High-toughness self-organized nano multilayer structure oxynitride coating and preparation method thereof

Abstract

The invention belongs to the technical field of coating materials, and particularly relates to a high-toughness self-organizing nano multilayer structure oxynitride coating and a preparation method thereof. The high-toughness oxynitride coating with the self-organizing nano multi-layer structure sequentially comprises a base body, a CrN transition layer and an AlCrNbSiON self-organizing nano multi-layer from bottom to top, and the self-organizing nano multi-layer is formed by alternately depositing a nitrogen-rich layer and an oxygen-rich layer. Wherein the nitrogen-rich layer is a hard layer, the oxygen-rich layer is a soft layer, and the nitrogen-rich layer and the oxygen-rich layer alternately form a'hard and soft 'nano multilayer structure. Due to the fact that the cracks are prone to being generated and propagated in the hard layer, when the cracks extend to a multi-layer interface, the high damage tolerance of the soft layer can effectively absorb energy and passivate the tips of the cracks, and therefore the cracks generated in the hard layer are prevented from continuing to propagate; and meanwhile, the coating can integrate the advantages of multiple strengthening mechanisms such as modulus difference strengthening, nano multi-layer strengthening and coherent strengthening, so that the toughness and hardness of the coating are synchronously improved.

Description

Technical Field

[0001] This invention belongs to the field of coating materials technology, specifically relating to a high-strength and tough self-organized nano-multilayer oxynitride coating and its preparation method. Background Technology

[0002] In the cutting of difficult-to-machine materials such as high-temperature alloys, the extremely low thermal conductivity of these alloys leads to heat dissipation difficulties, resulting in cutting temperatures exceeding 1000℃. This is accompanied by severe work hardening and cutting deformation, which in turn exacerbates tool wear. To address the problem of tool damage caused by the extreme environments in machining difficult-to-machine materials, coating the cutting tool surface with a wear-resistant and friction-reducing protective film is an effective technical solution. These coatings are mostly prepared by various PVD methods and are mainly divided into two categories in industrial applications: oxide coatings and nitride coatings. Nitride coatings typically possess high hardness and toughness, performing excellently in cutting high-temperature alloys at medium to low speeds, but their mechanical properties degrade significantly at high temperatures, and their oxidation resistance is insufficient. Oxide coatings, on the other hand, have better thermal and chemical stability, making them more suitable for high-speed cutting scenarios; however, their upper limit of hardness is relatively low, and due to their predominantly ion-bonded nature, their toughness is poor. Therefore, in the development of next-generation hard coatings for high-temperature alloy cutting, oxynitride coatings, which can combine the excellent mechanical properties of nitride coatings with the high-temperature stability of oxide coatings, are playing an increasingly important role and have broad application potential.

[0003] For many years, researchers have conducted a series of studies on oxynitride coatings. K. Bobzin et al. designed and prepared TiN / AlN / TiAlON multilayer coatings and found that as the oxygen content of the coating increases, its indentation hardness, indentation modulus and resistance to plastic deformation all show a decreasing trend (Bobzin K, Kalscheuer C, Grundmeier G, et al. Designof a TiAlON multilayer coating: oxidation stability and deformation behavior[J]. Surface and Coatings Technology, 2021, 421: 127417.). Marcus Hans et al. prepared TiAlON coatings using a substrate rotation process. Atomic probe chromatography (APT) analysis confirmed that the coatings consisted of alternating sublayers with relatively high oxygen content and sublayers with relatively high nitrogen content (Hans M, to Baben M, Chen YT, et al. Substrate rotation-induced chemical modulation in Ti-Al-ON coatings synthesized by cathodic arc in an industrial deposition plant[J]. Surface and Coatings Technology, 2016, 305: 249-253.).

