion source, and in-situ co-implants metal and carbon elements onto the rubber surface as a load-bearing layer, followed by carbon element injection, thereby obtaining a high-load-bearing, low-friction rubber surface. This invention utilizes in-situ ion co-implantation technology, avoiding the risk of interlayer peeling associated with deposited load-bearing layers on the rubber surface. The gradual change in ion concentration during implantation successfully achieves a natural transition in mechanical hardness from the soft rubber substrate to the hard carbon film, avoiding the risk of film breakage and peeling under ultra-high loads. The subsequent implantation of only carbon elements ensures perfect lattice matching between the carbon film and the load-bearing layer, thus guaranteeing high bonding strength. However, this method still exhibits tangential peeling under harsh, sealed environments and ultra-high load conditions, indicating that its bonding strength needs further improvement. Summary of the Invention

[0005] The purpose of this invention is to provide a method for constructing a high-bonding, high-load-bearing carbon-based composite lubricating film interface on a rubber surface. This method achieves high bonding and high load-bearing characteristics of the carbon-based solid lubricating film on the rubber surface through surface micro-nano texture and in-situ ion co-implantation, thereby reducing the technical risk of tangential peeling of the existing rubber surface deposited load-bearing layer + carbon film under ultra-high load.

[0006] I. High-bonding, high-load-bearing interface construction of carbon-based lubricating film on rubber surface

[0007] The present invention relates to the construction of a high-bonding, high-load-bearing carbon-based lubricating film on a rubber surface. The process involves first performing micro-nano texturing on the rubber surface, then using metal and carbon targets as ion co-implanting materials, and employing a vacuum arc ion source to co-implant metal and carbon elements in situ on the textured rubber surface to form a load-bearing reinforcement layer. Finally, a Ta-C film is deposited on the reinforced textured rubber surface to obtain a high-bonding, high-load-bearing carbon-based lubricating film on the rubber surface.

[0008] The rubber substrate is one of nitrile rubber, hydrogenated nitrile rubber, silicone rubber and EPDM rubber, with a surface roughness of ≤200nm and a thickness of 3~5mm.

[0009] The method for preparing the micron-sized holes is laser etching, and the laser used in the laser etching method is an ultrashort pulse laser; the shape of the micron-sized holes is circular, rectangular, triangular, and rhomboid; the arrangement of the micron-sized holes includes annular arrangement, crisscross arrangement, or lattice distribution arrangement.

[0010] The size of the micron-sized pores is 10-50 micrometers; the pore depth is 1 / 2 to 2 / 3 of the thickness of the Ta-C film; and the texture area accounts for 20-40% of the total contact area with the entire Ta-C film.

[0011] The method for in-situ injection of metal and carbon elements: vacuuming to 1×10⁻⁶ -6 Pa; adjust the carbon target current to 45~60A, the duty cycle to 40~50%, and the beam current density to 0.48~0.64A / 100cm. 2 •s; Simultaneously, adjust the metal target current to 20A~40A, duty cycle to 50%, and beam current density to 0.3A~0.42A / 100cm. 2 •s, total injection time is 0.5~2 hours; control acceleration voltage -20~-30kV, frequency 1~3 Hz.

[0012] The metal target material is one of Ti, Cr, or W targets, and the carbon target material is a graphite target; the in-situ co-implantation layer depth is 300~1200nm.

[0013] The magnetron sputtering deposition of Ta-C thin films involves: using a graphite target, adjusting the target-substrate distance to 12-15 cm, the target current to 3 A, the argon flow rate to 45-60 sccm, the substrate bias to -300 V, the gas pressure to 1-1.5 Pa, the duty cycle to 40-45%, the frequency to 60-70 kHz, and the deposition time to 10-15 min; the film thickness to be 500-800 nm.

