Altinn-ws2 low friction coefficient wear-resistant coating and preparation method thereof

Abstract

The application relates to the technical field of lubricating coating, in particular to an AlTiN-WS2 low-friction-coefficient wear-resistant coating and a preparation method thereof. The specific technical scheme is as follows: a preparation method of an AlTiN-WS2 low-friction-coefficient wear-resistant coating, comprising the following steps: (1) performing titanium ion cleaning on a pretreated base body by using a titanium ion arc target; (2) depositing a titanium transition layer on the base body by using multi-arc ion plating; (3) depositing an AlTiN coating by opening an AlTi alloy ion arc target; and (4) respectively preparing a Ti layer and a WS2 layer by opening a high-power pulsed magnetron sputtering device. The AlTiN hard layer is pre-deposited by using multi-arc ion plating, then the WS2 solid lubricating layer is deposited on the basis by using HiPIMS, and the wear-resistant coating with low friction coefficient is prepared.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lubricating coating, in particular to an AlTiN-WS2 low-friction coefficient wear-resistant coating and a preparation method thereof. BACKGROUND

[0002] Hard coatings can be mainly divided into nitride coatings, carbide coatings, oxide coatings and boride coatings. At present, the research on nitride is relatively mature and widely applied. The early commonly used nitride coatings mainly include TiN and CrN coatings. Compared with TiN, CrN coating has better friction performance and lower friction coefficient, so the application of CrN coating has more advantages. However, the CrN coating will be sharply reduced when the tool temperature exceeds 650℃, and is not suitable for high-temperature cutting machining.

[0003] In recent years, with the demand for high-speed and efficient cutting machining, the high-temperature oxidation resistance of the coating is required more and more. Generally, the addition of Al element can significantly improve the high-temperature oxidation resistance of the coating. Studies have shown that the addition of Al element in TiN coating can increase the oxidation temperature of the obtained TiAlN coating to 800℃ compared with binary nitride coating, which is mainly because the Al element in the coating can form an Al2O3 heat insulation protective layer in high-temperature service environment to prevent further high-temperature oxidation of the coating. However, the latest research shows that the Al2O3 oxidation layer formed by TiAlN coating is not dense, and there are scattered Al2O3 particles on the surface. In comparison, Cr has a higher melting point than Ti, and the high-temperature oxidation resistance of AlCrN coating with Cr instead of Ti can be improved compared with TiAlN coating. Although the Al-containing coating has improved in hardness and high-temperature resistance, the friction coefficient of the coating is still high. To solve this problem, Mo, V and other elements can be doped to reduce the friction coefficient. Overall, the friction coefficient of the nitride hard coating on steel is the smallest, between 0.4 and 0.5, and the friction coefficient is still relatively large, which cannot be directly used.

[0004] As a transition metal sulfide with a layered structure, WS2 has excellent thermal stability and oxidation resistance, a wide working temperature range, and is a solid lubricant with wide application prospects. Especially in some special application conditions, such as high pressure, heavy load or radiation and corrosion environment, its performance is particularly outstanding, and it is very suitable as a new type of lubricating material. But the pure WS2 coating prepared by magnetron sputtering is soft in texture and easy to lose lubricating performance in the friction process. In view of this defect, researchers improve the structure and performance of WS2 coating by doping TiO2, ZnO and other oxides and Ti, Cr, Ni, A, Zr, Cu, Ni-Co and other elements. Studies have shown that after doping, the composite coating structure is more dense, the surface is smoother, the adhesion to the substrate is stronger, and the hardness, anti-friction and wear resistance, oxidation resistance and humidity resistance of the composite coating are also improved. However, the hardness of WS2-based solid lubricating coating is generally not high, and it is suitable for application under low load, and its wear resistance under high load needs to be improved. SUMMARY

[0005] In view of the defects of the prior art, the present application provides an AlTiN-WS2 low friction coefficient wear-resistant coating and a preparation method thereof. The AlTiN hard layer is pre-deposited by using multi-arc ion plating, and then the WS2 solid lubricating layer is deposited by using HiPIMS (high power pulsed magnetron sputtering technology) on the basis, to prepare a wear-resistant coating with low friction coefficient.

