KR20190089657A - Method for manufacturing titanium alloys nano-composite coating - Google Patents

Abstract

The present invention relates to a method for manufacturing a titanium alloy nano-composite coating layer of a Ti-rich composition range with high hardness, low frictional resistance, and excellent adherence to a parent metal. According to the present invention, the method for manufacturing a titanium alloy nano-composite coating layer includes: a step of inputting and mounting the parent metal in a sputtering device; and a step of forming a coating layer having a Ti-Cu-Ni-Si-N five-element system ingredient on the surface of the parent material by sputtering a target while inputting nitrogen, reaction gas including nitrogen, and reaction gas including silicone (Si) into the sputtering device. The coating layer is a nano-composite fine structure including a nano-crystal including an amorphous base including Si and having Ti as a main ingredient and a TiN ingredient dispersed in the base. Therefore, the method for manufacturing a titanium alloy nano-composite coating layer can manufacture the coating layer with excellent adhesiveness and a high ratio of H/E (hardness/elasticity modulus) in the various parent metals.

Description

METHOD FOR MANUFACTURING TITANIUM ALLOYS NANO-COMPOSITE COATING BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a manufacturing method for forming a nanocomposite coating film having a Ti rich composition range having a high adhesion to a base material, a low friction resistance and a high hardness.

Driving parts or sliding parts of various mechanical devices including an automobile engine and the like are required to have excellent lubrication characteristics due to relative motion between the parts.

Also, household appliances such as air conditioners and refrigerators generally include mechanical devices such as compressors. Such a compressor utilizes a principle of applying mechanical energy to a fluid by compressing the fluid, so that reciprocating motion or rotational motion is essential for compressing the fluid.

In general, to improve friction in compressors, first use a separate mechanical component, such as a gas bearing, to reduce friction resistance. Further, a coating film is formed to reduce the frictional resistance of the bearing.

The solid coating film for reducing friction must also have a certain degree of hardness in addition to friction characteristics and high adhesion to the base material. As a material capable of satisfying such characteristics, a lubrite film, a nitride material of a carbide type, a diamond like carbon (DLC) material, or the like is used.

However, most of the conventional solid coating film components have technical limitations in that they are used in compact and high-speed compressors.

For example, since the lubricant coating layer is soft coated with the solid lubricant components to be used together, there is a problem that the abrasion resistance is poor or the environmental problem is caused in the case of molybdenum disulfide.

On the other hand, ceramic-based coatings have very high surface hardness, which is advantageous for wear resistance, but most of them have a high elastic modulus of about 400 to 700 MPa. Such high modulus of elasticity of the ceramic material differs greatly from the elastic modulus of the other metal parts on which the ceramic or the ceramic coating layer of the metallic material coated with the ceramic material is rubbed, It can cause problems in durability.

If a component having an interface at which the friction occurs is resiliently absorbed by stress that may occur during the reciprocating motion of the piston, friction and wear can be reduced, and the dimensional stability of the component can be remarkably improved. Furthermore, as the elastic strain of the component increases, it increases the fracture toughness of the component. Improved fracture toughness can dramatically improve the reliability of parts. However, the ceramic material has a disadvantage of low elastic strain.

On the other hand, in the case of DLC, an improvement in abrasion loss compared to the conventional Lubrite coating has been reported, but the affinity with the additive of the oil used in the compressor is insufficient, so there is a limit to improvement in characteristics at low speed operation.

Therefore, the conventional solid coating film or parts can be substituted. In particular, a demand for a new solid coating film having a small elastic modulus and high hardness and elastic deformation ability is increasing.

A related prior art is Korean Patent Laid-Open Publication No. 10-2014-0145219, which discloses a Zr-based amorphous alloy composition having amorphous forming ability.

It is an object of the present invention to provide a method of manufacturing a coating film having new components and microstructures through sputtering in order to improve friction characteristics and abrasion resistance in various mechanical devices and components such as air conditioners and compressors of air conditioners such as refrigerators .

Particularly, the present invention provides a method for producing a coating film having excellent adhesion to a base material and excellent abrasion resistance (ratio of hardness / elastic modulus) in a nanocomposite coating film containing an amorphous matrix having a high hardness and a Ti-rich composition .

According to one aspect of the present invention, there is provided a method of manufacturing a sputtering apparatus, comprising: injecting and mounting a base material into a sputtering apparatus; A reaction gas containing nitrogen or nitrogen and a reaction gas containing silicon are introduced into the sputtering apparatus to form a coating film of a Ti-Cu-Ni-Si-N quaternary component on the surface of the base material by sputtering the target Wherein the coating film is a nanocomposite microstructure including a nanocrystal including an amorphous matrix containing Si as a main component and a TiN component dispersed in the matrix; And a method for producing the coating film.

