A chemical vapor deposition hafnium boride multilayer coating tool and preparation method thereof

Abstract

The present invention relates to the technical field of coated tool technology, and provides a chemical vapor deposition hafnium boride multilayer coated tool and a preparation method thereof, which comprises a substrate and a multilayer coating sequentially arranged on the surface of the substrate; the multilayer coating comprises a first sub-coating HfBN layer and a second sub-coating HfB x layer, wherein 1.8≤x≤2.2; the first sub-coating HfBN layer is composed of HfB2, HfN and BN phases, wherein the volume fraction of the HfB2 phase is 60-90%, and the first sub-coating HfBN layer grows in columnar crystals; the second sub-coating HfBx layer grows in columnar crystals, and its grain size is greater than that of the first sub-coating HfBN layer. The present invention has high wear resistance, high bonding strength, high anti-adhesion and low friction coefficient to meet the cutting and processing requirements of difficult-to-process materials such as stainless steel, titanium alloy, and nickel-based high-temperature alloy.

Description

Technical Field

[0001] The invention belongs to the technical field of coated tool technology, and in particular relates to a chemical vapor deposition hafnium boride multilayer coating tool and a preparation method thereof. Background Art

[0002] Materials such as stainless steel, titanium alloy, and nickel-based high-temperature alloy have high strength, especially titanium alloy, which has the characteristics of high strength, low thermal conductivity, and high chemical reactivity. This also leads to high local cutting temperatures and severe tool wear during processing, resulting in low processing efficiency and high processing costs. Therefore, how to select and develop coated tools suitable for titanium alloy cutting, maximize the processing efficiency and quality of titanium alloy, and improve the service life of coated tools has become an important processing problem that needs to be solved in key fields such as aerospace. In addition to having high bonding strength with the tool substrate, suitable hardness, and high thermal conductivity, the tool coating for processing titanium alloy materials has high resistance to titanium adhesion due to low affinity with titanium alloy, which is an extremely important property.

[0003] As one of the transition metal nitrides, HfN is known as the most promising ultra-high temperature ceramic material because of its high melting point, high hardness, low resistivity, chemical inertness and relatively good oxidation resistance. HfB2 has a high melting point, high hardness and good wear resistance, but low toughness. HfB2 single-layer coating is easily detached from the substrate due to its own high residual stress during deposition, and has a low film-base bonding force. Combining nitrides with borides with high brittleness is expected to improve the toughness of boride coatings. HfBN coating combines the high toughness of nitrides and the high wear resistance of borides, and has good comprehensive properties. Depending on the preparation process, HfBN can have multiple crystal phase structures such as HfN, HfB2 and BN at the same time, which can reduce the internal stress of the coating, while the hardness is lower than that of HfB2. HfN, HfB2, and HfBN have low affinity with titanium alloys, stainless steel and nickel-based high-temperature alloys, and are suitable for cutting these materials.

