A chromium aluminum boron cerium nitride / niobium nitride multilayer ultra-thick coating and its deposition method

Abstract

The present invention discloses a chromium aluminum boron cerium / niobium nitride multilayer ultra-thick coating and a deposition method thereof. The chromium aluminum boron cerium / niobium nitride multilayer ultra-thick coating comprises a pure niobium bonding layer located outside a substrate, and an alternating multilayer structure formed by a niobium nitride layer and a chromium aluminum boron cerium nanocomposite layer is provided on the outer side of the pure niobium bonding layer. The pure niobium bonding layer has a thickness of 0.2-1.0 μm, and the alternating cycle of the niobium nitride layer and the chromium aluminum boron cerium nanocomposite layer is 5-50 times, with the thickness of the niobium nitride layer in any cycle being 0.1-1.0 μm, and the thickness of the chromium aluminum boron cerium nanocomposite layer in any cycle being 0.2-2 μm, for a total thickness of 10-150 μm. The chromium aluminum boron cerium / niobium nitride multilayer ultra-thick coating provided by the present invention combines the advantages of high hardness, high heat resistance, low internal stress, and high coating thickness.

Description

Technical Field

[0001] The present invention relates to the technical field of hard coatings, and in particular to a chromium aluminum boron cerium nitride / niobium nitride multilayer ultra-thick coating and a deposition method thereof. Background Art

[0002] With the development of my country's automotive, shipbuilding, aerospace, and other machinery manufacturing industries, and the increasing use of difficult-to-machine materials, my country's machining technology is evolving towards efficient machining and green manufacturing. High-speed machining and heavy-load machining place higher demands on cutting tools and molds. Surface deposition of hard coatings is one of the most effective methods for improving the wear resistance and thus extending the service life of tools, molds, and components. Currently, over 80% of tools in developed industrial countries are coated, and over 90% of cutting tools and precision molds used on CNC machine tools are coated. Physical vapor deposition (PVD) offers advantages over chemical vapor deposition (CVD), including lower deposition temperatures, a wide range of coating types, easily adjustable processes, and no environmental pollution. It is a key development direction for tool and mold coating technology. Currently, the hard, wear-resistant coatings used on tools, molds, and components are primarily single-phase coatings such as TiN, CrN, TiCN, TiAlN, and CrAlN. These coatings typically have hardnesses below 30 GPa and thicknesses generally not exceeding 10 microns. Multi-component composite coatings such as TiAlSiN and CrAlBN developed in recent years have high hardness and thermal stability, but the coatings have high stress and high brittleness, and the thickness is mostly between 2-6 microns; due to the high compressive stress and brittleness in the coatings, the coatings are prone to cracking and peeling, and it is difficult to deposit ultra-thick coatings with a thickness of more than 10 microns. They are not suitable for heavy-load processing of cutting tools and molds and long-term service wear-resistant parts.

[0003] Multi-component composite is an effective means to improve the hardness and oxidation resistance of coatings. Studies have shown that the introduction of transition metal nitride coatings such as AlN into B1 structure TiN, VN, ZrN, CrN to form B1 structure TM 1-x Al xAlN (TM: transition metal) solid solutions can significantly improve the hardness and oxidation resistance of coatings. However, the solid solubility of AlN in different nitrides and the stability of the metastable phase vary significantly. The solid solubility of AlN in fcc TiN can reach 65%, while that in fcc CrN can reach 77%, resulting in high-Al content CrAlN coatings. Both Cr and Al can form protective oxide films, significantly improving the coating's oxidation resistance. CrAlN coatings exhibit high room temperature hardness and red hardness (high-temperature hardness). CrAlN coatings deposited using different deposition processes and compositions have hardnesses of 30-40 GPa. CrAlN coatings exhibit excellent red hardness, reaching 22.5 GPa at 700°C, making them suitable for high-temperature wear-resistant applications. Solid solution strengthening contributes to the hardness improvement of these single-phase composite coatings, but compressive stress caused by energetic ion bombardment during deposition remains the primary mechanism for hardness enhancement. Annealing at high temperatures still results in a significant decrease in hardness.

[0004] Nanostructured multiphase composite coatings consist of at least two phases: a nanocrystalline phase embedded in a ceramic matrix. The small nanocrystals in this structure reduce dislocation density and hinder dislocation motion, thereby increasing hardness. The formation of the nc-TMN / a-ceramic dual-phase nanocomposite structure, where a nanocrystalline hard phase is embedded in an amorphous hard phase, relies on thermodynamically driven and diffusion-controlled spinodal phase separation during the deposition process. Typical examples include the Ti-Si-N system, under appropriate conditions, forming a structure where nanocrystalline TiN is embedded in amorphous Si3N4, while the Ti-BN system may form a structure where nanocrystalline TiN is embedded in amorphous BN. The nc-TMN / a-ceramic dual-phase nanocomposite structure can be viewed as a three-dimensional multilayer film, and the hardening and toughening mechanisms of multilayer films are also at work in this structure. Furthermore, the partially coherent interfaces between the two phases help inhibit crack propagation along grain boundaries. Meanwhile, the high density of grain boundaries deflects and bypasses cracks, dissipating the propagating force and improving the coating's toughness. However, because Ti-Si-N and Ti-BN cannot form a protective oxide film, their wear resistance under the dual effects of chemical abrasion and mechanical wear at high temperatures still needs to be improved.

