Titanium and titanium alloy cutting tool coating and preparation method thereof

Abstract

The invention discloses a titanium and titanium alloy cutting tool coating and a preparation method thereof, the titanium and titanium alloy cutting tool coating comprises a coating substrate and a double-layer coating deposited on the substrate, and the double-layer coating sequentially comprises a base layer and a functional layer from the substrate side to the surface side of the double-layer coating. The base layer is composed of a metal compound TiBx, and the functional layer is composed of a metal compound TaSiy. The titanium and titanium alloy cutting tool coating provided by the invention has relatively high wear resistance, high temperature resistance, oxidation resistance and bonding resistance, the bonding strength between the coating and a matrix is good, the production process is simple, the production cost is low, and the titanium alloy cutting efficiency can be effectively improved.

Description

Technical Field

[0001] The present invention relates to a sputtering coating of a material formed by coating, and in particular to a sputtering coating characterized by a coating material. Background Art

[0002] In pursuit of higher processing efficiency, titanium alloy cutting parameters are constantly improving. Higher processing line speeds and greater feed rates mean that the tool needs to withstand greater cutting forces and higher cutting temperatures. Therefore, compared with traditional processed materials, the adhesive wear in titanium alloy cutting is more prominent, which puts higher requirements on the friction coefficient and chemical inertness of the coating. At present, the coatings used for titanium alloy cutting in the tool industry are still concentrated on nitride and boride coatings represented by TiSiN, AlCrN, ZrN and TiB2. However, due to the limitations of elements and processes, nitride coatings have gradually shown problems such as large friction coefficient, low hardness, and limited oxidation resistance, while boride coatings also have problems such as poor oxidation resistance and greater brittleness.

[0003] Refractory metal silicide coatings are widely used in aerospace, optoelectronics and semiconductor fields due to their good oxidation resistance and special optoelectronic properties. Invention patent CN104630722A reports a method for preparing an oxidation-resistant coating on the surface of a tantalum alloy material, which uses a vacuum heat treatment process to prepare TaSi by diffusion between the surface MoSi2 layer and the tantalum alloy matrix. x The technical effect of this layer in the overall coating is to serve as an intermediate transition layer to improve the bonding force between the coating and the substrate. The purpose of this patent is to provide a method for preparing an anti-oxidation coating on the surface of a tantalum alloy material to improve the thermal shock resistance and high-temperature airflow ablation resistance of the tantalum alloy. However, the patent does not disclose the TaSi x Other functions and properties of coatings. Invention patent CN115612996A reports a cutting tool, TiB x Coating and preparation method and application thereof, wherein TiB is prepared by high-power pulsed magnetron sputtering x coating, and by adjusting the Ar + The ion source parameters are used to adjust the coating stoichiometric ratio to obtain a TiB with dense structure, high hardness, high toughness and low stress. x coating, but the patent states that TiB x The hardness of the coating does not reach 45Pa to 50GPa known to technicians in this field, and the coating structure is simple, and it also does not reveal its performance advantages in the field of metal processing.

[0004] At present, there are no reports on refractory metal silicide tool coatings. Therefore, developing a coating suitable for titanium and titanium alloy cutting tools based on the advantages of refractory metal silicides in high-temperature oxidation resistance and chemical inertness has become a difficult problem that technicians in this field need to solve urgently. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a titanium and titanium alloy cutting tool coating and a preparation method thereof, in view of the problem that the existing tool coating has insufficient lifespan during titanium and titanium alloy cutting processing, so as to solve the technical problem that the tool coating suffers from severe abrasive wear, adhesive wear and oxidative wear during titanium alloy cutting processing. To solve the above technical problem, the present invention provides the following technical solutions:

[0006] A titanium and titanium alloy cutting tool coating comprises a tool substrate and a double-layer coating deposited on the tool substrate, wherein the double-layer coating comprises a base layer and a functional layer in sequence from the tool substrate side toward the surface side of the double-layer coating.

