Composite coating based on texture alpha-Al2O3 and preparation method thereof

Abstract

The invention relates to the technical field of surface coating preparation, and discloses a texture-based composite coating and a preparation method thereof.The method comprises the following steps that a TiN layer, an MT-TiCN layer, a bonding layer, a modified layer and an outermost TiN layer are sequentially deposited on the surface of a base body through a hot wall type chemical vapor deposition technology, the deposition process meets the following conditions: the deposition temperature is in a range of 900-1050 DEG C, and is gradually reduced in the deposition process; the deposition pressure is 50 to 200 mbar; the introduced mixed gas contains CO and the volume ratio of CO to CO is controlled to be 0.5-3; the volume ratio of the mixed gas is not higher than 92% and not lower than 80%; the modified layer comprises an Al purging modified layer and an oxidation modified layer and is used for controlling the texture and the grain size. According to the method, the particle size can be considered while the strong (006) texture coating is obtained, the particle size of the coating is smaller than or equal to 1 micron, and the excellent comprehensive performance is achieved.

Description

Technical Field

[0001] This invention relates to the field of surface coating preparation technology, specifically to a texture-based method. Composite coatings and their preparation methods. Background Technology

[0002] MT-TiCN+ based materials were prepared using a hot-wall chemical vapor deposition (CVD) method. The composite coating has excellent wear resistance and high-temperature oxidation resistance, and has been widely used in the field of cemented carbide CNC cutting tools.

[0003] As a key functional layer in the coating system, its crystal structure exhibits significant anisotropy, with multiple crystal plane orientations including (012), (104), (110), (006), (214), (116), and (300). Among these, (012), (104), (110), (006), (214), (116), and (300) are crystal plane indices, used to identify the orientation of different atomic planes in the crystal. Through strict control of the growth process, different textures can be obtained. The coating, in turn, affects its mechanical properties and service behavior. For example, US patents US7455900B2, US7163735B2, and US2006 / 0115662A1 obtained coatings with (116), (012), and (110) textures respectively by controlling the oxidation potential of the oxidation process. Coating; while US Patent 2007 / 0104945A1 uses pulse oxidation technology and controls growth process The proportions obtained have a texture of (006). .

[0004] In recent years, in-depth international research has further revealed that those with strong (006) texture The coating is superior to other textures Coatings exhibit superior wear resistance and crack propagation resistance, making them a hot research topic. To achieve this ideal texture, numerous companies and scholars have explored various technical approaches, such as those employed in US Patent 7923101B2. and Alternating pulse oxidation and control growth process The proportion was used to obtain a texture with (006) Coating; US Patent US2022 / 0274892A1 by controlling the oxidation process The ratio and coating temperature of the main intake duct achieved a strong (006) texture. Coating; US Patent US2016 / 0175940A1 by adopting CO A strong (006) texture was obtained through co-oxidation treatment. Coating; US Patent US2014 / 0287210A1 obtained a strong (006) texture by Ti purging treatment of the bonding layer TiCNO. Coating; Chinese Patent CN118880276A utilizes a bonding layer TiAlCNO with a gradient increase in Al and O elements, forming a coating on top of it. Achieve strong (006) texture Coating. Actual cutting tests show that coatings based on (006) texture prepared through different paths... Composite coatings offer a longer service life than traditional non-woven coatings, whether in continuous high-speed turning or intermittent turning. The coating has been significantly improved, effectively promoting the improvement of product performance and processing efficiency in the machining field.

[0005] Despite the strong (006) texture The coating offers significant performance advantages, but it still faces a long-standing and unresolved technical challenge during the deposition process. During the coating growth process, The grains exhibit grain growth issues. The (006) texture obtained through the aforementioned route... The coating process did not take this issue into account, and there were no specific measures to control it in the process.

