Layered TiAlN hard wear-resistant coating and preparation method thereof

Abstract

The invention relates to a lamellar TiAlN hard wear-resistant coating and a preparation method thereof, and relates to the technical field of material surface modification. Comprising the following steps: adopting a Ti-Al target, carrying out reactive magnetron sputtering in a mixed atmosphere of Ar and N2, and obtaining a lamellar TiAlN hard wear-resistant coating on a substrate, the reaction magnetron sputtering comprises high-power pulse magnetron sputtering; the coating is prepared by adopting high-power pulse magnetron sputtering, the process is simple, the cost is low, the process is easy to control, and by changing the process parameters of the high-power pulse magnetron sputtering, the coating can have a lamellar structure, the hardness reaches 38 GPa, and the friction coefficient is low.

Description

Technical Field

[0001] The invention relates to the technical field of material surface modification, and in particular to a lamellar TiAlN hard wear-resistant coating and a preparation method thereof. Background Art

[0002] TiAlN, a common hard coating, has a B1-NaCl structure, in which Al replaces Ti in the TiN lattice, exhibiting excellent mechanical properties and thermal stability. However, when coatings are prepared using DC and RF magnetron sputtering, the low kinetic energy of the sputtered target atoms limits the deposition rate.

[0003] With the development of cutting technology, TiAlN is limited by its inherent hardness and is prone to cracking and falling off under high-load wear conditions. To address this problem, the commonly used methods in the industry are to optimize the structure and element doping of TiAlN. In other words, incorporating other elements into TiAlN or preparing multilayer films can increase the hardness and wear resistance of the coating. Although these two methods can effectively solve the hardness problem of TiAlN coating, they increase the difficulty of target material preparation and coating preparation. In view of this, the present invention provides a lamellar hard wear-resistant coating and a preparation method thereof. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a lamellar TiAlN hard wear-resistant coating and its preparation method. The purpose is to provide a TiAlN hard wear-resistant coating with high hardness and excellent wear resistance that meets the needs of industrial production and is suitable for coating high-speed cutting and dry cutting tools.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] In a first aspect, a method for preparing a lamellar TiAlN hard wear-resistant coating comprises the following steps: using a Ti-Al target, performing reactive magnetron sputtering in an Ar and N2 mixed atmosphere to obtain a lamellar TiAlN hard wear-resistant coating on a substrate, wherein the TiAlN in the lamellar TiAlN hard wear-resistant coating is generated by reacting sputtered metal Ti, Al and N2; the reactive magnetron sputtering comprises high-power pulsed magnetron sputtering;

[0007] The parameters of the high power pulse magnetron sputtering are: vacuum degree of 5×10 -4 MPa~1×10 -4 MPa; the sputtering gas is Ar, and the Ar gas flow rate is 80sccm~100sccm; the reaction gas is N2, and the N2 gas flow rate is 1sccm~20sccm; the duty cycle is 5%~10%, and the discharge frequency is 300Hz; the sputtering power is 1000W~4000W; the pressure during sputtering is 0.3Pa~0.5Pa.

[0008] Among them, high-power pulsed magnetron sputtering (HIPMS) can generate high-density plasma, which can ionize the sputtered material atoms and has a very high target material ionization rate (ionization rate is about 90%) and deposition rate; using HIPMS technology to prepare coatings will increase the atomic mobility on the coating surface, inhibit the growth of transgranular fractures, enhance the surface finish and hardness of the coating, and thus enhance the wear resistance of the coating.

[0009] The beneficial effects of the present invention are:

[0010] (1) The lamellar TiAlN hard wear-resistant coating prepared by the present invention is a single-layer coating with a lamellar surface morphology. The grains are mainly columnar crystals that grow obliquely. The growth orientation of the TiAlN grains is changed by increasing the peak power of high-power pulsed magnetron sputtering.

