CN107287555A - A kind of self-assembled nanometer oxynitride coating and its preparation method and application - Google Patents

Abstract

The invention discloses a method for preparing a self-assembled nano-oxynitride coating, which is prepared by using traditional PVD technology. According to the phenomenon of different distributions of plasma energy and density within different distances from the target, by adjusting the rotation and revolution speed of the sample turret, By changing the residence time of samples in different plasma regions, self-assembled nano-multilayer oxynitride coatings were prepared. The coating includes oxygen-rich layers and nitrogen-rich layers, and the oxygen-rich layers and nitrogen-rich layers are alternately deposited on the substrate. The coating composition is Al: 20-35 at.%, Cr: 10-25 at.%, Si: 0-15 at. .%, O: 5-50 at.%, N: 10-50 at.%. The preparation process of the present invention is simple, low in cost, good in adaptability, taking into account the advantages of nitride and oxide coatings, and has great potential for application and popularization.

Description

A self-assembled nano-oxynitride coating and its preparation method and application

technical field

The invention belongs to the field of material coatings, and more specifically relates to a self-assembled nano-oxynitride coating and its preparation method and application.

Background technique

In recent years, the use of PVD technology to coat metal nitrides, oxides, carbides, etc. on tools, molds, mechanical parts and other products to improve the surface properties and service life of products has become a widely used surface modification technology. Among them, metal nitride coating is the mainstream of tool coating. With the development of processing technology, high-temperature application environments such as high-speed cutting tools and hot-working molds have higher and higher requirements for high-temperature performance of coatings. The high-temperature oxidation resistance temperature of TiC, HfC, TiN, CrN, TiCN and other traditional carbon (nitride) coatings is below 600 ° C, which cannot meet the requirements of high-speed cutting. In order to improve the heat resistance, protective elements such as Al, Cr, Si and rare earth elements such as Y are added to the nitride coating, such as AlTiN, AlCrN, AlTiSiN, AlTiYN, etc., which improves the high temperature performance of the coating, but the improvement space is limited, and the high temperature performance The best AlCrN coating, the heat resistance temperature can only reach about 900-1000 ℃. In order to further improve the high temperature performance of hard coatings, it is necessary to develop new coating systems. Compared with nitride coatings, oxide coatings have better thermochemical stability. For example, the heat resistance of alumina coatings can reach above 1200 °C, but oxide coatings have high brittleness and low hardness (less than 20GPa). Composite coatings such as TiCN/Al ₂ O ₃ /TiN improve the high-temperature performance of the coating to a certain extent. Through the oxide/nitride alternate multi-layer (10-400 layers) design, the TiAlN/Al ₂ O ₃ multi-layer tool coating The layer has the advantages of nitride hardness, good toughness and excellent high-temperature chemical stability of the oxide, and performs well in high-speed cutting and hot-working die processing aluminum; due to the high insulation of alumina, the coating requires special RF ( Radio frequency) sputtering and BP-DMS (bipolar pulsed twin target sputtering) technologies increase the cost of equipment, and the deposition rate is low, which limits their popularization and application. Therefore, the development of a new type of coating with a simple process and the advantages of oxides and nitrides has become an urgent problem to be solved.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art and provide a method for preparing a self-assembled nano-oxynitride coating. The method is prepared by traditional arc ion plating and magnetron sputtering. The phenomenon of different bulk energy and density distribution, by adjusting the rotation and revolution speed of the sample turret, changing the time the sample stays in different plasma regions, so as to realize the self-assembly of nano-multilayers in the coating. The preparation process of the coating is simple, the cost is low, the adaptability is good, and the advantages of both nitride and oxide coatings are taken into account, so it has great potential for application and promotion.

Another object of the present invention is to provide a self-assembled AlCr(Si)ON nano-oxynitride coating prepared by the above method.

Another object of the present invention is to provide the application of the self-assembled nano-oxynitride coating.