[0006] Specifically, most existing texture control processes focus on optimizing crystal orientation through atmospheric composition, pulse programming, or interface modification, but generally neglect the simultaneous fine control of grain size. Grain coarsening reduces the density and toughness of the coating, making it prone to becoming a crack initiation point during service, leading to spalling failure and thus weakening the benefits of texture strengthening. Therefore, how to effectively suppress grain size while ensuring a high-strength (006) texture is a crucial issue. Grain growth, and stabilizing its size at the submicron level (e.g., below 1 μm), is a key challenge to further improve the overall performance of this type of coating and maximize its engineering application value. It is also the core problem that this invention aims to solve. Summary of the Invention

[0007] This invention aims to provide a texture-based The composite coating and its preparation method can achieve a strong (006) texture. While coating, take into account The particle size is adjusted to be ≤1μm to achieve better overall performance.

[0008] To achieve the above object, the present application provides the following basic scheme.

[0009] Scheme One Based on texture The preparation method of the composite coating comprises the following steps: Using a hot-wall chemical vapor deposition process, sequentially depositing a TiN layer, an MT-TiCN layer, a bonding layer, a modification layer, a layer, and an outermost TiN layer on the surface of the substrate, wherein: The The layer is composed of three sub-layers, and the deposition process includes sequentially depositing a first sub-layer, a second sub-layer, and a third sub-layer, and satisfies the following conditions: the deposition temperature is in the range of 900-1050℃, and gradually decreases during the deposition process; the deposition pressure is 50-200 mbar; the mixed gas introduced contains CO and , and the volume ratio of CO to is controlled between 0.5-3; the volume fraction of in the mixed gas is not higher than 92% and not lower than 80%; The modification layer includes an Al purge modification layer and an oxidation modification layer, for controlling the texture and grain size of , ensuring that The particle size is ≤1μm and has strong (006) texture.

[0010] Scheme Two Based on texture The composite coating deposited on the substrate comprises, from inside to outside, a TiN bottom layer, an MT-TiCN layer, a bonding layer, a modification layer, a layer, and an outermost TiN layer; wherein the modification layer includes an Al purge modification layer and an oxidation modification layer, the The layer has strong (006) texture, and The particle size of

[0011] The working principle and advantages of the present application are: The present application is based on the composite coating based on texture and its preparation method, which can obtain strong (006) texture coating while taking into account particle size, so that the particle size , achieving better comprehensive performance. The key points are: The present scheme successfully solves the current strong (006) texture A long-standing technical challenge in coating preparation is achieving a highly oriented texture while effectively suppressing abnormal alumina grain growth, thereby obtaining a high-performance coating with excellent texture and fine microstructure. This solution employs a strategy combining stepwise deposition and modification, specifically introducing a modified layer with finely controlled structure, and further... The layer employs a process that combines temperature gradient descent with a specific atmosphere ratio of mixed gas for synergistic control, ensuring high texture while maintaining stable grain size. The following improvements have been achieved in coating hardness, toughness, and bonding strength, resulting in more stable performance and a longer service life under harsh conditions such as high-speed and intermittent cutting.

[0012] Furthermore, compared to the traditional technological development trajectory, as described in the background section, existing technological solutions have all evolved along a path of "single-objective optimization." That is, their improvement strategies consistently revolve around how to further enhance texture strength or improve a single performance indicator of texture, without considering "grain size control" as a related problem that needs to be addressed simultaneously with "texture control." In the field of coating technology, texture formation and grain growth typically involve different physicochemical mechanisms. Therefore, traditional technological thinking usually treats them as independent process objectives that need to be optimized separately. Simultaneously considering both texture and grain size in the same process is quite challenging.