Preferably, the matrix has a composition of atomic% (hereinafter referred to as%), Ti: 59.2 to 80%, Cu: 4.6 to 20%, Ni: 4.6 to 25%, Si: 9% A method for producing a coating film, which is characterized in that

Preferably, the base material is steel, cast iron or an aluminum alloy; And a method for producing the coating film.

The coating layer may further include a buffer layer between the aluminum alloy base material and the coating layer.

On the other hand, the base material is steel or cast iron; In the step of forming the coating film, the flow rate of nitrogen is 10 to 55 sccm.

Alternatively, the base material is steel or cast iron; In the step of forming the coating film, the acceleration voltage is 0 to 120 V. A method of manufacturing a coating film may be provided.

Alternatively, the base material is an aluminum alloy; In the step of forming the coating film, the flow rate of HMDSO is 15 sccm or less.

Alternatively, the base material is an aluminum alloy; In the step of forming the coating film, the acceleration voltage is 0 to 120 V. A method of manufacturing a coating film may be provided.

According to the present invention, a nanocomposite coating film of Ti-Cu-Ni-Si-N is stably formed through reactive sputtering in which a target is sputtered while introducing a reaction gas containing nitrogen and a reaction gas containing silicon .

Particularly, the present invention can produce a coating film having excellent adhesion to a base material and excellent wear resistance by producing a nanocomposite coating film of an amorphous base using a target having a high hardness and a Ti-rich composition.

Specifically, in the method for producing a coating film of the present invention, the inclusion of silicon as a reactive gas through reactive sputtering to a Ti-Cu-Ni ternary target having a Ti-rich composition improves the hardness of the amorphous matrix of the nanocomposite microstructure, have.

In addition, in the method for producing a coating film of the present invention, Ti-rich Ti-Cu-Ni ternary target is reactively sputtered to contain nitrogen as a reactive gas to form TiN as a reinforcing phase in the nanocomposite microstructure to increase the hardness of the coating film .

Furthermore, the method of the present invention for producing a coating film can provide a process condition capable of forming a coating film having high H / E value and high adhesion even in base materials of various compositions, thereby maximizing the abrasion resistance, durability and adhesion of the coating film Can be established.

1 is a conceptual view for explaining a coating film of the present invention having an amorphous structure and a nanocrystal structure.
2 is a stress-strain curve diagram comparing an amorphous metal with a metal nitride and a crystalline metal.
FIG. 3 shows a Ti-Cu-Ni ternary Gibbs triangle showing a composition region irradiated with an amorphous forming ability in the present invention.
FIG. 4 shows X-ray diffraction (XRD) patterns of a Ti 65% -Cu 15% -Ni 20% ternary alloy near the composition E 5 of FIG.
FIG. 5 shows an XRD pattern in which the amorphous forming ability of a Ti-Cu-Ni ternary alloy containing 70% of Ti is investigated.
FIG. 6 shows an XRD pattern in which the amorphous forming ability of a Ti-Cu-Ni-Si quaternary alloy containing 70% of Ti is investigated.
FIG. 7 shows an XRD pattern in which the amorphous forming ability of a Ti-Cu-Ni ternary alloy containing 75% of Ti is investigated.
8 shows an XRD pattern in which amorphous forming ability of a Ti-Cu-Ni-Si quaternary alloy containing 75% of Ti is investigated.
FIG. 9 shows an XRD pattern in which the amorphous forming ability of a Ti-Cu-Ni-Si quaternary alloy containing 80% of Ti is investigated.
FIG. 10 summarizes the amorphous forming ability in the entire irradiated composition range of a Ti-Cu-Ni-Si quaternary alloy.
11 shows changes in the hardness (H), elastic modulus (E) and H / E value of the coating film depending on the flow rate of nitrogen (N ₂ ) and the acceleration voltage (bias).
FIG. 12 shows changes in adhesion and H / E value of the coating film with changes in power and acceleration bias.
FIG. 13 shows changes in the adhesion of the coating film and the H / E value according to the flow rate of nitrogen (N ₂ ) and the flow rate of silicon (HMDSO).
14 shows cross-sectional microstructures and XRD patterns of a coating film prepared by reactive sputtering using a nitrogen (N ₂ ) gas and a silicon (HMDSO) gas using a target of the reference composition and spheroidal graphite cast iron as the base material.
15 shows the cross-sectional microstructure and XRD pattern of a coating film prepared by a reactive sputtering method using a nitrogen (N ₂ ) gas and a silicon (HMDSO) gas with a target of a reference composition and an aluminum alloy as a base material.

Hereinafter, a method of manufacturing a coating film according to a preferred embodiment of the present invention will be described in detail with reference to the drawings attached hereto.