[0007] Preferably, the base layer is composed of a chemical formula of Ti (1-a) B a The metal compound of Ti (1-a) B a Specifically, it is a boride of Ti element with C32 structure, which has a two-dimensional network structure with alternating Ti atomic layers and B atomic layers. It is the most stable compound formed by Ti element and B element, has high hardness, and can play a good supporting role for the functional layer as a base layer. (1-a) B a In the formula, a represents the atomic ratio of element B in the compound relative to all elements in the compound, and satisfies 0.55≤a≤0.70, and more preferably 0.55≤a≤0.65. Because if a<0.55, the metal compound TiB x It may transform to Ti3B4 or TiB phase, and the wear resistance and lubricity of the coating will be affected; if x>0.70, there will be excessive solid solution B atoms in the metal compound, and the high temperature performance and wear resistance of the coating will be affected. According to the inventor's experiments, when the metal compound Ti (1-a) B a When the stoichiometric ratio is less than 0.67, the columnar Ti (1-a) B a There are Ti-rich stacking faults composed of excess Ti atoms in the grains, which can effectively block the movement of other dislocations. Therefore, it has higher hardness, lower elastic modulus and higher fracture strength. (1-a) B a The wear resistance is good.

[0008] Preferably, the functional layer is composed of a chemical formula of Ta (1-b) Si b The Ta (1-b) Si b Specifically, it is a silicide of Ta element with a close-packed hexagonal structure, wherein b represents the atomic ratio of Si element relative to all elements in the metal compound, and satisfies 0.55≤b≤0.65, and more preferably 0.60≤b≤0.65. Because if b<0.55, the anti-oxidation performance of the coating is affected, and if b>0.65, the high-temperature stability, thermal barrier performance and chemical inertness of the coating are affected. According to the inventor's experiments, when 060≤b≤0.65, the metal compound Ta (1-b) Si b It is mainly composed of TaSi2. This high-silicon compound can react with oxygen in a high-temperature oxidizing environment to form a low-silicon compound Ta5Si3 and an oxidation product SiO2. The dense SiO2 can seal the pores and cracks in the coating to block the entry of oxygen, thereby improving the high-temperature oxidation resistance of the coating and reducing oxidative wear. In addition, TaSi2 also has a low thermal conductivity, which can effectively reduce the influence of the heat generated during the cutting of titanium and titanium alloys on the tool matrix, thereby improving the overall wear resistance and chipping resistance of the tool. Thirdly, TaSi2 also has good chemical inertness and is not easy to react or diffuse with the processed material (titanium alloy), thereby improving the coating's anti-adhesive wear performance.

[0009] Preferably, the thickness of the functional layer accounts for 10% to 30% of the total thickness of the multilayer coating. Because, if the functional layer is too thick, the wear resistance of the coating will be affected; and if the functional layer is too thin, the high-temperature oxidation resistance, thermal barrier performance and chemical inertness of the coating will be affected. According to the inventor's experiments, the relationship between the thickness of the functional layer and the overall thickness of the double-layer coating can be approximately expressed by the function y=1-0.7 / x, where x is the overall thickness of the double-layer coating and y is the thickness of the functional layer. In the above relationship, the thickness of the functional layer increases with the increase of the thickness of the double-layer coating, but the growth rate gradually decreases and converges to y=1. This is because the role of the functional layer in improving the oxidation resistance and chemical inertness of the coating in the multilayer coating is self-limiting, and its related chemical properties are only effective within a certain thickness range of the surface layer of the coating and the surface layer. Excessive functional layer thickness will affect the wear resistance of the multilayer coating.

[0010] Preferably, in the X-ray reflectivity (XRR) analysis of the double-layer coating, the base layer density is greater than 4.0 g / cm 3 Because, if the base layer density is less than 4.0g / cm 3 , which means that the metal compound Ti in the base layer(1-a) B a There are many defects such as pores and cracks, which will affect the wear resistance of the coating. According to the inventor's research, the columnar metal compound Ti (1-a) B a The physical properties such as hardness and elastic modulus are directly related to its density. When the density is greater than 4.0g / cm 3 When the coating hardness can reach 40GPa~50GPa, the elastic modulus can reach 350GPa~420GPa, and the "Plastic Deformation Resistance Factor (H 3 / E 2 )” can reach 0.75-0.82, which means it has excellent wear resistance.

