Preparation method of niobium diselenide lubricating film serving for current-carrying friction

Abstract

The invention relates to a preparation method of a niobium diselenide lubricating film serving for current-carrying friction. The niobium diselenide lubricating film is prepared by adopting a radio frequency magnetron sputtering method. Sputtering gas is argon, a sputtering target material is niobium diselenide, the niobium diselenide thin film which is compact in structure and has good mechanical performance, electrical performance and lubricating performance is prepared by changing argon flow and substrate negative bias pressure, stable lubrication in 100 thousand cycles can be achieved in the atmospheric environment, and the friction coefficient is 0.08. Under a current-carrying friction working condition, compared with a traditional molybdenum disulfide film, the contact voltage is only 1 / 4, and the wear rate is reduced by more than half. The technology can be widely applied to antifriction and wear-resistant treatment of electric contact sliding parts in the fields of aerospace, electric power systems, semiconductor manufacturing and the like.

Description

Technical Field

[0001] This invention belongs to the field of lubricant preparation technology, and particularly relates to a method for preparing a niobium diselenide lubricating film for use in current-carrying friction. Background Technology

[0002] In emerging applications such as satellite conductive slip rings and robotic motion joints, contact surfaces face challenges related to mechanical wear, arc damage, and material oxidation caused by the coupling effect of current and friction. Electrically contacted sliding components require materials with not only excellent tribological properties but also high electrical and thermal conductivity, good mechanical properties, resistance to electro-erosion, and chemical stability. Currently, the demand for synergistic "electro-triboelectric" performance in lubricating materials is soaring in fields such as aerospace, power systems, and semiconductor manufacturing. Niobium diselenide materials, which combine lubricity and conductivity, offer a potential solution to this challenge.

[0003] As a member of the transition metal chalcogenides, NbSe2 retains its layered structure and lubricity; however, due to the unsaturated state of the outermost valence electrons of niobium, it can accept external electrons for interlayer free electron transport, thus exhibiting conductivity similar to metallic materials. However, developing a fabrication technology for NbSe2 thin films that can stably operate during current-carrying friction is a major challenge. Common methods for preparing thin films and coatings include electroplating, chemical vapor deposition (CVD), and physical vapor deposition (PVD). Electroplated coatings have coarse grains, difficult-to-control orientation, high surface roughness, and inevitably produce defects such as micropores within the coating. Yu Tongtong et al. prepared NbSe2 layers using CVD with Nb2O3 powder, NaCl powder, and Se powder as raw materials, introducing Ar and H2 gases, and heating to 700–1000℃ in a tube furnace. However, CVD requires waste gas treatment, resulting in poor environmental performance and certain safety hazards. The preparation of NbSe2 thin films with Ti substrates by DC magnetron sputtering requires high conductivity of the target material; otherwise, target poisoning may occur, leading to instability in the deposition process. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing niobium diselenide lubricating films used in current-carrying friction. This method avoids the drawbacks of existing technologies, such as the presence of a Ti substrate in niobium diselenide lubricating films prepared by magnetron sputtering, cumbersome process flow, and high cost, as well as the environmental problems associated with chemical vapor deposition (CVD) methods for preparing niobium diselenide lubricating films.

[0005] To solve the above problems, the present invention is implemented as follows: niobium diselenide lubricating films are prepared using radio frequency magnetron sputtering technology.

[0006] As a further optimization, the following steps are included:

[0007] (1) The substrate was ultrasonically cleaned for 15 minutes, dried and then placed in the deposition chamber;

[0008] (2) The chamber vacuum level is set to 1×10⁻⁶. -3 After the pressure drops below Pa, argon gas is introduced, and plasma sputtering cleaning is performed for 5–15 minutes.

[0009] (3) Argon gas is used as sputtering gas, niobium diselenide target is used as sputtering target material, and radio frequency power supply is used as sputtering source for preparation. The target sputtering power is 150-200W, the substrate negative bias voltage range is -25 to -100V, and the argon gas flow rate range is 30-90sccm.

[0010] As a further preferred option, in step (1), the substrate material is monocrystalline silicon or steel.