[0004] Chinese invention patent CN112063983B discloses a HfB2 (20-45% Hf and 55-80% B in atomic percentage) and MeN (35-65% Me and 35-65% N in atomic percentage) coating deposited alternately by magnetron sputtering, wherein the MeN coating is TiN, TiSiN, TiAlN, AlTiN, CrN, CrSiN or CrAlN coating, which is particularly suitable for high-speed cutting of difficult-to-cut materials. The document "Structural Modulation of HfN / HfB2 Nano-Multilayer Films and Their Mechanical Properties" discloses that a series of HfN / HfB2 nano-multilayer films with the same thickness and different modulation periods were prepared on a Si (100) substrate using multi-target magnetron sputtering technology. When the modulation period is 40nm, the hardness of the multilayer film reaches a maximum value of 36.72±1.3GPa. After high-temperature annealing, the hardness of the multilayer film does not change significantly, and the coating has good thermal stability. However, when the magnetron sputtering method is used to prepare HfN and HfB2 single-layer or multi-layer coatings, the coating is easy to peel off due to the high residual stress, so it is difficult to prepare thick coatings. The document "HfB2and Hf-BN hard coatings by chemical vapor deposition" published the HfB2 coating prepared by chemical vapor deposition (CVD) with Hf[BH4]4 as the precursor at a temperature below 350°C. The deposited coating is amorphous with a hardness of 20GPa. After annealing at 700°C, the amorphous state is transformed into nanocrystalline, and the hardness increases to 40GPa. The multilayer structure HfB2 / Hf-BN has high hardness (33GPa) and low elastic modulus (300GPa). However, the HfB2 coating prepared at low temperature has low crystallinity, resulting in low coating hardness and insufficient wear resistance. The document “Novel ZrB2and HfB2metadiboride coatings by LPCVD” published that HfB2 coatings were prepared by LPCVD at 800~1000℃ with HfCl4, BCl3, H2 and Ar as reaction gases, with a hardness of 3900HV [0.01] Before depositing HfB2, a TiN bonding layer is deposited, and the bonding strength reaches 90N. The service life of HfB2 coated inserts in face milling TiAl6V4 is better than that of commercially available CVD-TiB2 coated inserts. However, this document only reports the performance of HfB2 single-layer coating, and does not combine the high toughness and oxidation resistance of HfN and HfBN, so its application field is limited. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention aims to propose a chemical vapor deposition hafnium boride multilayer coating tool and a preparation method thereof, which has high wear resistance, high bonding strength, high anti-adhesion and low friction coefficient to meet the cutting processing requirements of difficult-to-process materials such as stainless steel, titanium alloy, and nickel-based high-temperature alloy.

[0006] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0007] A chemical vapor deposition hafnium boride multilayer coating tool, comprising:

[0008] A substrate and a multi-layer coating layer sequentially disposed on the surface of the substrate;

[0009] The multilayer coating comprises a first sub-coating HfBN layer and a second sub-coating HfB x Layer, wherein 1.8≤x≤2.2, specifically, x can be, for example, any one of 1.8, 1.85, 1.9, 1.95, 2.0, 2.05, 2.1, 2.15, 2.2, or a range between any two thereof;

[0010] The first sub-coating HfBN layer is composed of an HfB2 phase, an HfN phase and a BN phase, wherein the volume fraction of the HfB2 phase is 60-90%, and the first sub-coating HfBN layer grows in a columnar crystal; specifically, the volume fraction of the HfB2 phase can be, for example, any one of 60%, 65%, 70%, 75%, 80%, 85%, 90%, or a range between any two thereof;

[0011] Second sub-coating HfB x The layer grows in the form of columnar crystals, and its grain size is larger than that of the HfBN layer of the first sub-coating layer.

[0012] As a preferred solution of a chemical vapor deposition hafnium boride multilayer coating tool described in the present invention, the second sub-coating HfB x The texture coefficient of the (001) crystal plane of the layer is 2.0≤TC(001)≤6.0. Specifically, TC(001) can be, for example, any one of 2.0, 3.0, 4.0, 5.0, 6.0 or a range between any two thereof. The texture coefficient is defined as follows:

[0013]

[0014] Wherein, I(hkl) is the reflection intensity of the (hkl) crystal plane measured by X-ray diffraction, I0 is the standard intensity of diffraction reflection according to PDF card number 65-8677, n is the number of reflection crystal planes used in the calculation, and the (hkl) reflection crystal planes used are (001), (100), (101), (002), (110), (102), (111), (200), (201), and (112).

[0015] As a preferred solution of a chemical vapor deposition hafnium boride multilayer coating tool described in the present invention, the second sub-coating HfB xThe grain size of the layer is 0.5~2.0μm and the hardness is 35~45GPa; specifically, the second sub-coating HfB x The grain size of the layer can be, for example, any one of 0.5μm, 1.0μm, 1.5μm, 2.0μm, or a range between any two of them; the hardness can be, for example, any one of 35GPa, 36GPa, 37GPa, 38GPa, 39GPa, 40GPa, 41GPa, 42GPa, 43GPa, 44GPa, 45GPa, or a range between any two of them.

[0016] As a preferred solution of a chemical vapor deposition hafnium boride multilayer coating tool described in the present invention, the multilayer coating also includes a bonding layer deposited between the substrate surface and the first sub-coating HfBN layer, the bonding layer contains at least one of TiN, Ti, HfN, and Hf, and the thickness of the bonding layer is 0.5~3.0μm.

