CN110453190B

CN110453190B - A kind of composite magnetron sputtering preparation method of AlCrSiN/Mo self-lubricating film

Info

Publication number: CN110453190B
Application number: CN201910897051.1A
Authority: CN
Inventors: 王铁钢; 蒙德强; 刘艳梅; 阎兵; 尹照星; 许人仁
Original assignee: Tianjin University of Technology and Education China Vocational Training Instructor Training Center
Current assignee: Tianjin University of Technology and Education China Vocational Training Instructor Training Center
Priority date: 2019-09-23
Filing date: 2019-09-23
Publication date: 2021-06-15
Anticipated expiration: 2039-09-23
Also published as: CN110453190A

Abstract

The invention discloses a composite magnetron sputtering preparation method of an AlCrSiN/Mo self-lubricating film, which belongs to the technical field of film preparation. _The AlCrSiN/Mo self-lubricating film is prepared on the substrate by high-power pulsed magnetron sputtering technology and pulsed DC magnetron coating technology. 150sccm, Ar flow rate 50~250sccm, total _N2 and Ar flow rate 300sccm, deposition pressure 1.0~2.5Pa, CrMo target sputtering power 0.1~0.9kW, AlCrSi target power 0.2~1.5kW. The prepared AlCrSiN/Mo self-lubricating film has high hardness, good toughness, excellent wear-reducing properties, can significantly reduce the friction between knives and chips, and has good chemical stability and easy shearing lubricating properties.

Description

Composite magnetron sputtering preparation method of AlCrSiN/Mo self-lubricating film

Technical Field

The invention relates to the technical field of films and preparation thereof, in particular to a composite magnetron sputtering preparation method of an AlCrSiN/Mo self-lubricating film.

Background

The rapid development of modern manufacturing industry has higher and higher requirements on film cutters, and hard films have high hardness and thermal stability and are widely applied to the processing directions of metal parts, dies and the like. The film gradually develops from binary to diversified, so that the service life of the cutting tool can be effectively prolonged, particularly, the self-lubricating elements are doped in the composite film, the generation of cutting heat can be effectively reduced, the surface processing precision of a workpiece is improved, and the cutting efficiency of the tool is further improved.

Under the condition of high-speed or dry cutting, the surface of a binary TiN and Cr N film is easy to generate oxidation failure to limit the application of the film, and the Cr-Al-N film is prepared by adding Al element into the film, and research results show that the thermal stability of the Cr-Al-N film mainly depends on the Al-N phase combined by covalent bonds in the Cr-Al-N, and the increase of the Al element can lead the film structure to be gradually changed from fcc-AlN to hcp-AlN, so that the hardness of the film can be improved to a certain extent; and can form compact (Cr, Al) on the surface of the film₂O₃The film can effectively slow down the diffusion of external oxygen into the film in a high-temperature environment, thereby effectively improving the high-temperature oxidation resistance of the film. In the research, the a-Si is formed at the grain boundary of Cr-Al-N solid solution after the Si element is added into the Cr-Al-N film₃N₄Therefore, a mosaic composite structure is formed, so that the composite structure has the characteristics of high hardness, high toughness, excellent thermal stability and the like, is suitable for the surface of a cutting tool, has the defects of high friction coefficient, high cutting temperature and the like, and is difficult to ensure the service life of the tool and the surface quality of a workpiece.

In order to further apply the film cutter to the field of modern high-speed dry cutting machining and further prolong the service life of the cutter, the high-power Pulse magnetic control (HIPIMS) and Pulse direct current magnetic control (Pulse DC) composite coating technology is adopted to prepare the AlCrSiN/Mo film with high hardness, high-temperature oxidation resistance and super-lubricating wear resistance on the surface of the cutter substrate, so that the hard-machining cutting working conditions of dry type, high speed, high precision and the like can be met, the use of cutting fluid is reduced, and green manufacturing is realized.

