CN116180028A - Strong and wear-resistant gradient metal ceramic composite multilayer coating and preparation method thereof - Google Patents

Abstract

The invention discloses a tough and wear-resistant gradient cermet composite multilayer coating and a preparation method thereof. The coating comprises a multilayer nanocrystalline metal tantalum layer and a multilayer ceramic tantalum boride layer. The nanocrystalline metal The tantalum layer and the ceramic tantalum boride layer are arranged alternately, and the thicknesses of the nanocrystalline metal tantalum layer and the ceramic tantalum boride layer are different at different positions and form a gradient structure. The present invention adopts the above-mentioned strong and wear-resistant gradient cermet composite multilayer coating, and controls the sputtering time to control the proportion of nanocrystalline metal tantalum layer and ceramic tantalum boride layer at different positions under the magnetron sputtering method. Compared with the traditional metal-ceramic composite multi-layer coating, it overcomes the disadvantage of significantly lower hardness and improves wear resistance.

Description

A kind of tough and wear-resistant gradient cermet composite multilayer coating and its preparation method

technical field

The invention relates to the technical field of multilayer coating preparation, in particular to a tough and wear-resistant gradient cermet composite multilayer coating and a preparation method thereof.

Background technique

At present, transition group metal light element compounds composed of IVB～VIB group transition metal atoms and light element atoms (C, N and B) have attracted widespread attention. The transition group metal atoms themselves have high valence electron density, resulting in high incompressibility, combined with light element atoms to form covalent bonds with strong directionality, so that the compounds composed of them have excellent mechanical properties, such as high hardness and high abrasion resistance. In addition, this type of compound also has high thermodynamic stability, oxidation resistance, chemical inertness and melting point, and the synthetic raw materials are relatively cheap, and the synthetic conditions are not harsh. It is an ideal superhard/hard material used in complex environments. It has an irreplaceable important strategic position.

However, in general, high hardness is usually accompanied by brittleness, which is not conducive to resistance to crack initiation and propagation, thereby affecting the reliability and service life of the material. Therefore, the development of ceramic thin film materials with both high hardness and high toughness has become a major goal in the field of structural ceramics.

Metal/ceramic composite multilayer films (coatings) offer a strategy to combine the ductility and toughness of metals with the hardness and high-temperature strength of ceramics. It has received increasing attention due to its favorable mechanical, physical, and chemical properties that make it practically useful under a wide range of temperatures, mechanical loads, and environmental conditions. Generally speaking, the hardness of the composite multilayer is between its ceramic component and the metal component, and the hardness is actually exchanged for toughness. This leads to the same limited application scenarios. For example, ordinary metal/ceramic multilayer films are usually not wear-resistant due to the decrease in hardness. There are also some attempts to increase the hardness by reducing the layer thickness, but it is concluded that the hardness of the metal-ceramic composite multilayer has a weak dependence on the layer thickness, and the proportion of ceramic components has a greater influence.

Contents of the invention

The purpose of the present invention is to provide a tough and wear-resistant gradient cermet composite multilayer coating and its preparation method, to solve the above-mentioned cermet composite multilayer film (coating) in exchange for toughness at the expense of hardness, due to hardness The problem of lowering is usually not wear-resistant. For this reason, the present invention designs a composite multi-layer coating in which the thickness of the metal layer and the ceramic layer are distributed in gradients. Under the magnetron sputtering method, the sputtering time is adjusted to control the ceramics at different positions. The ratio of the layer to the metal layer achieves the advantages of traditional metal-ceramic composite multi-layer coatings while overcoming the disadvantage of a significant drop in hardness and improving wear resistance.

In order to achieve the above object, the present invention provides a tough and wear-resistant gradient cermet composite multilayer coating, the coating includes a multilayer nanocrystalline metal tantalum layer and a multilayer ceramic tantalum boride layer, the nanocrystalline The metal tantalum layer and the ceramic tantalum boride layer are arranged alternately, and the thicknesses of the nanocrystalline metal tantalum layer and the ceramic tantalum boride layer are different at different positions and form a gradient structure.