[0011] (2) The present invention adopts high-power pulsed magnetron sputtering to prepare the coating, which has a simple process, low cost, and easy process control. By changing the process parameters of high-power pulsed magnetron sputtering, the coating can have a lamellar structure, a hardness of 38GPa, and a low friction coefficient.

[0012] (3) The lamellar TiAlN hard wear-resistant coating of the present invention is deposited in one step, has a high deposition rate (50 nm / min), has a smooth surface with few large particles, is free of defects such as large particles, and has high hardness and a low friction coefficient; therefore, the lamellar TiAlN hard wear-resistant coating can be used in the fields of tool surfaces, turbine blades, etc.

[0013] On the basis of the above technical solution, the present invention can also be improved as follows.

[0014] Furthermore, the reactive magnetron sputtering also includes pre-sputtering before high-power pulsed magnetron sputtering;

[0015] The pre-sputtering parameters are: vacuum degree 5×10 -4 MPa~1×10 -4 MPa; the sputtering gas is Ar, and the Ar gas flow rate is 80 sccm to 100 sccm; the duty cycle is 5 to 15%; the sputtering power is 1000 W to 4000 W; and the sputtering chamber pressure is 0.5 Pa to 0.8 Pa.

[0016] The beneficial effect of adopting the above further solution is that a short high-energy pulse will generate a high-density plasma, thereby increasing the ionization rate of the sputtered atoms.

[0017] Furthermore, the pre-sputtering time is 10 minutes to 15 minutes; the high-power pulse magnetron sputtering time is 30 minutes to 60 minutes.

[0018] The beneficial effect of adopting the above further solution is that the pre-sputtering can increase the adhesion of the coating and stabilize the process.

[0019] Furthermore, when high-power pulsed magnetron sputtering is used, the coating deposition temperature is 150° C. to 200° C.

[0020] The beneficial effect of adopting the above further solution is that the crystallinity of the coating can be optimized and the mechanical properties of the coating can be improved.

[0021] Furthermore, the distance between the substrate and the Ti—Al target is 100 mm to 150 mm; the Ti—Al target includes the following elements in atomic percentage: Ti: 50 at.%, Al: 50 at.%.

[0022] The beneficial effects of adopting the above further solution are: ensuring the uniformity of the coating composition and improving the density of the coating.

[0023] Furthermore, the substrate includes any one of TC4 titanium alloy, 316 stainless steel, and cemented carbide.

[0024] In a second aspect, a lamellar TiAlN hard wear-resistant coating is provided, wherein the lamellar TiAlN hard wear-resistant coating is prepared by the preparation method.

[0025] Furthermore, the thickness of the lamellar TiAlN hard wear-resistant coating is 1 μm to 5 μm.

[0026] The beneficial effect of adopting the above further solution is that the coating with this thickness can effectively protect the substrate during friction and wear tests.

[0027] Furthermore, the lamellar TiAlN hard wear-resistant coating comprises the following elements in atomic percentage: Ti: 23-27 at.%, Al: 23-27 at.%, N: 46-54 at.%.

[0028] The beneficial effect of adopting the above further solution is that the performance of TiAlN under this composition is relatively stable and can maintain good mechanical properties.

[0029] Furthermore, the hardness of the lamellar TiAlN hard wear-resistant coating is 30 GPa to 38 GPa; and the friction coefficient of the lamellar TiAlN hard wear-resistant coating is 0.3 to 0.5. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The surface morphology of TiAlN prepared on the alloy substrate in Example 2 of the present invention;

[0031] Figure 2The TiAlN layered structure in Example 2 of the present invention;

[0032] Figure 3 This is the cross-sectional morphology of TiAlN prepared on an alloy substrate in Example 2 of the present invention;

[0033] Figure 4 This is the cross-sectional grain morphology of TiAlN in Example 2 of the present invention.