Disclosure of Invention

The invention aims to provide a composite magnetron sputtering preparation method of an AlCrSiN/Mo self-lubricating film, and the prepared AlCrSiN/Mo self-lubricating film is high in hardness and good in toughness, has excellent anti-wear characteristics, can remarkably reduce friction between a cutter and chips, and has good chemical stability and easy-shearing lubricating characteristics.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a composite magnetron sputtering preparation method of an AlCrSiN/Mo self-lubricating film is prepared on a substrate by adopting a high-power pulse magnetron sputtering technology and a pulse direct-current magnetron coating technology, and specifically comprises the following steps:

(1) fixing the substrate on a rotating frame in a vacuum chamber, and pumping the substrate to 3.0 × 10^-3Below Pa, the CrMo target is connected with a high Power Impulse Power supply of HiPIMS (high Power Impulse Magnetron sputtering), and the AlCrSi target is connected with a pulse direct current Power supply;

(2) the substrate is firstly subjected to glow cleaning to remove surface impurities; then, ion bombardment is carried out to improve the film/base binding force;

(3) preparing a CrN transition layer;

(4) preparing an AlCrSiN/Mo self-lubricating film: reducing the bias voltage to-50 to-150V after preparing a CrN transition layer, and introducing a reaction gas N₂The flow rate is 50-150 sccm, the flow rate of Ar is 50-250 sccm, and N₂And the total flow of Ar is 300sccm, the deposition pressure is kept at 1.0-2.5 Pa by adjusting a throttle valve, the sputtering power of a CrMo target is 0.1-0.9 kW, and the power of an AlCrSi target is 0.2-1.5 kW, so that the AlCrSiN/Mo self-lubricating film is obtained.

In the step (1), the substrate is fixed in front of the rotating frame, and is sequentially cleaned in acetone and ethanol for 10-35 min by ultrasonic waves respectively, and then dried by high-purity nitrogen.

In the step (2), the glow cleaning process includes: introducing Ar with the flow rate of 50-200 sccm under the bias action of-800V, adjusting the angle of the throttle valve to keep the working pressure of 0.5-1.5 Pa, performing glow discharge for 5-15 min, and cleaning the surface of the substrate to remove surface impurities.

In the step (2), the ion bombardment process is as follows: after glow cleaning, starting an electric arc Cr target for ion bombardment, setting the current of an arc source to be 80-100A and the voltage of the arc source to be 15-25V, introducing Ar with the flow rate of 50-200 sccm, and keeping the working pressure to be (5-10) multiplied by 10^-1Pa, and the bombardment time is 5-10 min.

In the step (3), after ion bombardment is carried out, parameters of the arc Cr target are kept unchanged, Ar is introduced with the flow rate of 40-60 sccm, and N₂The flow rate is 150-250 sccm, and the working pressure is kept at 8 multiplied by 10^-1And Pa, depositing a CrN transition layer for 10-20 min.

In the step (4), the deposition time is determined according to the technical requirements and the film deposition rate.

The AlCrSiN/Mo self-lubricating film prepared by the method is formed by doping Mo element into the AlCrSiN film, and the doping amount of the Mo element in the prepared AlCrSiN/Mo self-lubricating film is 0.3-6.3 at.%. The AlCrSiN/Mo self-lubricating film comprises the following chemical components in atomic percentage:

Al 14.3～25.5％，Cr 14.3～36.2％，Si 1.6～3.4％，N 33.6～56.9％，Mo 0.3～6.3％。

the AlCrSiN/Mo self-lubricating film is of a multi-phase composite structure, Mo is doped into the AlCrSiN, Mo atoms replace Al and/or Cr atomic sites in (Al, Cr) N lattices to form a replacement solid solution, and the AlCrSiN/Mo self-lubricating film comprises AlN, CrN and Mo₂N, etc. nanocrystalline phases.

A CrN transition layer is arranged between the AlCrSiN/Mo self-lubricating film and the substrate, the substrate is a stainless steel, single crystal Si sheet or hard alloy substrate, the thickness of the CrN transition layer is 150-250 nm, and the thickness of the AlCrSiN/Mo self-lubricating film is 2.5-4.0 mu m.