[0004] Adding an appropriate amount of Nb to transition metal nitride coatings can simultaneously improve coating toughness while increasing hardness or maintaining a small loss of hardness. However, Nb-doped coatings are prone to forming loose and porous niobium oxide at high temperatures, leading to accelerated oxidation and hindering applications in high-speed machining scenarios. Nb-based oxides possess metallic properties, which not only endow them with good toughness but also promote energy dissipation during friction, improving the coating's frictional compliance and having a positive impact on machining. Deposited coatings prepared by physical vapor deposition have a dense structure and low oxidation driving force; therefore, doping transition metal nitride coatings with oxygen is expected to improve their high-temperature oxidation resistance. Combining the advantages of Nb-based nitride coatings and oxide coatings to form oxynitride coatings is expected to give the coating both excellent toughness and high-temperature oxidation resistance. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides a high-toughness self-organized nano-multilayer oxynitride coating. This coating comprises an AlCrNbSiON nano-multilayer coating formed by alternating deposition of a CrN transition layer and nitrogen-rich and oxygen-rich layers, achieving a synergistic effect of high hardness and high toughness. The coating is prepared using arc ion plating technology. By controlling the coating's composition, modulating its structure, phase structure, and mechanical properties, and combining multiple strengthening mechanisms, a high-hardness and high-toughness nano-multilayer oxynitride toughened coating is ultimately obtained.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a high-toughness self-organized nano-multilayer oxynitride coating, wherein the coating comprises, from bottom to top, a substrate, a CrN transition layer and an AlCrNbSiON self-organized nano-multilayer; the AlCrNbSiON self-organized nano-multilayer is formed by alternating deposition of nitrogen-rich AlCrNbSiON layers and oxygen-rich AlCrNbSiON layers. The total thickness of the coating is 2–6 μm, and the modulation period is 1–70 nm. The thickness of a single nitrogen-rich AlCrNbSiON layer is 0.1–50 nm, and the thickness of a single oxygen-rich AlCrNbSiON layer is 0.1–20 nm.

[0007] Preferably, in the self-organized nanomultilayer AlCrNbSiON, the mass percentage of O atoms is 3-40 at.%, the mass percentage of N atoms is 3-60 at.%, the mass percentage of Cr atoms is 10-25 at.%, the mass percentage of Al atoms is 15-25 at.%, the mass percentage of Nb atoms is 1-10 at.%, and the mass percentage of Si atoms is 1-10 at.

[0008] The second aspect of this invention also provides a method for preparing the high-toughness self-organized nano-multilayer oxynitride coating described in the first aspect, the method comprising the following steps: S1. Loading into the furnace: Clamp the substrate sample onto the hanger of the PVD deposition equipment; S2, Heating / Vacuuming: First, evacuate the chamber to below 5 Pa, then set the temperature to 350℃~450℃; S3, Glow Glow Cleaning: Wait until the chamber vacuum level decreases to 3.0 × 10⁻⁶. -3 Pa ~ 6.0 × 10 -3 Below Pa, 250-350 sccm of argon gas is introduced to control the chamber pressure at 1.5-2.5 Pa. The substrate bias voltage is set to -800--1000 V, and glow discharge cleaning is performed for 20-40 min. S4. Ion etching: Position the mounting rod containing the substrate in front of the target and rotate it. Adjust the argon flow rate to 50-90 sccm, the chamber pressure to 0.2-0.7 Pa, set the substrate bias voltage to -700--900 V, set the target current to 90-110 A, and start Cr target etching for 1-3 min. Then adjust the substrate bias voltage to -500--700 V and etch for another 2-4 min. S5. Deposition of transition layer: CrN is selected as the transition layer. 200-400 sccm of N2 is introduced into the chamber, the chamber pressure is controlled at 0.8-1.4 Pa, the Cr target current is set at 90-110 A, and the Cr target is turned on to deposit the CrN transition layer for 5-15 min. Deposition of S6, AlCrNbSiON nanolayer coating: Initiating Al 50 Cr 30 Nb 10 Si 10 An alloy target with a target current of 60–100 A is used. 270–320 sccm of N2 and 0.1–25 sccm of O2 are introduced to maintain the cavity pressure at 2.5–3.5 Pa. The substrate bias voltage is -100–-200 V. An AlCrNbSiON coating is deposited for 40–100 min. S7. After deposition is complete, wait for the temperature to drop to room temperature and then remove the coated sample to obtain a self-organized nano-multilayer AlCrNbSiON coating.

[0009] Preferably, the substrate sample needs to be cleaned before use. Specifically, after polishing the surface of the substrate, it is immersed in acetone solution for ultrasonic cleaning for 15-30 minutes, and then immersed in anhydrous ethanol solution for ultrasonic cleaning for 15-30 minutes. After cleaning, the substrate is taken out and dried.