[0011] Preferably, in the X-ray reflectivity (XRR) analysis of the double-layer coating, the functional layer density is greater than 8.7 g / cm 3 Because, if the density of the base layer is less than 8.7g / cm 3 , which means that the metal compound Ta in the functional layer (1-b) Si b There are many defects such as pores and cracks, which will affect the high temperature oxidation resistance of the coating. (1-b) Si b When the density is low, that is, there are many defects such as pores and cracks, although the preferentially generated SiO2 can play a role in sealing and isolating oxygen, under the action of alternating stress, defects such as pores and cracks are still one of the causes of coating fracture and peeling.

[0012] Preferably, in the X-ray diffraction (XRD) analysis of the base layer, the metal compound Ta in the base layer (1-b) Si b The ratio of the diffraction peak intensity of the (111) crystal plane to the diffraction peak intensity of the (101) crystal plane is I (111) / I (101) Greater than 1.5. Among them, I (111) Indicates that Ta in the functional layer in an X-ray diffraction analysis (1-b) Si b The diffraction peak intensity of the (111) crystal plane of the metal compound, I (101) Indicates that Ta in the functional layer in an X-ray diffraction analysis (1-b) Si b The diffraction peak intensity of the (101) crystal plane of the metal compound. Because, if the diffraction peak intensity ratio I (111) / I (101)If the diffraction peak intensity ratio is less than 1.5, the wear resistance and oxidation resistance of the coating will be affected. (111) / I (101) When it is greater than 1.5, the Ta in the functional layer (1-b) Si b Metal compounds tend to grow along the (111) crystal plane, that is, they tend to stack in the closest-packed plane, and the material hardness and density are increased, and the wear resistance and oxidation resistance of the coating are improved.

[0013] Preferably, the overall average thickness of the double-layer coating is 0.5 μm to 8 μm, and more preferably 0.5 μm to 3 μm. Because, if the overall thickness of the double-layer coating is too small, the protective performance of the coating on the tool will not be obvious, and the wear resistance of the coating will be affected; if it is too large, it will cause stress cracking of the coating, and the resistance to cracking of the coating will be affected. According to the inventor's research, in general, the wear resistance of the coating has a positive relationship with its thickness, that is, the thicker the coating, the better its wear resistance. However, the residual stress level of the coating also has a positive relationship with its thickness, that is, the thicker the coating, the greater its residual stress. When the residual stress is greater than the film-base or interlayer bonding strength, the peeling resistance of the coating will be affected. In addition, the coating thickness will also affect the edge morphology of the cutting tool, that is, the thicker the coating, the greater the edge passivation value, the sharpness of the coating tool will be affected, the cutting load on the coating will increase, and the coating will fail faster.

[0014] In the above technical solutions, the thickness of each layer of the double-layer coating and the bonding layer can be directly measured from the cross section of the coated tool using an optical microscope (OM), a scanning electron microscope (SEM), a transmission electron microscope (TEM) and other detection equipment, or indirectly measured and calculated using the ball milling pit method (refer to the international standard ISO 26423:2009). The chemical composition of each layer of the double-layer coating can be analyzed and detected from the cross section of the coated tool using detection equipment such as an X-ray energy dispersive spectrometer (EDS) or an X-ray wavelength dispersive spectrometer (WDS). The crystal structure and density of each layer of the double-layer coating can be measured from the surface of the coated tool using an X-ray diffractometer (XRD / XRR). The hardness, elastic modulus and plastic deformation resistance factor of the double-layer coating can be measured and calculated from the coating surface using a nanoindenter. The friction coefficient of the double-layer coating in the friction pair composed of titanium alloy can be measured using a friction and wear tester. The detection method and standard of the above coating performance specifically refer to the international standard ISO 21874:2019.

