Coating, cutting device and preparation method

Abstract

The invention relates to a coating, a cutting tool and a preparation method. The texture coefficient TC of the aluminum oxide coating is TC (0 < 8 >) gt; 3, TC (01 2) lt; 1, TC (104) lt; 1, TC (1 < 0 >) < lt >; 1.5, TC (113) lt; 1, TC (02) lt; 1, TC (1 < 6 >) < lt >; 1, TC (214) lt; 1 and TC (3000) 1t; 1. The aluminum oxide coating provided by the invention has preferred orientation of a (018) crystal face, can improve the toughness during cutting on the basis of not reducing the toughness of the coating, and has obvious advantages in widely applied steel part cutting.

Description

Technical Field

[0001] The invention belongs to the technical field of wear-resistant coatings, designs a coating material, and particularly relates to a coating, a cutting device and a preparation method. Background Art

[0002] a-Al2O3 hard coating is favored by the industry due to its excellent oxidation resistance and high temperature red hardness. Chemical vapor deposition is currently the only means to continuously and mass-produce a-Al2O3 hard coating, so it is widely used in cemented carbide coated cutting tools.

[0003] In order to further improve the performance of a-Al2O3 hard coating, existing technologies have been continuously researching and optimizing a-Al2O3 from the perspective of grain boundary engineering. Before the mid-1990s, the improvements were mainly focused on the regulation of grain size, and then mainly focused on the preferential growth of a-Al2O3 grain orientation. The wear resistance and crater wear resistance of cutting tools with a-Al2O3 preferential coating layer are significantly improved compared with a-Al2O3 without preferential orientation.

[0004] However, the a-Al2O3 coating with preferential orientation provided by the prior art has the disadvantages of insufficient heat resistance and insufficient overall toughness in the medium and high speed processing of heat-treated steel parts. In view of this, it is necessary to provide an alumina coating, a cutting device and a preparation method that can improve the wear resistance during cutting without reducing the flexibility of the coating. Summary of the invention

[0005] The object of the present invention is to provide a coating, a cutting device and a preparation method. The aluminum oxide coating has a preferred orientation of the (01 8) crystal plane, which can improve the toughness during cutting without reducing the toughness of the coating, and has obvious advantages in the cutting of widely used steel parts.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a coating, including an aluminum oxide coating, wherein the texture coefficient TC of the aluminum oxide coating satisfies:

[0008] TC(0 1 8)>3, TC(0 1 2)<1, TC(1 0 4)<1, TC(1 1 0)<1.5, TC(1 1 3)<1, TC(024)<1, TC(1 1 6)<1, TC(2 1 4)<1 and TC(3 0 0)<1.

[0009] The aluminum oxide in the aluminum oxide coating of the present invention is α-Al2O3, and the texture coefficient TC is measured by CuKa radiation and 2θ scanning of the aluminum oxide coating, and the calculation formula is as follows:

[0010]

[0011] Wherein I(hkl) is the measured intensity of (hkl) diffraction, I0(hkl) is the standard intensity of ICDD PDF card No. 46-1212, n is the number of diffraction crystal planes, and in the present invention, the diffraction crystal planes used to characterize the aluminum oxide coating include 9 diffraction crystal planes: (0 1 8), (0 12), (1 0 4), (1 1 0), (1 1 3), (0 2 4), (1 1 6), (2 1 4) and (3 0 0).

[0012] Wherein, TC(0 1 8)>3, for example, it can be 3.5, 4, 5, 6, 7, 8 or 9, but not limited to the listed values, and the remaining values ​​not listed in the numerical range are also applicable. The texture coefficients TC of the remaining diffraction crystal planes are independently 1.5 or less, for example, it can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2 or 1.5, but not limited to the listed values, and the remaining values ​​listed in the numerical range are also applicable, preferably 1 or less.

[0013] The aluminum oxide coating provided by the present invention has a preferred orientation of the (0 1 8) crystal plane, and can improve the toughness during cutting without reducing the toughness of the coating, and has obvious advantages in the cutting of widely used steel parts.