[0017] As a preferred solution of the chemical vapor deposition hafnium boride multilayer coating tool described in the present invention, the bonding layer is preferably HfN.

[0018] As a preferred solution of the chemical vapor deposition hafnium boride multilayer coating tool described in the present invention, the total thickness of the multilayer coating is 4.0-10.0 μm.

[0019] As a preferred solution of a chemical vapor deposition hafnium boride multilayer coating tool according to the present invention, wherein: in the second sub-coating HfB x A surface layer is also deposited on the surface of the coating, the surface layer contains at least one of HfN and HfCN, and the thickness of the surface layer is 0.2-2.0 μm.

[0020] As a preferred solution of the chemical vapor deposition hafnium boride multilayer coating tool described in the present invention, the substrate is one of cemented carbide, high-speed steel, metal ceramic, polycrystalline diamond, and cubic boron nitride.

[0021] To solve the above technical problem, according to another aspect of the present invention, the present invention provides the following technical solution:

[0022] A method for preparing a chemical vapor deposition hafnium boride multilayer coating tool, wherein the hafnium boride multilayer coating is deposited on a substrate by a chemical vapor deposition method;

[0023] The first sub-coating HfBN layer is deposited at 800~1000℃ and 50~200mbar using H2, HfCl4, BCl3, N2 and Ar with a purity greater than 99.99% as raw materials.

[0024] As a preferred embodiment of the method for preparing a chemical vapor deposition hafnium boride multilayer coating tool of the present invention, the second sub-coating HfB x The layers are deposited at 800~1000℃ and 50~200mbar using H2, HfCl4, BCl3 and Ar with a purity greater than 99.99% as raw materials.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The multilayer coating includes a first sub-coating HfBN layer and a second sub-coating HfB x layer (1.8≤x≤2.2), which can effectively exert the low stress, high toughness characteristics of HfBN coating and HfB x The synergistic effect between the high hardness characteristics of the layers results in good comprehensive performance.

[0027] (2) The first sub-coating HfBN layer is composed of HfB2, HfN and BN phases, and the volume fraction of HfB2 phase is 60~90%, which ensures the high hardness of the first sub-coating HfBN layer.

[0028] (3) Second sub-coating HfB x The texture coefficient of the (001) crystal plane of the layer is 2.0≤TC(001)≤6.0, and the grain size is 0.5~2.0μm, which can make the coating obtain suitable high hardness. This effectively avoids the increase of brittleness caused by insufficient hardness or excessive hardness due to too low texture coefficient, and ensures the stability and wear resistance of the coating during cutting.

[0029] (4) Second sub-coating HfB x The B / Hf ratio of the layer is 1.8≤x≤2.2, which effectively avoids the low hardness problem caused by too low B content (such as x<1.8, there are vacancies in the coating) or too high B content (such as x>2.2, there are more free B elements in the coating). x The columnar crystal growth mode of the layer cooperates with the fine columnar crystal growth mode of the first sub-coating HfBN layer, which further enhances the bonding strength between the coatings and improves the overall performance of the coatings.

[0030] (5) The present invention adopts chemical vapor deposition method to prepare HfBN and HfB x Compared with the same coating prepared by magnetron sputtering method, the present invention can obtain higher thickness and higher bonding strength, thereby extending the service life of the coated tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0032] Figure 1 It is a schematic cross-sectional view of the coating of the present invention.

[0033] The reference numerals are as follows: 100 substrate, 200 multi-layer coating, 201 bonding layer, 202 first sub-coating, 203 second sub-coating, 204 surface layer.

[0034] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0035] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] like Figure 1 As shown, the substrate 100 of the chemical vapor deposition hafnium boride multilayer coating tool of the present invention can be one of cemented carbide, high-speed steel, metal ceramic and the like. The multilayer coating 200 is sequentially arranged on the surface of the substrate 100. The bonding layer 201 can be TiN, Ti, HfN, Hf, preferably HfN. The first sub-coating 202 is a HfBN layer, and the second sub-coating 203 is a HfBN layer. x Layer (1.8≤x≤2.2), the surface layer 204 is one or more materials such as HfN, HfCN, etc.