It is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to inform.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification. Further, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, the terms first, second, A, B, (a), (b), and the like can be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening "or that each component may be" connected, "" coupled, "or " connected" through other components.

The present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, 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. As shown in FIG.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, in which a Ti-rich amorphous alloy containing Si and a nanocomposite-containing nanocomposite-containing microstructure coating film, a method of forming the nanocomposite- The sputtering method will be described in detail.

Most solid materials are aggregates of microcrystals. In the three-dimensional space, each atom has a long range translational periodicity and is located in a defined crystal lattice. Alternatively, the liquid material has a disordered structure that lacks translational periodicity due to thermal vibrations.

In the dictionary sense, and in terms of atomic structure, amorphous metals have no long-range order patterns, which are typical atomic structures of crystalline alloys, and exist in a disordered state with a liquid structure In terms of solids, it is a concept that contrasts with crystalline alloys.

In the present invention, the term amorphous refers generally to an amorphous structure in which the general concept of the amorphous structure is a microstructure and the XRD pattern is a diffuse halo. And has a known amorphous phase characteristic.

Furthermore, in the present invention, the term amorphous refers not only to the case where the composition of the composition is 100% amorphous, but also to the case where the amorphous state exists in the main phase and does not lose the property of the amorphous state, . Specifically, some intermetallic compounds are present in the amorphous structure, or some silicides are present.

Particularly, in the present invention, a microstructure of a nano-composite, which is distinguished from the amorphous structure, is specifically defined. The nanocomposite in the present invention refers to a microstructure that contains amorphous as defined above as a base and additionally contains nano-sized crystal grains intentionally in the matrix and / or composition range desired. Here, the nano-sized crystal means a crystal grain having an average size of nano-sized crystal grains (when it is several hundreds nm or less).

Since the amorphous or nanocomposite microstructure in the present invention includes amorphous as a main component, the amorphous forming ability is a substantially very important factor.

In general, the glass forming ability (GFA) indicates how easily an alloy of a specific composition can be amorphized. The ability to form amorphous metals and / or alloys depends largely on their composition, which can form amorphous from a continuous-cooling transformation diagram or a time-temperature-transformation diagram The critical cooling rate (hereinafter referred to as " Rc ") can be directly calculated. However, in reality, it is not easy to obtain Rc by experiments or calculations because the physical properties such as melt viscosity and latent heat of fusion are different depending on the composition of each alloy.

In order to form amorphous alloys through the most common and common method of casting, a higher cooling rate above a certain level of Rc is required. If a casting method in which the solidification rate is relatively slow (for example, a mold casting method) is used, the composition range of the amorphous formation is reduced. Alternatively, the rapid solidification method, such as melt spinning, in which a molten alloy is dropped on a rotating copper roll to solidify the alloy with a ribbon or wire rod, is usually carried out using a maximized cooling rate of 10 ⁴ to 10 ⁶ K / sec or more An amorphous ribbon having a thickness of several tens of micrometers can be obtained, thereby widening the composition range capable of forming amorphous. Therefore, the evaluation of the degree of amorphous formability of a particular composition is generally characterized by a relative value depending on the cooling rate of a given cooling process.

In consideration of the relative characteristics of amorphous forming ability, the alloy having amorphous forming ability in the present invention means an alloy capable of obtaining an amorphous ribbon when casting using a melt spinning method.

The coating film of the present invention can be applied to various mechanical parts, for example, a compressor, more specifically, a coating film formed at a friction portion of a compressor including a gas bearing, and / or an inner ring. The coating film and the coating layer in the present invention can improve durability, low friction characteristics, wear resistance, and tame characteristics of various mechanical parts due to the nanocomposite microstructure according to the present invention.

1 is a conceptual diagram for explaining a nanocomposite or coating film of the present invention.

The coating film according to the present invention shown in Fig. 1 shows an example where the coating film is formed on the friction portion between the rotating shaft and the bearing. 1 shows a nanocomposite coating film 20 and a base material 11 on which the coating film 20 is formed. The base material 11 on which the coating film 20 is coated may comprise any material that can be used as a structural material. However, metal is more preferable than other materials because rapid cooling due to inherent high thermal conductivity of the metal is possible, which can promote the amorphous formation of the coating film 20.

2 is a stress-strain curve of an amorphous metal, a metal nitride, and a crystalline metal.

Here stress refers to resistance to deformation in the material when an external force is applied to the material. Strain rate refers to the ratio of deformation to material and the original length of material. The slope in the stress-strain curve corresponds to the modulus of elasticity.

In general, the durability (reliability against abrasion resistance) of the coating film can be evaluated by the ratio (H / E) between the hardness (H) and the elastic modulus (E). The relatively large value of the ratio of hardness to elastic modulus means that the coating film has a high durability and is therefore unlikely to be peeled or broken.