[0013] This solution solves this technical challenge by creatively employing a precise "temperature gradient descent" strategy within the high-temperature deposition range, supplemented by a special modification layer process and simultaneous control of the atmosphere ratio to regulate the gas phase reaction kinetics. This achieves both strong texture and fine grains without significantly sacrificing deposition rate and crystallization quality. Attached Figure Description

[0014] Figure 1 This invention is based on texture A schematic diagram of the coating structure in an embodiment of the composite coating and its preparation method; Figure 2 This is a SEM image of the fracture surface of the coating, representing an application example of the present invention. Figure 3 Here is a SEM image of the fracture surface of the coating in Comparative Example 1; Figure 4 The image shows the SEM morphology of the fracture surface of the coating in Comparative Example 2. Figure 5 Coating as an application example of the present invention ; Figure 6 Coating as an application example of the present invention Surface SEM morphology image; Figure 7 For Comparative Example 1, the coating Surface SEM morphology image; Figure 8 Comparative Example 2 Coating Surface SEM morphology image; Figure 9 The coating XRD pattern curve is an application example of the present invention; Figure 10 The XRD pattern of the coating in Comparative Example 1 is shown. Figure 11 The XRD pattern of the coating in Comparative Example 2 is shown. Figure 12 The images show the flank wear of the present invention under the same conditions, serving as application examples and comparative examples.

[0015] The markings in the accompanying drawings include: 00-matrix, 11-TiN, 12-MT-TiCN, 13-bonding layer, 14-modified layer, 15- 16-TiN; 131-HT-TiCN, 132-TiCNO, 133-TiAlCNO; 141-Al purging modified layer, 142-oxidation modified layer; 151-first sublayer, 152-second sublayer, 153-third sublayer. Detailed Implementation

[0016] The following detailed explanation illustrates the specific implementation methods: The basic implementation examples are as follows: Figure 1 As shown: Based on texture The method for preparing the composite coating includes the following steps: A hot-wall chemical vapor deposition (CVD) process was used to sequentially deposit a TiN layer, an MT-TiCN layer, a bonding layer, and a modification layer on the substrate surface. Layer and outermost TiN, where: The matrix is ​​a WC-based cemented carbide, TiCN-based ceramic, etc. ceramic base Ceramics, silane ceramics, CBN, carbon-based materials (such as graphite, carbon fiber, diamond), high-temperature alloys, or other materials that may be suitable for hot-wall CVD technology.

[0017] The TiN layer is used to ensure the adhesion between the coating and the substrate. The deposition temperature of the TiN layer is 850–1000℃, the coating thickness is 0.3–1.5 μm, the deposition pressure is 100–300 mbar, and the composition of the introduced mixed gas is 0.8–1.8 vol%. 20–40 vol% The margin is .

[0018] The MT-TiCN layer is used as a wear-resistant layer, and the coating thickness is 3-10 μm. The deposition temperature of the MT-TiCN layer is 800-900 ℃, the deposition pressure is 50-200 mbar, and the mixed gas composition is: 1.5-2.5 vol% , 0.5-1.5 vol% , 10-25 vol% , 1-5 vol% HCl, and the balance is . In this process, the reasonable ratio and HCl ratio help to refine the MT-TiCN particle size and increase the coating hardness under the condition of maintaining the toughness.

[0019] The bonding layer is used to ensure the bonding force of the MT-TiCN layer and the layer. The bonding layer is composed of a TiCN layer, a TiCNO layer and a TiAlCNO layer in turn, so that the MT-TiCN gradually transitions to a high-temperature , and the coating thickness is 0.5-1.5 μm.

[0020] The deposition temperature of the bonding layer is 900-1050 ℃, and the deposition pressure is respectively: the TiCN layer, 100-500 mbar; the TiCNO layer, 60-300 mbar; and the TiAlCNO layer, 60-300 mbar.

[0021] The mixed gas composition is respectively: The TiCN layer, 1-2 vol% , 2-5 vol% , 0-2 vol% HCl, the initial volume percentage is 15-35 vol% , and the balance is ; The TiCNO layer, 1-3 vol% , 20-30 vol% , 0.5-1 vol% , 1-2 vol% CO, 0-2 vol% HCl, and the balance is ; The TiAlCNO layer, 1.5-2.5 vol% , 20-30 vol% , 0.5-4 vol% CO, 1.5-3 vol% , and the balance is ; Among them, in the TiCN layer, The volume percentage decreases gradually, and decreases from 15-35 vol% to 3-5 vol%; the volume percentage of CO in the TiAlCNO layer increases gradually.