[0010] Preferably, the heating / vacuuming of S2 is as follows: close the furnace door, first use a mechanical pump + Roots pump to roughly evacuate the chamber to below 5Pa, then pre-start the molecular pump, and after the molecular pump is running at full speed, turn on the chamber heater and set the temperature to 350℃~450℃.

[0011] Preferably, the ion etching of S4 adopts the Cr ion etching process, and the target material used is a Cr target.

[0012] Preferably, in S6, the gas flow ratio of N2 to O2 is 294:6, 291:9, 287:13, or 282:18.

[0013] The third aspect of the present invention also provides the application of the high-toughness self-organized nano-multilayer oxynitride coating described in the first aspect in the field of high-temperature alloy cutting.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention discloses a high-toughness self-organized nano-multilayer oxynitride coating, comprising, from bottom to top, a substrate, a CrN transition layer, and an AlCrNbSiON self-organized nanolayer. The AlCrNbSiON self-organized nanolayer is formed by alternating deposition of nitrogen-rich AlCrNbSiON layers and oxygen-rich AlCrNbSiON layers. The self-organized nitrogen-rich AlCrNbSiON layers are hard layers, while the oxygen-rich layers are soft layers, forming a "hard-soft" nano-multilayer structure. This coating is prepared using arc ion plating technology. By controlling the coating's composition, modulating its structure, phase structure, and mechanical properties, and combining multiple strengthening mechanisms, the structure is designed and prepared to achieve high hardness and high toughness. Since cracks tend to initiate and propagate in hard layers, when cracks extend to multilayer interfaces, the high damage tolerance of soft layers can effectively absorb energy and passivate crack tips, thereby preventing cracks initiated in hard layers from continuing to propagate. At the same time, this coating can combine the advantages of multiple strengthening mechanisms such as modulus difference strengthening, nano-multilayer strengthening, and coherent strengthening, thereby simultaneously improving the toughness and hardness of the coating.

[0015] Specifically, the present invention has the following advantages: (1) The self-organized AlCrNbSiON nano-multilayer coating prepared by the present invention can take into account both the good mechanical properties of nitride coating and the good high-temperature stability of oxide coating. (2) By rotating the substrate support of the physical vapor deposition (PVD) equipment, AlCrNbSiON nanomultilayers with alternating self-organized growth of nitrogen-rich and oxygen-rich layers are formed, eliminating the need for frequent switching between multiple targets in traditional multilayer coatings. The preparation method and technology used are convenient, simple, controllable, fast, and low-cost, making them suitable for large-scale industrial production.

[0016] (3) This invention uses arc ion plating technology to innovatively design and construct a self-organized alternating multilayer structure of "one hard and one soft". By comprehensively integrating the synergistic advantages of various strengthening mechanisms such as modulus difference strengthening, nano multilayer strengthening, and coherent strengthening, the hardness and toughness of the coating are simultaneously improved. It has the technical characteristics of novel structural design and significant toughening effect. Attached Figure Description

[0017] Figure 1 The diagram shows the structure of the coatings obtained in Examples 1-4 and the comparative example; (a) is Example 1-4; (b) is the comparative example; Figure 2 The images show cross-sectional SEM images of the coatings obtained in the comparative examples and Examples 1-4; (a) cross-sectional SEM image of the comparative example; (b), (c), (d), and (e) cross-sectional SEM images of Examples 1-4, respectively. Figure 3Figure 1 shows TEM images of two groups of coatings, representing the comparative example and Example 4; Figure (a) is the TEM image of the comparative example; Figure (b) is the TEM image of Example 4. Figure 4 The mechanical property test results are for the AlCrNbSiN coating obtained in the comparative example and the nano-multilayer AlCrNbSiON coating obtained in Examples 1-4. Figure 5 The surface morphology of the indentation experiment of the AlCrNbSiN coating obtained in the comparative example and the nano-multilayer AlCrNbSiON coating obtained in Examples 1-4 are shown. Figure 6 The KIC values ​​are for the AlCrNbSiN coating obtained in the comparative example and the nano-multilayer AlCrNbSiON coating obtained in Examples 1-4. Figure 7 The micropillar indentation morphology and load-displacement curves of the AlCrNbSiN coating obtained in the comparative example and the nano-multilayer AlCrNbSiON coating obtained in Example 4 are shown. Figure 8 The hardness, elastic modulus, and K calculated by the micropillar method are compared between the AlCrNbSiN coating obtained in the comparative example and the nano-multilayer AlCrNbSiON coating obtained in Example 4. C value. Detailed Implementation