[0005] Patent No. CN110438442B discloses a nano-niobium aluminum yttrium nitride / amorphous silicon nitride dual-phase superhard coating and its deposition method, and Patent No. CN10346841B discloses a yttrium-modified chromium aluminum carbonitride / silicon nitride nanocomposite coating and its deposition method. Both of the above patents disclose a nanocomposite structure in which a nanocrystalline metal ceramic hard phase is implanted into an amorphous hard phase. The addition of rare earth yttrium and the dual-phase nanocomposite design have a significant effect on improving the hardness of the coating. Because the main wear-resistant layer is a single structure of a dual-hard phase composite with high hardness and high modulus, it is insufficient to resist plastic deformation and is prone to brittle cracking and peeling when large deformation occurs. It is not suitable for applications such as heavy loads and high impacts. In Patent CN110438442B, due to the large difference in the melting point of Nb and other elements, the poor uniformity of hot isostatic pressing of NbAlSiY, unstable discharge, and the solid-phase reaction of the target material itself that further deteriorates the discharge stability, there are still certain problems in the stability of the coating preparation process. In patent CN10346841B, adding reaction gas methane to introduce C element into the coating can reduce the friction coefficient of the coating to a certain extent. However, carbon black is easily formed in the coating furnace during the coating process, which pollutes the furnace body and affects the insulation of the target assembly. Summary of the Invention

[0006] In view of the above-mentioned shortcomings, the present invention provides a chromium aluminum boron cerium nitride / niobium nitride multilayer ultra-thick coating and a deposition method thereof, which has the advantages of high hardness, high heat resistance, low internal stress and high coating thickness.

[0007] To achieve the above objectives, the present invention provides a chromium aluminum boron cerium / niobium nitride multilayer ultra-thick coating, comprising a pure niobium bonding layer located on the outside of a substrate, wherein an alternating multilayer structure formed by a niobium nitride layer and a chromium aluminum boron cerium nanocomposite layer is provided on the outside of the pure niobium bonding layer; wherein the thickness of the pure niobium bonding layer is 0.2-1.0 μm, the alternating cycle of the niobium nitride layer and the chromium aluminum boron cerium nanocomposite layer is 5-50 times, the thickness of the niobium nitride layer in any cycle is 0.1-1.0 μm, the thickness of the chromium aluminum boron cerium nanocomposite layer in any cycle is 0.2-2 μm, and the total thickness of the coating is 10-150 μm.

[0008] According to one aspect of the present invention, the substrate comprises any one of a cutting tool, a machining die, and a service component.

[0009] According to one aspect of the present invention, the pure niobium bonding layer is a pure niobium bonding layer deposited by multi-arc ion plating of a pure niobium target and the introduction of pure argon gas; the niobium nitride layer is a niobium nitride layer deposited by multi-arc ion plating of a pure niobium target and the introduction of nitrogen gas; and the chromium aluminum boron cerium nanocomposite layer is a chromium aluminum boron cerium nanocomposite layer deposited by multi-arc ion plating of a chromium aluminum boron cerium alloy target and the introduction of nitrogen gas.

[0010] According to one aspect of the present invention, in the chromium-aluminum-boron-cerium alloy target, the atomic percentage of chromium is 30-60%, the atomic percentage of aluminum is 40-60%, the atomic percentage of boron is 5-15%, and the atomic percentage of cerium is 1-4%.

[0011] According to one aspect of the present invention, when depositing the niobium nitride layer, a negative bias of 20-50V is applied; when depositing the chromium aluminum boron cerium nitride nanocomposite layer, a negative bias of 100-300V is applied.

[0012] According to one aspect of the present invention, the bonding strength between the coating and the substrate is above 50N, the Vickers hardness under a load of 50g is above 25-45GPa, and the oxidation resistance temperature is above 750°C.

[0013] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned chromium aluminum boron cerium nitride / niobium nitride multilayer ultra-thick coating, comprising the following steps:

[0014] Step 1: Place the cleaned substrate into the coating furnace and perform plasma treatment on the substrate under a certain vacuum degree and temperature;

[0015] Step 2: Depositing a pure niobium bonding layer on the plasma-treated substrate;

[0016] Step 3: Alternately depositing niobium nitride layers and chromium aluminum boron cerium nitride nanocomposite layers on the substrate after depositing the pure niobium bonding layer.

[0017] According to one aspect of the present invention, in step 1, the vacuum degree is 3.0×10 -3 Pa below, the temperature is 300-550 ° C; the plasma treatment includes gas plasma cleaning and arc plasma cleaning in sequence; the gas plasma cleaning is specifically: Ar is introduced through a gas ion source with a pressure of 0.1-0.5 Pa, an ion source current of 2-20 A, a pulsed negative bias is applied to the substrate, the frequency is 20-100 KHz, the peak value is 50-500 V, and the duty cycle is 50-90%, and the substrate is plasma cleaned for 20-120 min at different bias peak values; the arc plasma cleaning is specifically: the gas ion source is turned off, the pulsed negative bias frequency is 20-80 KHz, the peak value is 800-1500 V, the duty cycle is 10-50%, the Ar partial pressure is 0.05-0.2 Pa, the arc ion plating pure niobium target is turned on, the arc source current is 40-120 A, and the workpiece is bombarded and sputtered for cleaning for 3-60 min.