[0022] By combining the step-by-step design of the bonding layer and the precise atmosphere control, the MT-TiCN can gradually transition to At the same time, by changing the flow rates of and CO, it is helpful to form a "needle-like" structure in the coating, realizing high bonding force of the coating.

[0023] The modified layer includes an Al purge modified layer and an oxidation modified layer, for controlling the texture and grain size, ensuring the particle size ≤1 μm and having strong (006) texture.

[0024] The deposition temperature of the Al purge modified layer in the modified layer is 900-1050℃, the deposition pressure is 50-100 mbar, and the composition of the mixed gas introduced is: 0.5-0.7 vol% , the balance being .

[0025] The deposition temperature of the oxidation modified layer in the modified layer is 900-1050℃, the deposition pressure is 50-100 mbar, and the composition of the mixed gas introduced is: 20-30 vol% , 1.5-3.5 vol% , 2.5-3.5 vol% CO, the balance being .

[0026] By designing the Al modified layer and the oxidation layer, the nucleation points of can be increased, while balancing the oxygen content in the bonding layer, ensuring the texture, while taking into account the refinement of the particles.

[0027] The layer has excellent high-temperature resistance and wear resistance, is strong (006) texture, and the coating thickness is 1-10 μm, which is composed of three sub-layers, and the deposition process includes sequentially depositing the first sub-layer, the second sub-layer and the third sub-layer, and meets the following conditions: The deposition temperature is in the range of 900-1050℃, and gradually decreases during the deposition process; the deposition pressure is 50-200 mbar; the mixed gas introduced contains CO and , and the volume ratio of CO to is controlled between 0.5-3; the volume percentage of in the mixed gas is not higher than 92% and not lower than 80%.

[0028] The The three sub-layers of the layer are: The first sub-layer corresponds to a mixed gas composition of: 4-15 vol% (CO ), 1-3 vol% HCl, 0.4-1 vol% , 1.5-3 vol% , and the balance being ; The second sub-layer corresponds to a mixed gas composition of: 2.5-5.5 vol% , 1.5-10 vol% CO, 1-3 vol% HCl, 0.45-1 vol% , 1.5-3 vol% , and the balance being ; The third sub-layer corresponds to a mixed gas composition of: 2.5-5.5 vol% , 1.5-5 vol% CO, 3.5-9 vol% HCl, 0.45-1 vol% , 1.5-3 vol% , and the balance being .

[0029] In this process, the gradual reduction of the deposition temperature helps to reduce the coating reaction rate thermodynamically, and plays a role in controlling the expansion of Al2O3 particles, but the temperature cannot be too low, otherwise the reaction is not sufficient, which affects the structure, and may cause crystallization to block the pores. By controlling the CO within a reasonable proportion range, the coating reaction rate can be appropriately reduced, and the growth along the (006) crystal plane can be promoted. The main carrier gas in the reaction process, due to the influence of the viscosity coefficient of part of the reaction gas, too high or too low will cause the uniformity of the distribution of key gases to change, affecting the uniformity of the texture, by limiting the volume ratio, it helps to ensure the uniformity of the texture, to achieve better coating quality.

[0030] In particular, the present scheme also introduces different proportion ranges of . In the growth process, it has a magical effect, which promotes the growth of by forming an intermediate reactant of AlO:SH, playing the role of a catalyst, and at the appropriate proportion, it can also promote the growth of ​​​It grows along the (006) crystal plane, acting as a stabilizer. If A low proportion will have an impact. In terms of growth direction, under extreme conditions, it can even form a (110) texture. ,at the same time The ratio cannot be too high, as it will not only affect... The structure, due to its own viscosity, will adhere to the coating fixture, and when it comes out of the oven, it will be accompanied by a strong "rotten egg" smell, which is not good for the on-site environment. This solution takes both into account.