[0006] To achieve the above object, the present application is realized by the following technical scheme:

[0007] The application discloses a preparation method of an AlTiN-WS2 low friction coefficient wear-resistant coating, comprising the following steps:

[0008] (1) the pretreated substrate is cleaned by titanium ion arc target;

[0009] (2) a titanium transition layer is deposited on the substrate by multi-arc ion plating;

[0010] (3) an AlTi alloy ion arc target is opened to deposit an AlTiN coating;

[0011] (4) a high power pulsed magnetron is opened to prepare a Ti layer and a WS2 layer.

[0012] Preferably, in step (1), the substrate is placed in a vacuum chamber, and the air pressure in the vacuum chamber is extracted to 7x10 -3Pa or below, the temperature in the cavity is heated and stabilized at 100-300 DEG C; then, using a titanium ion arc target, the target current is set to 60 A, 50-100 sccm of argon is introduced, the substrate bias is set to 600-800 V, the substrate is cleaned by titanium ions, and the cleaning time is 3-5 min.

[0013] Preferably, in step (2), after the titanium ion cleaning is completed, the substrate bias is set to 100-300 V, and a titanium transition layer with a thickness of 100-500 nm is deposited on the substrate surface by multi-arc ion plating.

[0014] Preferably, in step (3), the AlTi alloy ion arc target is opened, 20-100 sccm of argon and 200-400 sccm of nitrogen are introduced, the bias is set to 50-150 V, and a metal nitride hard coating with a thickness of 1-3 microns is deposited.

[0015] Preferably, in step (4), the temperature in the vacuum chamber is reduced to 100 DEG C, the nitrogen is turned off, 200-300 sccm of argon is introduced, a Ti layer with a thickness of 50-200 nm is prepared by high-power pulsed magnetron sputtering, and then a WS2 solid lubricating layer is prepared by high-power pulsed magnetron sputtering.

[0016] Correspondingly, the AlTiN-WS2 low-friction coefficient wear-resistant coating prepared by the above preparation method.

[0017] Correspondingly, the application of the AlTiN-WS2 low-friction coefficient wear-resistant coating prepared by the above preparation method to the needle bar of a sewing machine.

[0018] The application has the following beneficial effects:

[0019] The application provides an AlTiN-WS2 low-friction coefficient wear-resistant coating and a composite deposition method thereof. Based on the method, an AlTiN-WS2 wear-resistant coating with a relatively low friction coefficient can be prepared, and the wear rate of the AlTiN coating can be significantly reduced. When the coating is applied to the needle bar of a sewing machine, the difficulty that the movement mechanism of a high-end high-speed sewing machine is limited to a DLC coating can be overcome, and based on the method, a wear-resistant coating with a relatively low friction coefficient can be prepared on the movement structure of the needle bar of a sewing machine. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A cross-sectional SEM image of the AlTiN-WS2 composite coating prepared in Example 1;

[0021] Figure 2 A friction coefficient curve obtained after the AlTiN coating prepared in Comparative Example 1 and the AlTiN-WS2 composite coating prepared in Example 1 are rubbed;

[0022] Figure 3 Wear scar morphology of AlTiN coating prepared for Comparative Example 1 and AlTiN-WS2 composite coating prepared for Example 1;

[0023] Figure 4 Wear rate of AlTiN coating prepared for Comparative Example 1 and AlTiN-WS2 composite coating prepared for Example 1;

[0024] Figure 5 Figure of Ti target working time for titanium ion cleaning;

[0025] Figure 6 Figure of sewing machine needle bar;

[0026] Figure 7 Figure of running-in test after Example 2, Comparative Example 2 and Comparative Example 3; in the figure, 1 is the figure of running-in test after Example 2, 2 is the figure of running-in test after Comparative Example 2, 3 is the figure of running-in test after Comparative Example 3;