Preferably, the ratio of the total thickness of the multilayer nanocrystalline metal tantalum layer to the total thickness of the multilayer ceramic tantalum boride layer is 1:1.

Preferably, the thickness of the nanocrystalline metal tantalum layer decreases in a continuous gradient along the growth direction of the coating.

Preferably, the thickness of the ceramic tantalum boride layer increases in a continuous gradient along the coating growth direction.

Preferably, both the multi-layer nanocrystalline metal tantalum layer and the multi-layer ceramic tantalum boride layer have ten layers.

The preparation method of the tough and wear-resistant gradient cermet composite multilayer coating adopts magnetron co-sputtering technology to prepare the coating, and generates nanocrystalline metal tantalum layers of different thicknesses at different positions by controlling the sputtering time and ceramic tantalum boride layer.

Preferably, the preparation method of the tough and wear-resistant gradient cermet composite multi-layer coating comprises the following steps:

(1) Preparatory work: The targets used are tantalum targets and tantalum tetraboride targets with copper back plates, the substrates used are single-sided polished single crystal silicon, and the crystal plane orientation of the polished surface is (100);

The tantalum target and the tantalum tetraboride target are installed on the target position in the horizontal direction, and the two targets are connected to a DC power supply; the substrate is cut into a suitable size and ultrasonically cleaned with absolute ethanol and acetone for 15 minutes, and then dried with nitrogen. Installed on the sample stage;

Ensure that the coating chamber is clean before deposition, and wipe all the seals with an alcohol-free dust-free cloth to ensure the sealing of the coating chamber, and then use a vacuum system composed of a mechanical pump and a molecular pump to evacuate the coating chamber to keep the vacuum at 6×10 ^-4 Below Pa, and the substrate is heated to 400°C;

(2) Coating operation: Introduce high-purity Ar gas into the chamber with a gas flow rate of 80 sccm, use a regulating valve to control the total pressure to 0.8 Pa, and apply a negative bias of -80 V to the substrate;

Turn on the DC power supply connected to the tantalum target and the tantalum tetraboride target, and set the power to 100W for pre-sputtering. After 5 minutes, rotate the sample stage above the tantalum target, and determine the sputtering time according to the designed thickness requirements. After the injection is completed, the sample stage is rotated to the top of the tantalum tetraboride target, and the above process is repeated to obtain the coating.

Preferably, the sputtering time of the tantalum target for forming the nanocrystalline metal tantalum layer in step (2) decreases in a continuous gradient, and the sputtering time of the tantalum tetraboride target for forming the ceramic tantalum boride layer increases in a continuous gradient.

Preferably, the sputtering time of each layer of the tantalum target in step (2) is 3min30s, 3min10s, 2min50s, 2min30s, 2min10s, 1min50s, 1min30s, 1min10s, 50s, 30s;

The sputtering time of each layer of tantalum tetraboride target is: 1min, 1min40s, 2min20s, 3min, 3min40s, 4min20s, 5min, 5min40s, 6min20s, 7min;

The total sputtering time is controlled to be 1h, and the obtained coating thickness is 2.5um.

Preferably, the sputtering time of each layer of the tantalum target in step (2) is 7min, 6min20s, 5min40s, 5min, 4min20s, 3min40s, 3min, 2min20s, 1min40s, 1min;

The sputtering time of each layer of tantalum tetraboride target is 2min, 3min20s, 4min40s, 6min, 7min20s, 8min40s, 10min, 11min20s, 12min40s, 14min;

The total sputtering time is controlled to be 2h, and the obtained coating thickness is 4.8um.

Therefore, the present invention adopts a kind of tough and wear-resistant gradient cermet composite multi-layer coating and its preparation method with the above structure, which has the following beneficial effects:

(1) By adjusting the thickness of the nanocrystalline metal tantalum layer and the ceramic tantalum boride layer at different positions, a gradient structure is formed, which not only retains the advantages of strengthening and toughening the traditional metal-ceramic composite multilayer coating, but also overcomes the decline in its mechanical properties defects, improved wear resistance.