The above-mentioned purpose of the present invention is achieved through the following technical solutions:

A method for preparing a self-assembled nano-oxynitride coating, comprising the following specific steps:

S1. Metal substrate cleaning: polish the substrate, then use acetone and alcohol to ultrasonically clean it for 10-20 minutes, then dry it with nitrogen and put it into a vacuum chamber;

S2. Ar and metal ion bombardment: install the target Cr target and AlCr(Si) target into the equipment, turn on the heater to raise the temperature to 300-500°C, and evacuate the vacuum chamber to a vacuum degree of 1.0-8.0×10 ^-3 Pa; Then inject 200-300 sccm of Ar gas, set the bias voltage of the workpiece support to -800--1000V, and perform sputtering cleaning on the surface of the substrate. The bombardment time is 10-20min; , the target current is 60-150A, and the substrate is bombarded with high-energy Cr ions for 3-15 minutes to activate the surface of the metal substrate to improve the film-substrate binding force;

S3. Deposition of nanometer multi-layer coating: feed O ₂ and N ₂ , adjust the rotation speed and revolution speed of the sample turret, control the air pressure at 1.0-3.0Pa, ignite the AlCr(Si) target, the target current 60-150A, bias Voltage -60～-200V, deposition time 0.5～2h;

S4. Turn off the arc power supply, wait until the temperature of the vacuum chamber drops to room temperature, open the vacuum chamber to take out the substrate, and the coating formed on the surface of the substrate is the self-assembled nano-oxynitride coating.

Preferably, the rotation speed in step S3 is 1-6 r/min, and the revolution speed is 0-5 r/min.

Preferably, the atomic percentages of the elements of the AlCrSi target in step S3 are Al: 55-70 at.%, Cr: 20-35 at.%, Si: 0-20 at.%.

Preferably, the O ₂ in step S3 accounts for 1-25% of the total volume of O ₂ and N ₂ .

Preferably, the substrate in steps S1-S4 is metal, hard alloy or ceramics.

The self-assembled nano-oxynitride coating prepared by the above method, the self-assembled nano-oxynitride coating includes oxygen-rich layers and nitrogen-rich layers, and the oxygen-rich layers and nitrogen-rich layers are alternately deposited on the substrate.

Wherein, the composition of the self-assembled nano-oxynitride coating is Al: 20-35 at.%, Cr: 10-25 at.%, Si: 0-15 at.%, O: 5-50 at.%, N: 10 ~50at.%.

Preferably, the total thickness of the self-assembled nano-oxynitride coating is 2-10 μm.

Preferably, the single-layer thickness of the oxygen-enriched layer is 2-20 nm, and the single-layer thickness of the nitrogen-enriched layer is 5-100 nm.

Preferably, the substrate is metal, hard alloy or ceramics.

The application of the above-mentioned self-assembled nano-oxynitride coating in the field of protection of the surface of mechanical parts and tool mold products.

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

1. The present invention adopts arc ion plating and magnetron sputtering to prepare a self-assembled nano-multilayer oxynitride coating, which takes into account the advantages of both nitride and oxide coatings, and overcomes the shortcomings of oxide coatings that are difficult to manufacture. The process is simple, the operability is strong, the controllability is good, the cost is low, and the adaptability is good. It is suitable for the protection of the surface of mechanical parts, knife molds and other products, and has good economic benefits.

2. According to the phenomenon of different plasma energy and density distribution in different distance ranges of the target, the invention prepares a new type of self-assembled nanometer poly Layer oxynitride coating, can be applied to the working environment under harsh conditions.

Description of drawings

Fig. 1 is a schematic diagram of an arc deposition device used in the present invention.

Figure 2 is the SEM and TEM photographs of the self-assembled nano-oxynitride coating prepared in Example 1.

Fig. 3 is a schematic diagram of the structure of the self-assembled nano-oxynitride coating.

detailed description

The content of the present invention will be further described below in conjunction with specific examples, but it should not be construed as a limitation of the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field.