[0011] As a further preferred option, in step (2), the purity of argon gas is 99.99%, the base negative bias voltage is -500 to -700V, and the gas pressure is 1 to 2Pa.

[0012] As a further preferred option, in step (3), the purity of the niobium diselenide target is 99.9%, and the sample stage rotation speed in the deposition chamber during sputtering is 4-6 r / min.

[0013] As a further preferred option, the niobium diselenide lubricating film has a nanohardness of 1.5–4 GPa and a static resistivity of 0.038–0.675 Ω·cm.

[0014] The beneficial effects of this invention are as follows: Using niobium diselenide as the sputtering target, argon as the ionized sputtering gas, and an RF power supply as the sputtering source, charge accumulation on the target surface is eliminated; the deposition process can be completed in one step at room temperature without waste gas treatment, making the preparation process simple and environmentally friendly. The NbSe2 lubricating film prepared by this invention has a dense structure with a nanocrystalline / amorphous composite structure, exhibiting both excellent mechanical and electrical properties. This NbSe2 lubricating film can operate under harsh conditions of current-carrying friction, demonstrating excellent lubrication performance while ensuring electrical contact stability. It can be widely used in friction-reducing and wear-resistant treatment of electrical contact sliding components in power systems, semiconductor manufacturing, and other fields. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 Nb 3d (NbSe2 lubricating film prepared for Example 1) Figure 1a) and Se 3d( Figure 1 b) X-ray photoelectron spectroscopy analysis spectrum.

[0017] Figure 2 The surface of the NbSe2 lubricating film prepared in Example 1 ( Figure 2 a) and cross-section ( Figure 2 b) Field emission scanning electron microscope image.

[0018] Figure 3 The surface of the NbSe2 lubricating film prepared in Example 2 ( Figure 3 a) and cross-section ( Figure 3 b) Field emission scanning electron microscope image.

[0019] Figure 4 The X-ray diffraction pattern of the NbSe2 lubricating film prepared in Example 1.

[0020] Figure 5 The X-ray diffraction pattern of the NbSe2 lubricating film prepared in Example 2.

[0021] Figure 6 A high-resolution transmission electron microscope image of the NbSe2 lubricating film prepared in Example 1.

[0022] Figure 7 The friction coefficient curve of the NbSe2 lubricating film prepared in Example 1 in an atmospheric environment.

[0023] Figure 8 The friction coefficient curve of the NbSe2 lubricating film prepared in Example 2 in an atmospheric environment.

[0024] Figure 9 The real-time contact voltage-friction coefficient curve of the NbSe2 lubricating film prepared in Example 1 under current-carrying conditions. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] 1) Substrate pretreatment: Single crystal silicon (100) and steel (9Cr18) were ultrasonically cleaned in petroleum ether and anhydrous ethanol for 15 min respectively. After drying, they were placed on the sample selection stage in the deposition chamber and the sample stage speed was maintained at 5 r / min until the coating was completed.

[0028] 2) Plasma cleaning: Turn on the vacuum system and pump the air pressure in the vacuum chamber to 5×10⁻⁶. -4 At 70 sccm, argon gas is introduced to maintain a stable pressure of 2 Pa; the negative bias is adjusted to -600V, and argon plasma bombardment is performed to remove impurities and contaminants from the substrate surface. The cleaning process lasts for 10 minutes.

[0029] 3) Deposition of NbSe2 lubricating film: Introduce argon gas at 70 sccm to maintain the chamber pressure at 2 Pa; turn on the NbSe2 target RF sputtering power supply and adjust the power to 175 W; adjust the substrate negative bias voltage to -50 V; after deposition for 100 min, turn off the sputtering power supply and substrate negative bias voltage, allow it to cool naturally in an argon atmosphere for 1 h, and then release the vacuum to remove the sample.