The design mechanism of the invention is as follows:

according to the invention, the sixth subgroup Mo element is doped into AlCrSiN, so that Mo atoms replace Al or Cr atomic sites in (Al, Cr) N crystal lattices to form a substitutional solid solution, and the crystal lattices are distorted due to different atomic radiuses, so that the dislocation motion resistance between crystal boundaries is increased to play a role in strengthening the crystal boundaries, and the performance of the film is strengthened; meanwhile, MoO with self-lubricating function is easily generated in the friction process₃The friction coefficient and the generation of cutting heat can be effectively reduced, and good functions of reducing friction and resisting wear are achieved. Researches find that the influence of the content of the Mo element on the film is large, and the lubricating effect is not obvious when the content of the Mo element is too low; however, too high a content results in insufficient nitriding of Mo atoms and, depending on the metal atoms, far belowThe hardness of the metal nitride, thereby negatively affecting the hardness of the film; in addition, Mo is formed in the film in a large amount₂And the N phase cannot be coordinately deformed due to the difference of the performances of the two phases in the friction process, and the film is easy to crack and lose efficacy under the action of deformation stress.

The invention adopts the high-power pulse magnetron sputtering technology, and has the advantages of high instantaneous current density, high ionization rate, high sputtered ion energy and low duty ratio (less than 1 percent); the high-quality thin film with compact structure, adjustable internal stress and fine and smooth surface can be prepared; and combines the advantages of high deposition rate and low deposition temperature of the pulse direct current magnetron coating technology to prepare the AlCrSiN/Mo nano composite film on SUS304 stainless steel, single crystal Si sheets and hard alloy substrates. In the preparation process, the wear resistance of the film is further improved by strictly controlling the deposition parameters such as the introduced gas flow, the target power, the deposition pressure and the like on the premise of ensuring the hardness and the toughness of the film, the work realizes the solid solution strengthening mechanism of the nano composite film so as to realize the optimization of the performance of the Mo-doped AlCrSiN film, and the nano composite film is suitable for the modern processing fields such as dry type, high speed and the like and further improves the service life and the processing efficiency of a cutter.

The invention has the advantages and beneficial effects that:

(1) the AlCrSiN/Mo film contains AlN, CrN and Mo₂The nano composite structure formed by the N and other nano crystals has the advantages of high hardness, high toughness, low friction coefficient, good wear resistance and the like.

(2) The AlCrSiN/Mo film developed by the invention has smooth and compact surface and compact internal structure, and has good bonding strength with a substrate; the film/base binding force of the film is more than 150N, the friction coefficient is lower and the wear rate is lower than 1.62 multiplied by 10^-3μm³/N·μm。

(3) The AlCrSiN/Mo nano composite film developed by the invention has higher high-temperature thermal stability and can be used in the field of high speed, dry cutting and other difficult processing.

(4) The AlCrSiN/Mo film developed by the invention has good repeatability of the preparation process, and the prepared film has wider application prospect, can be used for parts difficult to process and has unique advantages.

Drawings

FIG. 1 is a diagram of a high power pulse and pulse DC magnetron sputtering target distribution.

FIG. 2 is an XRD pattern of the AlCrSiN/Mo film prepared in example 1.

FIG. 3 shows the scratch pattern of the AlCrSiN/Mo film prepared in example 1.

FIG. 4 shows the wear scar morphology after the pair grinding of the AlCrSiN/Mo film prepared in example 1 and the alumina balls.

FIG. 5 is a plot of the coefficient of friction of the AlCrSiN/Mo films prepared in example 1.

FIG. 6 is an XRD pattern of the AlCrSiN/Mo film prepared in example 2.

FIG. 7 shows the wear scar morphology after the pair grinding of the AlCrSiN/Mo film prepared in example 2 and the alumina balls.

FIG. 8 is a plot of the coefficient of friction for the AlCrSiN/Mo films prepared in example 2.