[0015] As a general technical concept, the present invention also provides a reference detection method for the crystal surface texture of titanium and titanium alloy cutting tool coatings. The detection equipment can be any commercially available X-ray diffraction device, for example, it can be an XRDynamic 500 automatic multi-purpose X-ray diffractometer produced by Anton Paar. The specific test parameters are as follows:

[0016] Output power: 3kW

[0017] Scanning step: 0.04°

[0018] Scanning speed: 2.4° / min

[0019] 2θ angle scanning range: 20°~90°

[0020] Grazing Angle: 0.5°

[0021] As a general technical concept, the present invention also provides a method for preparing a titanium and titanium alloy cutting tool coating, comprising the following preparation steps:

[0022] (1) Cleaning the tool substrate to remove impurities such as oil and dust on the surface, specifically, placing the tool substrate in an alkaline solution with a pH of 11 for ultrasonic cleaning, with an ultrasonic frequency of 40 kHz and a solution temperature of 60° C., followed by spraying with deionized water and drying for later use;

[0023] (2) Ion bombardment of the tool substrate to increase the surface activity of the substrate. Specifically, the tool is placed in a coating device and the furnace chamber pressure is less than 4×10 -4 Pa, when the temperature reaches 450℃, Ar gas is introduced into the furnace chamber until the furnace chamber pressure reaches 0.5Pa, and a -800V bias is applied to the tool substrate, and the ion source is turned on to bombard the tool substrate surface for 20min;

[0024] (3) depositing a base layer on the surface of the tool substrate, specifically maintaining the Ar gas pressure of the furnace chamber at 0.4 Pa and the furnace chamber temperature at 450° C., applying a pulse bias of -40 V to -80 V to the tool substrate, setting the cathode power supply power to 4000 W, performing high-energy pulse magnetron sputtering on the TiB2 target, with a pulse frequency of 0.5 kHz to 5 kHz, a duty cycle of less than or equal to 10%, and a substrate pulse bias offset time of 20 μs to 100 μs, to deposit the base layer;

[0025] (4) Depositing a functional layer on the surface of the base layer, specifically maintaining the Ar gas pressure of the furnace chamber at 0.4 Pa and the furnace chamber temperature at 450°C, applying a pulse bias of -40V to -80V to the tool substrate, setting the cathode power supply power to 500W to 1500W, performing high-energy pulse magnetron sputtering on the TsSi2 target, with a pulse frequency of 0.5kHz to 5kHz, a duty cycle of less than or equal to 10%, and a substrate pulse bias offset time of 20μs to 100μs to deposit the functional layer, and finally obtain the double-layer coating.

[0026] In the above technical solutions, the tool substrate can be various cutting tools known to those skilled in the art, and is suitable for cemented carbide tools, metal ceramic tools or high-speed steel tools, and is particularly suitable for cemented carbide tools.

[0027] Beneficial Effects

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention further improves on the traditional TiB2 coating, and through process optimization and structural design, a high-performance double-layer coating with good wear resistance, high temperature resistance, oxidation resistance and anti-adhesion performance is formed. A TiB2 base layer with dense structure, high hardness and good film-base bonding is prepared by adopting high-energy pulse magnetron sputtering technology, which not only provides good support for the TaSi2 functional layer, but also provides excellent wear resistance for the double-layer coating as a whole. A TaSi2 functional layer with smooth surface, dense structure, low thermal conductivity and good chemical inertness is prepared by adopting high-energy pulse magnetron sputtering technology, which not only directly provides good anti-adhesion and wear performance for the double-layer coating, but also inhibits the oxidation decomposition and degradation of the TiB2 base layer and the tool substrate at high temperature by reducing the influx of heat into the substrate, and indirectly improves the cutting performance of the coated tool in a high temperature environment. The present invention also provides a preparation method for titanium and titanium alloy cutting coated tools, which has simple process, conventional equipment and low production cost. The coated tool prepared by the method of the present invention has a wide application range, high processing efficiency, and long tool life, and can meet the titanium alloy cutting processing under various conditions, and is particularly suitable for the efficient processing of α-type titanium alloys such as TA2, TA7, TA18 and (α+β)-type titanium alloys such as TC3, TC4. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0031] Figure 1 This is a schematic diagram of the structure of the double-layer coating in Example 1 of the present invention;