[0031] The outermost TiN layer is golden yellow and serves as a marker layer to aid in determining the degree of coating wear. Its thickness is 0.5-2 μm, the deposition temperature is 850–1000℃, the deposition pressure is 300–800 mbar, and the composition of the introduced mixed gas is 1–2 vol%. 20–40 vol% The margin is .

[0032] This embodiment also provides a texture-based method. A composite coating is deposited on the substrate and applied as described above based on texture. The composite coating was prepared by a specific method; the coating, from the inside out, comprises: a TiN underlayer, an MT-TiCN layer, a bonding layer, and a modified layer. The layers, and the outermost TiN layer; wherein, the The layer has a strong (006) texture, and The particle size is ≤1μm.

[0033] The The layer consists of three sublayers with a texture coefficient TC(006)≥8, and the texture coefficient TC values ​​of the crystal planes (012), (104), (110), (113), (024), (116), (214), and (300) are all ≤0.5.

[0034] (006), (012), (104), (110), (113), (024), (116), (214), and (300) are all crystal plane indices, used to identify the orientation of different atomic planes in a crystal.

[0035] To verify the effectiveness and superiority of this solution, the following explanation is provided in conjunction with a specific application example and a simplified comparative example, supplemented by multiple test comparisons.

[0036] I. Application Examples: WNMG080408-TM CNC inserts (WC-8%Co cemented carbide) were selected as the coating substrate, with a cutting edge passivation value of 35μm. All inserts were sandblasted and cleaned before coating to ensure the cleanliness of the substrate surface.

[0037] In the SCT600TH hot-wall CVD coating furnace, according to Figure 1 Structure (i.e., a texture-based structure provided in this embodiment) (composite coating), applying a texture-based coating provided in this embodiment. The method for preparing the composite coating is described, and the coating is applied.

[0038] The coating components along the growth direction are, in order, TiN (11), MT-TiCN (12), bonding layer (13), and modified layer (14). (15) TiN (16). Figure 2 The SEM image shows the fracture surface morphology of the coating in this application example. The SEM image reveals that the underlying TiN (11) layer is approximately 0.88 μm thick, the MT-TiCN (12) layer is approximately 7.7 μm thick, and the bonding layer + modified layer (13+14) layer is approximately 0.95 μm thick. (15) Thickness is about 5.6 μm, and surface TiN (16) is about 0.6 μm.

[0039] The parameters such as coating temperature, pressure, gas type and ratio are shown in Table 1.

[0040] Table 1. Coating growth process parameters in the implementation case.

[0041] II. Comparative Example: The comparative examples include two coating schemes. The substrates used are the same batch of WNMG080408-TM CNC inserts (WC-8%Co cemented carbide) as the application examples, with a cutting edge passivation value of 35μm. Before coating, both were sandblasted and cleaned to ensure the cleanliness of the substrate surface.

[0042] The coating process was also carried out in an SCT600TH hot-wall CVD coating oven.

[0043] Figure 3 The SEM morphology of the coating fracture surface in Comparative Example 1 shows the coating composition along the growth direction as follows: TiN, MT-TiCN, bonding layer, ... TiN, where the bottom TiN, MT-TiCN, and top TiN are manufactured using the same process as in the application example. It is a single-layer structure with a non-strong texture, and its total thickness is close to that of the application example.

[0044] The key difference between Comparative Example 1 and the application example is that the modification layer (14) unique to this invention is omitted. The layer is a single-layer deposition, and the process parameters were not optimized for texture and grain size, resulting in a non-strong texture.

[0045] Figure 4 The SEM morphology of the coating fracture surface in Comparative Example 2 shows that the coating composition along the growth direction is, in order, TiN, MT-TiCN, and the bonding layer. TiN, wherein the bottom TiN, MT-TiCN, bonding layer, modified layer and top TiN are processed in the same way as in the application example of this invention.