[0014] Preferably, the thickness of the aluminum oxide coating in the present invention is 1-15 μm, for example, it can be 1 μm, 3 μm, 4 μm, 5 μm, 6 μm, 10 μm or 15 μm, but is not limited to the listed values, and the remaining unlisted values ​​within the numerical range are also applicable, preferably 3-10 μm, and more preferably 4-6 μm.

[0015] Preferably, the coating further comprises a nitrogen-containing layer and a transition layer sequentially deposited on the bottom of the aluminum oxide coating.

[0016] Preferably, the nitrogen-containing layer includes at least one of a titanium nitride layer, a titanium carbonitride layer or a titanium oxycarbonitride layer, and typical but non-limiting combinations include a combination of a titanium nitride layer and a titanium carbonitride layer, a combination of a titanium nitride layer and a titanium oxycarbonitride layer, a combination of a titanium carbonitride layer and a titanium oxycarbonitride layer, or a combination of a titanium nitride layer, a titanium carbonitride layer and a titanium oxycarbonitride layer.

[0017] Preferably, the transition layer is an aluminum titanium carbonitride oxide layer.

[0018] Preferably, the nitrogen-containing layer is a titanium nitride layer and a titanium carbonitride layer deposited sequentially.

[0019] In a second aspect, the present invention provides a method for preparing the coating according to the first aspect, the preparation method comprising the following steps:

[0020] A nitrogen-containing layer is deposited.

[0021] Performing a first chemical vapor deposition on the surface of the nitrogen-containing layer to obtain a transition layer; and then performing a second chemical vapor deposition on the outer side of the transition layer to obtain the aluminum oxide coating;

[0022] In the first chemical vapor deposition process, the usage ratio of TiCl4 to CO is 1.6-3.5, and the usage ratio of TiCl4 to AlCl3 is 0.9-4.6.

[0023] In the present invention, in order to obtain a technical solution in which the texture coefficient satisfies TC(0 1 8)>3, TC(0 1 2)<1, TC(1 0 4)<1, TC(11 0)<1.5, TC(1 1 3)<1, TC(0 2 4)<1, TC(1 1 6)<1, TC(2 1 4)<1 and TC(3 0 0)<1, it is key to control the usage ratio of TiCl4, AlCl3 and CO in the first chemical vapor deposition.

[0024] In the first chemical vapor deposition process, the usage ratio of TiCl4 and CO is TiCl4 / CO of 1.6-3.5, for example, it can be 1.6, 2, 2.5, 3 or 3.5, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] In which, in the first chemical vapor deposition process, the usage ratio of TiCl4 and AlCl3 is TiCl4 / AlCl3 is 0.9-4.6, for example, it can be 0.9, 1, 2, 3, 4 or 4.6, but is not limited to the listed values, and the other unlisted values ​​within the numerical range are also applicable.

[0026] Preferably, the material of the nitrogen-containing layer includes at least one of a titanium nitride layer, a titanium carbonitride layer or a titanium oxycarbonitride layer. Typical but non-limiting combinations include a combination of a titanium nitride layer and a titanium carbonitride layer, a combination of a titanium nitride layer and a titanium oxycarbonitride layer, a combination of a titanium carbonitride layer and a titanium oxycarbonitride layer, or a combination of a titanium nitride layer, a titanium carbonitride layer and a titanium oxycarbonitride layer.

[0027] Preferably, the transition layer is an aluminum titanium carbonitride oxide layer.

[0028] When the transition layer is obtained by the first chemical vapor deposition, it is necessary to provide the necessary active sites for the nucleation and growth of alumina. Controlling the appropriate temperature is not only beneficial to the structural transition between the alumina coating and the substrate layer, but also can provide the necessary active sites for the nucleation and growth of alumina, thereby obtaining an alumina coating with excellent performance and a preferred orientation of the (0 1 8) crystal plane.