[0027] Figure 8 Figure of local wear after running-in test of Example 2, Comparative Example 2 and Comparative Example 3; in the figure, 1 is the figure of local wear after running-in test of upper sleeve of Example 2, 2 is the figure of local wear after running-in test of upper sleeve of Comparative Example 2, 3 is the figure of local wear after running-in test of upper sleeve of Comparative Example 3, 4 is the figure of local wear after running-in test of lower sleeve of Example 2, 5 is the figure of local wear after running-in test of lower sleeve of Comparative Example 2, 6 is the figure of local wear after running-in test of lower sleeve of Comparative Example 3;

[0028] Figure 9 Wear mass after running-in test of Example 2, Comparative Example 2 and Comparative Example 3;

[0029] Figure 10 Wear rate of Example 1 and Comparative Example 1 under the condition of load 5N and friction frequency 2Hz;

[0030] Figure 11 Friction coefficient of Example 1 and Comparative Example 1 under the condition of load 5N and friction frequency 2Hz. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be apparently and completely described below with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0032] The technical means used in the examples are conventional means well known to those skilled in the art, unless otherwise specified.

[0033] The application discloses a preparation method of an AlTiN-WS2 low-friction coefficient wear-resistant coating.

[0034] (1) the pretreated substrate is cleaned by titanium ions using a titanium ion arc target;

[0035] The substrate pretreatment process is as follows: the substrate is first placed into acetone and ethanol respectively for ultrasonic cleaning for 10-30 min to remove surface oil stains, and then is cleaned by ultrasonic deionized water for 4-6 times; after drying, the substrate is installed on a sample holder.

[0036] The sample holder with the installed substrate is placed into a vacuum chamber, the chamber door is closed to perform vacuumizing, and when the air pressure in the vacuum chamber is reduced to 7x10 -3 Pa, the temperature in the chamber is heated and stabilized at 100-300 DEG C; then the target current of the titanium ion arc target is set to 60 A, 50-100 sccm of argon is introduced, the substrate bias is set to 600-800 V, the substrate is cleaned by metal ions using the titanium ions, and the working time of the Ti target is set to open the Ti target for 1 min and close it for 1-3 min to avoid high temperature of the substrate during the metal ion cleaning; the total cleaning time is 3-5 min, the impurities on the surface of the substrate are removed, and the film-substrate adhesion is improved.

[0037] (2) a titanium transition layer is deposited on the substrate by multi-arc ion plating;

[0038] Specifically, after the titanium ion cleaning, the substrate bias is set to 100-300 V, the Ti target current is 60 A, a titanium transition layer with a thickness of 100-500 nm is deposited on the surface of the substrate by multi-arc ion plating, or the multi-arc ion plating is directly performed for 30 min.

[0039] (3) an AlTiN coating is deposited by opening an AlTi alloy ion arc target;

[0040] Specifically, the AlTi alloy ion arc target is opened, the target current is set to 60 A, 20-100 sccm of argon and 200-400 sccm of nitrogen are introduced, the bias is set to 50-150 V, a metal nitride hard coating with a thickness of 1-3 microns is deposited, or the deposition is directly performed for 120-180 min.

[0041] (4) a Ti layer and a WS2 layer are prepared by opening a high-power pulsed magnetron sputtering, and after the preparation, the sample holder is taken out when the temperature drops to below 60 DEG C.

[0042] Specifically, the temperature of the vacuum chamber is reduced to 100 DEG C, the nitrogen gas is closed, 200-300 sccm argon gas is introduced, a Ti layer with a thickness of 50-200 nm is prepared by high-power pulsed magnetron sputtering, or directly deposited for 10 min, then a WS2 solid lubricating layer with a thickness of 1 micron is prepared by high-power pulsed magnetron sputtering, or directly deposited for 55 min. During the preparation of the Ti layer, the Ti target is set to 25 A, 1 KW, 1000 Hz, 100 microseconds, and deposited for 10 min; during the preparation of the WS2 layer, the target current is 8 A, the sputtering power is 1.5 KW, the pulse frequency is 1000 Hz, the pulse width is 300 microseconds, the substrate bias is set to 50 V, and the deposition time is 55 min.

[0043] The application will be further described below in combination with specific examples.