[0018] According to one aspect of the present invention, in step 2, the parameters for depositing the pure niobium bonding layer are: a pulsed negative bias voltage is adjusted to a frequency of 20-100 kHz, a peak value of 40-100 V, a duty cycle of 50-90%, an Ar pressure of 0.1-1.0 Pa, an ion plating pure niobium target arc source current of 60-200 A, and the deposition of the pure niobium bonding layer takes 4-20 minutes.

[0019] According to one aspect of the present invention, in step 3, the parameters for depositing the niobium nitride layer are as follows: the peak value of the pulsed negative bias is adjusted to 20-50 V, Ar is turned off, N2 is introduced at a pressure of 0.1-1.0 Pa, and the niobium nitride layer is deposited for 2-20 minutes; the parameters for depositing the chromium aluminum boron cerium nanocomposite layer are as follows: the niobium target is turned off, the peak value of the pulsed negative bias is adjusted to 100-300 V, the N2 pressure is 1.0-4.0 Pa, the chromium aluminum boron cerium alloy target is turned on, the arc current is 80-200 A, and the deposition time is 4-40 minutes; and the deposition of the niobium nitride layer and the deposition of the chromium aluminum boron cerium nanocomposite layer are repeated 5 to 50 times.

[0020] Mechanism of the present invention:

[0021] The present invention utilizes the thermodynamic properties of the Cr-Al-B-Ce-N system and controls the thermodynamic and kinetic conditions for spinodal phase separation during physical vapor deposition (PVD). A nanocomposite layer of nanocrystalline chromium aluminum cerium nitride embedded in amorphous boron nitride is self-assembled during coating growth. A small amount of the rare earth element Ce is added to the system. Ce has an atomic radius larger than Y and much larger than that of Cr, Al, and B, making it virtually insoluble in chromium aluminum nitride or boron nitride. Ce precipitates at the grain boundaries of chromium aluminum nitride and boron nitride, altering the grain boundary structure and strain energy and modulating the nanocrystal grain size to produce a chromium aluminum boron cerium nitride nanocomposite layer with high hardness and high heat resistance. Because Ce has a melting point much lower than Y and closer to that of Cr, Al, and other elements, its addition has little effect on the hot isostatic pressing (HIPP) preparation of the CrAlBCe target. In addition to forming amorphous BN, the introduction of B in the coating, under the high temperatures of the cutting process, forms high-temperature self-lubricating boron oxide, thereby reducing the coefficient of friction and cutting resistance. A high-melting-point pure niobium target is then injected with nitrogen to form a niobium nitride stress buffer layer. The niobium nitride has a hardness of approximately 16 GPa. Combined with bias voltage control during the process, the niobium nitride layer exhibits low stress and excellent plastic deformation capability, while avoiding the significant reduction in hardness that occurs with a pure metal layer. A multi-layer design alternates between an ultra-hard chromium aluminum boron cerium nanocomposite layer and a low-stress niobium nitride layer, resulting in a coating that combines high hardness, high heat resistance, low internal stress, and a high coating thickness.

[0022] Beneficial effects of the present invention:

[0023] The present invention forms a multilayer alternating structure of chromium aluminum boron cerium nanocomposite layers and niobium nitride layers, so that the coating has high hardness and high heat resistance, low internal stress and high coating thickness, and is suitable for wear-resistant coatings for heavy cutting tools, heavy-loaded molds and long-term service parts.

[0024] The coating of the present invention comprises a pure niobium bonding layer as its innermost layer, followed by a low-stress niobium nitride layer and a high-hardness chromium aluminum boron cerium nanocomposite layer. The niobium nitride layer and the chromium aluminum boron cerium nanocomposite layer form a thickness cycle, and the multi-layer alternating structure above the bonding layer consists of 5-50 thickness cycles. In this multi-layer alternating structure, the thickness of the niobium nitride layer, the thickness of the chromium aluminum boron cerium nanocomposite layer, and the number of alternating cycles can be adjusted according to application requirements, making it easy to adjust the thickness and hardness of ultra-thick coatings.

[0025] The ultra-thick coating achieved by this invention achieves a bond strength of over 50N to the substrate, an adjustable surface composite hardness of 25GPa to 45GPa under a 50g load, an operating temperature of over 750°C, and a coating thickness of 10 to 150 microns. Application of the multi-layer ultra-thick chromium aluminum boron cerium nitride / niobium nitride coating can extend the service life of tool molds or components by more than three times that of uncoated workpieces. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of a chromium aluminum boron cerium nitride / niobium nitride multilayer ultra-thick coating according to an embodiment of the present invention;

[0027] Explanation of the accompanying symbols: 1. chromium aluminum boron cerium nitride nanocomposite layer; 2. niobium nitride layer; 3. pure niobium bonding layer; 4. substrate. DETAILED DESCRIPTION

[0028] To facilitate understanding of the present invention, the present invention will be described in more comprehensive and detailed form below in conjunction with the accompanying drawings and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

[0029] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0030] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0031] In order to solve the problems mentioned in the background art, the inventors of this application provide a chromium aluminum boron cerium nitride / niobium nitride multilayer ultra-thick coating, such as Figure 1As shown, it includes a pure niobium bonding layer 3 located on the outside of a substrate 4, and an alternating multilayer structure formed by a niobium nitride layer 2 and a chromium aluminum boron cerium nitride nanocomposite layer 1 is provided on the outside of the pure niobium bonding layer 3; wherein the thickness of the pure niobium bonding layer 3 is 0.2-1.0 μm, the alternating cycle of the niobium nitride layer 2 and the chromium aluminum boron cerium nitride nanocomposite layer 1 is 5-50 times, the thickness of the niobium nitride layer 2 in any cycle is 0.1-1.0 μm, the thickness of the chromium aluminum boron cerium nitride nanocomposite layer 1 in any cycle is 0.2-2 μm, and the total thickness of the coating is 10-150 μm.