[0018] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0019] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0020] Example 1: A high-toughness self-organized nano-multilayer oxynitride coating and its preparation method The high-toughness self-organized nanomultilayer oxynitride coating consists of a CrN transition layer and an AlCrNbSiON self-organized nanomultilayer, wherein the AlCrNbSiON self-organized nanomultilayer is formed by alternating growth of nitrogen-rich AlCrNbSiON layers (referred to as nitrogen-rich layers) and oxygen-rich AlCrNbSiON layers (referred to as oxygen-rich layers). Its preparation method includes the following steps: (1) Cleaning the substrate: After polishing the surface of the substrate (hard alloy block YG8), it is immersed in acetone solution for ultrasonic cleaning for 20 min, and then immersed in anhydrous ethanol solution for ultrasonic cleaning for 20 min. After cleaning, the substrate is taken out and dried. (2) Loading into the furnace: clamp the cleaned sample onto the hanging rod of the PVD deposition equipment (Huasheng HD500).

[0021] (3) Heating / vacuuming: After closing the furnace door, first use the mechanical pump and Roots pump combination system to perform rough vacuuming of the chamber until the chamber vacuum drops below 5 Pa; then pre-start the molecular pump, and after it reaches full speed operation, turn on the chamber heater and set the heating temperature to 400℃.

[0022] (4) Glow Glow Cleaning: Wait until the vacuum level in the chamber drops to 5×10 -3 Below Pa, argon gas (flow rate 300 sccm) is introduced to stabilize the chamber pressure at 2.0 Pa; the substrate bias voltage is set to -1000 V, and the glow discharge cleaning program is started and cleaned continuously for 30 min.

[0023] (5) Ion etching: Using Cr ion etching process, the mounting rod of the substrate is positioned in front of the Cr target and rotates. First, the argon flow rate is adjusted to 70 sccm, the chamber pressure is maintained at 0.5 Pa, the substrate bias voltage is set to -800 V and the Cr target current is 100 A, and the Cr target etching is started for 2 min. Then the substrate bias voltage is adjusted to -600 V and etching continues for 3 min.

[0024] (6) Transition layer deposition: Using CrN as the transition layer, nitrogen gas (flow rate 300 sccm) is introduced into the chamber, the chamber pressure is controlled at 1.2 Pa, the Cr target current is set at 100 A, and the Cr target deposition of the CrN transition layer is started, with a deposition time of 10 min.

[0025] (7) AlCrNbSiON nanolayer coating deposition: opening up Al 50 Cr 30 Nb 10 Si 10An alloy target was used, with a target current of 80 A, a chamber pressure maintained at 3.0 Pa, and a substrate bias voltage of -150 V. Under an N2 / O2 gas flow ratio of 294 / 6, an AlCrNbSiON nanolayered coating was deposited for 60 min. During this process, with the continuous rotation of the substrate scaffold and the combined reaction environment of N2 and O2 gases, nitrogen-rich AlCrNbSiON and oxygen-rich AlCrNbSiON layers spontaneously and alternately formed on the substrate. The atomic percentages of the coating were: nitrogen 42.7 at.%, oxygen 9.2 at.%, aluminum 21.5 at.%, chromium 17.0 at.%, niobium 5.3 at.%, and silicon 4.2 at.%. The total coating thickness was 2.2 μm, with a CrN transition layer thickness of 400 nm. The nitrogen-rich and oxygen-rich layers constituted one modulation cycle, with a modulation cycle thickness of 10.3 nm, and approximately 214 modulation cycles were deposited.

[0026] (8) After the deposition is completed, the coated sample is taken out after the temperature drops to room temperature to obtain a self-organized nano-multilayer AlCrNbSiON coating.

[0027] Examples 2-4: The preparation methods of the coatings described in Examples 2-4 are basically the same as those in Example 1. The difference is that the flow rates of nitrogen and oxygen introduced during the coating preparation process are different (the N2 / O2 gas flow rates corresponding to Examples 2-4 are 291 / 9, 287 / 13, and 282 / 18, respectively). The specific operating parameters and the nitrogen and oxygen atom contents are shown in Table 1.