[0014] Figure 1 This is a schematic diagram of the cross-sectional structure of the high-bonding, ultra-low-friction carbon-based composite lubricating film on a rubber surface constructed according to the present invention. As can be seen, the in-situ ion co-implantation textured surface layer serves as both a reinforcing layer and an in-situ load-bearing layer, avoiding the risk of interlayer peeling present in the case of a load-bearing layer deposited on the rubber surface. Furthermore, the reinforced textured surface can achieve a mechanical interlocking effect with the Ta-C film, significantly improving the bonding strength of the film and preventing the risk of lateral peeling due to high tangential forces. The present invention effectively overcomes the technical defects of interlayer lateral peeling in the bonding and load-bearing layers deposited on soft rubber surfaces. Moreover, the process is easy to control and highly operable. The resulting carbon-based lubricating film on the rubber surface possesses high bonding and high load-bearing capacity, making it easy to achieve large-area industrial applications.

[0015] II. Performance of the interface of high-bonding, high-load-bearing carbon-based lubricating film on rubber surface

[0016] 1. Bond strength

[0017] The bonding strength between the film and rubber was tested using the scratch test, and the results showed that the bonding strength reached about 100N, indicating that the film has high bonding strength.

[0018] 2. Load-bearing capacity

[0019] Figure 2 shows the SEM image of the high-load-bearing, low-friction rubber surface constructed according to the present invention. SEM observation of the surface morphology of the wear tracks after friction reveals that the carbon film on the rubber surface without ion implantation experienced severe mechanical brittle fracture during friction, while the surface film of the structure designed in this invention did not exhibit significant brittle fracture under heavy loads of 30-50 N, indicating its high load-bearing characteristics.

[0020] In summary, the present invention has the following advantages compared with the prior art:

[0021] 1. In the later stages, this invention does not simply inject carbon elements or change the ion concentration gradient. Instead, it first creates a micro-nano texture on the rubber surface, and then uses in-situ ion co-implantation to form a ceramic phase to strengthen the textured surface (similar to first making a gear shape and then quenching it). This co-implanted surface layer is both a strengthening layer and an in-situ bearing layer, avoiding the risk of interlayer peeling that exists in bearing layers deposited on the rubber surface. Finally, a Ta-C film is deposited on the strengthened textured surface. The Ta-C film and the hardened textured structure on the rubber surface form an effect similar to mechanical interlocking to improve their bonding performance. This measure significantly improves the bonding strength of the carbon film, thereby reducing the risk of the carbon film peeling laterally under high tangential forces.

[0022] 2. The process of this invention is simple and easy to control, with strong operability. The obtained carbon-based lubricating film on the rubber surface has characteristics such as high bonding and high load-bearing capacity, and can be used for the preparation of dynamic sealing parts, making it easy to achieve large-scale industrial application. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the cross-sectional structure of the high-bonding, high-load-bearing carbon-based lubricating film on the rubber surface of the present invention.

[0024] Figure 2 shows the SEM images of the wear marks on the carbon-based lubricating film (a) constructed by the present invention and the original rubber surface carbon film with untextured + ion co-injection reinforcement (b). Detailed Implementation

[0025] The following specific embodiments further illustrate the interface construction method and performance of the high-bonding, high-load-bearing carbon-based lubricating film on the rubber surface of the present invention.

[0026] Example 1

[0027] (1) Cut a 300×300×2mm black nitrile rubber sheet (surface smoothness Ra<200nm, thickness 3mm) into 30×30mm pieces. 2The rubber sheet was immersed in a 60°C soapy water solution and ultrasonically cleaned for 30 minutes to remove grease and dirt from the rubber surface; then it was removed and immersed in 90-95°C distilled water and ultrasonically cleaned for 30 minutes to remove any remaining soapy water solution; finally, it was dried with dry nitrogen gas and placed in a drying oven at 120°C for 20 minutes to evaporate any remaining moisture from the rubber surface. This process was repeated 5 times.