[0046] The key difference between Comparative Example 2 and the application example is: No gradient cooling or stepwise component control was used during the growth process; the single layer grew continuously.

[0047] Under these conditions, since the bonding layer and the modified layer are consistent with the application example, therefore For a strong (006) texture, however, due to No gradient cooling or stepwise composition control was used during the growth process; instead, a single layer was grown continuously. Therefore, the particles are relatively coarser compared to those in application examples. The thickness is similar to that of the application example, but MT-TiCN is about 4 μm thicker than the application example.

[0048] III. Performance Comparison and Test Results 1. Coating adhesion test (scratch test): The coating adhesion was tested on the surface of WC carbide cutting tools using the scratch method with a load of 100N.

[0049] Application examples: Figure 5 The image shows the morphology of the coating scratches under a stereomicroscope. The figure shows that the coating did not crack when the loading force reached 100N, proving that the coating adhesion of the application example is excellent.

[0050] 2. Grain morphology and size (SEM analysis): Application example: After removing the surface TiN (16) by acid etching, the image was examined using a scanning electron microscope (SEM). Figure 6 ) Observe application examples Morphology and particle size were measured. (Through...) Figure 6 Observations show that, although The nominal size is 2.533 μm, but closer inspection reveals that the large particles are composed of 6 tiny [units / organisms]. It is composed of particles with a typical "pyramid" shape, each The size is only about 0.5μm, successfully achieving the goal of fine grains ≤1μm.

[0051] Comparative Example 1: Using early non-woven materials Coatings prepared by coating process ( Figure 6 Particles larger than 1 μm account for a large proportion, and the grains are obviously coarse.

[0052] Comparative Example 2: Using the same bonding layer and modification layer as the application example, No gradient cooling or stepwise composition control was used during the growth process; the growth was a single-layer continuous process, resulting in a large proportion of particles larger than 1 μm, and some particles larger than 2 μm. Figure 8 ).

[0053] 3. Texture analysis (XRD analysis): Calculation method: Determined through XRD The structure was analyzed and the texture factor TC value for each crystal plane was calculated. Because... Both the TiCN peak and the TiCN peak exhibit diffraction peaks around 41.67 degrees. To avoid interference from the TiCN diffraction peak, the parallel peak of (006) around 90.7 degrees, corresponding to the (00 12) peak, was selected for further analysis. The analysis was performed using PDF-10-1073.

[0054] Nine peaks (012), (104), (110), (113), (300), (024), (116), (214), and (00 12) were selected and their texture coefficients (TC) were calculated using the following formula. The maximum TC value was 9. ; Where I(hkl) represents Measured XRD intensity value of a certain crystal plane; Represents PDF-10-1073 card Standard strength value corresponding to the crystal plane; n=9.

[0055] The calculation results are shown in Table 2: Application examples ( Figure 9 (Table 2) Figure 9 The XRD pattern of the coating in the application example shows that the TC value of the (00 12) crystal plane is as high as 8.27, while the TC values ​​of all other crystal planes are <0.5, which proves that it is a strong (006) texture.

[0056] Comparative Example 1 ( Figure 10 (Table 2) Figure 10 The XRD pattern of the coating in Comparative Example 1 shows that the TC value of the (00 12) crystal plane is only 4.4, while the TC values ​​of the other crystal planes are significantly higher (0.37-1.15), proving that it is a non-strong texture or a mixed texture.

[0057] Comparative Example 2 (Table 2): Figure 11 Figure 11 The XRD pattern of the coating of Comparative Example 2 is shown in Table 2, and the (00 12) crystal face TC value is 8.42, and the TC values of the other crystal faces are all <0.5, which is strong (006) texture.

[0058] Table 2 Application Examples and Comparative Examples TC values of different crystal faces

[0059] 5. Cutting performance test: Test conditions: The cutting performance of the coating is verified by cutting test. The workpiece is set as 45# modulated steel bar with a length of 80mm; dry continuous turning is adopted, the linear speed Vc is 300m / min, and the spindle speed of the machine tool is adjusted to ensure that the cutting speed of each tool is uniform, the cutting depth is 2mm, and the feed amount is 0.3mm / revolution.