[0028] Comparative example: The preparation method of the coating described in the comparative example is basically the same as that in Example 1, except that the oxygen flow rate is 0 sccm and the nitrogen flow rate is 300 sccm during the coating preparation process (the corresponding N2 / O2 gas flow rate ratio is 300 / 0; specific operating parameters and nitrogen and oxygen atom contents are shown in Table 1).

[0029] Table 1. Nitrogen and oxygen flow rates during the preparation process of the comparative examples and Examples 1-4, and the nitrogen and oxygen atom content of the resulting coatings. Experimental Example: Coating Characterization and Performance Testing Figure 1The diagrams show the structures of the coatings obtained in Examples 1-4 and the comparative example. (a) is a structural diagram of the self-organized nano-multilayer AlCrNbSiON coating provided in Examples 1-4. This coating consists of AlCrNbSiON self-organized nano-multilayer functional layers with alternating deposition of CrN transition layer, nitrogen-rich layer and oxygen-rich layer. The nitrogen-rich layer and the oxygen-rich layer have a large hardness difference, forming a "hard and soft" multilayer structure composed of a harder nitrogen-rich layer and a softer oxygen-rich layer. Under the action of external load, cracks tend to initiate and propagate in the hard layer first. When the crack propagates to the multilayer interface, the high damage tolerance of the soft layer can absorb energy, and the crack becomes passivated, deflected and bridged, thereby eliminating the crack tip and blocking the crack initiated by the hard layer from continuing to propagate. (b) is a structural diagram of the AlCrNbSiN coating provided in the comparative example.

[0030] Figure 2 The images show cross-sectional SEM images of the coatings obtained in the comparative examples and Examples 1-4, where (a) is a cross-sectional SEM image of the AlCrNbSiN coating obtained in the comparative example, and (b), (c), (d), and (e) are cross-sectional SEM images of the self-organized nano-multilayer AlCrNbSiON coatings obtained in Examples 1-4, respectively. All coatings have dense structures and good adhesion to the substrate.

[0031] Figure 3 The images show TEM analysis data representing the two groups of coatings: the comparative example and Example 4. Figure 3 (a) is a TEM image of the AlCrNbSiON coating prepared under N2 / O2 gas flow rate of 300 / 0, which is a comparative example. The bright field image shows columnar crystal growth morphology. By measuring the interplanar spacing in regions I and II of the high resolution image and combining it with the selected area diffraction pattern, it can be determined that the coating lattice has dissolved a certain amount of Nb ions with larger diameters, which leads to an increase in interplanar spacing compared with the standard c-CrN. The coating is mainly composed of cubic nitride (Al,Cr,Nb)N phase. The EDS surface scan results show that there is no compositional modulation phenomenon in the coating, and the constituent elements are uniformly distributed in the coating. Figure 3 (b) is a TEM image of the AlCrNbSiON coating prepared in Example 4 with an N2 / O2 flow ratio of 282 / 18. From the bright field image and HAADF image (the contrasting bright and dark stripes in the image are typical features of the alternating stacking of different phases or components), it can be seen that the multilayer structure of the coating is obvious. The coating is formed by the overlapping growth of nitrogen-rich layers and oxygen-rich layers. From the high-resolution image, it can be found that both the nitrogen-rich layer and the oxygen-rich layer have multiple coherent growths. From the EDS surface scan results, it can be seen that the cation elements are evenly distributed, while the O and N elements exhibit composition modulation phenomenon due to the periodic changes in their content in each sublayer (the signal intensity of O and N elements shows complementary periodic fluctuations: the O signal is strong and the N signal is weak in the dark contrast layer (oxygen-rich layer); the opposite is true in the bright contrast layer (nitrogen-rich layer).