(2) The gradient structure realizes the dissipation of stress and the gradient distribution of mechanical properties in space through the gradient distribution of metal-ceramic composite multilayers, which significantly improves the wear resistance of the coating and maintains the high hardness of the boride. Structural design ideas have not been reported in boride-based thin film coatings.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is the coating structure schematic diagram of embodiment 1;

Fig. 2 is the coating structure schematic diagram of embodiment 2;

Fig. 3 is the coating structure schematic diagram of embodiment 3;

Fig. 4 is the XRD collection of illustrative plates of embodiment and comparative example;

Fig. 5 is the cross-sectional SEM figure of comparative example;

Fig. 6 is the cross-sectional SEM figure of embodiment 1;

Fig. 7 is the cross-sectional SEM figure of embodiment 2;

Fig. 8 is the cross-sectional SEM figure of embodiment 3;

Fig. 9 is the hardness contrast figure of embodiment and comparative example;

Fig. 10 is the frictional performance comparison figure of embodiment and comparative example;

Fig. 11 is the indentation morphology of the examples and comparative examples after the 600nm continuous stiffness nanoindentation test.

In the figure: 1. Silicon substrate; 2. Nanocrystalline metal tantalum layer; 3. Ceramic tantalum boride layer.

Detailed ways

The present invention will be further described below. It should be noted that this embodiment is based on the technical solution and provides detailed implementation and specific operation process, but the present invention is not limited to this embodiment.

Example 1

The preparation method of the tough and wear-resistant gradient cermet composite multi-layer coating comprises the following steps:

(1) Preparation:

The target used is a tantalum target and a tantalum tetraboride target with a copper back plate, and the substrate used is a single-sided polished single-crystal silicon, and the crystal plane orientation of the polished surface is (100);

The tantalum target and the tantalum tetraboride target are installed on the target position in the horizontal direction, and the two targets are connected to a DC power supply; the substrate is cut into a suitable size and ultrasonically cleaned with absolute ethanol and acetone for 15 minutes, and then dried with nitrogen. installed on the sample stage.

Ensure that the coating chamber is clean before deposition, and wipe all the seals with an alcohol-free dust-free cloth to ensure the sealing of the coating chamber, and then use a vacuum system composed of a mechanical pump and a molecular pump to evacuate the coating chamber to keep the vacuum at 6×10 ^-4 Pa below, and the substrate is heated to 400 ° C.

(2) Coating operation:

Introduce high-purity Ar gas into the cavity, the gas flow rate is 80 sccm, and the total pressure is controlled to 0.8Pa by using a regulating valve. And a negative bias of -80 V was applied to the substrate.

Turn on the DC power supply connected to the two targets, and set the power to 100W; perform pre-sputtering.

After 5 minutes, the sample stage was rotated above the tantalum target for formal sputtering, and after the designed sputtering time of this layer was reached, the sample stage was rotated above the tantalum tetraboride target for ten cycles.

The sputtering time of each layer of the tantalum target is 2 min, and the sputtering time of each layer of the tantalum tetraboride target is 4 min.

The total sputtering time is controlled to 1h, and a tantalum/tantalum boride composite multilayer coating with a uniform layer thickness and a film thickness of about 2.4um is obtained.

It can be seen from Fig. 1 that the coating comprises ten layers of nanocrystalline metal tantalum layers and ten layers of ceramic tantalum boride layers, and the nanocrystalline metal tantalum layers and ceramic tantalum boride layers are arranged alternately, wherein the nanometer metal tantalum layers are first deposited on On the substrate, a ceramic tantalum boride layer is deposited on the nano-metal tantalum layer, and the cycle is repeated ten times, and finally a metal-ceramic composite multilayer coating is formed. From the perspective of sputtering time, the sputtering time of the tantalum target and the tantalum tetraboride target are unchanged, the former is 2 minutes, and the latter is 4 minutes, so the nano-metal tantalum layer generated by each sputtering The thickness of the ceramic tantalum boride layer produced by each sputtering is also constant. It can also be seen from FIG. 1 that the total thickness of the ten nanocrystalline metal tantalum layers is the same as that of the ten ceramic tantalum boride layers.