[0060] The cutting performance of the coating is determined by the wear of the relief surface after cutting the same distance.

[0061] Test results: Comparative Example 1 (non-strong texture coating): the relief surface wear is 0.43mm, and the blade edge is damaged, which cannot continue to cut.

[0062] Comparative Example 2 (strong (006) texture coarse grain coating): the relief surface wear value is 0.34mm, which can still continue to cut.

[0063] Application Example (strong (006) texture fine grain coating): the relief surface wear is only 0.22mm, and it can still continue to cut.

[0064] Conclusion: Figure 12 The relief surface wear of the application example and the comparative example is compared, and it can be known from the comparison that the wear resistance of the coating of the application is much better than that of the traditional non-texture coating, and it is also obviously improved compared with the conventional strong texture coating with coarse particles.

[0065] In summary, through the detailed process parameter table and the systematic comparison test (combined with force, microstructure, texture, cutting performance), it is fully proved that the process scheme of "modified layer + three-stage deposition + atmosphere control + temperature gradient" provided by the application can realize the two key targets of strong (006) texture and fine grain (≤1μm) at the same time, so as to significantly improve the comprehensive mechanical properties and cutting life of the coating. The comparative example serves as a counterexample, highlighting the performance gap caused by omitting the key technical means.

[0066] The composite coating based on texture and the preparation method thereof provided in the embodiment can obtain strong (006) texture​ Coating, while taking into account Particle size, so that the particle size is ≤1 μm, to achieve a better overall performance.

[0067] Specifically, the present scheme by introducing composite modification layer (Al purge + oxidation modification) pretreatment combined with layer surface, can be for subsequent Uniform nucleation and directional growth to create favorable conditions; again through three-stage Deposition and synchronous implementation of temperature gradient descent and low hydrogen atmosphere control, can be guided nucleation, texture orientation and grain refinement, respectively, to form an optimized dynamic growth environment, to ensure the interface to the body phase performance optimization, to ensure the uniformity and stability of the organization and structure. This combination strategy cleverly avoids the contradiction between high temperature strong texture and low temperature fine grain in the traditional process, and realizes the optimization of the comprehensive performance of the coating.

[0068] The above is only an embodiment of the present application, and the well-known specific structure and characteristics of the scheme are not described in detail, and the ordinary skilled person in the art knows all the ordinary technical knowledge in the field of the present application before the filing date or the priority date, can know all the prior art in this field, and has the ability to apply conventional experimental means before that date, and the ordinary skilled person in the art can improve and implement the present scheme based on their own ability under the guidance of this application, and some typical known structures or known methods should not be an obstacle for the ordinary skilled person in the art to implement the present application. It should be noted that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, and these will not affect the effect and practicality of the patent.

Claims

1. A method of making a composite coating based on texture , characterized in that comprising the following steps: The TiN layer, the MT-TiCN layer, the bonding layer, the modification layer, the layer and the outermost TiN layer are sequentially deposited on the surface of the substrate by a hot-wall chemical vapor deposition process, layer and the outermost TiN layer. The layer is composed of three sub-layers, and the deposition process includes sequentially depositing the first sub-layer, the second sub-layer and the third sub-layer, and meets the following conditions: the deposition temperature is in the range of 900-1050℃, and gradually decreases during the deposition process; the deposition pressure is 50-200 mbar; the mixed gas introduced contains CO and , and the volume ratio of CO to is controlled between 0.5-3; the volume ratio of in the mixed gas is not higher than 92% and not lower than 80%. The modification layers include Al purge modification layers and oxidation modification layers for controlling the texture and grain size, ensuring a particle size of ≤1 μm and a strong (006) texture.