[0034] Figure 5 The surface morphology of TiAlN prepared on the alloy substrate in Comparative Example 1 of the present invention is shown;

[0035] Figure 6 The TiAlN layered structure in Comparative Example 1 of the present invention;

[0036] Figure 7 This is the cross-sectional morphology of TiAlN prepared on an alloy substrate in Comparative Example 1 of the present invention;

[0037] Figure 8 This is the cross-sectional grain morphology of TiAlN in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0038] The principles and features of the present invention are described below. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this field or the product instructions are used. Where the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be purchased through regular channels.

[0039] Sources of materials and reagents:

[0040] The Ti-Al target was prepared by Zhongnuo New Materials Co., Ltd., and the composition was expressed in atomic percentage as follows: Ti: 50 at.%, Al: 50 at.%.

[0041] Example 1

[0042] This embodiment provides a method for preparing a lamellar TiAlN hard wear-resistant coating, comprising the following steps:

[0043] S1 grinds, polishes and ultra-clean the alloy substrate.

[0044] S2 preparation of layered TiAlN hard wear-resistant coating:

[0045] S21 installation: Install the Ti-Al target on the high-power pulse cathode, load the substrate into the sample stage, and fix the distance between the target and the substrate to be 120 mm;

[0046] S22 pre-sputtering: Pump the vacuum chamber to 5.4×10 -4Pa, then introduce Ar into the vacuum chamber, control the Ar flow rate to 100 sccm, the working pressure to 0.5 Pa, turn on the high power supply, and the sputtering time is 15 min;

[0047] S23 Preparation of a lamellar TiAlN hard coating: Ar and N2 were introduced into the vacuum chamber simultaneously, with the Ar flow rate adjusted to 100 sccm, the N2 flow rate adjusted to 10 sccm, the operating pressure adjusted to 0.5 Pa, the bias power supply set to 100 V, the high-power pulse power to 1000 W, the duty cycle to 10%, the deposition temperature to 200°C, and the sputtering time to 60 min to prepare a TiAlN coating on the alloy substrate;

[0048] Under the above process conditions, it was determined that the composition of the lamellar TiAlN hard wear-resistant coating prepared by high-power pulsed magnetron sputtering was Ti: 23 at.%, Al: 25 at.% and N: 52 at.%.

[0049] Example 2

[0050] This embodiment provides a method for preparing a lamellar TiAlN hard wear-resistant coating, comprising the following steps:

[0051] S1 grinds, polishes and ultra-clean the alloy substrate.

[0052] S2 preparation of layered TiAlN hard wear-resistant coating:

[0053] S21 installation: Install the Ti-Al target on the high-power pulse cathode, load the substrate into the sample stage, and fix the distance between the target and the substrate to be 120 mm;

[0054] S22 pre-sputtering: Pump the vacuum chamber to 5.4×10 -4 Pa, then introduce Ar into the vacuum chamber, control the Ar flow rate to 100 sccm, the working pressure to 0.5 Pa, turn on the high power supply, and the sputtering time is 15 min;

[0055] S23 preparation of lamellar TiAlN hard coating: Ar and N2 are introduced into the vacuum chamber at the same time, the Ar flow rate is adjusted to 100 sccm, the N2 flow rate is 15 sccm, the working pressure is 0.5 Pa, the bias power supply is set to 100 V, the high-power pulse power is 4000 W, the duty cycle is 10%, the deposition temperature is 200 ° C, the sputtering time is 60 min, and the TiAlN coating is prepared on the alloy substrate.

[0056] Under the above process conditions, the composition of the TiAlN coating prepared by high-power pulsed magnetron sputtering was measured to be Ti: 28 at.%, Al: 27 at.%, and N: 45 at.%.

[0057] Example 3

[0058] This embodiment provides a method for preparing a lamellar TiAlN hard wear-resistant coating, comprising the following steps:

[0059] S1 grinds, polishes and ultra-clean the alloy substrate.