Detailed Description

The technical scheme of the invention is further explained by combining specific examples.

Example 1

This example utilized a HiPIMS/Pulse DC hybrid magnetron sputtering system to deposit AlCrSiN/Mo composite films on single crystal tungsten steel sheets (20 mm. times.10 mm. times.1.0 mm), SUS304 stainless steel sheets (40 mm. times.40 mm. times.2.0 mm), and cemented carbide substrates (35 mm. times.35 mm. times.4.5 mm). The preparation process of the film is as follows:

(1) all substrates were sequentially cleaned in acetone and alcohol solutions for 30min each, followed by high purity N₂Drying, and then placing on a rotating frame facing the target material in a vacuum chamber. FIG. 1 is a diagram of a high power pulse and pulse DC magnetron sputtering target distribution. As can be seen, the AlCrSi target was loaded onto a pulsed DC Power supply and the CrMo target was loaded onto a high Power Impulse Magnetron spraying high Power pulsed Power supply.

The rotating speed of the rotating frame is selected to be 2.5r/min, and the target base distances are 80mm (AlCrSi target) and 280mm (CrMo target) respectively. Ar and N with the purity of 99.999 percent are respectively selected as working gas and reaction gas in the film plating process₂。

(2) Glow cleaning: the background of the vacuum chamber is vacuumized to3.0×10^-3Pa, heating to 400 ℃, then applying-800V bias voltage, introducing Ar into the vacuum chamber with the flow rate of 200sccm, keeping the working pressure at 1.5Pa, and glow-cleaning for 15 min; to remove impurities on the surface of the substrate.

(3) Ion bombardment: after glow cleaning, starting an arc Cr target for ion bombardment, setting an arc source current of 90A and an arc source voltage of 20V-20.3V, introducing Ar with the flow of 200sccm, and keeping the working pressure of 5 multiplied by 10^-1Pa, bombardment time is 8min to improve the film-base bonding interface, thereby improving the film/base bonding force of the film.

(4) Depositing a CrN transition layer: keeping the parameters of the arc Cr target unchanged, introducing Ar with the flow rate of 50sccm and N₂The flow rate is 200sccm, and the working pressure is kept at 8 multiplied by 10^-1Pa, depositing a CrN transition layer for 15min, wherein the thickness of the CrN transition layer is about 200nm, and the aim is to reduce the mismatch of the thermal expansion coefficients of the film and the substrate.

(5) Preparing an AlCrSiN/Mo self-lubricating film: reducing the bias voltage to-150V, and introducing a reaction gas N₂Flow 50sccm Ar flow 250sccm maintaining Ar (99.99%) and N₂(99.99%) the total gas flow is 300sccm, the deposition pressure is kept to be 2.0Pa by adjusting a throttle valve, the CrMo target sputtering power is selected to be 0.3kW, 0.6kW or 0.9kW, the AlCrSi target power is 1.5kW, the deposition time is strictly controlled to be 240min, and a series of AlCrSiN/Mo composite films are prepared, wherein the thickness of the AlCrSiN/Mo self-lubricating film is about 3.0 mu m.

The surface and cross-sectional morphology of the film prepared in this example were observed by a field emission Scanning Electron Microscope (SEM), and the elemental composition of the film was analyzed by an energy spectrometer (EDS) equipped with the SEM. The phase analysis of the film is carried out by an X-ray diffractometer (XRD), X-ray diffraction data are collected in a step scanning mode, incident X-rays are radiated by a Cu target Ka characteristic spectral line (lambda is 0.154056nm), the tube voltage is 40kV, the tube current is 40mA, the scanning range of the diffraction angle (2 theta) is 20-80 degrees, the scanning step is 0.02 degree, and the counting time of each step is 0.2 s.