If the interfacial elastic properties (or mechanical properties) between the base material 11 and the coating film 20 are not similar, the coating film 20 may easily peel off from the base material 11 due to the influence of residual stress during deformation, . The similar inverse elastic properties mean that the difference in elastic modulus between the base material 11 and the coating film 20 is large.

Conventional coating materials generally have a high modulus of elasticity due to the high hardness ceramic phase. Accordingly, even though the conventional coating materials have a large elastic modulus difference with the base material 11 even when the soft crystalline phase is precipitated, they show low interfacial stability even when the initial coating performance is excellent. As a result, conventional coating materials are easily peeled or destroyed from the base material 11 and thus have insufficient sustainability. The occurrence of peeling or fracture of the coating film 20 means that the durability (reliability against abrasion resistance) of the coating film 20 is low.

In general, metal nitrides have very high hardness. However, the metal nitride has a high modulus of elasticity, as can be seen from the slope of the graph shown in Fig. Also, the metal nitride has a low elastic deformation limit of 0.5% or less. Therefore, if a metal nitride is used as a base, the metal nitride can form a hard coating layer due to a relatively high hardness, but it is difficult to secure durability due to a high elastic modulus.

On the other hand, the crystalline metal has a very low modulus of elasticity, as can be seen from the slope of the graph shown in Fig. The crystalline metal has a low elastic deformation limit of 0.5% or less like the metal nitride. The elastic deformation limit of the crystalline metal is so small that a plastic deformation typically occurs from a strain of 0.2% or more (0.2% Offset yield strain). Further, the hardness of the crystalline metal has a much lower hardness than the metal nitride. As a result, the crystalline metal has a low modulus of elasticity to some extent to ensure the durability of the coating film, but it is difficult to form a hard coating film due to its relatively low hardness.

As can be seen from the above results of the metal nitride and the crystalline metal, the higher the hardness, the higher the elastic modulus tends to be. On the contrary, when the elastic modulus is lowered, the hardness also tends to be lowered. Therefore, it is very difficult to simultaneously improve the ratio of hardness and modulus of elasticity. This means that it is difficult to ensure the durability of the hard coating film by high hardness and low elastic modulus.

However, the present invention can achieve high hardness and low elastic modulus through the microstructure of nanocomposite including amorphous and metal nitride nanocrystals.

The hardness of the amorphous metal is lower than that of the metal nitride, but has a higher hardness than the crystalline metal. Referring to FIG. 2, the modulus of elasticity of the amorphous metal is much lower than that of the crystalline metal or metal nitride. In addition, since the elastic deformation limit of amorphous metal is 1.5% or more, amorphous metal exhibits a wide elastic limit and serves as a buffer between the coating film and the friction material. Therefore, unlike the general tendency in the metal materials described above, the amorphous metal has a high hardness, a low elastic modulus and a large elastic deformation limit.

On the other hand, the metal nitride may be used very effectively as a reinforcing phase other than the main phase to achieve high hardness. For example, in the case of a composite in which a metal nitride is present in a reinforcing phase in a matrix having a relatively low elastic modulus such as a crystalline metal or an amorphous material, a metal nitride having a high hardness and a high hardness is used for ensuring durability There is a possibility that both hardness and durability can be secured.

Accordingly, the nanocomposite microstructure including the metal nitride in the amorphous metal matrix formed according to the manufacturing method of the present invention has a hardness and a modulus of elasticity (the ratio of hardness and modulus of elasticity) to the microstructure of the conventional crystalline metal or metal nitride, H / E) has a large value.

As a result, the nanocomposite coating film using amorphous metal and metal nitride has an advantage of not only abrasion resistance caused by amorphous hardness but also reliability (durability).

On the other hand, even in the same amorphous microstructure, the hardness of the coating film changes depending on the component and / or composition range. For example, in the case of Ti-alloy, especially Ti-Cu-Ni ternary amorphous alloy, it is known that the Ti rich composition region having the highest Ti content has the highest hardness. This is because the higher the content of Ti, the easier it is for Ti to form an intermetallic compound or a silicide which is advantageous for realizing other alloying elements and ultrahigh hardness characteristics.

On the other hand, the Ti rich composition region has a higher melting point than the Ti lean composition range due to the high Ti content, so that it is difficult to have the amorphous forming ability. Thus, the crystalline base of β Ti is obtained mainly by the melt spinning method. In the ternary amorphous alloy of Ti-Cu-Ni, it is practically very important to improve the amorphous forming ability in the Ti rich composition region.

Therefore, the present invention has invented a method for producing a coating film capable of maintaining amorphous forming ability at a base and having high hardness and low elastic modulus at a wide composition range of Ti-rich.