[0032] In the present invention, the niobium nitride layer serves as a stress relief layer.

[0033] As an optional embodiment, the substrate includes any one of a cutting tool, a machining mold, and a service component.

[0034] As an optional embodiment, the pure niobium bonding layer is a pure niobium bonding layer deposited by multi-arc ion plating of a pure niobium target and the introduction of pure argon gas; the niobium nitride layer is a niobium nitride layer deposited by multi-arc ion plating of a pure niobium target and the introduction of nitrogen gas; and the chromium nitride aluminum boron cerium nanocomposite layer is a chromium nitride aluminum boron cerium nanocomposite layer deposited by multi-arc ion plating of a chromium aluminum boron cerium alloy target and the introduction of nitrogen gas.

[0035] As an optional embodiment, in the chromium-aluminum-boron-cerium alloy target, the atomic percentage of chromium is 30-60%, the atomic percentage of aluminum is 40-60%, the atomic percentage of boron is 5-15%, and the atomic percentage of Ce is 1-4%.

[0036] As an optional embodiment, when depositing the niobium nitride layer, a negative bias voltage of 20-50V is applied; when depositing the chromium aluminum boron cerium nitride nanocomposite layer, a negative bias voltage of 100-300V is applied.

[0037] As an optional embodiment, the bonding strength between the coating and the substrate is above 50N, the Vickers hardness under a load of 50g is above 25-45GPa, and the oxidation resistance temperature is above 750°C.

[0038] The embodiments of the present application also provide a method for preparing the above-mentioned chromium aluminum boron cerium nitride / niobium nitride multilayer ultra-thick coating, comprising the following steps:

[0039] Step 1: Place the cleaned substrate into the coating furnace and perform plasma treatment on the substrate under a certain vacuum degree and temperature;

[0040] Step 2: Depositing a pure niobium bonding layer on the plasma-treated substrate;

[0041] Step 3: Alternately depositing niobium nitride layers and chromium aluminum boron cerium nitride nanocomposite layers on the substrate after depositing the pure niobium bonding layer.

[0042] As an optional embodiment, in step 1, the vacuum degree is 3.0×10 -3 Pa below, the temperature is 300-550 ° C; the plasma treatment includes gas plasma cleaning and arc plasma cleaning in sequence; the gas plasma cleaning is specifically: Ar is introduced through a gas ion source with a pressure of 0.1-0.5 Pa, an ion source current of 2-20 A, a pulsed negative bias is applied to the substrate, the frequency is 20-100 KHz, the peak value is 50-500 V, and the duty cycle is 50-90%, and the substrate is plasma cleaned for 20-120 min at different bias peak values; the arc plasma cleaning is specifically: the gas ion source is turned off, the pulsed negative bias frequency is 20-80 KHz, the peak value is 800-1500 V, the duty cycle is 10-50%, the Ar partial pressure is 0.05-0.2 Pa, the arc ion plating pure niobium target is turned on, the arc source current is 40-120 A, and the workpiece is bombarded and sputtered for cleaning for 3-60 min.

[0043] As an optional embodiment, in step 2, the parameters for depositing the pure niobium bonding layer are: a pulsed negative bias voltage is adjusted to a frequency of 20-100 kHz, a peak value of 40-100 V, a duty cycle of 50-90%, an Ar pressure of 0.1-1.0 Pa, an ion plating pure niobium target arc source current of 60-200 A, and the pure niobium bonding layer is deposited for 4-20 minutes.

[0044] As an optional embodiment, in step 3, the parameters for depositing the niobium nitride layer are: the peak value of the pulsed negative bias is adjusted to 20-50 V, Ar is turned off, N2 is introduced with a pressure of 0.1-1.0 Pa, and the niobium nitride layer is deposited for 2-20 minutes; the parameters for depositing the chromium aluminum boron cerium nanocomposite layer are: the niobium target is turned off, the peak value of the pulsed negative bias is adjusted to 100-300 V, the N2 pressure is 1.0-4.0 Pa, the chromium aluminum boron cerium alloy target is turned on, the arc current is 80-200 A, and the deposition time is 4-40 minutes; and the deposition of the niobium nitride layer and the deposition of the chromium aluminum boron cerium nanocomposite layer are repeated 5 to 50 times.

[0045] The above describes the specific implementation methods of the present application. In order to objectively illustrate the technical effects produced by the present application, the following examples and comparative examples will be used for description.