[0032] Figure 2 This is a cross-sectional SEM morphology image of the double-layer coating in Example 1 of the present invention;

[0033] Figure 3 is the XRD spectrum of the functional layer in the double-layer coating in Example 1 of the present invention;

[0034] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0035] 1. Tool substrate; 2. Multi-layer coating; 3. Base layer; 3. Functional layer. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0037] This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contribution as needed, but they are protected by the patent law as long as they are within the scope of the claims of the present invention. Unless otherwise specified, the drugs used in the following examples can be purchased from regular channels.

[0038] Embodiment 1:

[0039] A titanium and titanium alloy cutting tool coating and a preparation method thereof according to the present invention, Figure 1 As shown, it comprises a tool substrate 1 and a double-layer coating 2 deposited on the tool substrate 1. The double-layer coating 2 comprises a base layer 3 deposited on the tool substrate 1 and a functional layer 4 deposited on the base layer 3.

[0040] A titanium alloy cutting tool coating and a preparation method thereof of the present invention comprises the following preparation steps:

[0041] (1) Cleaning the tool substrate to remove impurities such as oil and dust on the surface, specifically, placing the tool substrate in an alkaline solution with a pH of 11 for ultrasonic cleaning, with an ultrasonic frequency of 40 kHz and a solution temperature of 60° C., followed by spraying with deionized water and drying for later use;

[0042] (2) Ion bombardment of the tool substrate to increase the surface activity of the substrate. Specifically, the tool is placed in a coating device and the furnace chamber pressure is less than 4×10 -4 Pa, when the temperature reaches 450℃, Ar gas is introduced into the furnace chamber until the furnace chamber pressure reaches 0.5Pa, and a -800V bias is applied to the tool substrate, and the ion source is turned on to bombard the tool substrate surface for 20min;

[0043] (3) depositing a base layer on the surface of the tool substrate, specifically maintaining the Ar gas pressure of the furnace chamber at 0.4 Pa and the furnace chamber temperature at 450° C., applying a pulse bias of -40 V to -80 V to the tool substrate, setting the cathode power supply power to 4000 W, performing high-energy pulse magnetron sputtering on the TiB2 target, with a pulse frequency of 0.5 kHz to 5 kHz, a duty cycle of less than or equal to 10%, and a substrate pulse bias offset time of 20 μs to 100 μs, to deposit the base layer;

[0044] (4) Depositing a functional layer on the surface of the base layer, specifically maintaining the Ar gas pressure of the furnace chamber at 0.4 Pa and the furnace chamber temperature at 450°C, applying a pulse bias of -40V to -80V to the tool substrate, setting the cathode power supply power to 500W to 1500W, performing high-energy pulse magnetron sputtering on the TsSi2 target, with a pulse frequency of 0.5kHz to 5kHz, a duty cycle of less than or equal to 10%, and a substrate pulse bias offset time of 20μs to 100μs to deposit the functional layer, and finally obtain the double-layer coating.

[0045] Therefore, the main preparation steps in this embodiment can be summarized as follows: (1) pre-treating the tool substrate; (2) using a high-power pulsed magnetron sputtering method to deposit a base layer through a TiB2 target and a functional layer through a TaSi2 target to obtain the titanium and titanium alloy cutting coating tool. Unless otherwise specified, the following other embodiments have the same main preparation steps as this embodiment.

[0046] In this embodiment, the tool base 1 adopts a four-edge round nose carbide milling cutter, and the tool structure and material parameters are as follows:

[0047] Peripheral rake angle: 2°;

[0048] The back angle of the peripheral blade shovel: 10°;

[0049] Helix angle: 36°~39°;

[0050] Tip radius: 0.5mm;

[0051] Blade diameter: 8mm;

[0052] Handle diameter: 8mm;

[0053] Tool base material: Cobalt content 12%, hardness 1780HV, grain size 0.2~0.4.

[0054] The tool structures and material parameters in the following other embodiments and comparative examples are the same as those in Embodiment 1 unless otherwise specified.