More specifically, based on a Ti-Cu-Ni ternary alloy, a quaternary alloy containing Si, which is an alloying element, is designed to improve the amorphous forming ability of the base in the Ti rich composition region.

Next, by forming a microstructure containing (5-element) nanocrystals containing a TiN component finely dispersed in an amorphous matrix having an alloy composition containing Si added thereto, the elastic modulus is not greatly increased, Thereby producing a composite coating film.

FIG. 3 shows a Ti-Cu-Ni ternary Gibbs triangle showing a composition region irradiated with an amorphous forming ability in the present invention. As shown in Fig. 3, the ternary alloy has two ternary process points in the composition range; One is the Ti 73.2% -Ni 17.7% -Cu 9.1% process point named E4 and the other is the Ti 65.1% -Ni 21.8% -Cu 12.9% process point named E5. In the present invention, the Ti-Cu-Ni- (Si) ternary system and the quaternary alloy (Ti) in a wide range from the compositional range (Ti lean) lower in Ti content than the E5 composition to the Ti rich than the E4, Were investigated.

As the term eutectic indicates, the process point is the temperature at which the liquid phase can be maintained at the lowest temperature in any alloy system. As a result, the composition near the process point corresponds to a composition that can exist at the lowest temperature of the liquid phase in terms of thermodynamics, and in addition, undercooling occurs in nucleation in terms of kinetics, Cu-Ni ternary alloy is the most advantageous composition that can secure amorphous forming ability.

Of course, there is an additional processing point in the Ti-Cu-Ni ternary alloy. However, in the present invention, in addition to the effect of low elastic modulus (E) through the amorphous alloy, Ti rich Area alloy.

Figure 4 shows the XRD results of a Ti 65% -Cu 15% -Ni 20% ternary alloy near the E 5 composition. FIG. 4 shows a typical diffraction halo form, which is a typical XRD pattern of amorphous phases, indicating that almost all of the microstructure of the ternary alloy of the above composition is amorphous.

5 and 6 are XRD results of investigating the amorphous forming ability of Ti-Cu-Ni ternary alloy and Ti-Cu-Ni-Si ternary alloy each containing 70% Ti.

First, in a composition region where the content of Cu + Ni in the Ti-Cu-Ni ternary alloy is 30%, the content of Cu is 20 to 10% and the content of Ni is 10 to 20%, the main phase is amorphous. (Fig. 5). Furthermore, when the Ni content in the composition range is increased from 10% to 20%, weak diffraction peaks on Ti ₂ Ni are observed in the XRD results. This means that the Ti-Cu 10% -Ni 20% ternary alloy has a complex microstructure in which the Ti ₂ Ni phase coexists within the amorphous matrix.

On the other hand, a Ti-Cu-Ni-Si quaternary alloy containing 3% Si added to the Ti-Cu-Ni ternary alloy has a Cu + Ni content of 30%, a Cu content of 20 to 10% and a Ni content of 10 To 20% in the composition range (FIG. 6). However, in the Ti-10% Cu-20% Ni ternary alloy, a part of the microstructure has a Ti ₂ Ni phase, which is a crystalline phase, whereas (Ti-Cu 10% -Ni 20%) ₉₇ Si ₃ 4 It can be seen from FIG. 6 that only the nearly pure amorphous phase is formed which does not substantially contain the crystalline Ti ₂ Ni phase. These results directly indicate that the addition of 3% Si greatly improves the amorphous formability of the Ti-Cu-Ni-Si quaternary alloy.

7 and 8 are XRD results of investigating the amorphous forming ability of Ti-Cu-Ni ternary alloy and Ti-Cu-Ni-Si ternary alloy each containing 75% Ti.

First, in the Ti-Cu-Ni ternary alloy, it was confirmed that there was no amorphous forming ability in the irradiated ternary system total composition region where Ti was 75% (FIG. 7). This means that the T-Cu-Ni ternary alloy system in which Ti is contained more than the E4 composition substantially lacks amorphous forming ability.

However, in the T-Cu-Ni-Si quaternary alloy system in which 5% of Si is contained in the Ti-Cu-Ni ternary alloy system, unlike the ternary system, the content of Cu + Ni is 25% (Composition satisfying Ti + Cu + Ni = 95%) in a wide composition range of 5 to 15% and a Ni content of 10 to 20% (FIG. 8). It was also found that the quaternary alloy exists only in a substantially pure amorphous phase substantially free of an intermetallic compound or a silicide.

9 is an XRD result of examining the amorphous forming ability of a Ti-Cu-Ni-Si quaternary alloy containing 80% of Ti.