[0037] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0038] Example 1

[0039] A method for preparing a chemical vapor deposition hafnium boride multilayer coating tool, wherein the substrate 100 is a WC-Co based cemented carbide, the bonding layer 201 is a HfN layer, the first sub-coating 202 is a HfBN layer, the second sub-coating 203 is a HfB2 layer, the surface layer 204 is a HfN layer, and the multilayer coating 200 is deposited on the surface of the substrate 100 in sequence. The total thickness of the multilayer coating 200 is 7 μm, and the preparation method of each layer is as follows:

[0040] (1) Bonding layer 201 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm;

[0041] (2) The first sub-coating 202 (HfBN layer) was deposited at a temperature of 900°C and a pressure of 100 mbar. The reaction gases were H2, HfCl4, BCl3, N2, and Ar. The purity of each gas was greater than 99.99%. The volume fraction of the HfB2 phase in the coating was 60%. The deposition time was 360 min and the coating thickness was 3.0 μm.

[0042] (3) Second sub-coating 203 (HfB2 layer), deposition temperature 900°C, deposition pressure 100 mbar, reaction gases H2, HfCl4, BCl3, Ar, purity of each gas greater than 99.99%. TC(001)=2.0, deposition time 360 ​​min, coating thickness 3.0 μm;

[0043] (4) Surface layer 204 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm.

[0044] Example 2

[0045] A method for preparing a chemical vapor deposition hafnium boride multilayer coating tool, wherein the substrate 100 is a WC-Co based cemented carbide, the bonding layer 201 is a HfN layer, the first sub-coating 202 is a HfBN layer, the second sub-coating 203 is a HfB2 layer, the surface layer 204 is a HfN layer, and the multilayer coating is deposited on the surface of the substrate 100 in sequence. The total thickness of the multilayer coating is 7 μm, and the preparation method of each layer is as follows:

[0046] (1) Bonding layer 201 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm;

[0047] (2) The first sub-coating 202 (HfBN layer) was deposited at a temperature of 900°C and a pressure of 100 mbar. The reaction gases were H2, HfCl4, BCl3, N2, and Ar. The purity of each gas was greater than 99.99%. The volume fraction of the HfB2 phase in the coating was 75%. The deposition time was 360 min and the coating thickness was 3.0 μm.

[0048] (3) Second sub-coating 203 (HfB2 layer), deposition temperature 900°C, deposition pressure 100 mbar, reaction gases H2, HfCl4, BCl3, Ar, purity of each gas greater than 99.99%. TC(001)=2.0, deposition time 360 ​​min, coating thickness 3.0 μm;

[0049] (4) Surface layer 204 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm.

[0050] Example 3

[0051] A method for preparing a chemical vapor deposition hafnium boride multilayer coating tool, wherein the substrate 100 is a WC-Co based cemented carbide, the bonding layer 201 is a HfN layer, the first sub-coating 202 is a HfBN layer, the second sub-coating 203 is a HfB2 layer, the surface layer 204 is a HfN layer, and the multilayer coating is deposited on the surface of the substrate 100 in sequence. The total thickness of the multilayer coating is 7 μm, and the preparation method of each layer is as follows:

[0052] (1) Bonding layer 201 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm;

[0053] (2) The first sub-coating 202 (HfBN layer) was deposited at a temperature of 900°C and a pressure of 100 mbar. The reaction gases were H2, HfCl4, BCl3, N2, and Ar. The purity of each gas was greater than 99.99%. The volume fraction of the HfB2 phase in the coating was 90%. The deposition time was 360 min and the coating thickness was 3.0 μm.

[0054] (3) Second sub-coating 203 (HfB2 layer), deposition temperature 900°C, deposition pressure 100 mbar, reaction gases H2, HfCl4, BCl3, Ar, purity of each gas greater than 99.99%. TC(001)=2.0, deposition time 360 ​​min, coating thickness 3.0 μm;

[0055] (4) Surface layer 204 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm.