Example 1

A self-assembled nano-oxynitride coating comprises an oxygen-rich layer AlCrSiON and a nitrogen-rich layer AlCrSiON. Among them, the thickness of the oxygen-enriched layer is 2nm, the thickness of the nitrogen-enriched layer is 5nm, and the atomic percentage content of each element in the coating is: Al: 20at.%, Cr: 10at.%, Si: 15at.%, O: 50at. .%, N: 5 at.%.

Polish the high-speed steel substrate, ultrasonically clean it with acetone and alcohol for 10 minutes, dry it with nitrogen, and put it into a vacuum chamber. Install the target material Cr target and AlCrSi target into the equipment, turn on the heater to raise the temperature to 300°C, and evacuate the vacuum chamber to a vacuum degree below 1.0×10 ^-3 Pa. 300 sccm of Ar gas was introduced, the bias voltage of the workpiece support was set to -1000V, and the surface of the substrate was cleaned by sputtering, and the bombardment time was 10 minutes. Afterwards, the bias voltage was reduced to -600V, the Cr target was ignited, the target current was 150A, and the substrate was bombarded with high-energy Cr ions for 15 minutes. Adjust the bias voltage to -200V, feed 300sccm of N ₂ gas and O ₂ , control the air pressure at 3.0Pa, the ratio of O ₂ /O ₂ +N ₂ is 25%, ignite the CrAlSi target, the target current is 60A, and the deposition time is 0.5 hours, wherein the revolution speed of the turret is 0r/min, and the rotation speed is 6r/min. After the coating is completed, after the temperature of the vacuum chamber drops to room temperature, the vacuum chamber is opened to take out the substrate to obtain a self-assembled nano-multilayer oxynitride coating.

FIG. 1 is a schematic diagram of an arc deposition device used in the present invention. In the process of depositing the coating, the substrate rotates. When the substrate is facing the target, the plasma energy and density are higher, the reaction is more sufficient, the nitrogen content is higher, and the layer is thicker; while the plasma density is lower when the substrate is far away from the target. , the more reactive oxygen and metal generate an oxygen-rich layer, and the nanolayer is thinner, so the coating will self-assemble to form a nanomultilayer structure during the coating preparation process.

Figure 2 is the TEM and SEM photographs of the self-assembled nano-multilayer oxynitride coating. Among them, Fig. 2(a) is a TEM photo, and Fig. 2(b) is a SEM photo. It can be seen from Figure 2(b) that the coating structure is dense and the multi-layer structure cannot be clearly distinguished. However, after TEM observation of the coating part, it is found that there is a nano-multi-layer structure in the coating, and the color is brighter. The thinner one is the oxygen-rich layer, while the darker and thicker one is the nitrogen-rich layer.

Example 2

A self-assembled nanometer multilayer oxynitride coating comprises an oxygen-rich layer AlCrSiON and a nitrogen-rich layer AlCrSiON. Among them, the thickness of the oxygen-rich layer is 8nm, the thickness of the nitrogen-rich layer is 30nm, the atomic percentage content of each element in the coating is: Al: 25at.%, Cr: 15at.%, Si: 5at.%, O: 5at. .%, N: 50 at.%.

Polish the cemented carbide substrate, ultrasonically clean it with acetone and alcohol for 15 minutes, dry it with nitrogen, and put it into a vacuum chamber. Install the target material Cr target and AlCrSi target into the equipment, turn on the heater to raise the temperature to 350°C, and evacuate the vacuum chamber to a vacuum degree below 5.0×10 ^-3 Pa. Introduce 250 sccm of Ar gas, set the bias voltage of the workpiece support to -800V, and perform sputter cleaning on the surface of the substrate, and the bombardment time is 20 minutes. Afterwards, the bias voltage was reduced to -800V, the Cr target was ignited, the target current was 120A, and the substrate was bombarded with high-energy Cr ions for 3 minutes. Adjust the bias voltage to -150V, feed 300sccm of N ₂ gas and O ₂ , control the air pressure at 1.5Pa, the ratio of O ₂ /O ₂ +N ₂ is 2%, ignite the CrAlSi target, the target current is 80A, and the deposition time is 1 hour, wherein the revolution speed of the turret is 2r/min, and the rotation speed is 4r/min. After the coating is completed, wait until the temperature of the vacuum chamber drops to room temperature, open the vacuum chamber and take out the substrate to obtain a self-assembled nano-oxynitride coating.