[0028] (2) Place a metal mask with a circular structure on a clean rubber surface in advance, and use an ultra-short pulse laser to etch circular crisscross micron pits on the rubber surface for later use;

[0029] (3) After etching, remove the metal mask and place the etched rubber substrate into a magnetron sputtering vacuum chamber integrated with a Mevva-V.Ru vacuum arc ion source (Ti and graphite targets are pre-placed in the vacuum chamber as ion co-implanting materials). Close the vacuum chamber door and evacuate the vacuum to ≤1.0×10⁻⁶. –6 Pa; Turn on the DC pulsed arc power supply, adjust the carbon target current to 45A, the duty cycle to 40%, and the beam current density to 0.48A / 100cm. 2 Simultaneously, the metal target current was adjusted to 20 A, the duty cycle to 50%, and the beam current density to 0.42 A / 100 cm⁻¹. 2 •s, injection time is 0.5 hours; control acceleration voltage -20kV, frequency 1Hz;

[0030] (4) Turn off the arc power supply, immediately introduce argon gas (flow rate of 45 sccm), turn on the graphite target sputtering power supply, adjust the target-substrate distance to 12 cm, the target current to 3 A, the substrate bias voltage to -300 V, the gas pressure to 1.0 Pa, the duty cycle to 40%, the frequency to 60 kHz, and the deposition time to 10 min.

[0031] (5) After deposition, the sample was removed after the temperature inside the vacuum chamber cooled to room temperature. The bonding strength of the carbon-based lubricating film on the surface of the nitrile rubber can reach 100N, and no obvious brittle fracture occurred under the heavy-load friction condition of 30N, indicating that it has high bonding and high load-bearing characteristics.

[0032] Example 2

[0033] (1) The pre-cleaning steps for silicone rubber are the same as in Example 1. Wherein: the surface finish of the silicone rubber Ra < 200 nm, and the thickness is 3 mm;

[0034] (2) Place a metal mask with a rhombic structure on a clean rubber surface in advance, and use an ultrashort pulse laser to etch rhombic regular dot matrix micron pits on the rubber surface for later use;

[0035] (3) After etching, remove the metal mask and place the etched rubber substrate into a magnetron sputtering vacuum chamber integrated with a Mevva-V.Ru vacuum arc ion source (a Cr target and a graphite target are pre-placed in the vacuum chamber as ion co-implantation materials). Close the vacuum chamber door and evacuate the vacuum to ≤1.0×10⁻⁶. –6 Pa; Turn on the DC pulsed arc power supply, adjust the graphite target current to 60A, the duty cycle to 50%, and the beam current density to 0.64A / 100cm. 2 Simultaneously, the metal target current was adjusted to 40 A, the duty cycle to 50%, and the beam current density to 0.42 A / 100 cm⁻¹. 2 •s, injection time is 1 hour; control acceleration voltage -30kV, frequency 3Hz;

[0036] (4) Turn off the arc power supply, immediately introduce argon gas (flow rate of 45 sccm), turn on the graphite target sputtering power supply, adjust the target-substrate distance to 12 cm, the target current to 3 A, the substrate bias voltage to -300 V, the gas pressure to 1.0 Pa, the duty cycle to 40%, the frequency to 60 kHz, and the deposition time to 10 min;

[0037] (5) After deposition, the sample was removed after the temperature inside the vacuum chamber cooled to room temperature. The bonding strength of the carbon-based lubricating film on the surface of the silicone rubber can reach 105N, and no obvious brittle fracture occurred under the heavy friction condition of 40N, indicating that it has high bonding and high load-bearing characteristics.

[0038] Example 3

[0039] (1) The pre-cleaning steps for EPDM rubber are the same as in Example 1. Wherein: the surface finish of the rubber Ra < 200 nm, and the thickness is 3 mm;

[0040] (2) Place a metal mask with a triangular structure on a clean rubber surface in advance, and use an ultrashort pulse laser to etch triangular regular dot matrix micron pits on the rubber surface for later use;

[0041] (3) After etching, remove the metal mask and place the etched rubber substrate into a magnetron sputtering vacuum chamber integrated with a Mevva-V.Ru vacuum arc ion source (a Cr target and a graphite target are pre-placed in the vacuum chamber as ion co-implantation materials). Close the vacuum chamber door and evacuate the vacuum to ≤1.0×10⁻⁶. –6 Pa; Turn on the DC pulsed arc power supply, adjust the graphite target current to 60A, the duty cycle to 50%, and the beam current density to 0.64A / 100cm. 2 Simultaneously, the metal target current was adjusted to 40 A, the duty cycle to 50%, and the beam current density to 0.42 A / 100 cm⁻¹. 2 .s, injection time is 2 hours; control acceleration voltage -30kV, frequency 3Hz;