[0055] The titanium alloy cutting performance of the coated tool in this embodiment is obtained by conducting a milling test. The test adopts a method of comparing the wear condition of the tool edge under a certain processing time or removal amount. In the same embodiment, at least 5 four-edge round nose cemented carbide coated milling cutters are tested, and the average wear width of the back face is taken as the wear condition parameter of this embodiment. The specific cutting test processing parameters are as follows:

[0056] Processed material: Grade 4 titanium alloy;

[0057] Test equipment: FANUCα-D14MiB;

[0058] Spindle speed: 6500rpm;

[0059] Feed rate: 2000mm / min;

[0060] Cutting width: 6mm;

[0061] Cutting depth: 0.3mm;

[0062] Cooling conditions: 20% emulsion;

[0063] Off-machine conditions: continuous processing for 15 minutes.

[0064] The cutting test processing parameters in the following other embodiments and comparative examples are the same as those in Example 1 unless otherwise specified.

[0065] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the double-layer coating are as follows:

[0066]

[0067] Embodiment 2:

[0068] The invention discloses a titanium and titanium alloy cutting tool coating and a preparation method thereof, comprising a tool substrate and a double-layer coating deposited on the tool substrate. The double-layer coating comprises a base layer deposited on the tool substrate and a functional layer deposited on the base layer.

[0069] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the double-layer coating are as follows:

[0070]

[0071] It can be seen from the above table that, under the same tool structure and cutting conditions, the wear width of the coated tool in this embodiment is reduced by 8% compared with that in Example 1. Compared with Example 1, while ensuring that the chemical composition of the base layer and the functional layer is the same, this embodiment increases the overall thickness of the double-layer coating by 200%, and the technical effect is slightly improved.

[0072] Embodiment three:

[0073] The invention discloses a titanium and titanium alloy cutting tool coating and a preparation method thereof, comprising a tool substrate and a double-layer coating deposited on the tool substrate. The double-layer coating comprises a base layer deposited on the tool substrate and a functional layer deposited on the base layer.

[0074] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the double-layer coating are as follows:

[0075]

[0076] As can be seen from the table above, under the same tool structure and cutting conditions, the wear width of the coated tool in this embodiment is increased by 33% compared with that in Example 1. Compared with Example 1, under the condition of ensuring that the chemical composition of the base layer and the functional layer is the same, this embodiment increases the overall thickness of the double-layer coating by 700%, but the technical effect is significantly reduced.

[0077] Comparative Example 1:

[0078] A titanium and titanium alloy cutting tool coating and a preparation method thereof according to the present invention comprises a tool substrate and a functional layer deposited on the tool substrate.

[0079] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the coating are as follows:

[0080]

[0081] As can be seen from the table above, under the same tool structure and cutting conditions, the wear width of the coated tool in this embodiment is 15% larger than that in Example 1. Compared with Example 1, while ensuring the same chemical composition of the functional layer, this embodiment increases the thickness of the functional layer to 1 μm and removes the base layer, but the technical effect is significantly reduced. Because, although Ti 0.35 B 0.65 The base layer has good wear resistance, but poor high-temperature oxidation resistance and high-temperature stability.

[0082] Comparative Example 2:

[0083] A titanium and titanium alloy cutting tool coating and a preparation method thereof according to the present invention comprises a tool substrate and a base layer deposited on the tool substrate.

[0084] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the double-layer coating are as follows:

[0085]

[0086] As can be seen from the table above, under the same tool structure and cutting conditions, the wear width of the coated tool in this embodiment is 42% larger than that in Example 1. Compared with Example 1, while ensuring the same chemical composition of the base layer, this embodiment increases the thickness of the base layer to 1 μm and removes the functional layer, but the technical effect is significantly reduced. 0.35 B 0.65 The base layer has good wear resistance, but poor high-temperature oxidation resistance and high-temperature stability.

[0087] Comparative Example 3:

[0088] A titanium and titanium alloy cutting tool coating and its preparation method according to the present invention comprises a tool substrate and a double-layer coating deposited on the tool substrate. The double-layer coating comprises a base layer deposited on the tool substrate and a functional layer deposited on the base layer.