Example 3

A self-assembled nanometer multilayer oxynitride coating comprises an oxygen-rich layer AlCrSiON and a nitrogen-rich layer AlCrSiON. Among them, the thickness of the oxygen-rich layer is 12nm, the thickness of the nitrogen-rich layer is 60nm, and the atomic percentage content of each element in the coating is: Al: 30at.%, Cr: 20at.%, Si: 10at.%, O: 15at. .%, N: 25 at.%.

The high-speed steel substrate is polished, ultrasonically cleaned with acetone and alcohol for 15 minutes, dried with nitrogen, and then placed in a vacuum chamber. Install the target material Cr target and AlCrSi target into the equipment, turn on the heater to raise the temperature to 400°C, and evacuate the vacuum chamber to a vacuum degree below 5.0×10 ^-3 Pa. 300 sccm of Ar gas was introduced, the bias voltage of the workpiece support was set at -900V, and the surface of the substrate was cleaned by sputtering, and the bombardment time was 15 minutes. Afterwards, the bias voltage was reduced to -700V, the Cr target was ignited, the target current was 100A, and the substrate was bombarded with high-energy Cr ions for 10 minutes. Adjust the bias voltage to -120V, feed 250sccm of N ₂ and O ₂ , control the air pressure at 1.5Pa, the ratio of O ₂ /O ₂ +N ₂ is 10%, ignite the AlCrSi target, the target current is 100A, and the deposition time is 1.5 hours , wherein the revolution speed of the turret is 3r/min, and the rotation speed is 3r/min. After the coating is completed, wait until the temperature of the vacuum chamber drops to room temperature, open the vacuum chamber and take out the substrate to obtain a self-assembled nano-oxynitride coating.

Example 4

A self-assembled nanometer multilayer oxynitride coating comprises an oxygen-rich layer AlCrON and a nitrogen-rich layer AlCrON. Among them, the thickness of the oxygen-rich layer is 20nm, the thickness of the nitrogen-rich layer is 100nm, the atomic percentage content of each element in the coating is: Al: 35at.%, Cr: 25at.%, Si: 0at.%, O: 30at. .%, N: 10 at.%.

Polish the ceramic substrate, ultrasonically clean it with acetone and alcohol for 20 minutes, dry it with nitrogen, and put it into a vacuum chamber. Install the target material Cr target and AlCr target into the equipment, turn on the heater to raise the temperature to 450°C, and evacuate the vacuum chamber to a vacuum degree below 8.0×10 ^-3 Pa. Introduce 200 sccm of Ar gas, set the bias voltage of the workpiece support to -900 ~ -1000 V, and perform sputter cleaning on the surface of the substrate, and the bombardment time is 20 minutes. Afterwards, the bias voltage was reduced to -800V, the Cr target was ignited, the target current was 60A, and the substrate was bombarded with high-energy Cr ions for 15 minutes. Adjust the bias voltage to -100V, feed 200 sccm of N ₂ gas, adjust the gas pressure to 1.0 Pa, and deposit CrN for 5 minutes. Introduce O ₂ , control the air pressure at 3.0Pa, the ratio of O ₂ /O ₂ +N ₂ is 1%, ignite the AlCr target, the target current is 150A, the bias voltage is -150V, the deposition time is 2 hours, and the revolution speed of the turntable is 5r /min, the rotation speed is 1r/min. After the coating is completed, wait until the temperature of the vacuum chamber drops to room temperature, open the vacuum chamber and take out the substrate to obtain a self-assembled nano-oxynitride coating.

