KR20140141767A - Hardness Coating Layer and Method for Manufacturing the Same - Google Patents

Abstract

In the present invention, a SiAlN layer and a TiAlN layer are sequentially coated on the substrate by using a TiAl target as a cathode arc source and an Si target as a sputtering source in one vacuum container while rotating the substrate while rotating the substrate There is provided a method of manufacturing a composite hard coating layer which forms a multi-layered TiAlSiN multi-component nitride.

Description

Technical Field [0001] The present invention relates to a hard coating layer and a method of manufacturing the same,

The present invention relates to a hard film formed by a physical vapor deposition and formed by a nanostructure and a manufacturing method thereof. More particularly, the present invention relates to a method of manufacturing a hard film having a nanostructure by using sputtering, which is one of physical vapor deposition methods, And a method for producing such a hard coating.

The hard film has high hardness and excellent abrasion resistance and is used as a functional coating material for improving the service tool life.

The most widely used material for the hard film is nitride, which is a nitride of a transition metal. One of these representative nitrided electro-metals is titanium nitride (TiN), which is most commonly used for tools.

Although TiN has excellent physical properties, it has a disadvantage that its performance drops sharply when the temperature rises according to the use environment, so that nitrides containing aluminum or the like having excellent oxidation resistance at high temperature are attracting attention.

Further, in order to improve the hardness and abrasion resistance of the nitride, nanostructures are formed when three or more materials are used. It has been reported that the nanostructure improves hardness and abrasion resistance.

There are several conditions for producing a hard film of nanostructures, the important condition being that at least one of the three materials should be immiscible with the other two materials.

When a material that is not mixed with each other is used, the coating layer forms a small grain structure during the production of the coating layer, thereby exhibiting nanostructure.

Copper (Cu), nickel (Ni), yttrium (Y) and silicon (Si) are used for the formation of the nano structure (Reference: Thin Solid Films 476 (2005) 1-29, Surface & Coatings Technology 207 (2012) 50-65).

A sputtering method and a cathodic arc source method are often used to fabricate a hard film of a nanostructure, and chemical vapor deposition may be used.

In order to nitride the transition metal, it is necessary to ionize the nitrogen gas to perform the reaction, and therefore, a highly reactive source is used.

Sputtering uses a relatively reactive unbalanced magnetron source. It is common to use only one of two sources (see Materials Science and Engineering A 502 (2009) 139-143), but if you use more than one source (see Surface & Coatings Technology 205 -586, Thin Solid Films 518 (2010) S34-S37).

The hard film of the nanostructure shows excellent hardness compared to the existing nitride, and the hardness may be improved up to 2 times or more.

However, such a nanocomposite hard coating is required not only for hardness but also for wear resistance and oxidation resistance, so that coating layers capable of replacing existing nitrides are required.

The present invention provides a method for producing a hard coating by simultaneously using sputtering and a cathode arc source. The present invention provides a method of manufacturing a hard coating, .

The nanostructured hard coating layer provided in this manner can form a coating layer having better oxidation resistance than the conventional nitride coating.

According to an aspect of the present invention, there is provided a method of manufacturing a composite hard coating layer,

In one vacuum container, a TiAl target is used as a cathode arc source, an Si target is used as a sputtering source, a SiN layer and a TiAlN layer are sequentially coated on the substrate while rotating the substrate, thereby forming a multilayered TiAlSiN A method for producing a multi-component nitride is provided.

Also, in one embodiment of the present invention, the sputtering source preferably uses one of a balanced and an unbalanced magnetron sputtering source.

The substrate used in the method of manufacturing a composite hard coating layer according to an embodiment of the present invention is preferably a silicon wafer or a stainless steel cemented carbide.

The thickness of each layer in the multi-layer structure is preferably 1 to 5 nm, and the coating layer of the TiAlSiN multi-component nitride preferably has a diameter of 1 to 10 nm .

The TiAlSiN hard coat layer produced by the method of the present invention has excellent oxidation resistance.

The TiAlSiN hard coating layer thus prepared has a technical effect of increasing the oxidation resistance of the coating layer by increasing the content of silicon.

Also, the TiAlSiN hard coat layer thus produced has a technical effect that the hardness becomes maximum when the silicon content and the TiAlN crystal grain size are constant.

1 is a conceptual view of an apparatus for manufacturing a hard coating layer by a composite process used in an embodiment of the present invention.
FIG. 2 is a scanning electron microscope (SEM) image of a hard coating layer prepared according to an embodiment of the present invention, which shows a change in the size of the hard coating layer grains and a change in texture of the coating layer according to the content of silicon.
FIG. 3 is a graph showing XRD results of a hard coating layer prepared according to an embodiment of the present invention.
4 is a transmission electron microscope photograph of a specimen 3 prepared according to an embodiment of the present invention.
FIG. 5 is a graph showing the hardness of a hard coating layer prepared according to an embodiment of the present invention.
FIG. 6 is a graph showing the results of evaluating the oxidation resistance of the hard coat layer according to the content of silicon in the hard coat layer prepared according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. However, it should be understood that the present invention is not limited to the disclosed embodiments, but can be implemented in various forms, and that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The hard coating layer according to an embodiment of the present invention uses a composite source to produce a nitride thin film, and the hard coating layer, for example, TiAlSiN multi-nitride is coated on various substrates. In this case, it is preferable to use a TiAl target for the cathode arc source and an Si target for the sputtering source, while simultaneously using the cathode arc source and the sputtering source in one vacuum container.