[0044] Example 1

[0045] The coating preparation process is as follows:

[0046] 1) Stainless steel is selected as the substrate, the stainless steel substrate is first placed in acetone and ethanol for ultrasonic cleaning for 20 min to remove surface oil stains, and then cleaned with deionized water for 4 times, and after drying, the substrate is installed on a sample holder.

[0047] 2) Then the sample holder with the substrate installed is placed in the vacuum chamber, the chamber door is closed and vacuumized, the pressure in the vacuum chamber is reduced to 6x10 -3 Pa, and the temperature in the chamber is heated and stabilized at 100 DEG C.

[0048] 3) The titanium ion arc target is used, the target current is set to 60 A, 50 sccm argon gas is introduced, the substrate bias is set to 800 V, the titanium ion is used to clean the substrate with metal ions, and the cleaning time is 3 min.

[0049] 4) Then the substrate bias is set to 300 V, a Ti transition layer is deposited on the surface of the substrate by multi-arc ion plating, and the deposition time is 30 min.

[0050] 5) Then the AlTi alloy ion arc target is opened, the target current is set to 60 A, 20 sccm argon gas and 320 sccm nitrogen gas are introduced respectively, the bias is set to 150 V, and the deposition time is 170 min to prepare an AlTiN hard coating.

[0051] 6) Then the temperature of the vacuum chamber is reduced to 100 DEG C, the nitrogen gas is closed, 300 sccm argon gas is introduced, and a Ti layer is prepared by high-power pulsed magnetron sputtering, and the Ti target is set to 25 A, 1 KW, 1000 Hz, 100 microseconds, and deposited for 10 min.

[0052] 7) Finally, high-power pulsed magnetron sputtering was used to prepare the WS2 layer. The target current was 8A, the sputtering power was 1.5KW, the pulse frequency was 1000Hz, the pulse width was 300μs, the substrate bias voltage was 50V, and the deposition time was 55min.

[0053] 8) After the coating preparation is completed, turn off the power and gas, and remove the sample holder when the temperature drops below 60°C.

[0054] The AlTiN-WS2 low-friction coefficient wear-resistant coating prepared in this embodiment was subjected to cross-sectional analysis using SEM, and the results are as follows: Figure 1 As shown, the coating transition layer is uniform and smooth, and the structures of AlTiN and WS2 are clearly visible. The third layer is an AlTiN coating, used to protect the substrate and improve wear resistance. Its structure exhibits typical columnar crystal growth with coarse grains. The second layer is a Ti layer, approximately 200 μm thick, located between the AlTiN and WS2 coatings. It is mainly used to improve the bonding force between AlTiN and WS2. The top layer is a WS2 coating with a dense structure and fine grains, primarily serving to lubricate and improve the coating's friction and wear performance.

[0055] Comparative Example 1

[0056] The coating preparation process is as follows:

[0057] 1) Stainless steel was selected as the substrate. The stainless steel substrate was first placed in acetone and ethanol for 20 minutes of ultrasonic cleaning to remove surface oil. Then it was ultrasonically cleaned 4 times with deionized water. After drying, it was installed on the sample holder.

[0058] 2) Then, place the sample holder with the substrate installed into the vacuum chamber, close the chamber door, and evacuate the chamber to a pressure of 6 × 10⁻⁶. -3 The pressure is below Pa, which stabilizes the temperature inside the cavity at 100℃.

[0059] 3) Using a titanium ion arc target, set the target current to 60A, introduce argon gas at 50sccm, set the substrate bias voltage to 800V, and use titanium ions to clean the substrate with metal ions for 3 minutes.

[0060] 4) Next, set the substrate bias voltage to 300V and deposit a Ti transition layer on the substrate surface using multi-arc ion plating for 30 minutes.

[0061] 5) Then turn on the AlTi alloy ion arc target, set the target current to 60A, introduce 20sccm of argon gas and 320sccm of nitrogen gas respectively, set the bias voltage to 150V, and deposit for 170min to prepare the AlTiN coating.

[0062] 6) After the coating preparation, turn off the power and gas, and take out the sample holder when the temperature drops to below 60°C.

[0063] The same device as in Example 1 was used, and the method was basically the same as in the first 5 steps of Example 1. No WS2 coating was plated in this comparative example.