As a result of experiments conducted by the inventors of the present invention, it was confirmed that the T-Cu-Ni ternary alloy system to which Ti was added in an amount of 80% or more had no amorphous forming ability in the entire irradiated composition range. However, in the T-Cu-Ni-Si quaternary alloy system containing 7% of Si, unlike the ternary system, the content of Cu + Ni is 20%, the content of Cu is 5 to 10% and the content of Ni is 10 To 25% (in which Ti + Cu + Ni = 93%). It was also found that this quaternary alloy also exists only in a substantially pure amorphous phase substantially containing no intermetallic compound or silicide.

FIG. 10 summarizes the amorphous forming ability of the Ti-Cu-Ni-Si quaternary alloy tested in the whole composition range irradiated. First, in FIG. 10, the XRD pattern experiment results show that the composition region on the dotted arrow extending from the lower left to the upper right has amorphous forming ability, and furthermore, microstructure is formed almost entirely of amorphous. On the other hand, the XRD pattern results show that the shaded composition region on the left side of the arrow has amorphous ability to form and the main phase is amorphous and contains some intermetallic compounds in terms of microstructure. On the other hand, the shaded composition region on the right side of the arrow has an amorphous forming ability, and in the microstructure side, a composition region containing amorphous phase and containing some silicide in the main phase.

From the above experimental results, Ti-Cu-Ni-X 4 having a composition range of 59.2 to 80% of Ti, 4.6 to 20% of Cu, 4.6 to 25% of Ni and 9% It was confirmed that the amorphous formability of the alloy was stable.

On the other hand, the nanocomposite microstructure of the present invention includes a metal nitride of nanocrystals, more specifically, TiN as a reinforcing phase in addition to amorphous.

At this time, the TiN nanocrystals as reinforcements can be formed in various ways. For example, a physical chemical vapor deposition method such as sputtering, a chemical vapor deposition method, or the like can be used.

The addition of Si as an alloying element in the Ti amorphous matrix containing Si in the present invention can also be externally added through the gas phase. More specifically, it may be provided in the form of a volatile organosilicon compound such as HMDSO (hexamethyldisiloxane, O [Si (CH ₃ ) ₃ ] ₂ ) in a physical chemical vapor deposition method or a chemical vapor deposition method.

In general, in order to deposit a nonconductor such as TiN on a substrate by a sputtering method, a high frequency RF (radio frequency) sputtering should first be used. Such an RF method is more expensive than the DC sputtering used for sputtering a conductor such as a metal, and it is also difficult to make the non-conductor target itself necessary for deposition and it is disadvantageous in that it is expensive. In addition, in the present invention, since the base Ti amorphous alloy uses DC sputtering, it is disadvantageous to use another RF sputtering process.

Thus, if Si can be deposited in a Ti amorphous matrix using DC sputtering and the TiN nanocrystals can be deposited with a base Ti amorphous alloy, the productivity in the process can be increased and furthermore, the nanocomposite microstructure is more advantageous, As a result, the characteristics of the coating film can also be improved. Such a method is reactive sputtering.

In addition, the Ti amorphous alloy containing Si as the coating film base of the present invention can be deposited by reactive sputtering, and furthermore, the TiN nanocrystals as reinforcement of the present invention must be dispersed in the matrix rather than being coated on the matrix It is more preferable to use reactive sputtering for the TiN nanocrystals as the reinforcing material of the present invention.

Reactive sputtering is a sputtering method in which a gas of a desired component required for a reaction is added in a DC sputtering system. For example, oxygen is added to the deposition of the oxide, and a reaction gas (e.g., NH ₃ ) containing nitrogen or nitrogen is added to deposit the nitride, and the target metal reacts with the reactive gas to form a desired component and / A nitride film, a carbonized film, or a mixed composition thereof. In addition, Si may be added to a coating formed by introducing a gas containing Si (for example, HMDSO gas) into the reactive gas.

The constituent stoichiometric ratio of the film formed at this time can be mainly controlled by the amount of the reactive gas. More specifically, a mass flow controller (MFC) is usually installed in each line of the reactive gas of a sputtering deposition apparatus, and the desired components and / or composition range can be controlled by controlling the MFC.

Hereinafter, specific embodiments of the present invention will be described with reference to examples.

< Example >

In the method for producing a coating film of the present invention, a coating film is formed by sputtering after preparing an alloy having a composition of Ti: 72%, Cu: 12% and Ni: 16% as a reference composition.

In the present invention, a Ti-Cu-Ni ternary alloy having a composition as shown in the above-mentioned amorphous forming ability is dissolved by vacuum arc melting, and then an amorphous alloy in the form of a ribbon or a foil is obtained by melt spinning. Then, the sputtering target having a crystalline quality was obtained by stacking a plurality of the above-mentioned ribbons, and then heat-pressing at a temperature higher than the crystallization start temperature in the composition of the ribbons and lower than the melting temperature.