[0089] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the double-layer coating are as follows:

[0090]

[0091] It can be seen from the above table that, under the same tool structure and cutting conditions, the wear width of the coated tool in this embodiment is 15% larger than that in Example 1. Compared with Example 1, under the condition of ensuring that the chemical composition of the base layer and the functional layer is the same, the thickness of the functional layer in this embodiment is increased to 0.7 μm and the thickness of the base layer is reduced to 0.3 μm, but the technical effect is slightly reduced.

[0092] Embodiment 4:

[0093] The invention discloses a titanium and titanium alloy cutting tool coating and a preparation method thereof, comprising a tool substrate and a double-layer coating deposited on the tool substrate. The double-layer coating comprises a base layer deposited on the tool substrate and a functional layer deposited on the base layer.

[0094] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the double-layer coating are as follows:

[0095]

[0096] It can be seen from the above table that, under the same tool structure and cutting conditions, the wear width of the coated tool in this embodiment is 10% larger than that in Example 1. Compared with Example 1, under the same coating structure, this embodiment increases the content of B element in the base layer, so that the atomic ratio of B element to Ti element B:Ti reaches 1.99, but the technical effect is slightly reduced.

[0097] Embodiment five:

[0098] The invention discloses a titanium and titanium alloy cutting tool coating and a preparation method thereof, comprising a tool substrate and a double-layer coating deposited on the tool substrate. The double-layer coating comprises a base layer deposited on the tool substrate and a functional layer deposited on the base layer.

[0099] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the double-layer coating are as follows:

[0100]

[0101] As can be seen from the table above, under the same tool structure and cutting conditions, the wear width of the coated tool in this embodiment is reduced by 9% compared with that in Example 1. Compared with Example 1, under the same coating structure, this embodiment reduces the content of B element in the base layer, so that the atomic ratio of B element to Ti element B:Ti reaches 1.56, and the technical effect is slightly improved. Because, when TiB is prepared by high-energy pulse magnetron sputtering, x When coating, the lower the B element content, the higher the coating hardness, the lower the elastic modulus, and the better the wear resistance of the coating. However, this does not mean that TiB x The B content in the coating can be reduced without limit, since a slight deviation from the stoichiometric ratio will result in a x A Ti-rich strengthening layer is formed in the TiB to improve the strength and hardness of the coating, and a significant deviation from the stoichiometric ratio will x In addition, because TiB is prepared by high-energy pulsed magnetron sputtering, x The target material used for coating is TiB x For sintered targets, the content of element B in the coating cannot be reduced indefinitely by adjusting process parameters such as bias voltage, duty cycle, and pulse offset time.

[0102] Embodiment six:

[0103] The invention discloses a titanium and titanium alloy cutting tool coating and a preparation method thereof, comprising a tool substrate and a double-layer coating deposited on the tool substrate. The double-layer coating comprises a base layer deposited on the tool substrate and a functional layer deposited on the base layer.

[0104] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the double-layer coating are shown in the following table:

[0105]

[0106] It can be seen from the above table that, under the same tool structure and cutting conditions, the wear width of the coated tool in this embodiment is 4% larger than that in Example 1. Compared with Example 1, under the same coating structure, this embodiment increases the content of Si element in the functional layer, so that the atomic ratio Si:Ta of Si element to Ta element reaches 1.77, but the technical effect is slightly reduced.

[0107] Embodiment seven:

[0108] The invention discloses a titanium and titanium alloy cutting tool coating and a preparation method thereof, comprising a tool substrate and a double-layer coating deposited on the tool substrate. The double-layer coating comprises a base layer deposited on the tool substrate and a functional layer deposited on the base layer.

[0109] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the double-layer coating are as follows:

[0110]

[0111] It can be seen from the above table that, under the same tool structure and cutting conditions, the wear width of the coated tool in this embodiment is reduced by 5% compared with that in Example 1. Compared with Example 1, under the same coating structure, this embodiment reduces the content of Si element in the functional layer, so that the atomic ratio Si:Ta of Si element to Ta element reaches 1.40, and the technical effect is slightly improved.