Example 2

The preparation method of the tough and wear-resistant gradient cermet composite multi-layer coating comprises the following steps:

(1) Preparation:

The target used is a tantalum target and a tantalum tetraboride target with a copper back plate, and the substrate used is a single-sided polished single-crystal silicon, and the crystal plane orientation of the polished surface is (100);

The tantalum target and the tantalum tetraboride target are installed on the target position in the horizontal direction, and the two targets are connected to a DC power supply; the substrate is cut into a suitable size and ultrasonically cleaned with absolute ethanol and acetone for 15 minutes, and then dried with nitrogen. installed on the sample stage.

Ensure that the coating chamber is clean before deposition, and wipe all the seals with an alcohol-free dust-free cloth to ensure the sealing of the coating chamber, and then use a vacuum system composed of a mechanical pump and a molecular pump to evacuate the coating chamber to keep the vacuum at 6×10 ^-4 Pa below, and the substrate is heated to 400 ° C.

(2) Coating operation:

Introduce high-purity Ar gas into the cavity, the gas flow rate is 80 sccm, and the total pressure is controlled to 0.8Pa by using a regulating valve. And a negative bias of -80 V was applied to the substrate.

Turn on the DC power supply connected to the two targets, and set the power to 100W; perform pre-sputtering.

After 5 minutes, the sample stage was rotated above the tantalum target for formal sputtering, and after the designed sputtering time of this layer was reached, the sample stage was rotated above the tantalum tetraboride target for ten cycles.

The sputtering time of each layer of the tantalum target is 3min30s, 3min10s, 2min50s, 2min30s, 2min10s, 1min50s, 1min30s, 1min10s, 50s, 30s;

The sputtering time of each layer of tantalum tetraboride target is 1min, 1min40s, 2min20s, 3min, 3min40s, 4min20s, 5min, 5min40s, 6min20s, 7min.

The total sputtering time is controlled to 1h, and a tantalum/tantalum boride composite multilayer coating with a uniform layer thickness and a film thickness of about 2.4um is obtained.

It can be seen from Fig. 2 that the coating comprises ten layers of nanocrystalline metal tantalum layers and ten layers of ceramic tantalum boride layers, and the nanocrystalline metal tantalum layers and ceramic tantalum boride layers are arranged alternately, wherein the nanometer metal tantalum layers are first deposited on On the substrate, a ceramic tantalum boride layer is deposited on the nano-metal tantalum layer, and the cycle is repeated ten times, and finally a metal-ceramic composite multilayer coating is formed. From the perspective of sputtering time, the sputtering time of the tantalum target decreases linearly from 3min30s to 30s, each time by 20s, and the sputtering time of the tantalum tetraboride target increases linearly from 1min to 7min, each time by 40s, so each time The thickness of the nano-metal tantalum layer generated by sputtering decreases all the time, and the thickness of the nano-metal tantalum layer decreases continuously along the coating growth direction to form a gradient structure. The thickness of the ceramic tantalum boride layer generated by each sputtering is along the The growth direction of the coating is in a state of continuous gradient increase to form a gradient structure. It can also be seen from FIG. 2 that the total thickness of the ten nanocrystalline metal tantalum layers is the same as that of the ten ceramic tantalum boride layers.

The total sputtering time (20min) of the tantalum target and the total sputtering time (40min) of the tantalum tetraboride target in embodiment 1 and embodiment 2 are the same, but embodiment 2 will set the tantalum target and tantalum tetraboride The change of the target sputtering time makes the thickness of the nanocrystalline metal tantalum layer and the thickness of the ceramic tantalum boride layer change in a gradient manner and finally form a gradient structure of the two. Embodiment 1 is due to the tantalum target and the tantalum tetraboride target. The sputtering time remains constant, and the same gradient structure as in Example 2 is not formed. Adopt nano-indentation technology to measure the hardness of embodiment and comparative example among the present invention, it should be noted that nano-indentation technology can measure the hardness and fracture toughness of coating, as can be seen from Fig. 9, the hardness of embodiment 1 is less than Embodiment 2 illustrates that embodiment 1 introduces a nanocrystalline metal tantalum layer in the coating in order to increase the toughness of the coating, but at the same time the hardness of the coating is reduced. In embodiment 2, by setting the nanocrystalline metal tantalum layer and ceramic boron The gradient structure of the tantalum oxide layer avoids the problem of decreasing hardness while increasing toughness.