[0046] Example 1

[0047] Base: M35 high-speed steel hob, diameter 200mm, height 200mm, module 8;

[0048] Step 1: The substrate is sequentially degreased, rinsed, micro-sandblasted for edge passivation, ultrasonically cleaned with detergent, rinsed with deionized water, and dried before being loaded into a coating furnace; the vacuum is drawn to 2.0×10 -3Pa, with the temperature maintained at 400±5°C. The high-speed steel hob was first cleaned with gas plasma: Ar was introduced through a gas ion source at a pressure of 0.15 Pa and a source current of 10A. A pulsed negative bias voltage with a frequency of 80 kHz and a duty cycle of 90% was applied to the workpiece. Argon ion cleaning was performed at peak negative bias voltages of 100 V, 200 V, and 300 V for 20 minutes each, for a total of 60 minutes. The gear hob was then cleaned with arc plasma: the gas ion source was turned off, and a pulsed negative bias voltage with a frequency of 80 kHz, a peak value of 1200 V, a duty cycle of 30%, and an Ar partial pressure of 0.1 Pa was applied. The workpiece was then sputtered with a pure niobium target using an arc ion plating current of 60A for 20 minutes.

[0049] Step 2: Depositing a pure niobium bonding layer; the parameters for depositing the pure niobium bonding layer are: pulsed negative bias voltage adjusted to a frequency of 80 kHz, a peak of 50 V, a duty cycle of 80%, an Ar pressure of 0.5 Pa, an ion plating pure niobium target arc source current of 100 A, and the deposition of the pure niobium bonding layer for 6 minutes with a thickness of 0.3 microns.

[0050] Step 3: Depositing a niobium nitride stress relief layer and a chromium aluminum boron cerium nanocomposite layer; wherein, the parameters for depositing the niobium nitride stress relief layer are as follows: the pulse negative bias frequency and duty cycle remain unchanged, the peak value is adjusted to 30V, Ar is turned off, N2 is introduced, the pressure is 0.3Pa, and the NbN transition layer is deposited for 12 minutes with a thickness of 0.4 microns; the parameters for depositing the chromium aluminum boron cerium nanocomposite layer are as follows: turning off the niobium target, adjusting the pulse negative bias peak value to 150V, the N2 pressure is 3.0Pa, turning on the chromium aluminum boron cerium (Cr29Al59B10Ce2) alloy target, the arc current is 150A, the deposition time is 12 minutes, and the thickness is 0.6 microns; depositing the niobium nitride stress relief layer and depositing the chromium aluminum boron cerium nanocomposite layer are alternately performed 15 times in total to obtain a multi-layer ultra-thick coating.

[0051] After testing, the thickness of the above-mentioned multi-layer ultra-thick coating is 15.3 microns, the hardness of the coating under a load of 50g reaches 38GPa, the scratch bonding strength between the coating and the substrate is 62N, and the number of workpieces processed by the coated high-speed steel hob is 6.8 times that of the uncoated hob.

[0052] Example 2

[0053] Base: Special-shaped copper bar cold-drawn carbide drawing die, hole diameter 20mm;

[0054] Step 1: The substrate is sequentially polished, degreased, rinsed, ultrasonically cleaned with detergent, rinsed with deionized water, and dried before being loaded into the coating furnace. The vacuum is pumped to 1.3×10 -3Pa, and the temperature is maintained at 500±5℃. First, gas plasma cleaning is performed on the cemented carbide drawing die: Ar is introduced through the gas ion source with a pressure of 0.15Pa and an ion source current of 15A. A pulsed negative bias voltage is applied to the die with a frequency of 80KHz and a duty cycle of 90%. The workpiece is cleaned with argon ions at peak values ​​of 150V, 250V, and 350V for 25 minutes each, for a total of 75 minutes. Then, arc plasma cleaning is performed on the cemented carbide drawing die: the gas ion source is turned off, the pulsed negative bias voltage is adjusted to a frequency of 80KHz, a peak value of 1500V, and a duty cycle of 30%, the Ar gas pressure is adjusted to 0.1Pa, the arc ion plating Nb target is turned on, the arc source current is 80A, and the die workpiece is bombarded and sputtered for 30 minutes.

[0055] Step 2: Depositing a pure niobium bonding layer; the parameters for depositing the pure niobium bonding layer are: pulsed negative bias voltage adjusted to 80 kHz frequency, 50 V peak value, 80% duty cycle, Ar pressure adjusted to 0.5 Pa, ion plating pure niobium target arc source current of 100 A, depositing the pure niobium bonding layer for 8 minutes, and a thickness of 0.4 microns.

[0056] Step 3: Depositing a niobium nitride stress relief layer and a chromium aluminum boron cerium nanocomposite layer; wherein, the parameters for depositing the niobium nitride stress relief layer are as follows: the pulse negative bias frequency and duty cycle remain unchanged, the peak value is adjusted to 40V, Ar is turned off, N2 is introduced, the pressure is 0.3Pa, and the NbN transition layer is deposited for 3 minutes with a thickness of 0.1 micron; the parameters for depositing the chromium aluminum boron cerium nanocomposite layer are as follows: turning off the niobium target, adjusting the pulse negative bias peak value to 120V, the N2 pressure is 2.5Pa, turning on the chromium aluminum boron cerium (Cr29Al59B10Ce2) alloy target, the arc current is 150A, the deposition time is 8 minutes, and the thickness is 0.4 micron; depositing the niobium nitride stress relief layer and depositing the chromium aluminum boron cerium nanocomposite layer are alternately performed 20 times in total to obtain a multi-layer ultra-thick coating.