[0029] Therefore, as a preferred technical solution, the absolute pressure during the first chemical vapor deposition is 80-120 mbar, for example, it can be 80 mbar, 90 mbar, 100 mbar, 110 mbar or 120 mbar, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] The temperature during the first chemical vapor deposition is 950-1020° C., for example, 950° C., 980° C., 1000° C. or 1020° C., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0031] The time of the first chemical vapor deposition is 50-70 minutes, for example, 50 minutes, 55 minutes, 60 minutes, 65 minutes or 70 minutes, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0032] In the present invention, the time of the first chemical vapor deposition is positively correlated with the thickness of the resulting transition layer. In order to ensure that the resulting aluminum oxide coating has a preferred orientation of the (0 1 8) crystal plane, the time of the first chemical vapor deposition only needs to be more than 50 minutes. However, too long a time will cause the preparation efficiency of the aluminum oxide coating to decrease. Therefore, as a preferred technical solution of the present invention, the time of the first chemical vapor deposition is 50-70 minutes.

[0033] Preferably, the temperature of the second chemical vapor deposition is 950-1020° C., the time is 5-7 hours, and the absolute pressure is 60-70 mbar.

[0034] The temperature of the second chemical vapor deposition is 950-1020° C., for example, 950° C., 980° C., 1000° C. or 1020° C., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] The absolute pressure of the second chemical vapor deposition is 60-70 mbar, for example, 60 mbar, 65 mbar or 70 mbar, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0036] In the present invention, the time of the second chemical vapor deposition is positively correlated with the thickness of the resulting transition layer. In order to ensure that the thickness of the resulting aluminum oxide coating is 1-15 μm, the time of the second chemical vapor deposition is 5-7 hours, for example, it can be 5 hours, 5.5 hours, 6 hours, 6.5 hours or 7 hours, but is not limited to the listed values, and the remaining unlisted values ​​within the numerical range are also applicable.

[0037] In the first chemical vapor deposition process, on the premise that the usage ratio of TiCl4 to CO is TiCl4 / CO of 1.6-3.5 and the usage ratio of TiCl4 to AlCl3 is TiCl4 / AlCl3 of 0.9-4.6, it is preferred that the volume fraction of TiCl4 is 1-3vol%, the volume fraction of N2 is 3.5-4.5vol%, the volume fraction of CH3CN is 0.1-1vol%, the volume fraction of CO is 0.3-1.5vol%, the volume fraction of AlCl3 is 0.5-2.5vol%, and the balance is H2.

[0038] Specifically, in the first chemical vapor deposition process, the volume fraction of TiCl4 is 1-3 vol%, for example, it can be 1 vol%, 1.5 vol%, 2 vol%, 2.5 vol% or 3 vol%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] During the first chemical vapor deposition process, the volume fraction of N2 is 3.5-4.5 vol%, for example, it can be 3.5 vol%, 3.8 vol%, 4 vol%, 4.2 vol% or 4.5 vol%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] During the first chemical vapor deposition process, the volume fraction of CH3CN is 0.1-1 vol%, for example, it can be 0.1 vol%, 0.3 vol%, 0.5 vol%, 0.8 vol% or 1 vol%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0041] In the first chemical vapor deposition process, the volume fraction of CO is 0.3-1.5 vol%, for example, it can be 0.3 vol%, 0.5 vol%, 1 vol% or 1.5 vol%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0042] During the first chemical vapor deposition process, the volume fraction of AlCl3 is 0.5-2.5 vol%, for example, it can be 0.5 vol%, 1 vol%, 1.5 vol%, 2 vol% or 2.5 vol%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0043] When the process conditions of the first chemical vapor deposition meet the requirements of the present invention, an aluminum oxide coating can be obtained whose texture coefficients satisfy TC(0 1 8)>3, TC(0 1 2)<1, TC(1 0 4)<1, TC(1 1 0)<1.5, TC(1 1 3)<1, TC(02 4)<1, TC(1 16)<1, TC(2 1 4)<1 and TC(3 0 0)<1.

[0044] Preferably, in the second chemical vapor deposition process, the volume fraction of CO is 0.3-0.5 vol%, the volume fraction of CO2 is 3.3-3.7 vol%, the volume fraction of AlCl3 is 2.3-2.7 vol%, the volume fraction of HCl is 1.8-2.2 vol%, the volume fraction of H2S is 0.3-0.5 vol%, and the balance is H2.