[0030] The NbSe2 lubricating film prepared in Example 1 was subjected to Nb 3d ( Figure 1 a) and Se 3d( Figure 1 b) X-ray photoelectron spectroscopy analysis, see [reference] Figure 1 Due to residual oxygen in the vacuum chamber and unavoidable oxidation during film transfer, two oxides, Nb₂O₅ and SeO₂, appeared in the film; however, its basic material remains NbSe₂. (See also...) Figure 2 The surface of the prepared NbSe2 lubricating film ( Figure 2 a) and cross-section ( Figure 2 b) Morphological analysis revealed that the deposited NbSe2 film had a uniform and dense structure. (See also...) Figure 4 The X-ray diffraction pattern only shows diffraction peaks on the (002), (101), and (112) crystal planes of NbSe2, indicating that Nb2O5 and SeO2 exist as amorphous substances. (See also...) Figure 6 As can be seen from the high-resolution transmission electron microscope images, the NbSe2 lubricating film has a nanocrystalline / amorphous composite structure, and its lattice fringes are consistent with the X-ray diffraction pattern results.

[0031] Example 2

[0032] 1) Substrate pretreatment: Single crystal silicon (100) and steel (9Cr18) were ultrasonically cleaned in petroleum ether and anhydrous ethanol for 15 min respectively. After drying, they were placed on the sample selection stage in the deposition chamber and the sample stage speed was maintained at 5 r / min until the coating was completed.

[0033] 2) Plasma cleaning: Turn on the vacuum system and pump the air pressure in the vacuum chamber to 1×10⁻⁶. -3 At 70 sccm, argon gas is introduced to maintain a stable pressure of 2 Pa; the negative bias is adjusted to -600V, and argon plasma bombardment is performed to remove impurities and contaminants from the substrate surface. The cleaning process lasts for 10 minutes.

[0034] 3) Deposition of NbSe2 lubricating film: Introduce argon gas at 70 sccm to maintain the chamber pressure at 2 Pa; turn on the NbSe2 target RF sputtering power supply and adjust the power to 175 W; adjust the substrate negative bias voltage to -75 V; after deposition for 100 min, turn off the sputtering power supply and substrate negative bias voltage, allow it to cool naturally in an argon atmosphere for 1 h, and then release the vacuum to remove the sample.

[0035] See Figure 3 The surface of the NbSe2 lubricating film prepared in Example 2 ( Figure 3 a) and cross-section ( Figure 3 b) Morphological analysis showed that the NbSe2 thin film deposited in Example 2 had a uniform and dense structure.

[0036] See Figure 5 The X-ray diffraction pattern only shows the diffraction peaks of the (002), (101) and (112) crystal planes of NbSe2, indicating that Nb2O5 and SeO2 are amorphous.

[0037] Experimental Example

[0038] Performance experiments of NbSe2 lubricating films

[0039] 1. Mechanical properties: hardness and elastic modulus, film-substrate adhesion.

[0040] Test method: Nanoindentation instrument

[0041] Test results: The NbSe2 lubricating film of the present invention has a hardness of 1.5–4 GPa, an elastic modulus of 30–90 GPa, and a film-substrate adhesion strength of 0.5–1.2 N. The NbSe2 lubricating film obtained in Example 1 has a thickness of 1.54 μm, a hardness of 2.24 GPa, and a film-substrate adhesion strength of 1.03 N. The NbSe2 lubricating film obtained in Example 2 has a thickness of 1.07 μm, a hardness of 3.88 GPa, and a film-substrate adhesion strength of 0.69 N.

[0042] 2. Electrical properties: Static resistivity

[0043] Test method: Four-probe tester

[0044] Test results: The static resistivity of the NbSe2 lubricating film of the present invention is 0.038–0.675 Ω·cm, and there is no significant change after 30 days of storage. The resistivity of the NbSe2 lubricating film obtained in Example 1 is 0.107 Ω·cm, and the resistivity of the NbSe2 lubricating film obtained in Example 2 is 0.048 Ω·cm.

[0045] 3. Tribological properties

[0046] Test method: Pin-disc friction and wear testing machine

[0047] Test results: Tests were conducted in an atmospheric environment with a normal load of 1 N, a reciprocating sliding amplitude of 4 mm, and a frequency of 5 Hz. The NbSe2 lubricating film of this invention maintains a stable coefficient of friction over 100,000 cycles. (See also...) Figure 7 and Figure 8 The figures show the friction coefficient curves of the NbSe2 lubricating films from Examples 1 and 2 in an atmospheric environment. The NbSe2 lubricating film obtained in Example 1 has a friction coefficient of approximately 0.08 in an atmospheric environment and a wear life of up to 100,000 cycles. The NbSe2 lubricating film obtained in Example 2 has a friction coefficient of approximately 0.14 in an atmospheric environment and a wear life of up to 100,000 cycles.