[0057] After testing, the thickness of the above-mentioned multi-layer ultra-thick coating is 10.4 microns, the coating hardness reaches 42GPa under a load of 50g, the scratch bonding strength between the coating and the substrate is 67N, the life of the coated drawing die is 4.8 times that of the uncoated drawing die, and it solves the problem of copper sticking on the mold surface, especially in the special-shaped areas.

[0058] Example 3

[0059] Matrix: plasma nitriding H13 hot forging die;

[0060] Step 1: The substrate is sandblasted to remove the white bright layer on the surface, polished, rinsed, ultrasonically cleaned with detergent, rinsed with deionized water, dried and then loaded into the coating furnace; vacuum pumped to 3.0×10 -3Pa, and the temperature was maintained at 450±5℃; first, the H13 mold was gas plasma cleaned: Ar was introduced through the gas ion source at a pressure of 0.15Pa and an ion source current of 20A. A pulsed negative bias voltage was applied to the mold with a frequency of 100KHz and a duty cycle of 90%. The workpiece was then cleaned with argon ions at peak values ​​of 150V, 250V, and 350V for 40 minutes each, for a total of 120 minutes. Then, arc plasma cleaning was performed on the nitriding H13 hot forging mold: the gas ion source was turned off, the pulsed negative bias frequency was maintained at 100KHz, the peak value was adjusted to 1000V, the duty cycle was 30%, the Ar gas pressure was adjusted to 0.1Pa, the arc ion plating Nb target was turned on, the arc source current was 80A, and the mold workpiece was bombarded and sputtered for 60 minutes.

[0061] Step 2: Depositing a pure niobium bonding layer; the parameters for depositing the pure niobium bonding layer are: pulsed negative bias maintaining a frequency of 100 kHz, adjusting the peak value to 50 V, a duty cycle of 80%, an Ar pressure adjusted to 0.5 Pa, an ion plating pure niobium target arc source current of 100 A, and depositing the pure niobium bonding layer for 12 minutes with a thickness of 0.6 microns.

[0062] Step 3: Depositing a niobium nitride stress relief layer and a chromium aluminum boron cerium nanocomposite layer; wherein, the parameters for depositing the niobium nitride stress relief layer are as follows: the pulse negative bias frequency and duty cycle remain unchanged, the peak value is adjusted to 30V, Ar is turned off, N2 is introduced, the pressure is 0.3Pa, and the NbN transition layer is deposited for 10 minutes with a thickness of 0.5 microns; the parameters for depositing the chromium aluminum boron cerium nanocomposite layer are as follows: turning off the niobium target, adjusting the pulse negative bias peak value to 100V, the N2 pressure is 4.0Pa, turning on the chromium aluminum boron cerium (Cr44Al44B8Ce4) alloy target, the arc current is 150A, the deposition time is 10 minutes, and the thickness is 0.5 microns; depositing the niobium nitride stress relief layer and depositing the chromium aluminum boron cerium nanocomposite layer are alternately performed 30 times in total to obtain a multi-layer ultra-thick coating.

[0063] After testing, the thickness of the above-mentioned multi-layer ultra-thick coating is 30.6 microns, the coating hardness reaches 30GPa under a load of 200g, the scratch bonding strength between the coating and the substrate is 72N, and the life of the coated H13 hot forging die is 6 times that of the uncoated hot forging die.

[0064] Example 4

[0065] Base: ASP23 powder metallurgy high-speed steel punch, working part diameter 6mm;

[0066] Step 1: The substrate is micro-sandblasted, then rinsed with deionized water, ultrasonically cleaned with detergent, rinsed with deionized water, dried, and then loaded into the coating furnace; vacuum is drawn to 1.0×10 -3Pa, the temperature is maintained at 400±5℃; first, the punch needle is gas plasma cleaned: Ar is introduced through the gas ion source with a pressure of 0.15Pa and an ion source current of 10A. A pulsed negative bias voltage is applied to the mold with a frequency of 80KHz and a duty cycle of 80%. The workpiece is cleaned with argon ions at peak values ​​of 100V, 200V, and 300V for 20 minutes each, for a total of 60 minutes; then the punch needle is arc plasma cleaned: the gas ion source is turned off, the pulsed negative bias voltage frequency is maintained at 80KHz, the peak value is adjusted to 1200V, the duty cycle is 35%, the Ar gas pressure is adjusted to 0.05Pa, the arc ion plating Nb target is turned on, the arc source current is 80A, and the mold workpiece is bombarded and sputtered for 40 minutes.

[0067] Step 2: Depositing a pure niobium bonding layer; the parameters for depositing the pure niobium bonding layer are: pulsed negative bias maintaining a frequency of 80 kHz, adjusting the peak value to 50 V, a duty cycle of 80%, an Ar pressure adjusted to 0.5 Pa, an ion plating pure niobium target arc source current of 100 A, and depositing the pure niobium bonding layer for 8 minutes with a thickness of 0.4 microns.