[0045] In the second chemical vapor deposition process, the volume fraction of CO is 0.3-0.5 vol%, for example, it can be 0.3 vol%, 0.4 vol% or 0.5 vol%, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0046] During the second chemical vapor deposition process, the volume fraction of CO2 is 3.3-3.7 vol%, for example, it can be 3.3 vol%, 3.4 vol%, 3.5 vol%, 3.6 vol% or 3.7 vol%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] In the second chemical vapor deposition process, the volume fraction of AlCl3 is 2.3-2.7 vol%, for example, it can be 2.3 vol%, 2.4 vol%, 2.5 vol%, 2.6 vol% or 2.7 vol%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0048] In the second chemical vapor deposition process, the volume fraction of HCl is 1.8-2.2 vol%, for example, it can be 1.8 vol%, 1.9 vol%, 2 vol%, 2.1 vol% or 2.2 vol%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0049] In the second chemical vapor deposition process, the volume fraction of H2S is 0.3-0.5 vol%, for example, it can be 0.3 vol%, 0.4 vol% or 0.5 vol%, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0050] In a third aspect, the present invention provides a cutting device, comprising a cemented carbide substrate and the coating described in the first aspect.

[0051] In the present invention, the composition of the cemented carbide substrate is 7.4wt% Co, 8.24wt% (Ti, Ta, Nb)C cubic carbide, and the balance WC, and the surface cobalt-rich layer of the cemented carbide substrate is at least 18μm, for example, it can be 18μm, 20μm, 21μm, 24μm or 25μm, but is not limited to the listed values, and the remaining values ​​not listed in the numerical range are also applicable.

[0052] Exemplarily, the method for preparing the cutting device comprises the following steps:

[0053] (1) sequentially depositing a nitrogen-containing layer on the surface of a cemented carbide substrate by chemical vapor deposition;

[0054] (2) performing a first chemical vapor deposition to obtain a transition layer;

[0055] (3) performing a second chemical vapor deposition to obtain an aluminum oxide coating, thereby preparing a cutting device;

[0056] In the first chemical vapor deposition process, the usage ratio of TiCl4 to CO is 1.6-3.5, and the usage ratio of TiCl4 to AlCl3 is 0.9-4.6.

[0057] Preferably, the nitrogen-containing layer includes a titanium nitride layer and a titanium carbonitride layer disposed in sequence.

[0058] Exemplarily, the conditions for depositing a titanium nitride layer on the surface of a cemented carbide substrate by chemical vapor deposition in the present invention are: the gas used includes 1.7 vol% TiCl4, 39 vol% N2 and the remainder H2; the temperature is 900°C, the absolute pressure is 160 mbar, and the time is 60 min.

[0059] Exemplarily, the conditions for obtaining the titanium carbonitride layer by chemical vapor deposition in the present invention are: the gas used includes 2 vol% TiCl4, 39 vol% N2, 0.8 vol% CH3CN and the balance H2; the temperature is 850°C, the absolute pressure is 80 mbar, and the time is 480 min.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] The texture coefficient TC of the aluminum oxide coating provided by the present invention satisfies the following conditions: TC(0 1 8)>3, TC(0 1 2)<1, TC(10 4)<1, TC(1 1 0)<1.5, TC(1 1 3)<1, TC(0 2 4)<1, TC(1 1 6)<1, TC(2 1 4)<1 and TC(3 0 0)<1. The aluminum oxide coating with the (0 1 8) crystal plane preferential orientation can improve the toughness during cutting without reducing the toughness of the coating, and has obvious advantages in the cutting of widely used steel parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is the XRD spectrum of the aluminum oxide coating obtained in Example 1.

[0063] Figure 2 This is the XRD spectrum of the aluminum oxide coating obtained in Comparative Example 1. DETAILED DESCRIPTION

[0064] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0065] In a specific embodiment of the present invention, the substrate layer used in preparing the aluminum oxide coating is a laminated cemented carbide substrate, a titanium nitride layer and a titanium carbonitride layer, and a transition layer (aluminum titanium carbonitride layer) is deposited on the surface of the titanium carbonitride layer; and the cemented carbide substrate is a cemented carbide insert of specification CNMG120408-QM, composed of 7.4wt% Co, 8.24wt% (Ti, Ta, Nb) C cubic carbide, and the balance WC, and the surface cobalt-rich layer of the cemented carbide substrate is 24μm; the titanium nitride layer is formed The chemical vapor deposition conditions are as follows: the gas used includes 1.7 vol% TiCl4, 39 vol% N2 and the balance H2; the temperature is 900°C, the absolute pressure is 160 mbar, and the time is 60 min; the chemical vapor deposition conditions for forming the titanium carbonitride layer are as follows: the gas used includes 2 vol% TiCl4, 39 vol% N2, 0.8 vol% CH3CN and the balance H2; the temperature is 850°C, the absolute pressure is 80 mbar, and the time is 480 min.