Example 3

The preparation method of the tough and wear-resistant gradient cermet composite multi-layer coating comprises the following steps:

(1) Preparation:

The target used is a tantalum target and a tantalum tetraboride target with a copper back plate, and the substrate used is a single-sided polished single-crystal silicon, and the crystal plane orientation of the polished surface is (100);

The tantalum target and the tantalum tetraboride target are installed on the target position in the horizontal direction, and the two targets are connected to a DC power supply; the substrate is cut into a suitable size and ultrasonically cleaned with absolute ethanol and acetone for 15 minutes, and then dried with nitrogen. installed on the sample stage.

Ensure that the coating chamber is clean before deposition, and wipe all the seals with an alcohol-free dust-free cloth to ensure the sealing of the coating chamber, and then use a vacuum system composed of a mechanical pump and a molecular pump to evacuate the coating chamber to keep the vacuum at 6×10 ^-4 Pa below, and the substrate is heated to 400 ° C.

(2) Coating operation:

Introduce high-purity Ar gas into the cavity, the gas flow rate is 80 sccm, and the total pressure is controlled to 0.8Pa by using a regulating valve. And a negative bias of -80 V was applied to the substrate.

Turn on the DC power supply connected to the two targets, and set the power to 100W; perform pre-sputtering.

After 5 minutes, the sample stage was rotated above the tantalum target for formal sputtering, and after the designed sputtering time of this layer was reached, the sample stage was rotated above the tantalum tetraboride target for ten cycles.

The sputtering time of each layer of the tantalum target is 7min, 6min20s, 5min40s, 5min, 4min20s, 3min40s, 3min, 2min20s, 1min40s, 1min;

The sputtering time of each layer of tantalum tetraboride target is 2min, 3min20s, 4min40s, 6min, 7min20s, 8min40s, 10min, 11min20s, 12min40s, 14min.

The total sputtering time is controlled to 1h, and a tantalum/tantalum boride composite multilayer coating with a uniform layer thickness and a film thickness of about 4.8um is obtained.

It can be seen from Fig. 3 that the coating comprises ten layers of nanocrystalline metal tantalum layers and ten layers of ceramic tantalum boride layers, and the nanocrystalline metal tantalum layers and ceramic tantalum boride layers are arranged alternately, wherein the nanometer metal tantalum layers are first deposited on On the substrate, a ceramic tantalum boride layer is deposited on the nano-metal tantalum layer, and the cycle is repeated ten times, and finally a metal-ceramic composite multilayer coating is formed. From the perspective of sputtering time, the sputtering time of the tantalum target decreases linearly from 7min to 1min, each time by 40s, and the sputtering time of the tantalum tetraboride target increases linearly from 2min to 14min, and each time increases by 1min20s, so each time The thickness of the nano-metal tantalum layer generated by sputtering decreases all the time, and the thickness of the nano-metal tantalum layer decreases continuously along the coating growth direction to form a gradient structure. The thickness of the ceramic tantalum boride layer generated by each sputtering is along the The growth direction of the coating is in a state of continuous gradient increase to form a gradient structure. It can also be seen from FIG. 3 that the total thickness of the ten nanocrystalline metal tantalum layers is the same as that of the ten ceramic tantalum boride layers.

The principle of embodiment 3 is the same as that of embodiment 2, and a gradient structure is also formed, but the thickness of each layer of nano-metal tantalum layer and the thickness of each layer of ceramic tantalum boride layer in embodiment 3 are 2 times that of embodiment 2, from As can be seen from Figure 9, Example 3 has further improved the hardness of the coating, indicating that the present invention overcomes the hardness in the prior art by adjusting the thicknesses of the nanocrystalline metal tantalum layer and the ceramic tantalum boride layer at different positions to form a gradient structure Falling flaws.

comparative example

The preparation method of tantalum boride coating comprises the following steps:

(1) Preparation:

The tantalum tetraboride target was installed on the target position in the horizontal direction, and connected to a DC power supply; the substrate was cut into a suitable size and cleaned ultrasonically for 15 minutes with absolute ethanol and acetone, then dried with nitrogen, and installed on the sample stage.