[0068] Step 3: Depositing a niobium nitride stress relief layer and a chromium aluminum boron cerium nanocomposite layer; wherein, the parameters for depositing the niobium nitride stress relief layer are as follows: the pulse negative bias frequency and duty cycle remain unchanged, the peak value is adjusted to 30V, Ar is turned off, N2 is introduced, the pressure is 0.3Pa, and the NbN transition layer is deposited for 2 minutes with a thickness of 0.1 micron; the parameters for depositing the chromium aluminum boron cerium nanocomposite layer are as follows: turning off the niobium target, adjusting the pulse negative bias peak value to 100V, the N2 pressure is 4.0Pa, turning on the chromium aluminum boron cerium (Cr44Al44B8Ce4) alloy target, the arc current is 150A, the deposition time is 6 minutes, and the thickness is 0.3 micron; depositing the niobium nitride stress relief layer and depositing the chromium aluminum boron cerium nanocomposite layer are alternately performed 50 times in total to obtain a multi-layer ultra-thick coating.

[0069] After testing, the thickness of the above-mentioned multi-layer ultra-thick coating is 20.4 microns, the coating hardness reaches 36GPa under a load of 50g, and the scratch bonding strength between the coating and the substrate is 70N. When used for punching 2mm thick 304 stainless steel, the uncoated punching needle punches 42,000 holes, the coated punching needle punches 156,000 holes, and the life of the coated punching needle reaches 3.7 times that of the uncoated punching needle.

[0070] Comparative Example 1

[0071] Base: M35 high-speed steel hob, diameter 200mm, height 200mm, module 8;

[0072] Step 1: The substrate is sequentially degreased, rinsed, micro-sandblasted for edge passivation, ultrasonically cleaned with detergent, rinsed with deionized water, and dried before being loaded into a coating furnace; the vacuum is drawn to 2.0×10 -3Pa, with the temperature maintained at 400±5°C. The high-speed steel hob was first subjected to gas plasma cleaning: Ar was introduced through a gas ion source at a pressure of 0.15 Pa and an ion source current of 10A. A pulsed negative bias voltage with a frequency of 80 kHz and a duty cycle of 90% was applied to the workpiece. Argon ion cleaning was performed at negative bias peaks of 100 V, 200 V, and 300 V for 20 minutes each, for a total of 60 minutes. The gear hob was then subjected to arc plasma cleaning: the gas ion source was turned off, and a pulsed negative bias frequency of 80 kHz, a peak of 1200 V, a duty cycle of 30%, and an Ar partial pressure of 0.1 Pa was applied. The arc ion plating of a pure niobium target was then initiated with an arc source current of 60A, and the workpiece was bombarded and sputtered for 20 minutes.

[0073] Step 2: Depositing a pure niobium bonding layer; the parameters for depositing the pure niobium bonding layer are: pulsed negative bias voltage adjusted to a frequency of 80 kHz, a peak of 50 V, a duty cycle of 80%, an Ar pressure of 0.5 Pa, an ion plating pure niobium target arc source current of 100 A, and the deposition of the pure niobium bonding layer for 6 minutes with a thickness of 0.3 microns.

[0074] Step 3: Deposition of a chromium aluminum boron cerium nanocomposite layer. Parameters for the chromium aluminum boron cerium nitride nanocomposite layer deposition: The niobium target was turned off. The pulsed negative bias frequency and duty cycle remained unchanged, with the peak adjusted to 150V. The N₂ pressure was 3.0Pa. The chromium aluminum boron cerium (Cr₂9Al₅9B₁ ...

[0075] Testing revealed a coating thickness of 15.3 microns. Compared to Example 1, this comparative example lacked a niobium nitride stress-relieving layer, resulting in a non-multilayer structure. After the coated hob emerged from the furnace, numerous cracks appeared on the surface coating, and the coating peeled off from the hob's blade.

[0076] Comparative Example 2

[0077] Base: M35 high-speed steel hob, diameter 200mm, height 200mm, module 8;

[0078] Step 1: The substrate is sequentially degreased, rinsed, micro-sandblasted for edge passivation, ultrasonically cleaned with detergent, rinsed with deionized water, and dried before being loaded into a coating furnace; the vacuum is drawn to 2.0×10 -3Pa, with the temperature maintained at 400±5°C. The high-speed steel hob was first subjected to gas plasma cleaning: Ar was introduced through a gas ion source at a pressure of 0.15 Pa and an ion source current of 10A. A pulsed negative bias voltage with a frequency of 80 kHz and a duty cycle of 90% was applied to the workpiece. Argon ion cleaning was performed at negative bias peaks of 100 V, 200 V, and 300 V for 20 minutes each, for a total of 60 minutes. The gear hob was then subjected to arc plasma cleaning: the gas ion source was turned off, and a pulsed negative bias frequency of 80 kHz, a peak of 1200 V, a duty cycle of 30%, and an Ar partial pressure of 0.1 Pa was applied. The arc ion plating of a pure niobium target was then initiated with an arc source current of 60A, and the workpiece was bombarded and sputtered for 20 minutes.

[0079] Step 2: Depositing a pure niobium bonding layer; the parameters for depositing the pure niobium bonding layer are: pulsed negative bias voltage adjusted to a frequency of 80 kHz, a peak of 50 V, a duty cycle of 80%, an Ar pressure of 0.5 Pa, an ion plating pure niobium target arc source current of 100 A, and the deposition of the pure niobium bonding layer for 6 minutes with a thickness of 0.3 microns.