Measuring the residual Stress of the Film by using a Film Stress tester FST-150 model of Film Stress of SuPro Instruments, testing the curvature radius of the front and back surfaces of the Film of the single crystal Si sheet by using the optical lever curvature amplification principle, and calculating the residual Stress of the Film by using a Stoney formula; and testing the hardness and the elastic modulus of the film by using a nanoindenter, wherein in order to reduce the influence of a matrix on a measurement result, 1/10 with the pressing depth being the thickness of the film is taken, and 15 points are measured to obtain the average value of the hardness and the elastic modulus. The bond strength of the thin film to the cemented carbide substrate was measured using a scratch tester (Anton Paar RST-3 type). The parameters of the scratch test are as follows: the scratch speed is 6mm/s, the scratch length is 3mm, and the load is 1-150N. The friction, coefficient of friction and acoustic emission signal were all recorded during the scratch test in order to measure the critical load.

Coefficient of friction in Friction wear tester (J)&L Tech, Tribometer), this time with Al of 5.99mm diameter₂O₃The ball (hardness 22 + -1 GPa), sliding linear velocity 10cm/s, normal load 6N, grinding track radius 4mm, sliding distance 125.6 m. The rubbing experiment was performed at room temperature 25 ± 3 ℃ and humidity 30%, and each sample was tested 3 times in duplicate, with the wear rate formula W ═ V/(F × S) (V is wear volume, F is load, and S is sliding distance), and post-wear scar topography analysis was performed using a super depth of field microscope (VHX-1000C, Keyence).

The chemical composition of the AlCrSiN/Mo self-lubricating film prepared in this example is shown in Table 1.

TABLE 1 content of the elements of the coating at different CrMo target powers

FIG. 2 is an XRD spectrum of the AlCrSiN/Mo composite film. As can be seen from the figure, the AlCrSiN/Mo composite film exhibits a polycrystalline state, mainly composed of AlN, CrN and Mo₂Nanocrystalline such as N and amorphous Si₃N₄And (4) forming. At 31.4 degrees and 35.8 degrees, hcp-AlN phase diffraction peaks growing along the (101_1) crystal plane appear in the AlCrSiN/Mo film, and more obvious diffraction peaks are detected in the film. Meanwhile, at diffraction angles 2 θ of 31.9 ° and 36.2 °, hcp-AlN diffraction peaks growing along the (101 — 1) crystal plane can be detected with gradually decreasing peak intensity due to the AlN crystal growth having anisotropy; diffraction angle 2 θ was 37.8 °, 43.9 °, and 64.fcc-AlN and tetra-Mo grown along the (111), (200), (220) and (311) crystal planes were detected in the vicinity of 1 ℃ and 75.5 ℃₂N, fcc-CrN, and the diffraction peak growing along the (200) crystal face shows preferential growth because the density values of dangling bonds and non-equilibrium bonds on the (200) crystal face of the NaCl-type face-centered cubic structure (Al, Cr) N phase are low, and thus the NaCl-type face has the lowest surface energy; and the increase of the target power promotes the preferential growth of the coating along the (200) crystal plane according to the principle of minimum thermodynamic free energy. Meanwhile, the enhancement of the particle bombardment effect can increase the atom moving capability on the surface of the film, and promote the preferential growth of the film along the (200) crystal plane with the minimum surface free energy.

FIG. 3 is a graph of the scratch topography of a thin film. The film was not scratched under a normal load of 150N, mainly for the following reasons: on one hand, the CrN transition layer prepared by adopting the arc ion plating technology can evaporate more high-energy metal particles, and under the action of negative bias, high-energy and high-density particle beams can etch the surface of a substrate and inject the particles into the interface of the film and the substrate so as to promote the particles to locally grow epitaxially along the surface of the film to obtain a chemical bond bonding interface, thereby greatly enhancing the bonding force between the film and the substrate; on the other hand, when the energy of the charged particles impacting the matrix reaches a certain degree, the charged particles directly enter the inside of the film to form a so-called shallow injection effect, and the shallow injection effect not only can improve the combination condition of the film and the matrix, but also can improve the density of the film, thereby ensuring that the film has excellent comprehensive performance. Meanwhile, the scratch appearance is white, which is probably caused by gradual oxidation of the film during the test process when more Mo element exists in the film.