Ensure that the coating chamber is clean before deposition, and wipe all the seals with an alcohol-free dust-free cloth to ensure the sealing of the coating chamber, and then use a vacuum system composed of a mechanical pump and a molecular pump to evacuate the coating chamber to keep the vacuum at 6×10 ^-4 Below Pa.

(2) Coating operation:

Introduce high-purity Ar gas into the cavity, the gas flow rate is 80 sccm, and the total pressure is controlled to 0.8Pa by using a regulating valve.

A negative bias of -80 V was applied to the substrate and heated to 400 °C.

Turn on the DC power supply connected to the tantalum tetraboride target, set the power to 100W, and perform pre-sputtering.

After 5 min, the sample stage was rotated above the target for formal sputtering.

Control the sputtering time to 1h, and obtain a tantalum boride coating with a film thickness of about 1.2um.

The comparative example is a pure tantalum boride sample prepared under the same conditions using only a tantalum tetraboride target. Different sputtering times are set in each example to generate coatings with different structures. From the cross-sectional SEM images of Figures 5-8 Different structures of the coatings can be observed in .

From the XRD spectrum of Fig. 2, it can be seen that the comparative example has a structure close to amorphous, while the peaks of metal tantalum appear in Examples 1 to 3, and the crystal phase is standard tantalum, which verifies the generation of the nanometer metal tantalum layer in the present invention .

Fig. 9 is the hardness result obtained by the nanoindentation test of the embodiment and the comparative example. The hardness of the embodiments 1 to 3 shows a very large change due to the different structure. After the nanocrystalline metal tantalum layer is added to the coating of the embodiment 1, the corresponding Compared with the pure tantalum boride coating in the comparative example, the hardness decreases, indicating that although the addition of the metal layer can increase the toughness of the coating, it is at the expense of hardness. Embodiment 2-3 is all provided with the gradient structure of nanocrystalline metal tantalum layer and the gradient structure of ceramic tantalum boride layer, test result shows that the hardness of embodiment 2-3 is all higher than embodiment 1 and comparative example, illustrates that the present invention utilizes The magnetron sputtering method can increase the hardness of the coating by controlling the sputtering time to prepare multi-layer nanocrystalline metal tantalum layers and multi-layer ceramic tantalum boride layers with different thicknesses. Among them, the hardness of Example 3 is the highest, about 36GPa, which is higher than that of the comparative example. This is because the coating gradient structure is formed in Example 3. Compared with the pure tantalum boride coating, a cermet composite multilayer coating is added. hardness.

Figure 10 is the friction test results of Example 3 and Comparative Example, it can be seen that Example 3 has a lower wear rate and stronger wear resistance than Comparative Example. Figure 11 is the indentation morphology of Comparative Example and Examples 1-3 after the 600nm continuous stiffness nano-indentation test. Compared with the Comparative Example, the ring cracks inside the indentation of the Example are less, which proves that its toughness is stronger good.

Therefore, the present invention adopts the above-mentioned tough and wear-resistant gradient cermet composite multilayer coating and its preparation method, and adjusts the nanocrystalline metal tantalum layer and ceramics at different positions by controlling the sputtering time under the magnetron sputtering method. The proportion of the tantalum boride layer has achieved the advantages of traditional metal-ceramic composite multi-layer coatings while overcoming the disadvantage of a significant decrease in hardness and improving wear resistance.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it still Modifications or equivalent replacements can be made to the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims (10)