The substrate provided in the vacuum chamber is coated while being rotated, and a SiN layer and a TiAlN layer are sequentially coated on the substrate to form a multi-layered TiAlSiN multi-nitride structure.

The sputtering source used in this case is preferably one of a balanced and an unbalanced magnetron sputtering source.

Further, the rotating speed of the substrate rotated in the vacuum container is preferably 0.1 to 10 rpm.

And the thickness of each layer in the multi-layer structure of the coated TiAlSiN multi-layer nitride is preferably 1 to 5 nm.

It is also preferable that the diameter of the crystal grains in the coated TiAlSiN multi-component nitride coating layer is 1 to 10 nm.

Hereinafter, a composite process manufacturing apparatus for forming a TiAlSiN multi-material nitride coating layer will be described.

1 is a conceptual view of an apparatus for manufacturing a hard coating layer by a composite process used in an embodiment of the present invention.

An apparatus for manufacturing a hard coating layer such as a TiAlSiN multi-component nitride according to an embodiment of the present invention includes a cathode arc source (003) and a sputter source (004) mounted on both sides of a vacuum vessel (001) A rotatable substrate holder 007 is provided inside the container 001.

Two substrate holders 007 may be provided symmetrically in the vacuum chamber 001. A substrate 008 may be detachably installed at the center of each substrate holder 007 and two substrate holders 007 May be provided with a substrate rotating device 006 capable of rotating the substrate holder 007 while supporting the substrate holder 007 thereon.

 The substrate rotating device 006 is provided with driving means, for example, an electric motor, which is rotatably coupled to one side of either the upper portion or the lower portion of the vacuum cleaner. It is controlled by the power supply.

A gas injection port 002 and a gas exhaust port 005 are provided at one side of the upper and lower sides of the vacuum container 001 in the central portion of the vacuum container 001, So that the inside of the vacuum chamber 001 can be controlled by the atmospheric gas.

A TiAl target metal is mounted on the cathode arc source 003 provided on the side of the vacuum vessel 001 and a Si target metal is mounted on the sputtering source 004 to manufacture the TiAlSiN multi-element nitride.

As a substrate to be mounted on the center of the substrate holder 008, a silicon wafer or a stainless steel cemented carbide may be used.

In addition, when the power is supplied to the power supply to operate the motor, the gear-coupled substrate rotating device 006 rotates at a given speed.

Hereinafter, one embodiment for manufacturing a TiAlSiN multi-component hard nitride coating layer using the above-described composite processing apparatus will be described in detail.

A TiAl target metal is mounted on the cathode arc source 003 and a sputtering source 004 is coated on the sputtering source 004 to form a silicon wafer (Si wafer) on the substrate holder 008 as a substrate 008 and to coat TiAlSiN multi- Si target metal.

The diameter of the Si target metal used was 152.4 mm and the diameter of the TiAl target metal was 120 mm.

In the vacuum vessel (001), an inert atmosphere was maintained by injecting a mixed gas of Ar and N ₂ , and the Si content of the TiAlSiN coating layer was controlled by controlling the intensity of power applied to the sputtering source.

The substrate used here was stainless steel and tungsten carbide in addition to the silicon wafer. The silicon wafer substrate was evaluated by scanning electron microscope and X-ray diffraction characteristics of the TiAlSiN coating layer coated on the substrate, a stainless steel substrate was used to evaluate the oxidation resistance of the TiAlSiN coating layer coated on the substrate and a tungsten carbide substrate was used to evaluate the mechanical properties such as hardness of the TiAlSiN coating layer coated on the substrate.

The substrates were ultrasonically cleaned with alcohol and acetone and mounted on vacuum coating equipment. The vacuum vessel was evacuated to ~ 10 ^-6 torr. The inside of the vacuum chamber was evacuated to a vacuum state, and a mixed gas of Ar and N ₂ was injected into the vacuum chamber to reach a vacuum of 1 × 10 ^-2 torr.

Then, a current of 70 A was applied to the cathode arc source, and a DC voltage of about -1,000 V was applied to the substrate holder 007 to clean the surface of the specimen.

In the course of cleaning the specimen, the oxide on the surface of the substrate is removed, and at the same time, the TiAlN coating layer is formed first, thereby improving the adhesion of the subsequently formed TiAlSiN coating layer.

After the sample was cleaned, a TiAlSiN coating layer was prepared by supplying power to the sputtering source. The substrate was cleaned and the coating layer was prepared while rotating the substrate holder at 3 rpm.