FIG. 4 is a graph of the wear scar appearance of the AlCrSiN/Mo composite film, where it can be observed that a plurality of stripe-shaped scribe lines are distributed in the wear scar. Because the coating has higher hardness value, the film is cracked under the action of compressive stress to generate hard particles serving as abrasion media in the friction process, and the surface of the coating is scraped to cause fatigue damage. On one hand, Mo element in the film is subjected to oxidation reaction in the air in the friction process to generate MoO with self-lubricating effect₃Can slow down the anti-shearing capability of the film under the action of external load, thereby further reducing the stress on the filmThe abrasion resistance of the film is improved; on the other hand, Al is generated during the opposite grinding process due to the higher hardness of the film₂O₃The balls are ground away and accumulated around the grinding marks; more white abrasive dust is distributed on two sides of the corresponding grinding scar, and the quantity of the white abrasive dust is increased. The film's main wear mechanism then gradually changes from severe adhesive wear and plastic deformation to slight abrasive wear.

FIG. 5 graph of coefficient of friction. The friction is in a running state and the curve fluctuation is obvious in the initial stage, all friction curves fluctuate slightly as the friction experiment is continuously carried out, and the fluctuation of the friction coefficient is obvious due to the fact that the number of hard phases in the film is large and the hard phases fall off in the friction process to participate in the friction, abrasion of abrasive particles is generated, but the friction coefficient is maintained at a low value of 0.6 due to the fact that a lubricating phase in the film can play a role in reducing the friction.

Example 2:

this example used a HiPIMS/Pulse DC hybrid magnetron sputtering system to deposit an AlCrSiN/Mo composite film on a single crystal Si sheet (40 mm. times.40 mm. times.0.67 mm), an SUS304 stainless steel sheet (40 mm. times.40 mm. times.2.0 mm), and a cemented carbide substrate (35 mm. times.35 mm. times.4.5 mm). The preparation process of the film is as follows:

(1) all substrates were sequentially cleaned in acetone and alcohol solutions for 30min each, followed by high purity N₂Drying, and then placing on a rotating frame facing the target material in a vacuum chamber. The CrMo target is loaded on a pulse direct current Power supply, and the AlCrSi target is loaded on a high Power Impulse Power supply of high PIMS (high Power Impulse Magnetron sputtering).

(2) Glow cleaning: the background of the vacuum chamber is vacuumized to 3.0 x 10^-3Pa, heating to 400 ℃, then applying-800V bias voltage, introducing Ar into the vacuum chamber with the flow rate of 200sccm, keeping the working pressure at 1.5Pa, and glow-cleaning for 15 min; to remove impurities on the surface of the substrate.

(3) Ion bombardment: after glow cleaning, starting an electric arc Cr target for ion bombardment, and settingConstant arc source current 90A, arc source voltage 20V-20.3V, Ar flow of 200sccm, and working pressure of 5 × 10^-1Pa, bombardment time is 8min to improve the film-base bonding interface, thereby improving the film/base bonding force of the film.

(4) Depositing a CrN transition layer: keeping the parameters of the arc Cr target unchanged, introducing Ar with the flow rate of 50sccm and N₂The flow rate is 200sccm, and the working pressure is kept at 8 multiplied by 10^-1Pa, depositing CrN transition layer for 15min to reduce the mismatch of the thermal expansion coefficient of the film and the substrate and improve the film/substrate bonding force.

(5) Preparing an AlCrSiN/Mo self-lubricating film: reducing the bias voltage to-150V, and introducing a reaction gas N₂Flow 50sccm Ar flow 250sccm maintaining Ar (99.99%) and N₂(99.99%) the total flow of gas is 300sccm, the deposition pressure is kept to be 1.0Pa, 1.2Pa, 1.6Pa or 2.0Pa by adjusting a throttle valve, the CrMo target sputtering power is 0.4kW, the AlCrSi target sputtering power is 1.2kW, and the deposition time is strictly controlled to be 360min, so that a series of AlCrSiN/Mo composite films are prepared.