[0064] The AlTiN coating prepared in Comparative Example 1 and the AlTiN-WS2 composite coating prepared in Example 1 were subjected to a friction and wear test. The specific friction and wear test parameters were as follows: a GCr15 steel ball with a diameter of 10 mm was used as the friction pair in the atmosphere, the load was set to 10 N, the wear track length was 5 mm, and the linear reciprocating friction was continuously performed at a friction frequency of 5 Hz for one hour. Friction was performed at a load of 5 N and a counter friction frequency of 2 Hz as a comparison.

[0065] The results are shown in Figure 2 From the graph, it can be seen that the friction coefficient of the AlTiN coating was initially 0.8, and then decreased to 0.63 after 150 s, and then decreased to 0.4 after a period of time. This situation occurred because as the friction time increased, the wear debris also increased and accumulated in the wear track, and when the steel ball rubbed again, the wear debris acted as a filler between the coating and the steel ball, reducing the contact area and causing the friction coefficient to decrease. When the wear debris was worn out, the friction coefficient increased to about 0.6. The friction coefficient of the AlTiN-WS2 composite coating remained stable at about 0.07 before 40 min, indicating that the WS2 coating formed a lubricating transfer film on the steel ball, and a sustainable friction was formed between the two. However, the friction coefficient of the AlTiN-WS2 composite coating suddenly increased to 0.72 between 2400-2600 s, which may be because the WS2 coating on top was worn out, and the steel ball began to rub against the AlTiN coating, causing the friction coefficient to suddenly increase. Subsequently, the friction coefficient of the AlTiN-WS2 composite coating decreased and stabilized to about 0.6.

[0066] The wear track morphology is shown in Figure 3 From the graph, it can be seen that the wear track width of the AlTiN coating is significantly wider than that of the AlTiN-WS2 composite coating at the same magnification, and the wear track is biased to one side, while the composite coating is worn more evenly and does not show a bias to one side.

[0067] The wear rate results are shown in Figure 4 It can be directly seen that the wear rate of the AlTiN-WS2 composite coating is much lower than that of the AlTiN coating. The wear rate of the AlTiN-WS2 composite coating is 4.77 x 10 -6 mm 3 / (N·m), and the wear rate of the AlTiN coating is 13.04 x 10 -6 mm 3The wear rate of the AlTiN coating is 2.6 times that of the AlTiN-WS2 composite coating. The wear scar of the AlTiN-WS2 composite coating shows that the WS2 layer not only plays a lubricating role but also bears part of the wear during the friction, and when the steel ball contacts the AlTiN layer, the high wear resistance of the AlTiN layer prevents the wear of the composite coating, thereby protecting the substrate.

[0068] The friction coefficient and wear rate of Example 1 and Comparative Example 1 under a load of 5 N and a friction frequency of 2 Hz are shown in Table 1. Figure 10 、 Figure 11

[0069] Example 2

[0070] The coating on the needle bar of the sewing machine is currently a diamond-like carbon (DLC) coating, which has good self-lubricating, wear resistance and chemical stability, but the DLC coating has a low heat resistance temperature, and the diamond-like carbon coating is a metastable amorphous carbon coating mixed with SP 2 hybrid bonds (graphite phase) and SP 3 hybrid bonds (diamond phase), and the graphite phase will be converted to the diamond phase at high temperatures, affecting the stability. Therefore, the AlTiN-WS2 low friction coefficient wear-resistant coating prepared by the application is applied to the needle bar of the sewing machine.

[0071] The preparation process is as follows:

[0072] 1) Put the needle bar of the sewing machine into the oil removal cleaning solution and ultrasonic clean for 10-30 min, then ultrasonic clean with deionized water for 4 times, then dry with hot air and load on the sample holder.

[0073] 2) Then load the sample holder with the needle bar into the vacuum chamber, close the chamber door and evacuate, evacuate the vacuum chamber to below 7x10 -3 Pa, and heat the temperature in the chamber to be stable at 100℃.