[0066] The above content is only to clearly illustrate the technical solution of the present invention and is not to be regarded as further limiting the technical solution of the present invention.

[0067] Example 1

[0068] The present embodiment provides a coating, including an aluminum oxide coating, wherein the texture coefficient TC of the aluminum oxide coating satisfies: TC(0 1 8) is 6.14, TC(0 1 2) is 0.57, TC(1 0 4) is 0.62, TC(1 1 0) is 0.48, TC(1 1 3) is 0.22, TC(0 2 4) is 0.39, TC(1 1 6) is 0.35, TC(2 1 4) is 0.19 and TC(3 00) is 0.01, and its XRD spectrum is as shown in FIG. Figure 1 shown.

[0069] The preparation method of the aluminum oxide coating in this embodiment comprises the following steps:

[0070] (a) performing a first chemical vapor deposition on the surface of the substrate layer to obtain a transition layer (titanium oxycarbonitride layer);

[0071] In the first chemical vapor deposition process, the volume fraction of TiCl4 is 2.4 vol%, the volume fraction of N2 is 4 vol%, the volume fraction of CH3CN is 0.5 vol%, the volume fraction of CO is 1.3 vol%, the volume fraction of AlCl3 is 1.8 vol%, and the balance is H2;

[0072] The first chemical vapor deposition temperature is 1000°C, the time is 60 min, and the absolute pressure is 100 mbar;

[0073] (b) then performing a second chemical vapor deposition on the outer side of the transition layer to obtain an aluminum oxide coating;

[0074] In the second chemical vapor deposition process, the volume fraction of CO is 0.4 vol%, the volume fraction of CO2 is 3.5 vol%, the volume fraction of AlCl3 is 2.5 vol%, the volume fraction of HCl is 2 vol%, the volume fraction of H2S is 0.4 vol%, and the balance is H2;

[0075] The temperature of the second chemical vapor deposition was 1000° C., the time was 6 h, and the absolute pressure was 65 mbar.

[0076] Example 2

[0077] This embodiment provides a coating, including an aluminum oxide coating, and a method for preparing the aluminum oxide coating includes the following steps:

[0078] (a) performing a first chemical vapor deposition on the surface of the substrate layer to obtain a transition layer (titanium oxycarbonitride layer);

[0079] In the first chemical vapor deposition process, the volume fraction of TiCl4 is 2.4 vol%, the volume fraction of N2 is 4 vol%, the volume fraction of CH3CN is 0.5 vol%, the volume fraction of CO is 1.3 vol%, the volume fraction of AlCl3 is 1.8 vol%, and the balance is H2;

[0080] The first chemical vapor deposition temperature is 950°C, the time is 70 min, and the absolute pressure is 80 mbar;

[0081] (b) then performing a second chemical vapor deposition on the outer side of the transition layer to obtain an aluminum oxide coating;

[0082] In the second chemical vapor deposition process, the volume fraction of CO is 0.3 vol%, the volume fraction of CO2 is 3.3 vol%, the volume fraction of AlCl3 is 2.3 vol%, the volume fraction of HCl is 1.8 vol%, the volume fraction of H2S is 0.3 vol%, and the balance is H2;

[0083] The temperature of the second chemical vapor deposition was 950° C., the time was 7 h, and the absolute pressure was 60 mbar.