[0056] Example 4

[0057] A method for preparing a chemical vapor deposition hafnium boride multilayer coating tool, wherein the substrate 100 is a WC-Co based cemented carbide, the bonding layer 201 is a HfN layer, the first sub-coating 202 is a HfBN layer, the second sub-coating 203 is a HfB2 layer, the surface layer 204 is a HfN layer, and the multilayer coating is deposited on the surface of the substrate 100 in sequence. The total thickness of the multilayer coating is 7 μm, and the preparation method of each layer is as follows:

[0058] (1) Bonding layer 201 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm;

[0059] (2) The first sub-coating 202 (HfBN layer) was deposited at a temperature of 900°C and a pressure of 100 mbar. The reaction gases were H2, HfCl4, BCl3, N2, and Ar. The purity of each gas was greater than 99.99%. The volume fraction of the HfB2 phase in the coating was 75%. The deposition time was 360 min and the coating thickness was 3.0 μm.

[0060] (3) Second sub-coating 203 (HfB2 layer), deposition temperature 900°C, deposition pressure 100 mbar, reaction gases H2, HfCl4, BCl3, Ar, purity of each gas greater than 99.99%. TC(001)=4.0, deposition time 360 ​​min, coating thickness 3.0 μm;

[0061] (4) Surface layer 204 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm.

[0062] Example 5

[0063] A method for preparing a chemical vapor deposition hafnium boride multilayer coating tool, wherein the substrate 100 is a WC-Co based cemented carbide, the bonding layer 201 is a HfN layer, the first sub-coating 202 is a HfBN layer, the second sub-coating 203 is a HfB2 layer, the surface layer 204 is a HfN layer, and the multilayer coating is deposited on the surface of the substrate 100 in sequence. The total thickness of the multilayer coating is 7 μm, and the preparation method of each layer is as follows:

[0064] (1) Bonding layer 201 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm;

[0065] (2) The first sub-coating 202 (HfBN layer) was deposited at a temperature of 900°C and a pressure of 100 mbar. The reaction gases were H2, HfCl4, BCl3, N2, and Ar. The purity of each gas was greater than 99.99%. The volume fraction of the HfB2 phase in the coating was 75%. The deposition time was 360 min and the coating thickness was 3.0 μm.

[0066] (3) Second sub-coating 203 (HfB2 layer), deposition temperature 900°C, deposition pressure 100 mbar, reaction gases H2, HfCl4, BCl3, Ar, purity of each gas greater than 99.99%. TC(001)=6.0, deposition time 360 ​​min, coating thickness 3.0 μm;

[0067] (4) Surface layer 204 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm.

[0068] Example 6

[0069] A method for preparing a chemical vapor deposition hafnium boride multilayer coating tool, wherein the substrate 100 is a WC-Co based cemented carbide, the bonding layer 201 is a HfN layer, the first sub-coating 202 is a HfBN layer, and the second sub-coating 203 is a HfBN layer. 1.8 The surface layer 204 is a HfN layer, and multiple layers of coating are deposited on the surface of the substrate 100 in sequence. The total thickness of the multilayer coating is 7 μm. The preparation method of each layer is as follows:

[0070] (1) Bonding layer 201 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm;

[0071] (2) The first sub-coating 202 (HfBN layer) was deposited at a temperature of 900°C and a pressure of 100 mbar. The reaction gases were H2, HfCl4, BCl3, N2, and Ar. The purity of each gas was greater than 99.99%. The volume fraction of the HfB2 phase in the coating was 75%. The deposition time was 360 min and the coating thickness was 3.0 μm.

[0072] (3) Second sub-coating 203 (HfB 1.8 layer), deposition temperature 900℃, deposition pressure 100mbar, reaction gases H2, HfCl4, BCl3, Ar, purity of each gas is greater than 99.99%. TC(001)=4.0, deposition time 360min, coating thickness 3.0μm;

[0073] (4) Surface layer 204 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm.