[0074] 3) Use titanium ion arc target, set the target current to 60 A, input 50 sccm of argon, set the substrate bias to 800 V, use titanium ion to clean the needle bar, set the Ti target working time, open the Ti target for 1 minute and close it for 2 minutes, and the Ti target working time is shown in Table 2. Figure 5

[0075] 4) Then set the bias to 300 V, deposit a 300 nm thick Ti transition layer on the surface of the needle bar by multi-arc ion plating; then open the AlTi alloy target, input 320 sccm of nitrogen, set the bias to 100 V, and deposit a 1.5 μm thick AlTiN hard coating.

[0076] ​​5) Then, close the nitrogen, and introduce 300 sccm argon, open the high-power pulsed magnetron sputtering to prepare a Ti layer with a thickness of 200 nm, and then open the high-power pulsed magnetron sputtering to prepare a WS2 solid lubricating layer with a thickness of 1 μm.

[0077] 6) After the coating preparation is completed, the power and the gas are turned off, and the sample holder is taken out after the temperature is reduced to below 60°C. The appearance is as shown in Figure 6 .

[0078] Comparative Example 2

[0079] The preparation process is as follows:

[0080] 1) The needle bar of the sewing machine is placed in the oil removal cleaning solution for ultrasonic cleaning for 10-30 min, and then ultrasonic cleaning is performed four times using deionized water, and then hot air drying is performed, and the sample holder is loaded.

[0081] 2) Then, the sample holder loaded with the needle bar is placed in the vacuum chamber, the chamber door is closed, and vacuum is drawn, the pressure in the vacuum chamber is drawn to 7x10 -3 Pa or below, and the temperature in the chamber is heated and stabilized at 100°C.

[0082] 3) The titanium ion arc target is used, the target current is set to 60 A, 50 sccm argon is introduced, the substrate bias is set to 800 V, the needle bar is cleaned using titanium ions, the Ti target working time is set, the Ti target is opened for 1 min and closed for 2 min, and the Ti target working time is as shown in Figure 5 .

[0083] 4) Then, the bias is set to 300 V, a Ti transition layer with a thickness of 300 nm is deposited on the surface of the needle bar using multi-arc ion plating, then the AlTi alloy target is opened, 320 sccm nitrogen is introduced, the bias is set to 100 V, and an AlTiN hard coating layer with a thickness of 1.5 μm is deposited.

[0084] 5) After the coating preparation is completed, the power and the gas are turned off, and the sample holder is taken out after the temperature is reduced to below 60°C.

[0085] Comparative Example 3

[0086] The preparation process is as follows:

[0087] 1) The needle bar of the sewing machine is placed in the oil removal cleaning solution for ultrasonic cleaning for 10-30 min, and then ultrasonic cleaning is performed four times using deionized water, and then hot air drying is performed, and the sample holder is loaded.

[0088] 2) Then, the sample holder loaded with the needle bar is placed in the vacuum chamber, the chamber door is closed, and vacuum is drawn, the pressure in the vacuum chamber is drawn to 7x10 -3 Pa or below, and the temperature in the chamber is heated and stabilized at 100°C.

[0089] 3) Using titanium ion arc target, the target current is set to 60 A, 50 sccm of argon is introduced, the substrate bias is set to 800 V, the needle rod is cleaned by titanium ion, the working time of Ti target is set, the Ti target is opened for 1 minute and closed for 2 minutes, and the working time of Ti target is as shown in the figure. Figure 5

[0090] 4) Then, 300 sccm of argon is introduced, a Ti transition layer with a thickness of 200 nm is prepared by opening the high-power pulsed magnetron sputtering, and then a WS2 solid lubricating layer with a thickness of 1 μm is prepared by opening the high-power pulsed magnetron sputtering.

[0091] 5) After the preparation of the coating is completed, the power and gas are turned off, and the sample holder is taken out when the temperature drops to below 60℃.

[0092] The device used in Comparative Example 2 is the same as that in Example 2, and the method is basically the same as that in Example 2. In this comparative example, only an AlTiN hard coating is prepared on the needle rod, and no WS2 solid lubricating coating is plated.

[0093] The device used in Comparative Example 3 is the same as that in Example 2, and the method is basically the same as that in Example 2. In this comparative example, no AlTiN coating is plated, and only a WS2 solid lubricating coating is plated on the surface of the needle rod.