As described above, the Si content of the TiAlSiN coating layer was controlled by controlling the current applied to the sputtering source equipped with the Si target.

The content of each component of the TiAlSiN coating layer coated on the silicon wafer substrate by the above method is shown in Table 1 below.

                                                             (unit: at %) division Psalm 1 Psalm 2 Psalm 3 Psalm 4 Psalm 5 Psalm 6 Psalm 7 Ti 32 25.2 24.9 22.8 21.3 18.2 15 Al 18 17.2 16.8 14.4 14.3 12.1 9 N 50 55.3 55.1 58.3 59.2 63.1 65 Si 0 2.3 3.2 4.5 5.2 6.6 11 Sum 100 100 100 100 100 100 100

The change in Si content in the TiAlSiN coating layer in Table 1 is a change depending on the current applied to the sputtering source.

As shown in Table 1, when the Si content is increased, the content of Ti and Al decreases and the content of nitrogen (N) increases. These results show that the content of Ti and Al is decreased when the Si content is increased in the known TiAlSiN coating layer, but the nitrogen content is not maintained as it is.

The microstructure and texture of the TiAlSiN coating layer coated on the following silicon wafer substrate were analyzed by a scanning electron microscope, and the result is shown in FIG.

As shown in FIG. 2, when the Si content is increased, the coating layer structure becomes dense.

Next, X-ray diffraction analysis was performed to evaluate the crystallinity and grain size of the TiAlSiN coating layer on the TiAlSiN coating layer coated on the silicon wafer substrate, and the results are shown in FIG.

As can be seen from FIG. 3, the TiAlN coating layer can confirm the formation of TiAlN grains. As the Si content increases, the intensity of the TiAlN peak decreases and the full width at half maximum increases.

When the Si content is increased to 5 at% or more, the peak indicating TiAlN crystal grains is reduced to an undetectable level.

Further, as shown in FIG. 2, when the grain size is calculated based on the TiAlN (220) peak, it can be confirmed that the grain size decreases as the Si content increases.

The grain size of the TiAlN coating layer not containing Si is 14 nm or more, and when the Si content is increased to 5 at% or more, the grain size is about 2 nm.

In the section where the Si content is 2 to 5 at%, the crystal grain diameter of the coating layer is kept constant at about 5.5 nm.

As a result that the grain size of TiAlN existing in the coating layer is decreased by the increase of the Si content, it is judged that the coating layer prepared in this embodiment forms a nanostructure.

This fact can be confirmed by the transmission electron microscopic analysis of the coating layer. A transmission electron microscope photograph of the specimen 3, which is one of the results, is shown in FIG.

As can be seen from FIG. 4, it can be confirmed that crystal grains having a size of several nm are formed.

In order to confirm the hardness of the following coating layer, the hardness was evaluated using a Vickers hardness meter of a TiAlSiN coating layer coated on a tungsten carbide substrate, and the results are shown in FIG.

As can be seen from FIG. 5, it can be seen that as the Si content increases, the hardness increases and has a maximum hardness at about 5 at%.

When the Si content is increased to 5 at% or more, a phenomenon that the hardness is lowered can be observed.

Next, the oxidation resistance of the TiAlSiN coating layer coated on the stainless steel substrate was evaluated using an atmospheric furnace. The results are shown in FIG.

FIG. 6 shows the evaluation results of the oxidation resistance of the TiAlN and TiAlSiN coating layers.

As can be seen from FIG. 6, in the case of specimen 1 containing no Si, the weight of the coated specimen increased at a temperature of 600 ° C or higher, and the coating layer was peeled off at 900 ° C or higher.

However, as shown in Specimen 6 and Specimen 7, in the case of the Si-containing coating layer, the oxidation resistance was improved when the Si content was increased, and the weight of the coated specimen did not increase even if the temperature was higher than 1,000 ° C., Was confirmed to be good.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand.

001: Vacuum container 002: Gas inlet
003: cathode arc source 004: sputtering source
005: exhaust port 006: substrate rotating device
007: substrate holder 008: substrate
009: Power supply 010: Heater

Claims (6)

A SiAlN layer and a TiAlN layer are successively coated on the substrate while rotating the substrate while using a TiAl target as a cathode arc source and an Si target as a sputtering source in one vacuum container, TiAlSiN multi-component nitride. The method according to claim 1,
Wherein the sputtering source is one of a balanced and an unbalanced magnetron sputtering source. 3. The method according to claim 1 or 2,
Wherein the substrate is any one of a silicon wafer (Si wafer) and a stainless steel cemented carbide (Tungsten Carbide). The method of claim 3,
Wherein the rotating speed of the substrate is 0.1 to 10 rpm. 5. The method of claim 4,
Wherein the thickness of each layer in the multi-layer structure is 1 to 5 nm. 6. The method of claim 5,
Wherein the diameter of the crystal grains in the coating layer of the TiAlSiN multi-component nitride is 1 to 10 nm.

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