[0074] Example 7

[0075] A method for preparing a chemical vapor deposition hafnium boride multilayer coating tool, wherein the substrate 100 is a WC-Co based cemented carbide, the bonding layer 201 is a HfN layer, the first sub-coating 202 is a HfBN layer, and the second sub-coating 203 is a HfBN layer. 2.2 The surface layer 204 is a HfN layer, and multiple layers of coating are deposited on the surface of the substrate 100 in sequence. The total thickness of the multilayer coating is 7 μm. The preparation method of each layer is as follows:

[0076] (1) Bonding layer 201 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm;

[0077] (2) The first sub-coating 202 (HfBN layer) was deposited at a temperature of 900°C and a pressure of 100 mbar. The reaction gases were H2, HfCl4, BCl3, N2, and Ar. The purity of each gas was greater than 99.99%. The volume fraction of the HfB2 phase in the coating was 75%. The deposition time was 360 min and the coating thickness was 3.0 μm.

[0078] (3) Second sub-coating 203 (HfB 2.2 layer), deposition temperature 900℃, deposition pressure 100mbar, reaction gases H2, HfCl4, BCl3, Ar, purity of each gas is greater than 99.99%. TC(001)=4.0, deposition time 360min, coating thickness 3.0μm;

[0079] (4) Surface layer 204 (HfN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm.

[0080] Comparative Example 1

[0081] A method for preparing a chemical vapor deposition multilayer coating tool, wherein the substrate is a WC-Co based cemented carbide, the bonding layer is a TiN layer, the first sub-coating is a TiBN layer, the second sub-coating is a TiB2 layer, the surface layer is a TiN layer, and the multilayer coating is deposited on the substrate surface in sequence. The total thickness of the multilayer coating is 7 μm, and the preparation method of each layer is as follows:

[0082] (1) Bonding layer (TiN layer), deposition temperature 900 ° C, deposition pressure 100 mbar, reaction gas HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm;

[0083] (2) The first sub-coating (TiBN layer) was deposited at a temperature of 850°C and a pressure of 100 mbar. The reaction gases were H2, HfCl4, BCl3, N2, and Ar. The purity of each gas was greater than 99.99%. The volume fraction of the HfB2 phase in the coating was 60%. The deposition time was 360 min and the coating thickness was 3.0 μm.

[0084] (3) The second sub-coating (TiB2 layer) was deposited at a temperature of 850°C and a pressure of 100 mbar. The reaction gases were H2, HfCl4, BCl3, and Ar. The purity of each gas was greater than 99.99%. The deposition time was 360 min and the coating thickness was 3.0 μm.

[0085] (4) Surface layer (TiN layer), deposition temperature 900 °C, deposition pressure 100 mbar, reaction gases HfCl4, N2, H2, the purity of each gas is greater than 99.99%, deposition time 60 min, coating thickness 0.5 μm.

[0086] Comparative Example 2

[0087] A method for preparing a chemical vapor deposition multilayer coating tool, wherein the substrate is a WC-Co based cemented carbide, the bonding layer is an HfN layer, the first sub-coating is an HfBN layer, the second sub-coating is an HfB2 layer, and the multilayer coating is sequentially deposited on the substrate surface. The total thickness of the multilayer coating is 4.0 μm, and each layer is prepared by a PVD high-power pulsed magnetron sputtering method:

[0088] (1) Bonding layer (HfN layer), deposition temperature 450 ° C, deposition pressure 0.05 mbar, target material is Hf (purity greater than 99.9%), target power 8 kW, duty cycle 80%, reaction gas N2, Ar, the purity of each gas is greater than 99.99%, deposition time 40 min, coating thickness 0.5 μm;

[0089] (2) The first sub-coating (HfBN layer) was deposited at a temperature of 450°C and a pressure of 0.05 mbar. The target material was HfB2 (purity greater than 99.9%), the target power was 5 kW, the duty cycle was 80%, and the reaction gases were N2 and Ar. The purity of each gas was greater than 99.99%. The volume fraction of the HfB2 phase in the coating was 75%, the deposition time was 240 min, and the coating thickness was 2.0 μm.

[0090] (3) Second sub-coating (HfB2 layer), deposition temperature 450°C, deposition pressure 0.05 mbar, target material HfB2 (purity greater than 99.9%), target power 5 kW, duty cycle 80%, reaction gas Ar (purity greater than 99.99%). TC(001)=4.0, deposition time 240 min, coating thickness 1.5 μm;

[0091] The performance of the cutting tools prepared in the embodiments and comparative examples was tested, and the results are shown in Table 1.