On the other hand, a crystalline sputtering target can also be produced by using an amorphous alloy powder having a Ti-Cu-Ni- (Mo) ternary or quaternary alloy composition of the present invention. In this case, a crystalline sputtering target can be produced by bonding aggregates of amorphous alloy powders produced by atomization or the like by high-temperature sintering or high-temperature sintering. In this case, the sintering temperature is higher than the crystallization start temperature in the composition of the alloy powder and is lower than the melting temperature.

As a specific sputtering condition, a coating film was formed by sputtering while changing process conditions in an Ar atmosphere or in a mixed gas atmosphere of Ar, HMDSO, and N ₂ .

On the other hand, CrN was used as a buffer layer on the base material of the spheroidal graphite cast iron or 4000 series aluminum alloy used as the substrate.

Of course, the substrate (in other words, the base material) in the present invention is not necessarily limited thereto. For example, in addition to special castings such as spheroidal graphite cast iron, metals based on Fe, such as ordinary steel or ordinary cast iron (eg GC100), high grade cast iron (eg GC250) and alloy cast iron are all available Do. Aluminum alloys can be applied to 2000 series to 9000 series as well as 4000 series.

In general, the buffer layer is used to perform the function of improving the adhesion force between the coating film and the base material, performing the function of relaxing the stress between the base material and the coating film, or improving other surface characteristics. However, the present invention does not necessarily include a buffer layer, nor does the buffer layer in the present invention necessarily perform the above-mentioned functions.

Table 1 shows the relationship between the acceleration voltage bias, the flow rate of nitrogen (N ₂ ), and the flow rate of nitrogen (N ₂ ) using a target of a reference composition of Ti: 72%, Cu: 12% and Ni: The evaluation of the mechanical properties of the coating film according to the flow rate of HMDSO is summarized.

At this time, the adhesion of the coating film was measured using a JLST022 tester according to ISO 20502 (adhesion of coating layer using a scratch test) using a scratch tester. On the other hand, the hardness and elastic modulus were measured using an HM2000 tester from FISCHERSCOPE according to ISO 14577 (Instrumentation Indentation Test Method for Metal and Nonmetal Coating) using a nanoindenter.

<Table 1> Mechanical properties according to sputtering conditions

11 is a graph showing the influence of nitrogen (N ₂ ) flow rate and acceleration voltage on the experimental results of Table 1.

First, the results of 1 to 3 of Table 1 and FIG. 11 show the results of evaluation of the mechanical properties of a composite of a TiCuNiN 4 -type Ti alloy according to the flow rate of nitrogen (N ₂ ). As the injection amount of nitrogen increases, the hardness and the elastic modulus do not increase or decrease simply, but the injection amount of nitrogen shows the maximum value at the middle value. Therefore, in the case of the coating film production method of the present invention, it can be seen that there is a maximum value of hardness (H), elastic modulus (E) and H / E in the range of nitrogen injection amount of 40 to 55 sccm.

On the other hand, adhesion did not increase or decrease simply according to the amount of nitrogen injected, nor showed maximum value. However, it has been investigated that it has a good adhesion force so that it can be used normally in a range of 10 N or more in the total amount of nitrogen injected.

Next, the results of 4 to 7 in Table 1 and FIG. 11 show the mechanical properties of the nano-composite of the TiCuNiN quaternary Ti alloy according to the change of the accelerating voltage.

It can be seen that as the acceleration voltage increases, the hardness and elastic modulus do not simply increase or decrease, but show the maximum value at the mid range acceleration voltage. However, the acceleration voltage range having the maximum value of the hardness (H) and the elastic modulus (E) is slightly different from the acceleration voltage range having the maximum value of H / E. However, since the most important factor in determining the actual wear resistance or durability of the coating film is the value of H / E, it can be seen that a maximum value of H / E exists in the acceleration voltage range of about 95 to 115 V.

On the other hand, adhesion was measured to have a tendency to simply decrease with increasing acceleration voltage. However, according to the present invention, as the acceleration voltage is changed, it has been found that the adhesion force is as high as 10 N or more in the range of 95 to 115 V which is the maximum value of H / E.

Results 8 to 10 of Table 1 show the mechanical properties of the TiCuNiSi quaternary Ti alloy nanocomposite composite according to the silicon (HMDSO) flow rate. As a result, the hardness (H), elastic modulus (E) and H / E value of the coating film were steadily decreased as the injection amount of HMDSO increased. Therefore, the optimal composition for Si was determined to be 10 sccm of HMDSO.

Next, Table 2 shows the relationship between the acceleration voltage and the power of the coating film using a target having a reference composition of Ti: 72%, Cu: 12% and Ni: 16%, a 4007 aluminum substrate and a CrN buffer layer. And the evaluation of mechanical properties is summarized.