[0042] (4) Turn off the arc power supply, immediately introduce argon gas (flow rate of 60 sccm), turn on the graphite target sputtering power supply, adjust the target-substrate distance to 15 cm, the target current to 3 A, the substrate bias voltage to -300 V, the gas pressure to 1.5 Pa, the duty cycle to 45%, the frequency to 70 kHz, and the deposition time to 15 min.

[0043] (5) After deposition, the sample was removed after the temperature inside the vacuum chamber cooled to room temperature. The bonding strength of the carbon-based lubricating film on the surface of the silicone rubber can reach 97N, and no obvious brittle fracture occurred under 50N heavy-load friction conditions, indicating that it has high bonding and high load-bearing characteristics.

Claims

1. A method for constructing a high-bonding and high-load-bearing carbon-based composite lubricating film interface on a rubber surface, comprising the following steps: 1) constructing micropores on the surface of the rubber substrate by using an ultra-short pulse laser; 2) depositing a metal layer on the micropores; and 3) depositing a Ta-C film on the surface of the rubber substrate after the strengthening structure. 1) Constructing micropores on the surface of the rubber substrate by using an ultra-short pulse laser. 2) Co-injection of metal and carbon elements in situ: vacuum extraction to ≤ 1 x 10 -6 Pa; carbon target current adjusted to 45-60 A, duty cycle 40-50%, beam density 0.48-0.64 A / 100 cm 2 ·s; at the same time, metal target current adjusted to 20-40 A, duty cycle 50%, beam density 0.3-0.42 A / 100 cm 2 ·s, co-injection time 0.5-2 h; acceleration voltage controlled to -20 to -30 kV, frequency 1-3 Hz; 3) Depositing a Ta-C film: using a graphite target, adjusting the target-substrate distance to 12-15 cm, the target current to 3 A, the argon flow rate to 45-60 sccm, the substrate bias to -300 V, the gas pressure to 1-1.5 Pa, the duty cycle to 40-45%, the frequency to 60-70 KHz, and the deposition time to 10-15 min.

2. The method of claim 1, wherein the method is a method of constructing a high load bearing carbon-based composite lubricating film interface on a rubber surface. The rubber substrate is one of nitrile rubber, hydrogenated nitrile rubber, silicone rubber, and ethylene-propylene-diene rubber, the surface roughness of the rubber is less than or equal to 200 nm, and the thickness of the rubber is 3-5 mm.

3. The method for constructing a high-bonding, high-load-bearing carbon-based composite lubricating film interface on a rubber surface as described in claim 1, characterized in that: The micropores are circular, rectangular, triangular, or diamond-shaped, and the arrangement of the micropores is one of circular ring arrangement, vertical and horizontal interlaced arrangement, or dot matrix distribution arrangement.

4. The method of claim 3, wherein the method further comprises: applying a carbon-based lubricating film to the surface of the rubber article; and applying a carbon-based lubricating film to the surface of the metal article. 5 The micropores have a diameter of 10-50 microns, a depth of 1 / 2-2 / 3 of the thickness of the Ta-C film, and a structural area ratio of 20-40%.

5. The method of claim 1, wherein the method is a method of constructing a high load bearing carbon-based composite lubricating film interface on a rubber surface. The metal target is one of Ti, Cr, and W targets, and the carbon target is a graphite target.

6. The method of claim 1, wherein the method is a method of constructing a high load carrying carbon-based composite lubricating film interface on a rubber surface. The depth of the load-bearing strengthening layer is 300-1200 nm.

7. The method of claim 1, wherein the method is a method of constructing a high load carrying carbon-based composite lubricating film interface on a rubber surface. The thickness of the deposited Ta-C film is 500-800 nm.

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