The chemical composition of the AlCrSiN/Mo self-lubricating film prepared in this example is shown in Table 2.

TABLE 2 elemental contents of the coatings at different deposition pressures

FIG. 6 is an XRD pattern of the AlCrSiN/Mo composite film. As can be seen from the figure, the AlCrSiN/Mo composite film exhibits a polycrystalline state, mainly composed of AlN, CrN and Mo₂N, etc. of nanocrystalline, the Si₃N₄Possibly in amorphous form. AlN and Cr in a hexagonal close-packed structure grown along the (101_1) and (112_1) crystal planes were detected in the coating at 2 θ 37.916 ° and 42.610 °, respectively₂And (4) N phase. Meanwhile, Mo growing along the (200) crystal plane can be detected at 2 θ of 43.45 °, 43.737 ° and 43.915 °₂N, CrN and AlN. The diffraction peak intensity is strongest and wider, which shows that the crystallinity of the coating is high and the crystal grains are gradually refined; meanwhile, the simple substance Si and the corresponding compound are not detected in the coatingThe diffraction peak indicates that the Si element may exist in the form of amorphous Si3N4, which acts to suppress grain growth, and this is an important cause of broadening the diffraction peak.

FIG. 7 is a pattern diagram of wear scar of the AlCrSiN/Mo composite film. It can be observed that a number of stripe-shaped scribe lines are distributed in the wear scar. Because the coating has higher hardness value, the film is cracked under the action of compressive stress to generate hard particles serving as abrasion media in the friction process, and the surface of the coating is scraped to cause fatigue damage. On one hand, Mo element in the film is subjected to oxidation reaction in the air in the friction process to generate MoO with self-lubricating effect₃The anti-shearing capability of the film under the action of external load can be slowed down, and the anti-abrasion capability of the film is further improved; on the other hand, the hardness of the film reaches up to 20.6GPa, which can effectively reduce the effective contact area between the alumina ball and the coating, so that the wear resistance of the film can be improved, and the corresponding wear rate is reduced to be at least 1.52 multiplied by 10^-3μm³μ m, when the film main wear mechanism gradually changes from severe adhesive wear and plastic deformation to slight abrasive wear.

FIG. 8 graph of coefficient of friction. The friction is in a running state in the initial stage and the curve fluctuation is obvious, all friction curves fluctuate slightly as the friction experiment continues, and the friction coefficient fluctuation is obvious due to the fact that the number of hard phases in the film is large and the hard phases fall off in the friction process to participate in the friction, abrasive grain abrasion is generated, and the friction coefficient fluctuation is obvious. However, the coefficient of friction value was lower at 0.6. On the one hand, the friction-reducing effect is achieved by the formation of a lubricating phase during the friction process. On the other hand, according to Archard's theory, it is pointed out that the hardness of a coating is inversely proportional to the coefficient of friction, i.e., higher hardness corresponds to lower coefficient of friction, which also provides a theoretical basis for reducing the coefficient of friction of the coating.

The invention has been described in an illustrative manner, and it is to be understood that any simple variations, modifications or other equivalent changes which can be made by one skilled in the art without departing from the spirit of the invention fall within the scope of the invention.

Claims

1. a composite magnetron sputtering preparation method of AlCrSiN/Mo self-lubricating film is characterized in that: described AlCrSiN/Mo self-lubricating film is formed by doping Mo element into the AlCrSiN film, by atomic percentage, the described The chemical composition of the AlCrSiN/Mo self-lubricating film is: Al 14.3~25.5 at.%, Cr 14.3~36.2 at.%, Si 1.6~3.4 at.%, N33.6~56.9 at.%, Mo 0.3~6.3 at.% %;

The AlCrSiN/Mo self-lubricating film is prepared on the substrate by high-power pulsed magnetron sputtering technology and pulsed DC magnetron coating technology, which specifically includes the following steps:

(1) Fix the substrate on the rotating frame in the vacuum chamber, then pump the substrate pressure of the vacuum chamber to below 3.0×10 ^-3 Pa, connect the CrMo target to the high-power pulsed power supply, and the AlCrSi target to the pulsed DC power supply;

(2) The substrate is first subjected to glow cleaning to remove surface impurities; then ion bombardment is performed to improve the film/substrate binding force;

(3) Preparation of CrN transition layer;

(4) Preparation of AlCrSiN/Mo self-lubricating film: after preparing the CrN transition layer, reduce the bias voltage to -50~-150 V, and then pass in the reaction gas N ₂ flow rate of 50~150 sccm, Ar flow rate of 50~250 sccm, N The total flow rate of ₂ and Ar was 300 sccm, the deposition pressure was maintained at 1.0~2.5 Pa by adjusting the throttle valve, the sputtering power of CrMo target was 0.1~0.9 kW, and the power of AlCrSi target was 0.2~1.5 kW, and AlCrSiN/Mo self-lubricating was obtained. film.

2. The composite magnetron sputtering preparation method of the AlCrSiN/Mo self-lubricating film according to claim 1, characterized in that: in step (1), before the substrate is fixed on the rotating frame, it is firstly immersed in acetone and ethanol in sequence. Each was cleaned with ultrasonic waves for 10~35min, and then dried with high-purity nitrogen.

3 . The composite magnetron sputtering preparation method of the AlCrSiN/Mo self-lubricating film according to claim 1 , wherein in step (2), the glow cleaning process is: a bias voltage of -800 V. 4 . Under the action, the flow rate of 50~200 sccm of Ar was introduced, the throttle valve was adjusted to keep the working pressure at 0.5~1.5 Pa, and the glow discharge was performed for 5~15 min to clean the surface of the substrate to remove surface impurities.

4. The composite magnetron sputtering preparation method of AlCrSiN/Mo self-lubricating film according to claim 1, characterized in that: in step (2), the process of the ion bombardment is: after glow cleaning, the arc Cr is turned on The target is bombarded with ions, the arc source current is set at 80~100 A, the arc source voltage is 15 V~25 V, and the Ar flow rate is 50~200 sccm, and the working pressure is maintained at (5~10)×10 ^-1 Pa, and the bombardment is carried out. The time is 5~10 minutes.

5. The composite magnetron sputtering preparation method of AlCrSiN/Mo self-lubricating film according to claim 1, characterized in that: in step (3), after the ion bombardment, the parameters of the arc Cr target are maintained unchanged, and the flow of Ar is 40 ~60 sccm, N ₂ flow rate 150~250 sccm, keep the working pressure at 8×10 ^-1 Pa, and deposit CrN transition layer for 10~20 min.

6 . The composite magnetron sputtering preparation method of the AlCrSiN/Mo self-lubricating film according to claim 1 , wherein in step (4), the deposition time is determined according to technical requirements and film deposition rate. 7 .

7. The composite magnetron sputtering preparation method of the AlCrSiN/Mo self-lubricating film according to claim 1, wherein the AlCrSiN/Mo self-lubricating film is a multiphase composite structure, and Mo element is doped into the AlCrSiN, The AlCrSiN/Mo self-lubricating thin film contains AlN, CrN and Mo ₂ N nanocrystalline phases so that Mo atoms replace Al and/or Cr atom sites in the (Al,Cr)N lattice to form a substitutional solid solution.

8. The composite magnetron sputtering preparation method of the AlCrSiN/Mo self-lubricating film according to claim 2, characterized in that: between the AlCrSiN/Mo self-lubricating film and the substrate is a CrN transition layer, and the substrate is stainless steel , single crystal Si sheet or cemented carbide sheet, the thickness of the CrN transition layer is 150-250 nm, and the thickness of the AlCrSiN/Mo self-lubricating film is 2.5-4.0 μm.