[0060] S2 preparation of layered TiAlN hard wear-resistant coating:

[0061] S21 installation: Install the Ti-Al target on the high-power pulse cathode, load the substrate into the sample stage, and fix the distance between the target and the substrate to be 120 mm;

[0062] S22 pre-sputtering: Pump the vacuum chamber to 5.4×10 -4 Pa, then introduce Ar into the vacuum chamber, control the Ar flow rate to 100 sccm, the working pressure to 0.5 Pa, turn on the high power supply, and the sputtering time is 15 min;

[0063] S23 Preparation of lamellar TiAlN hard coating: Ar and N2 are introduced into the vacuum chamber at the same time, the Ar flow rate is adjusted to 80sccm, the N2 flow rate is 10sccm, the working pressure is 0.5Pa, the bias power supply is set to 100V, the high-power pulse power is 2000W, the duty cycle is 10%, the deposition temperature is 200℃, the sputtering time is 60min, and the TiAlN coating is prepared on the alloy substrate.

[0064] Under the above process conditions, the composition of the TiAlN coating prepared by high-power pulsed magnetron sputtering was measured to be Ti: 27 at.%, Al: 25 at.%, and N: 48 at.%.

[0065] Comparative Example 1

[0066] This embodiment provides a method for preparing a lamellar TiAlN hard wear-resistant coating, comprising the following steps:

[0067] S1 grinds, polishes and ultra-clean the alloy substrate.

[0068] S2 preparation of layered TiAlN hard wear-resistant coating:

[0069] S21 installation: Install the Ti-Al target on the high-power pulse cathode, load the substrate into the sample stage, and fix the distance between the target and the substrate to be 120 mm;

[0070] S22 pre-sputtering: Pump the vacuum chamber to 5.4×10 -4 Pa, then introduce Ar into the vacuum chamber, control the Ar flow rate to 100 sccm, the working pressure to 0.5 Pa, turn on the high power supply, and the sputtering time is 15 min;

[0071] S23 Preparation of lamellar TiAlN hard coating: Ar and N2 are introduced into the vacuum chamber at the same time, the Ar flow rate is adjusted to 120sccm, the N2 flow rate is adjusted to 25sccm, the working pressure is 0.7Pa, the bias power supply is set to 100V, the pulse power is 500W, the duty cycle is 10%, the deposition temperature is 200℃, the sputtering time is 60min, and the TiAlN coating is prepared on the alloy substrate.

[0072] Under the above process conditions, the composition of the TiAlN coating prepared by high-power pulsed magnetron sputtering was measured to be Ti: 28 at.%, Al: 26 at.%, and N: 46 at.%.

[0073] Comparative Example 2

[0074] This embodiment provides a method for preparing a lamellar TiAlN hard wear-resistant coating, comprising the following steps:

[0075] S1 grinds, polishes and ultra-clean the alloy substrate.

[0076] S2 preparation of layered TiAlN hard wear-resistant coating:

[0077] S21 installation: Install the Ti-Al target on the high-power pulse cathode, load the substrate into the sample stage, and fix the distance between the target and the substrate to be 120 mm;

[0078] S22 pre-sputtering: Pump the vacuum chamber to 5.4×10 -4 Pa, then introduce Ar into the vacuum chamber, control the Ar flow rate to 100 sccm, the working pressure to 0.5 Pa, turn on the high power supply, and the sputtering time is 15 min;

[0079] S23 preparation of lamellar TiAlN hard coating: Ar and N2 are introduced into the vacuum chamber at the same time, the Ar flow rate is adjusted to 100 sccm, the N2 flow rate is adjusted to 25 sccm, the working pressure is 0.5 Pa, the bias power supply is set to 100 V, the high-power pulse power is 5000 W, the duty cycle is 10%, the deposition temperature is 200 ° C, the sputtering time is 60 min, and the TiAlN coating is prepared on the alloy substrate.

[0080] Under the above process conditions, the composition of the TiAlN coating prepared by high-power pulsed magnetron sputtering was measured to be Ti: 35 at.%, Al: 30 at.%, and N: 35 at.%.