[0112] Comparative Example 4:

[0113] A titanium and titanium alloy cutting tool coating and its preparation method according to the present invention comprises a tool substrate and a double-layer coating deposited on the tool substrate. The double-layer coating comprises a base layer deposited on the tool substrate and a functional layer deposited on the base layer.

[0114] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the double-layer coating are as follows:

[0115]

[0116] As can be seen from the table above, under the same tool structure and cutting conditions, the wear width of the coated tool in this comparative example is 19% larger than that in Example 1. Compared with Example 5, under the same coating structure, this example further reduces the content of element B in the functional layer, so that the atomic ratio of element B to element Ti reaches 1.56, but the technical effect is significantly reduced.

[0117] Comparative Example 5:

[0118] A titanium and titanium alloy cutting tool coating and its preparation method according to the present invention comprises a tool substrate and a double-layer coating deposited on the tool substrate. The double-layer coating comprises a base layer deposited on the tool substrate and a functional layer deposited on the base layer.

[0119] By adjusting the target material composition and deposition parameters, the specific chemical composition, thickness and some performance parameters of the double-layer coating are as follows:

[0120]

[0121] It can be seen from the above table that, under the same tool structure and cutting conditions, the wear width of the coated tool in this comparative example is 25% larger than that in Example 1. Compared with Example 7, under the same coating structure, this example further reduces the content of Si element in the functional layer, so that the atomic ratio Si:Ta of Si element to Ta element reaches 1.17, but the technical effect is significantly reduced.

[0122] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A titanium and titanium alloy cutting tool coating, characterized in that: A double-layer coating is deposited on a tool substrate, wherein the double-layer coating comprises a base layer and a functional layer in sequence from the tool substrate side toward the surface side of the double-layer coating; The base layer is composed of a chemical formula of Ti (1-a) B a The metal compound is composed of, wherein a represents the atomic ratio of element B in the compound relative to all elements in the compound, and satisfies 0.55≤a≤0.70; The functional layer is composed of a chemical formula of Ta (1-b) Si b wherein b represents the atomic ratio of Si element relative to all elements in the metal compound and satisfies 0.55≤b≤0.65; In the X-ray diffraction (XRD) analysis of the base layer, the metal compound Ta in the base layer (1-b) Si b The ratio of the diffraction peak intensity of the (111) crystal plane to the diffraction peak intensity of the (101) crystal plane is I (111) / I (101) Greater than 1.

5.

2. The titanium and titanium alloy cutting tool coating according to claim 1, characterized in that: The percentage of the thickness of the functional layer to the total thickness of the multi-layer coating is 10% to 30%.

3. A titanium and titanium alloy cutting tool coating according to any one of claims 1 to 2, characterized in that: The overall thickness of the double-layer coating is 0.5 μm to 8 μm.

4. The titanium and titanium alloy cutting tool coating according to claim 1, characterized in that: In the X-ray reflectivity (XRR) analysis of the double-layer coating, the density of the base layer is greater than 4.0 g / cm 3 The density of the functional layer is greater than 8.7 g / cm 3 .

5. The titanium and titanium alloy cutting tool coating according to claim 1, characterized in that: The tool base material is any one of cemented carbide, metal ceramic or high-speed steel tool.

6. The titanium and titanium alloy cutting tool coating according to claim 1, characterized in that: The Ti (1-a) B a It is a boride of Ti element with C32 type structure.

7. The titanium and titanium alloy cutting tool coating according to claim 1, characterized in that: The (1-b) Si b It is a silicide of Ta element with a close-packed hexagonal structure.

8. A method for preparing a titanium and titanium alloy cutting tool coating as claimed in any one of claims 1 to 7, comprising the following preparation steps: (1) Pretreatment of the tool substrate; (2) A titanium alloy cutting coating tool is obtained by using a high-power pulsed magnetron sputtering method to deposit a base layer using a TiB2 target and a functional layer using a TaSi2 target.

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