[0032] Figure 4 The mechanical property test results are shown for the AlCrNbSiN coating obtained in the comparative example and the nano-multilayer AlCrNbSiON coatings obtained in Examples 1-4. As the O2 flow rate increases during the deposition process, the hardness of the coating first increases and then decreases. The AlCrNbSiON coating prepared in Example 1 with an N2 / O2 gas flow rate ratio of 291 / 9 reaches the maximum mechanical property of 29.5 GPa. The reason for the increased hardness due to a small amount of oxygen doping is related to the coating structure design of the present invention. As can be seen from the above TEM results, the coatings of Examples 1-4 form a nano-multilayer structure with alternating nitrogen-rich and oxygen-rich layers due to the rotational self-organization of the substrate. The multilayer interface hinders the movement of dislocations. In addition, the local coherent epitaxial growth of the oxygen-rich layer along the nitrogen-rich layer also has a strengthening effect on the mechanical properties of the coating.

[0033] Figure 5 The images show the surface morphology of the indentation test. Indentation tests were conducted on AlCrNbSiON coatings prepared at different N2 / O2 flow ratios using a Vickers hardness tester at a load of 20 N for 10 s. The images show that AlCrNbSiON exhibits the largest number of annular cracks, with the radial cracks (cracks along the diagonal of the indentation) being the longest. The indentation fracturing behavior of oxygen-doped AlCrNbSiON coatings is improved in all cases, with coatings at N2 / O2 flow ratios of 294 / 6 and 282 / 18 showing a significant reduction in the number of annular cracks and a shorter radial crack length.

[0034] Figure 6 To quantitatively characterize the coating toughness based on the Vickers indentation morphology, the calculated K... IC A graph showing the trend of K values ​​as oxygen flow rate changes. Compare the K values ​​of different coatings. IC The values ​​show that as the oxygen flow rate increases from 6 sccm to 18 sccm, the coating K... IC The values ​​first decreased and then increased, and were both higher than those of the undoped O coating. The combination of a high-hardness nitrogen-rich layer and a low-hardness oxygen-rich layer in the self-organized nano-multilayer AlCrNbSiON coating, forming a "hard-soft" nano-multilayer structure, may be the reason for the increased toughness of the high-oxygen-content coating (N2 / O2=287 / 13, N2 / O2=282 / 18).

[0035] Two coating samples prepared under N2 / O2=300 / 0 and N2 / O2=282 / 18 conditions were selected, and their toughness was further verified by the microcolumn method. Figure 7The micropillar indentation morphology and load-displacement curves of the two coatings are shown. It can be seen that the indentation depth of both coatings is basically the same, 350 nm. However, the ultimate load that the AlCrNbSiON coating can withstand (i.e., the load corresponding to the first appearance of the "plateau" in the load-displacement curve) is higher than that of the AlCrNbSiN coating. From the micropillar indentation morphology of the two coatings, it can be seen that after the AlCrNbSiN coating is fractured, the crack penetrates the micropillar longitudinally, while the crack depth along the longitudinal direction of the AlCrNbSiON coating is shallower.

[0036] Figure 8 The hardness, elastic modulus, and K0 calculated by the micropillar method were determined for AlCrNbSiON coatings prepared under N2 / O2 = 300 / 0 and N2 / O2 = 282 / 18. C Value. K C The value represents the quantitative value of the coating toughness. It can be seen that the hardness and elastic modulus of the coating both decrease slightly after a significant amount of oxygen doping. The Kt value of the AlCrNbSiN coating with an N2 / O2 flow ratio of 300 / 0 is [value missing]. C The value is 2.853 MPa·m 1 / 2 K of AlCrNbSiON coating with N2 / O2 flow ratio of 282 / 18 C The value is 4.012 MPa·m 1 / 2 The results are close to those obtained using the indentation method, and the trend is consistent. The combination of a high-hardness nitrogen-rich layer and a low-hardness oxygen-rich layer forms a "hard-soft" nano-multilayer structure, which may be the reason for the improved toughness of the self-organized nano-multilayer AlCrNbSiON coating. Under external load, cracks tend to initiate and propagate first in the hard layer. When the crack propagates to the multilayer interface, the high damage tolerance of the soft layer leads to crack bridging, deflection, or passivation, absorbing energy and effectively eliminating the crack tip. These results indicate that appropriate oxygen doping in the AlCrNbSiN coating can improve the coating's toughness.