[0081] Comparative Example 3

[0082] This embodiment provides a method for preparing a lamellar TiAlN hard wear-resistant coating, comprising the following steps:

[0083] S1 grinds, polishes and ultra-clean the alloy substrate.

[0084] S2 preparation of layered TiAlN hard wear-resistant coating:

[0085] S21 installation: Install the Ti-Al target on the high-power pulse cathode, load the substrate into the sample stage, and fix the distance between the target and the substrate to be 120 mm;

[0086] S22 pre-sputtering: Pump the vacuum chamber to 5.4×10 -4 Pa, then introduce Ar into the vacuum chamber, control the Ar flow rate to 100 sccm, the working pressure to 0.5 Pa, turn on the high power supply, and the sputtering time is 15 min;

[0087] S23 preparation of lamellar TiAlN hard coating: Ar and N2 are introduced into the vacuum chamber at the same time, the Ar flow rate is adjusted to 100 sccm, the N2 flow rate is 30 sccm, the working pressure is 0.55 Pa, the bias power supply is set to 100 V, the high-power pulse power is 1000 W, the duty cycle is 10%, the deposition temperature is 200 ° C, the sputtering time is 60 min, and the TiAlN coating is prepared on the alloy substrate.

[0088] Under the above process conditions, the composition of the TiAlN coating prepared by high-power pulsed magnetron sputtering was measured to be Ti: 23 at.%, Al: 20 at.%, and N: 57 at.%.

[0089] Test example

[0090] (1) Coating characterization.

[0091] Figure 1 This is the surface morphology of TiAlN prepared on the alloy substrate in Example 2 of the present invention. It can be seen that the coating surface is smooth without obvious large particles. Figure 2 This is a diagram of the TiAlN layered structure in Example 2 of the present invention. It can be seen that the organizational structure is lamellar, which is conducive to improving hardness and wear resistance. Figure 3 This is a cross-sectional morphology of TiAlN prepared on an alloy substrate in Example 2 of the present invention, with a thickness of about 3 μm. It can be seen that the coating structure is complete without delamination. Figure 4 This is a cross-sectional grain morphology diagram of TiAlN in Example 2 of the present invention. It can be seen that the coating structure is columnar crystals and the growth direction is oblique growth.

[0092] Figure 5 This is the surface morphology of TiAlN prepared on the alloy substrate in Comparative Example 1 of the present invention. It can be seen that the coating surface is rough and has large particles. Figure 6 This is a diagram of the TiAlN layered structure in Comparative Example 1 of the present invention. It can be seen that the organizational structure is blocky. Figure 7This is a cross-sectional morphology of TiAlN prepared on an alloy substrate in Comparative Example 1 of the present invention, with a thickness of about 1.5 μm. It can be seen that the coating structure is complete without delamination. Figure 8 This is a cross-sectional grain morphology diagram of TiAlN in Comparative Example 1 of the present invention. It can be seen that the coating structure is columnar crystals, and the growth direction is vertical growth.

[0093] (2) Coating inspection.

[0094] The prepared coating was subjected to friction and wear tests and hardness tests, and the results are shown in Table 1.

[0095] The hardness test is specifically performed as follows: a TTX-NHT2 nanoindenter is used for testing, the indentation depth is 10% of the coating thickness, and the hardness of 5 points is measured and the average value is taken.

[0096] The friction and wear test was carried out at room temperature using a ball-on-disc friction and wear tester (TRB3). The wear part was a ZrO2 ceramic ball with a diameter of 6 mm. The load was 1 N, the reciprocating length was 6 mm, the frequency was 5 Hz, the time was 1800 s, and the maximum linear velocity was 2 mm / s.