2. The textured-based composite coating of claim 1, prepared by a method comprising: The base body is a WC-based cemented carbide, a TiCN-based ceramic, ceramic, ceramic, sialon ceramic, CBN, carbon-based material or high-temperature alloy. ​ 3. The texture-based method according to claim 1 The method for preparing the composite coating is characterized in that, The deposition temperature of the TiN layer is 850-1000 °C, the deposition pressure is 100-300 mbar, the composition of the mixed gas introduced is: 0.8-1.8 vol% , 20-40 vol% , the balance being ; The deposition temperature of the MT-TiCN layer is 800-900 °C, the deposition pressure is 50-200 mbar, the composition of the mixed gas fed in is: 1.5-2.5 vol% , 0.5-1.5 vol% , 10-25 vol% , 1-5 vol% HCI, the balance being .

4. The textured-based composite coating of claim 1, prepared by the method comprising: The binding layer is composed of TiCN layer, TiCNO layer and TiAlCNO layer in turn, the deposition temperature is 900-1050℃, the deposition pressure is 100-500 mbar, 60-300 mbar, 60-300 mbar respectively, the composition of the mixed gas introduced is respectively: ​ 1 - 2 vol% , 2 - 5 vol% , 0 - 2 vol% HCI, initial volume percent 15 - 35 vol% , the balance being ; 1 -3 vol % , 20-30 vol % , 0.5-1 vol % , 1 -2 vol % CO, 0-2 vol % HCI, remainder ; 1.5 - 2.5 vol% , 20 - 30 vol% , 0.5 - 4 vol% CO, 1.5 - 3 vol% , the balance being ; wherein, in the TiCN layer, The volume percentage decreases; in the TiAlCNO layer, the volume percentage of CO changes in a gradient.

5. The textured based composite coating of claim 1, prepared by the method comprising: The Al purge modified layer deposition temperature is 900-1050 °C, the deposition pressure is 50-100 mbar, the mixed gas composition is: 0.5-0.7 vol% , the balance is . ​ 6. The textured-based composite coating of claim 1, prepared by the method comprising: The deposition temperature of the oxidation modification layer in the modification layer is 900-1050℃, the deposition pressure is 50-100 mbar, the composition of the mixed gas is: 20-30 vol% , 1.5-3.5 vol% , 2.5-3.5 vol% CO, and the balance is . ​ 7. The texture-based method according to claim 1 The method for preparing the composite coating is characterized in that, The In the three-layer sub-layers of the layer: The mixed gas composition corresponding to the first sub-layer is: 4-15 vol% (H2+Ar) + ), 1-3 vol% HCl, 0.4-1 vol% , 1.5-3 vol% , and the balance is ; The mixed gas composition corresponding to the second sub-layer is: 2.5-5.5 vol% , 1.5-10 vol% CO, 1-3 vol% HCl, 0.45-1 vol% , 1.5-3 vol% , and the balance is ; The mixed gas composition corresponding to the third sub-layer is: 2.5-5.5 vol% , 1.5-5 vol% CO, 3.5-9 vol% HCI, 0.45-1 vol% , 1.5-3 vol% , and the balance is .

8. The textured-based composite coating of claim 1, prepared by the method comprising: The deposition temperature of the outermost layer TiN is 850-1000℃, the deposition pressure is 300-800 mbar, the composition of the mixed gas introduced is: 1-2 vol% , 20-40 vol% , and the balance is . ​ 9. A composite coating based on a texture deposited on a substrate, characterized in that From inside to outside in turn includes: TiN bottom layer, MT-TiCN layer, binding layer, modified layer, layer, and the outermost layer TiN; wherein, the modified layer includes Al purge modified layer and oxidation modified layer, the layer has strong (006) texture, and The particle size of the modified layer is ≤1 μm.

10. The textured based composite coating of claim 9, characterized in that, The The layer is composed of three sub-layers, the texture coefficient TC(006) is greater than or equal to 8, and the texture coefficients TC of the (012), (104), (110), (113), (024), (116), (214), and (300) crystal planes are all less than or equal to 0.

5. ​

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