[0084] Example 3

[0085] This embodiment provides a coating, including an aluminum oxide coating, and a method for preparing the aluminum oxide coating includes the following steps:

[0086] (a) performing a first chemical vapor deposition on the surface of the substrate layer to obtain a transition layer;

[0087] In the first chemical vapor deposition process, the volume fraction of TiCl4 is 2.4 vol%, the volume fraction of N2 is 4 vol%, the volume fraction of CH3CN is 0.5 vol%, the volume fraction of CO is 1.3 vol%, the volume fraction of AlCl3 is 1.8 vol%, and the balance is H2;

[0088] The first chemical vapor deposition temperature is 1020°C, the time is 50 min, and the absolute pressure is 120 mbar;

[0089] (b) then performing a second chemical vapor deposition on the outer side of the transition layer to obtain the aluminum oxide coating;

[0090] In the second chemical vapor deposition process, the volume fraction of CO is 0.5 vol%, the volume fraction of CO2 is 3.7 vol%, the volume fraction of AlCl3 is 2.7 vol%, the volume fraction of HCl is 2.2 vol%, the volume fraction of H2S is 0.5 vol%, and the balance is H2;

[0091] The temperature of the second chemical vapor deposition was 1020° C., the time was 6 h, and the absolute pressure was 70 mbar.

[0092] Example 4

[0093] This embodiment provides a coating, including an aluminum oxide coating. The preparation method of the aluminum oxide coating is the same as that of Embodiment 1, except that the volume fraction of CO in the first chemical vapor deposition process is set to 1.5 vol%.

[0094] That is, during the first chemical vapor deposition, the usage ratio of TiCl4 to CO is 1.6.

[0095] Example 5

[0096] This embodiment provides a coating, including an aluminum oxide coating. The preparation method of the aluminum oxide coating is the same as that of Embodiment 1, except that the volume fraction of CO in the first chemical vapor deposition process is set to 0.69 vol%.

[0097] That is, during the first chemical vapor deposition, the usage ratio of TiCl4 to CO is 3.48.

[0098] Example 6

[0099] This embodiment provides a coating, including an aluminum oxide coating. The preparation method of the aluminum oxide coating is the same as that of Embodiment 1, except that the volume fraction of AlCl 3 in the first chemical vapor deposition process is set to 2.5 vol%.

[0100] That is, during the first chemical vapor deposition, the usage ratio of TiCl4 to AlCl3 is 0.96.

[0101] Example 7

[0102] This embodiment provides a coating, including an aluminum oxide coating. The preparation method of the aluminum oxide coating is the same as that of Embodiment 1, except that the volume fraction of AlCl 3 in the first chemical vapor deposition process is set to 0.53 vol%.

[0103] That is, during the first chemical vapor deposition, the usage ratio of TiCl4 to AlCl3 is 4.53.

[0104] Example 8

[0105] This embodiment provides a coating, which is the same as Embodiment 1 except that the conditions of the first chemical vapor deposition are different from those of Embodiment 1.

[0106] The conditions for the first chemical vapor deposition in this embodiment are:

[0107] In the first chemical vapor deposition process, the volume fraction of TiCl4 is 1 vol%, the volume fraction of N2 is 3.5 vol%, the volume fraction of CH3CN is 0.1 vol%, the volume fraction of CO is 0.3 vol%, the volume fraction of AlCl3 is 0.5 vol%, and the balance is H2.

[0108] Example 9

[0109] This embodiment provides a coating, which is the same as Embodiment 1 except that the conditions of the first chemical vapor deposition are different from those of Embodiment 1.

[0110] The conditions for the first chemical vapor deposition in this embodiment are:

[0111] In the first chemical vapor deposition process, the volume fraction of TiCl4 is 3 vol%, the volume fraction of N2 is 4.5 vol%, the volume fraction of CH3CN is 1 vol%, the volume fraction of CO is 0.9 vol%, the volume fraction of AlCl3 is 2.5 vol%, and the balance is H2.

[0112] Comparative Example 1

[0113] The present comparative example provides a coating, comprising an aluminum oxide coating, wherein the texture coefficient TC of the aluminum oxide coating satisfies: TC(0 1 8) is 0.3, TC(0 1 2) is 1.8, TC(1 0 4) is 2.2, TC(1 1 0) is 1.2, TC(11 3) is 0.3, TC(02 4) is 1, TC(1 1 6) is 0.6, TC(2 1 4) is 0.1 and TC(3 0 0) is 1.5, and its XRD spectrum is as shown in Figure 2 shown.