<Table 2> Mechanical properties according to sputtering conditions

On the other hand, FIG. 12 shows the adhesion and the H / E value according to the change of power with respect to the acceleration voltage based on the experimental results of Table 2 above.

Based on the H / E characteristics that determine the abrasion resistance and durability of the coating film, a region having a maximum value at a power of 3 kW having the highest power was observed first.

On the other hand, as the substrate was changed to Al material, the adhesion was decreased compared with the previous spheroidal graphite cast iron. Adhesion was also shown to be the highest at 3kW, which is the highest power, and it was found that the adhesion tends to converge constantly as the acceleration voltage increases at 3kW power condition.

Therefore, in the case of the coating film production method of the present invention, when the substrate is Al, the H / E characteristics are maximized at an acceleration voltage of 10 to 60 V and the adhesion is also saturated.

Next, Table 3 shows the results of measurement of a reactive gas (nitrogen gas) at a constant acceleration voltage and power at a constant acceleration voltage and a bias voltage using a target with a reference composition of Ti: 72%, Cu: 12%, Ni: The evaluation of the mechanical properties of the coating film according to the present invention is summarized.

<Table 3> Mechanical properties according to sputtering conditions

On the other hand, FIG. 13 shows the adhesion and the H / E value according to the change of the flow rate of HMDSO with respect to the acceleration voltage based on the experimental results of Table 3 above.

Based on the H / E characteristics, which determine the abrasion resistance and durability of the coating film, the flow rate of nitrogen (N ₂ ) is the highest when the flow rate of nitrogen is 10 sccm regardless of the flow rate of HMDSO, H / E &lt; / RTI &gt; value.

On the other hand, as the substrate was changed to Al material, the adhesion was decreased compared with the previous spheroidal graphite cast iron. In the case of adhesion, the coating film having the highest nitrogen flow rate of 10 sccm was observed to have the highest adhesion.

In addition, the H / E value and the adhesion according to the flow rate of silicon (HDMSO) are not simply increased or decreased as the flow rate of silicon increases, but have a maximum value at the flow rate of the middle range silicon. Especially, in the range of the flow rate of silicon of 2 to 8 sccm, both the H / E value and the adhesion were found to have a maximum value.

14 and 15 are graphs showing the results of a reactive sputtering process using an HDMSO gas and a nitrogen gas using a spherical graphite cast iron and a 4007 Al alloy as targets, respectively, with a target having a reference composition of 72% Ti, 12% Cu, and 16% Sectional photographs of microstructures and XRD results of a coating film prepared by the method of the present invention.

As shown in FIGS. 14 and 15, it can be seen that a uniform and dense coating film is formed regardless of the type of the substrate. In addition, some peaks were observed in the XRD pattern. These peaks were found to be mostly diffraction peaks formed by TiN, and diffraction peaks due to the substrate were partially observed in Al alloy substrates. From the result of the microstructure and XRD pattern of the coating film and the result of the XRD pattern of the TiCuNiSi alloy, the coating film of the present invention is a nano-composite containing a nanocrystal of a TiN component in a TiCuNiSi amorphous alloy matrix, . &Lt; / RTI &gt;

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the invention is not limited to the disclosed exemplary embodiments. It is obvious that a transformation can be made. Although the embodiments of the present invention have been described in detail above, the effects of the present invention are not explicitly described and described, but it is needless to say that the effects that can be predicted by the configurations should also be recognized.

Claims (7)

Injecting and mounting a base material into a sputtering apparatus;
A reaction gas containing nitrogen or nitrogen and a reaction gas containing silicon are introduced into the sputtering apparatus to form a coating film of a Ti-Cu-Ni-Si-N quaternary component on the surface of the base material by sputtering the target Comprising:
Wherein the coating film is a nanocomposite microstructure including a nanocrystal including an amorphous base containing Si as a main component and a TiN component dispersed in the matrix;
&Lt; / RTI &gt; The method according to claim 1,
The base material may be steel, cast iron or aluminum alloy;
&Lt; / RTI &gt; 3. The method of claim 2,
Further comprising a buffer layer between the aluminum alloy base material and the coating film;
&Lt; / RTI &gt; 3. The method of claim 2,
The base material is steel or cast iron;
In the step of forming the coating film, the flow rate of nitrogen is 10 to 55 sccm;
&Lt; / RTI &gt; 3. The method of claim 2,
The base material is steel or cast iron;
In the step of forming the coating film, the acceleration voltage is 0 to 120 V;
&Lt; / RTI &gt; 3. The method of claim 2,
The base material is an aluminum alloy;
In the step of forming the coating film, the flow rate of HMDSO is not more than 15 sccm;
&Lt; / RTI &gt; 3. The method of claim 2,
The base material is an aluminum alloy;
In the step of forming the coating film, the acceleration voltage is 0 to 120 V;
&Lt; / RTI &gt;

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