Fig. 3 is a schematic diagram of the structure of the self-assembled nano-oxynitride coating. It can be seen that the structure of the self-assembled nano-oxynitride coating is composed of an oxygen-rich layer and a nitrogen-rich layer. This coating takes into account the advantages of both nitride and oxide coatings, and overcomes the shortcomings of oxide coatings that are difficult to manufacture. In the process of layering, when the substrate rotates to face the target, the plasma energy and density are higher, the reaction is more sufficient, the nitrogen content is higher, and the layer is thicker; when the substrate is far away from the target, the plasma density is lower and it is easier to The reacting oxygen and metal create an oxygen-rich layer, which is thinner. The process is simple, the operability is strong, the controllability is good, the cost is low, and the adaptability is good. It is suitable for the protection of the surface of mechanical parts, knife molds and other products, and has good economic benefits.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations and modifications made without departing from the spirit and principles of the present invention Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (10)

1. a kind of preparation method of self-assembled nanometer oxynitride coating, it is characterised in that comprise the following specific steps that：

S1. metallic matrix is cleaned：By matrix polishing, then successively it is cleaned by ultrasonic 10~20min with acetone, alcohol, then is used Load after nitrogen drying in vacuum chamber；

S2.Ar and metal ion bombardment：Target Cr targets and AlCr (Si) target are installed into equipment, heater is opened and is warming up to 300 ~500 DEG C, by vacuum chamber to vacuum 1.0~8.0 × 10^-3Pa；200~300sccm Ar gas is then passed to, is set Work support biases -800~-1000V, and sputter clean, 10~20min of bombardment time are carried out to matrix surface；Bias is dropped again To -600~-800V, Cr targets, 60~150A of target current, with high energy Cr Ions Bombardment 3~15min of matrix, activated metal are lighted Matrix surface is made a concerted effort with improving film-base junction；

S3. nano laminated coating is deposited：It is passed through O₂And N₂, sample pivoted frame rotational velocity and revolution speed are adjusted, control air pressure exists 1.0~3.0Pa, lights AlCr (Si) target, and 60~150A of target current biases -60~-200V, 0.5~2h of sedimentation time；

S4. arc power is closed, treats that vacuum room temperature is down to room temperature, vacuum chamber is opened and takes out matrix, in matrix surface formation Coating, as self-assembled nanometer oxynitride coating.

2. the preparation method of self-assembled nanometer oxynitride coating according to claim 1, it is characterised in that institute in step S3 Rotational velocity is stated for 1~6r/min, the revolution speed is 0~5r/min.

3. the preparation method of self-assembled nanometer oxynitride coating according to claim 1, it is characterised in that institute in step S3 The each element atomic percent for stating AlCrSi targets is Al：55~70at.%, Cr：20~35at.%, Si：0~20at.%.

4. the preparation method of self-assembled nanometer oxynitride coating according to claim 1, it is characterised in that institute in step S3 State O₂Account for O₂And N₂The 1~25% of cumulative volume.

5. the preparation method of self-assembled nanometer multilayer oxygen nitride coatings according to claim 1, it is characterised in that step Matrix described in S1-S4 is metal, hard alloy or ceramics.

6. the self-assembled nanometer oxynitride coating prepared according to any one of claim 1-5 methods described, it is characterised in that institute Stating self-assembled nanometer oxynitride coating includes oxygen-rich layer and nitrogen-enriched layer, and oxygen-rich layer and the nitrogen-enriched layer alternating deposit is in matrix On.

7. self-assembled nanometer oxynitride coating according to claim 6, it is characterised in that the self-assembled nanometer oxynitriding The composition of thing coating is Al：20~35at.%, Cr：10~25at.%, Si：0~15at.%, O：5~50at.%, N：10~ 50at.%.

8. self-assembled nanometer oxynitride coating according to claim 6, it is characterised in that the self-assembled nanometer oxynitriding The gross thickness of thing coating is 2~10 μm, and the thickness in monolayer of the oxygen-rich layer is 2~20nm, and the thickness in monolayer of the nitrogen-enriched layer is 5 ~100nm.

9. self-assembled nanometer oxynitride coating according to claim 6, it is characterised in that described matrix is metal, hard Alloy or ceramics.

10. the self-assembled nanometer oxynitride coating described in claim any one of 6-9 is in component of machine and knife mold product Application in the protection field on surface.