[0114] The preparation method of the aluminum oxide coating provided in this comparative example comprises the following steps:

[0115] (a) performing a first chemical vapor deposition on the surface of the substrate layer to obtain a transition layer;

[0116] In the first chemical vapor deposition process, the volume fraction of TiCl4 is 1.2 vol%, the volume fraction of N2 is 5 vol%, the volume fraction of CH4 is 3.5 vol%, the volume fraction of CO is 1 vol%, the volume fraction of AlCl3 is 0.8 vol%, and the balance is H2;

[0117] The first chemical vapor deposition temperature is 1000° C., the time is 60 min, and the absolute pressure is 100 mbar;

[0118] (b) then performing a second chemical vapor deposition on the outer side of the transition layer to obtain the aluminum oxide coating;

[0119] In the second chemical vapor deposition process, the volume fraction of CO2 is 3 vol%, the volume fraction of AlCl3 is 2.1 vol%, the volume fraction of HCl is 2.2 vol%, the volume fraction of H2S is 0.2 vol%, and the balance is H2;

[0120] The temperature of the second chemical vapor deposition is 1000° C., the time is 6 hours, and the absolute pressure is 65 mbar.

[0121] Comparative Example 2

[0122] This comparative example provides an aluminum oxide coating, and the preparation method thereof is the same as that of Example 1 except that the volume fraction of CO in the first chemical vapor deposition process is set to 0.6 vol%.

[0123] That is, during the first chemical vapor deposition, the usage ratio of TiCl4 to CO is 4.

[0124] Comparative Example 3

[0125] This comparative example provides an aluminum oxide coating, the preparation method of which is the same as that of Example 1 except that the volume fraction of AlCl3 in the first chemical vapor deposition process is 3 vol%.

[0126] That is, during the first chemical vapor deposition, the usage ratio of TiCl4 to AlCl3 is 0.8.

[0127] Comparative Example 4

[0128] This comparative example provides an aluminum oxide coating, the preparation method of which is the same as that of Example 1 except that the volume fraction of AlCl3 in the first chemical vapor deposition process is 0.5 vol%.

[0129] That is, during the first chemical vapor deposition, the usage ratio of TiCl4 to AlCl3 is 4.8.

[0130] In the above embodiments and comparative examples of the present invention, the conditions of the first chemical vapor deposition are shown in Table 1.

[0131] Table 1

[0132]

[0133] The X-ray diffraction patterns of the aluminum oxide coatings obtained in the above embodiments and comparative examples were measured by CuKa radiation and 2θ scanning, and the texture coefficients of the crystal planes (0 1 8), (0 1 2), (1 0 4), (1 1 0), (1 1 3), (0 2 4), (1 1 6), (2 14) and (3 0 0) were calculated. The results are shown in Table 2.

[0134] Table 2

[0135]

[0136]

[0137] The substrate layer in the above-mentioned embodiment and comparative example is a laminated cemented carbide substrate, a titanium nitride layer and a titanium carbonitride layer, and the product after preparing the aluminum oxide coating is a cutting device; a cutting experiment is carried out on the obtained cutting device, and the experimental parameters are:

[0138] Workpiece: heat-treated 45# steel, cylindrical; cutting speed Vc=250m / min; cutting depth ap=2mm; feed rate f=0.3mm / rev; cutting method: continuous wet cutting; cooling method: water cooling;

[0139] Tool life judgment criteria: the wear of the back face is more than 300μm;

[0140] Measurement method: Measure every 2 minutes or the time when the abnormal wear sound is emitted during processing.

[0141] Three sets of data were measured for each cutting tool, and the average value was taken as the tool life. The results are shown in Table 3.

[0142] Table 3

[0143]

[0144]

[0145] The substrate layer in the above-mentioned embodiment and comparative example is a laminated cemented carbide substrate, a titanium nitride layer and a titanium carbonitride layer, and the product after preparing the aluminum oxide coating is a cutting device; a cutting experiment is carried out on the obtained cutting device, and the experimental parameters are:

[0146] Workpiece: heat-treated 45# steel, cylindrical with four grooves; cutting speed 200m / min; cutting depth ap=1.5mm; feed rate 0.3mm / rev; cutting method: intermittent wet cutting; cooling method: water cooling;

[0147] Tool life judgment criteria: the wear of the back face is more than 300μm;

[0148] Measurement method: Measure every 30 seconds or the time when the abnormal wear sound is emitted during processing.