[0037] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A high toughness self-organizing nanomultilayered oxynitride coating, characterized by, The coating comprises, from bottom to top, a substrate, a CrN transition layer, and an AlCrNbSiON self-organizing nanomultilayer; the AlCrNbSiON self-organizing nanomultilayer is formed by alternately depositing a nitrogen-rich AlCrNbSiON layer and an oxygen-rich AlCrNbSiON layer. The total thickness of the coating is 2-6 μm, the modulation period is 1-70 nm, the single-layer thickness of the nitrogen-rich AlCrNbSiON layer is 0.1-50 nm, and the single-layer thickness of the oxygen-rich AlCrNbSiON layer is 0.1-20 nm.

2. The high toughness self-organizing nanomultilayered oxy-nitride coating according to claim 1, characterized in that, In the AlCrNbSiON self-organizing nanomultilayer, the mass percentage of O atoms is 3-40 at.%, the mass percentage of N atoms is 3-60 at.%, the mass percentage of Cr atoms is 10-25 at.%, the mass percentage of Al atoms is 15-25 at.%, the mass percentage of Nb atoms is 1-10 at.%, and the mass percentage of Si atoms is 1-10 at.%.

3. The method of producing a high-toughness self-organizing nanomultilayer oxy- nitride coating according to claim 1 or 2, characterized in that, The method comprises the following steps: S1, furnace entry: clamping the substrate sample on a hanging rod of a PVD deposition device; S2, heating / vacuumizing: first vacuumizing the chamber to below 5 Pa, and then setting the temperature to 350-450℃; S3, glow cleaning: when the vacuum degree of the chamber is reduced to 3.0*10 -3 Pa~6.0*10 -3 Pa, argon gas with a flow rate of 250-350 sccm is introduced to control the chamber pressure at 1.5-2.5 Pa, the substrate bias is set at -800--1000 V, and the glow cleaning is performed for 20-40 min; S4, ion etching: positioning the hanging rod with the substrate to self-rotate in front of the target material, adjusting the argon flow to 50-90 sccm, setting the chamber pressure to 0.2-0.7 Pa, setting the substrate bias to -700 to -900 V, setting the target material current to 90-110 A, starting the Cr target etching for 1-3 min, then adjusting the substrate bias to -500 to -700 V, and etching for another 2-4 min; S5, deposition of the transition layer: selecting CrN as the transition layer, introducing 200-400 sccm of N2 into the chamber, controlling the chamber pressure to 0.8-1.4 Pa, setting the Cr target current to 90-110 A, and starting the Cr target etching and deposition of the CrN transition layer for 5-15 min; S6, deposition of AlCrNbSiON nanolayer coating: turn on Al 50 Cr 30 Nb 10 Si 10 alloy target, target current 60-100 A, pass 270-320 sccm N2, pass 0.1-25 sccm O2, maintain chamber pressure at 2.5-3.5 Pa, substrate bias -100 to -200 V, deposit AlCrNbSiON coating for 40-100 min; S7, deposition end: taking out the plated sample after the temperature drops to room temperature, and obtaining the self-organizing nanomultilayer AlCrNbSiON coating.

4. The method of producing a high-toughness self-organizing nanomultilayer structure oxynitride coating according to claim 3, characterized in that, The substrate sample needs to be cleaned before use, specifically: after polishing the surface of the substrate, immersing it in an acetone solution for ultrasonic cleaning for 15-30 min, then immersing it in anhydrous ethanol solution for ultrasonic cleaning for 15-30 min, and taking out the substrate for drying after the cleaning is completed.

5. The method of producing a high-toughness self-organizing nanomultilayer oxy- nitride coating according to claim 3, characterized in that The heating / vacuumizing of S2 is specifically: closing the device furnace door, first using a mechanical pump + Roots pump to coarsely vacuumize the chamber to below 5 Pa, then pre-starting the molecular pump, and after the molecular pump is running at full speed, starting the chamber heater and setting the temperature to 350-450℃.

6. The method of producing a high-toughness self-organizing nanomultilayer structure oxynitride coating according to claim 3, characterized in that, The ion etching of S4 adopts a Cr ion etching process, and the target material used is a Cr target.

7. The method of producing a high-toughness self-organizing nanomultilayer structure of an oxynitride coating according to claim 3, characterized in that, In S6, the gas flow ratio of N2 to O2 is 294:6, 291:9, 287:13, or 282:

18.

8. Application of the high-toughness self-organizing nanomultilayer structured oxynitride coating of claim 1 or 2 in the field of high-temperature alloy cutting.

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