[0080] Step 3: Depositing a niobium nitride layer; the parameters for depositing the niobium nitride layer are: the pulse negative bias frequency and duty cycle remain unchanged, the peak value is adjusted to 30V, Ar is turned off, N2 is introduced, the pressure is 0.3Pa, and the NbN transition layer is deposited for 450 minutes with a thickness of 15 microns to obtain a coating.

[0081] Testing revealed that the coating had a thickness of 15.3 microns, a hardness of 16 GPa under a 50g load, a scratch bond strength of 78N between the coating and the substrate, and could process 2.1 times more workpieces with the coated high-speed steel hob than with the uncoated hob. Compared to Example 1, this comparative example deposited only a niobium nitride layer as the primary wear-resistant layer. Since it lacked a multilayer structure with the ultra-hard chromium aluminum boron cerium nitride layer, the coating hardness was significantly lower than that of the multilayer coating. This suggests that the niobium nitride coating exhibits a certain degree of wear resistance and improves the hob's service life, but the improvement is much smaller than that achieved with the multilayer coating.

[0082] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A chromium aluminum boron cerium nitride / niobium nitride multilayer ultra-thick coating, characterized in that: The invention relates to a method for depositing an ultra-thick chromium aluminum boron cerium / niobium nitride multilayer coating, comprising a pure niobium bonding layer located on the outside of a substrate, and an alternating multilayer structure formed by a niobium nitride layer and a chromium aluminum boron cerium nanocomposite layer on the outside of the pure niobium bonding layer; wherein the thickness of the pure niobium bonding layer is 0.2-1.0 μm, the alternating cycle of the niobium nitride layer and the chromium aluminum boron cerium nanocomposite layer is 5-50 times, the thickness of the niobium nitride layer in any cycle is 0.1-1.0 μm, the thickness of the chromium aluminum boron cerium nanocomposite layer in any cycle is 0.2-2 μm, and the total thickness of the coating is 10-150 μm; the method for depositing the ultra-thick chromium aluminum boron cerium / niobium nitride multilayer coating comprises the following steps: Step 1: Place the cleaned substrate into the coating furnace and perform plasma treatment on the substrate under a certain vacuum degree and temperature; wherein the vacuum degree is 3.0×10 -3 Pa below, the temperature is 300-550 ° C; the plasma treatment includes gas plasma cleaning and arc plasma cleaning in sequence; the gas plasma cleaning is specifically: Ar is introduced through a gas ion source, the pressure is 0.1-0.5 Pa, the ion source current is 2-20A, a pulsed negative bias is applied to the substrate, the frequency is 20-100KHz, the peak value is 50-500V, and the duty cycle is 50-90%, and the substrate is plasma cleaned for 20-120min at different bias peaks; the arc plasma cleaning is specifically: the gas ion source is turned off, the pulsed negative bias frequency is 20-80KHz, the peak value is 800-1500V, the duty cycle is 10-50%, the Ar partial pressure is 0.05-0.2Pa, the arc ion plating pure niobium target is turned on, the arc source current is 40-120A, and the workpiece is bombarded and sputtered for cleaning for 3-60min; Step 2: depositing a pure niobium bonding layer on the plasma-treated substrate; wherein the parameters for depositing the pure niobium bonding layer are: pulsed negative bias voltage adjusted to a frequency of 20-100 kHz, a peak value of 40-100 V, a duty cycle of 50-90%, an Ar pressure of 0.1-1.0 Pa, an ion plating pure niobium target arc source current of 60-200 A, and depositing the pure niobium bonding layer for 4-20 minutes; Step 3: Alternately depositing a niobium nitride layer and a chromium aluminum boron cerium nitride nanocomposite layer on the substrate after the pure niobium bonding layer is deposited. The parameters for depositing the niobium nitride layer are as follows: adjusting the peak value of the pulsed negative bias to 20-50 V, turning off the Ar, introducing N2 at a pressure of 0.1-1.0 Pa, and depositing the niobium nitride layer for 2-20 minutes. The parameters for depositing the chromium aluminum boron cerium nanocomposite layer are as follows: turning off the niobium target, adjusting the peak value of the pulsed negative bias to 100-300 V, the N2 pressure of 1.0-4.0 Pa, turning on the chromium aluminum boron cerium alloy target, the arc current of 80-200 A, and the deposition time of 4-40 minutes. The deposition of the niobium nitride layer and the deposition of the chromium aluminum boron cerium nanocomposite layer are repeated 5-50 times. The atomic percentage of chromium in the chromium aluminum boron cerium alloy target is 30-60%, the atomic percentage of aluminum is 40-60%, the atomic percentage of boron is 5-15%, and the atomic percentage of cerium is 1-4%.

2. The chromium aluminum boron cerium nitride / niobium nitride multilayer ultra-thick coating according to claim 1, characterized in that: The substrate includes any one of a cutting tool, a machining mold, and a service component.

3. The chromium aluminum boron cerium nitride / niobium nitride multilayer ultra-thick coating according to claim 1, characterized in that: The bonding strength between the coating and the substrate is above 50N, the Vickers hardness under a load of 50g is above 25-45GPa, and the anti-oxidation temperature is above 750°C.

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