[0149] Six sets of data were measured for each cutting tool, and the average value was taken as the tool life. The results are shown in Table 4.

[0150] Table 4

[0151]

[0152] In summary, the texture coefficient TC of the alumina coating provided by the present invention satisfies the following conditions: TC(0 1 8)>3, TC(01 2)<1, TC(1 0 4)<1, TC(1 1 0)<1.5, TC(1 1 3)<1, TC(0 2 4)<1, TC(1 1 6)<1, TC(2 1 4)<1 and TC(3 0 0)<1. The alumina coating with the (0 1 8) crystal plane preferential orientation can improve the toughness during cutting without reducing the toughness of the coating, and has obvious advantages in the widely used cutting of steel parts.

[0153] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A coating, characterized in that: The invention comprises an aluminum oxide coating, wherein the texture coefficient TC of the aluminum oxide coating satisfies: TC(0 1 8)>3, TC(0 1 2)<1, TC(1 0 4)<1, TC(1 1 0)<1.5, TC(1 1 3)<1, TC(02 4)<1, TC(1 1 6)<1, TC(2 1 4)<1 and TC(3 0 0)<1.

2. The aluminum oxide coating according to claim 1, characterized in that: The texture coefficient TC of the aluminum oxide coating satisfies: TC(0 1 8)≥5, TC(0 1 2)<0.7, TC(1 0 4)<0.7, TC(1 1 0)<1.0, TC(1 1 3)<0.7, TC(02 4)<0.7, TC(1 1 6)<0.7, TC(2 1 4)<0.7 and TC(3 0 0)<0.

7.

3. The coating according to claim 1, characterized in that The coating also includes a nitrogen-containing layer and a transition layer sequentially deposited on the bottom of the aluminum oxide coating.

4. The coating according to claim 3, characterized in that The nitrogen-containing layer includes at least one of a titanium nitride layer, a titanium carbonitride layer, or a titanium oxycarbonitride layer.

5. The coating according to claim 4, characterized in that The nitrogen-containing layer is a titanium nitride layer and a titanium carbonitride layer deposited in sequence.

6. The coating according to claim 4, characterized in that The transition layer is an aluminum titanium carbonitride oxide layer.

7. A method for preparing a coating according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: Deposition of nitrogen-containing layers; Performing a first chemical vapor deposition on the surface of the nitrogen-containing layer to obtain a transition layer; and then performing a second chemical vapor deposition on the outer side of the transition layer to obtain the aluminum oxide coating; In the first chemical vapor deposition process, the usage ratio of TiCl4 to CO is TiCl4 / CO is 1.6-3.5, and the usage ratio of TiCl4 to AlCl3 is TiCl4 / AlCl3 is 0.9-4.

6.

8. The preparation method according to claim 7, characterized in that: The absolute pressure during the first chemical vapor deposition is 80-120 mbar, the temperature is 950-1020° C., and the time is 50-70 min; And / or, the temperature of the second chemical vapor deposition is 950-1050° C., the time is 5-7 hours, and the absolute pressure is 60-70 mbar.

9. The preparation method according to claim 7 or 8, characterized in that: In the first chemical vapor deposition process, the volume fraction of TiCl4 is 1-3 vol%, the volume fraction of N2 is 3.5-4.5 vol%, the volume fraction of CH3CN is 0.1-1 vol%, the volume fraction of CO is 0.3-1.5 vol%, the volume fraction of AlCl3 is 0.5-2.5 vol%, and the balance is H2; Or / and, in the second chemical vapor deposition process, the volume fraction of CO is 0.3-0.5vol%, the volume fraction of CO2 is 3.3-3.7vol%, the volume fraction of AlCl3 is 2.3-2.7vol%, the volume fraction of HCl is 1.8-2.2vol%, the volume fraction of H2S is 0.3-0.5vol%, and the balance is H2.

10. A cutting device, characterized in that: The invention comprises a cemented carbide substrate and a coating as claimed in any one of claims 1 to 6.

Images