1. A tough and wear-resistant gradient cermet composite multilayer coating, characterized in that: the coating comprises a multilayer nanocrystalline metal tantalum layer and a multilayer ceramic tantalum boride layer, and the nanocrystalline metal tantalum layer Alternately arranged with the ceramic tantalum boride layer, the thickness of the nanocrystalline metal tantalum layer is different from that of the ceramic tantalum boride layer at different positions and forms a gradient structure. 2. A kind of strong and wear-resistant gradient cermet composite multilayer coating according to claim 1, characterized in that: the total thickness of the multilayer nanocrystalline metal tantalum layer and the multilayer ceramic tantalum boride The ratio of the total thickness of the layer is 1:1. 3. A tough and wear-resistant gradient cermet composite multi-layer coating according to claim 1, characterized in that: the thickness of the nanocrystalline metal tantalum layer decreases in a continuous gradient along the coating growth direction . 4. A tough and wear-resistant gradient cermet composite multi-layer coating according to claim 3, characterized in that: the thickness of the ceramic tantalum boride layer increases in a continuous gradient along the growth direction of the coating. 5. A kind of tough and wear-resistant gradient cermet composite multilayer coating according to claim 1, characterized in that: the multilayer nanocrystalline metal tantalum layer and the multilayer ceramic tantalum boride layer are both ten floors. 6. According to the preparation method of the tough and wear-resistant gradient cermet composite multilayer coating according to any one of claims 1-5, it is characterized in that: the coating is prepared by magnetron co-sputtering technology, by controlling The sputtering time produces nanocrystalline metal tantalum layers and ceramic tantalum boride layers of different thicknesses at different locations. 7. The preparation method of the tough and wear-resistant gradient cermet composite multilayer coating according to claim 6, characterized in that: comprising the following steps: (1) Preparatory work: The targets used are tantalum targets and tantalum tetraboride targets with copper back plates, the substrates used are single-sided polished single crystal silicon, and the crystal plane orientation of the polished surface is (100); The tantalum target and the tantalum tetraboride target are installed on the target position in the horizontal direction, and the two targets are connected to a DC power supply; the substrate is cut into a suitable size and ultrasonically cleaned with absolute ethanol and acetone for 15 minutes, and then dried with nitrogen. Installed on the sample stage; Ensure that the coating chamber is clean before deposition, and wipe all the seals with an alcohol-free dust-free cloth to ensure the sealing of the coating chamber, and then use a vacuum system composed of a mechanical pump and a molecular pump to evacuate the coating chamber to keep the vacuum at 6×10 ^-4 Below Pa, and the substrate is heated to 400°C; (2) Coating operation: Introduce high-purity Ar gas into the chamber with a gas flow rate of 80 sccm, use a regulating valve to control the total pressure to 0.8 Pa, and apply a negative bias of -80 V to the substrate; Turn on the DC power supply connected to the tantalum target and the tantalum tetraboride target, and set the power to 100 W for pre-sputtering. After 5 minutes, rotate the sample stage above the tantalum target, and determine the sputtering time according to the designed thickness requirements. After the sputtering is completed, the sample stage is rotated to the top of the tantalum tetraboride target, and the above process is repeated to obtain the coating. 8. The method for preparing a tough and wear-resistant gradient metal-ceramic composite multilayer coating according to claim 7, characterized in that: the sputtering time of the tantalum target for generating the nanocrystalline metal tantalum layer in step (2) presents a continuous gradient The sputtering time of the tantalum tetraboride target to form ceramic tantalum boride layer increases continuously in a gradient. 9. The preparation method of the tough and wear-resistant gradient cermet composite multi-layer coating according to claim 8, characterized in that: in step (2), the sputtering time of each layer of the tantalum target is 3min30s, 3min10s, 2min50s, 2min30s, 2min10s, 1min50s, 1min30s, 1min10s, 50s, 30s; The sputtering time of each layer of tantalum tetraboride target is: 1min, 1min40s, 2min20s, 3min, 3min40s, 4min20s, 5min, 5min40s, 6min20s, 7min; The total sputtering time is controlled to be 1 h, and the obtained coating thickness is 2.4 μm. 10. The method for preparing a tough and wear-resistant gradient cermet composite multilayer coating according to claim 8, characterized in that: in step (2), the sputtering time of each layer of the tantalum target is 7min, 6min20s, 5min40s, 5min, 4min20s, 3min40s, 3min, 2min20s, 1min40s, 1min; The sputtering time of each layer of tantalum tetraboride target is 2min, 3min20s, 4min40s, 6min, 7min20s, 8min40s, 10min, 11min20s, 12min40s, 14min; The total sputtering time is controlled to be 2h, and the obtained coating thickness is 4.8um.

Images