[0092] Table 1

[0093]

[0094] The following tests were conducted on the processing performance of the cutting tools prepared by the embodiments of the present invention and the comparative examples, wherein:

[0095] Test condition 1 is as follows:

[0096] Titanium alloy milling comparison

[0097] Material: TC18

[0098] Blade type: RPHT120408M8E-MM3

[0099] Cutting conditions: cutting speed 60m / min, feed 0.4mm / z, cutting depth 1.5mm, cutting width ae60mm, wet cutting

[0100] On the premise of no chipping, the number of blade parts to be processed is calculated after the blade wear reaches 0.3mm. The results are shown in Table 2.

[0101] Table 2

[0102]

[0103] Test condition 2 is as follows:

[0104] High temperature alloy milling comparison

[0105] Processing method: continuous turning

[0106] Material: GH4169

[0107] Blade type: WNMG080408-SC3

[0108] Cutting conditions: cutting speed 60m / min, feed 0.25mm, cutting depth 1.0mm, dry cutting

[0109] Under the condition of no chipping, the blade life is calculated by the cutting time when the wear of the blade surface reaches 0.3 mm. The test results are shown in Table 3. The wear of the blade flank is measured using an OLYMPUS SZ61 optical super-depth microscope with a scale.

[0110] Table 3

[0111]

[0112] It can be seen that the blade prepared by the present invention has a greatly improved service life compared with the comparative example.

[0113] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A chemical vapor deposition hafnium boride multilayer coating tool, characterized in that: include: A substrate and a multi-layer coating layer sequentially disposed on the surface of the substrate; The multilayer coating comprises a first sub-coating HfBN layer and a second sub-coating HfB x Layer, where 1.8≤x≤2.2; The first sub-coating HfBN layer is composed of HfB2 phase, HfN phase and BN phase, wherein the volume fraction of the HfB2 phase is 60-90%, and the first sub-coating HfBN layer grows in columnar crystals; The second sub-coating HfB x The layer grows in columnar crystals, and its grain size is larger than that of the first sub-coating HfBN layer. x The texture coefficient of the (001) crystal plane of the layer is 2.0≤TC(001)≤6.

0.

2. The chemical vapor deposition hafnium boride multilayer coating tool according to claim 1, characterized in that: The second sub-coating HfB x The grain size of the layer is 0.5~2.0μm and the hardness is 35~45GPa.

3. The chemical vapor deposition hafnium boride multilayer coating tool according to claim 1, characterized in that: The multilayer coating further comprises a bonding layer deposited between the substrate surface and the first sub-coating HfBN layer, the bonding layer comprises at least one of TiN, Ti, HfN, and Hf, and the thickness of the bonding layer is 0.5 to 3.0 μm.

4. The chemical vapor deposition hafnium boride multilayer coating tool according to claim 3, characterized in that: The bonding layer is HfN.

5. The chemical vapor deposition hafnium boride multilayer coating tool according to claim 1, characterized in that: The total thickness of the multi-layer coating is 4.0-10.0 μm.

6. The chemical vapor deposition hafnium boride multilayer coating tool according to claim 1, characterized in that: In the second sub-coating HfB x A surface layer is also deposited on the surface of the coating, wherein the surface layer comprises at least one of HfN and HfCN, and the thickness of the surface layer is 0.2-2.0 μm.

7. The chemical vapor deposition hafnium boride multilayer coating tool according to claim 1, characterized in that: The matrix is ​​one of cemented carbide, high-speed steel, metal ceramic, polycrystalline diamond and cubic boron nitride.

8. A method for preparing a chemical vapor deposition hafnium boride multilayer coating tool according to any one of claims 1 to 7, characterized in that: Depositing a multilayer coating of hafnium boride on a substrate by chemical vapor deposition; The first sub-coating HfBN layer is deposited at 800~1000℃ and 50~200mbar using H2, HfCl4, BCl3, N2 and Ar with a purity greater than 99.99% as raw materials.

9. The method for preparing a chemical vapor deposition hafnium boride multilayer coating tool according to claim 8, characterized in that: Second sub-coating HfB x The layers are deposited at 800~1000℃ and 50~200mbar using H2, HfCl4, BCl3 and Ar with a purity greater than 99.99% as raw materials.

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