[0094] A commercial sewing machine is used to perform a running-in test on Example 2, Comparative Example 2 and Comparative Example 3 without adding any form of lubricating material. The sewing machine rotates at 4000 r / min during the running-in test, and works for 2 h. Figure 7 The photos of Example 2, Comparative Example 2 and Comparative Example 3 after the running-in test are shown in the figure. As can be seen from the figure, the three needle rod samples all have different degrees of wear after the running-in test. The friction parts of the needle rod are mainly concentrated in the middle and upper parts and the lower end position. The middle and upper parts of the No. 2 needle rod have relatively serious wear marks, and part of the lower end friction position is peeled off, exposing the metal surface of the needle rod. The wear mark of the No. 1 needle rod is relatively shallow, and almost no wear mark can be seen. The No. 3 needle rod has obvious wear in both the upper and lower parts, exposing a large area of the needle rod substrate.

[0095] Figure 8 The local wear photos of Example 2, Comparative Example 2 and Comparative Example 3 after the running-in test are shown in the figure. As can be seen from the figure, the wear of Example 2 of the application is relatively light. In the upper sleeve and lower sleeve positions which form relative friction with the needle rod, slight wear occurs. The wear of Comparative Example 2 is relatively serious, and a large area of the coating is peeled off in the upper sleeve position. In Comparative Example 3, a large area of the WS2 coating is almost worn out in both the upper end and the lower end of the needle rod, exposing the silver substrate, which indicates that the single WS2 is easily worn out during work. ​

[0096] Figure 9 Wear mass plots after running the test for Example 2, Comparative Example 2 and Comparative Example 3.

[0097] The above described examples are only to describe the preferred modes of the present application, and are not intended to limit the scope of the present application. Any modification and improvement made by those skilled in the art to the technical solutions of the present application without departing from the design spirit of the present application shall fall within the protection scope of the present application.

Claims

1. A method for preparing an AlTiN-WS2 low-friction coefficient wear-resistant coating, characterized in that: Includes the following steps: (1) The pretreated matrix was cleaned with titanium ions using a titanium ion arc target. The substrate is placed in a vacuum chamber, and the pressure in the chamber is evacuated to 7 × 10⁻⁶. -3 Below Pa, the temperature inside the cavity is heated and stabilized at 100-300℃; then, using a titanium ion arc target, the target current is set to 60A, argon gas is introduced at 50-100 sccm, the substrate bias voltage is set to 600-800V, and the substrate is cleaned with metal ions using titanium ions. The Ti target working time is set to 1 minute on and 1-3 minutes off, with a cleaning time of 3-5 minutes. (2) Deposit a titanium transition layer on the substrate using multi-arc ion plating; after completing titanium ion cleaning, set the substrate bias voltage to 100-300V and deposit a titanium transition layer with a thickness of 100-500nm on the substrate surface using multi-arc ion plating. (3) Deposit AlTiN coating by opening the AlTi alloy ion arc target; open the AlTi alloy ion arc target, introduce 20-100 sccm of argon and 200-400 sccm of nitrogen, set the bias voltage to 50-150V, and deposit a metal nitride hard coating with a thickness of 1-3μm. (4) High-power pulsed magnetron sputtering is turned on to prepare Ti layer and WS2 layer respectively; the temperature of the vacuum chamber is reduced to 100℃, the nitrogen gas is turned off, 200-300 sccm of argon gas is introduced, and high-power pulsed magnetron sputtering is turned on to prepare a Ti layer with a thickness of 50-200 nm. Then, high-power pulsed magnetron sputtering is turned on to prepare a WS2 solid lubricating layer. Specifically, when preparing the Ti layer, the Ti target parameters were set to 25A, 1KW, 1000Hz, 100μs, and deposition time of 10min; when preparing the WS2 layer, the target current was 8A, the sputtering power was 1.5KW, the pulse frequency was 1000Hz, the pulse width was 300μs, the substrate bias was set to 50V, and the deposition time was 55min.

2. The AlTiN-WS2 low friction coefficient wear-resistant coating prepared by the preparation method according to claim 1.

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