[0097] Table 1

[0098] hardness Friction coefficient Example 1 30GPa 0.45 Example 2 38Ga 0.3 Example 3 31GPa 0.48 Comparative Example 1 16GPa 0.58 Comparative Example 2 13GPa 0.64 Comparative Example 3 24GPa 0.53

[0099] In summary, the present invention adopts high-power pulsed magnetron sputtering to prepare the coating, which has a simple process, low cost, and easy process control. By changing the process parameters of high-power pulsed magnetron sputtering, the coating can have a lamellar structure, a hardness of 38GPa, and a low friction coefficient.

[0100] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a lamellar TiAlN hard wear-resistant coating, characterized in that: The method comprises the following steps: using a Ti-Al target, performing reactive magnetron sputtering in an Ar and N2 mixed atmosphere, and obtaining a lamellar TiAlN hard wear-resistant coating on a substrate, wherein the TiAlN in the lamellar TiAlN hard wear-resistant coating is generated by the reaction of sputtered metal Ti, Al and N2; the reactive magnetron sputtering comprises high-power pulsed magnetron sputtering; The parameters of the high power pulse magnetron sputtering are: vacuum degree of 5×10 -4 MPa~1×10 -4 MPa; the sputtering gas is Ar, and the Ar gas flow rate is 80sccm~100sccm; the reaction gas is N2, and the N2 gas flow rate is 1sccm~20sccm; the duty cycle is 5%~10%, and the discharge frequency is 300Hz; the sputtering power is 1000W~4000W; the pressure during sputtering is 0.3Pa~0.5Pa.

2. The method for preparing a lamellar TiAlN hard wear-resistant coating according to claim 1, characterized in that: The reactive magnetron sputtering also includes pre-sputtering before high-power pulsed magnetron sputtering; The pre-sputtering parameters are: vacuum degree 5×10 -4 MPa~1×10 -4 MPa; the sputtering gas is Ar, and the Ar gas flow rate is 80 sccm to 100 sccm; the duty cycle is 5 to 15%; the sputtering power is 1000 W to 4000 W; and the sputtering chamber pressure is 0.5 Pa to 0.8 Pa.

3. The method for preparing a lamellar TiAlN hard wear-resistant coating according to claim 2, characterized in that: The pre-sputtering time is 10 minutes to 15 minutes; the high-power pulse magnetron sputtering time is 30 minutes to 60 minutes.

4. The method for preparing a lamellar TiAlN hard wear-resistant coating according to claim 1, characterized in that: When high-power pulsed magnetron sputtering is used, the coating deposition temperature is 150°C to 200°C.

5. The method for preparing a lamellar TiAlN hard wear-resistant coating according to claim 1, characterized in that: The distance between the substrate and the Ti—Al target is 100 mm to 150 mm; the Ti—Al target includes the following elements in atomic percentage: Ti: 50 at.%, Al: 50 at.%.

6. The method for preparing a lamellar TiAlN hard wear-resistant coating according to any one of claims 1 to 5, characterized in that: The substrate includes any one of TC4 titanium alloy, 316 stainless steel, and cemented carbide.

7. A lamellar TiAlN hard wear-resistant coating, characterized in that: The lamellar TiAlN hard wear-resistant coating is prepared by the preparation method according to any one of claims 1 to 6.

8. The lamellar TiAlN hard wear-resistant coating according to claim 7, characterized in that: The thickness of the lamellar TiAlN hard wear-resistant coating is 1 μm to 5 μm.

9. The lamellar TiAlN hard wear-resistant coating according to claim 7, characterized in that: The lamellar TiAlN hard wear-resistant coating comprises the following elements in atomic percentage: Ti: 23-30 at.%, Al: 23-30 at.%, N: 35-54 at.%.

10. The lamellar TiAlN hard wear-resistant coating according to claim 7, characterized in that: The hardness of the lamellar TiAlN hard wear-resistant coating is 30 GPa to 38 GPa; the friction coefficient of the lamellar TiAlN hard wear-resistant coating is 0.3 to 0.5.

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