[0048] 4. Current-carrying tribological properties

[0049] Test method: Current-carrying tribological wear tester

[0050] Test results: The test was conducted in an atmospheric environment with a normal load of 1N, an applied current of 0.2A, a reciprocating sliding amplitude of 4mm, and a frequency of 5Hz. Figure 9 The real-time contact voltage-friction coefficient curves of the NbSe2 lubricating film prepared in Example 1 under current-carrying conditions are shown. It can be seen that compared with the traditional molybdenum disulfide film, the contact voltage of the niobium diselenide film decreases from 0.8V to 0.2V, indicating a more stable electrical contact state. The friction curves also reflect the friction-reducing effect of the niobium diselenide film during current-carrying friction. Calculations show that the wear rate of the molybdenum disulfide film is 4.03 × 10⁻⁶. -5 mm 3 / Nm, the wear rate of the niobium diselenide thin film is 1.66×10 -5 mm 3 / Nm, which can reduce wear by more than half and provide wear resistance under current-carrying conditions. The NbSe2 lubricating film obtained in Example 1 has an internal friction coefficient of approximately 0.12 after 6000 cycles under current-carrying conditions. The NbSe2 lubricating film obtained in Example 2 has an internal friction coefficient of approximately 0.17 after 6000 cycles under current-carrying conditions.

[0051] The beneficial effects of this invention are as follows: Using niobium diselenide as the sputtering target, argon as the ionized sputtering gas, and an RF power supply as the sputtering source, charge accumulation on the target surface is eliminated; the deposition process can be completed in one step at room temperature without waste gas treatment, making the preparation process simple and environmentally friendly. The NbSe2 lubricating film prepared by this invention has a dense structure with a nanocrystalline / amorphous composite structure, exhibiting both excellent mechanical and electrical properties. This NbSe2 lubricating film can operate under harsh conditions of current-carrying friction, demonstrating excellent lubrication performance while ensuring electrical contact stability. It can be widely used in friction-reducing and wear-resistant treatment of electrical contact sliding components in power systems, semiconductor manufacturing, and other fields.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a niobium diselenide lubricating film for use in current-carrying friction, characterized in that, Niobium diselenide lubricating films were prepared using radio frequency magnetron sputtering technology.

2. The method for preparing a niobium diselenide lubricating film for current-carrying friction as described in claim 1, characterized in that, Includes the following steps: (1) The substrate was ultrasonically cleaned for 15 minutes, dried and then placed in the deposition chamber; (2) The chamber vacuum level is set to 1×10⁻⁶. -3 After the pressure drops below Pa, argon gas is introduced, and plasma sputtering cleaning is performed for 5–15 minutes. (3) Argon gas is used as sputtering gas, niobium diselenide target is used as sputtering target material, and radio frequency power supply is used as sputtering source for preparation. The target sputtering power is 150-200W, the substrate negative bias voltage range is -25 to -100V, and the argon gas flow rate range is 30-90sccm.

3. The method for preparing a niobium diselenide lubricating film for current-carrying friction as described in claim 2, characterized in that, In step (1), the substrate material is monocrystalline silicon or steel.

4. The method for preparing a niobium diselenide lubricating film for current-carrying friction as described in claim 2, characterized in that, In step (2), the argon gas has a purity of 99.99%, a base negative bias of -500 to -700V, and a gas pressure of 1 to 2Pa.

5. The method for preparing a niobium diselenide lubricating film for current-carrying friction as described in claim 2, characterized in that, In step (3), the purity of the niobium diselenide target is 99.9%, and the sample stage rotation speed in the deposition chamber during sputtering is 4-6 r / min.

6. The method for preparing a niobium diselenide lubricating film for current-carrying friction as described in claim 1, characterized in that, The niobium diselenide lubricating film has a nanohardness of 1.5–4 GPa and a static resistivity of 0.038–0.675 Ω·cm.

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