KR102241852B1 - Coating materials and Coating System for Members of Eco-friendly Hybride Car - Google Patents

Abstract

An objective of the present invention is to design a high functional coating material having wear resistance, high temperature corrosion resistance, low friction, lubricity, and lightweightness, which is suitable for a driving part of an eco-friendly hybrid car, and provide a coating method and a coating system thereof. Accordingly, with respect to the driving part of the car, the coating material comprises: a coating film on which Al-Sn is complexly coated; and a composite coating film comprising a NiCr layer as a base layer in order to improve adhesion of the coating material and prevent separation and precipitation of Sn.

Description

Coating materials and Coating System for Members of Eco-friendly Hybride Car}

The present invention relates to a coating material and a coating system for eco-friendly hybrid vehicle parts, and more particularly, to a coating material required for an eco-friendly hybrid vehicle component having an internal combustion engine and an electric vehicle or a hydrogen vehicle, and a coating system thereof.

Demand for a hybrid vehicle equipped with both an electric vehicle or a hydrogen vehicle and an internal combustion engine to improve fuel efficiency and eco-friendliness is steadily increasing. Compared to electric/hydrogen cars, this trend will continue until they are more cost-competitive and the charging infrastructure and charging time shortening issues are completely resolved. In the case of a hybrid vehicle, since both the internal combustion engine drive and the battery drive motor are provided, the Go-Stop operation from one drive to the other increases the wear factor due to the initial drive of the component. High-performance coatings are required for high-temperature corrosion resistance under the combustion engine driving environment, interaction with engine oil, and lightweight factors, as well as metal-metal lubrication and grease-free, non-lubricating driving environment suitability as an electric vehicle driving motor part. It is a necessary situation.

In the case of Korean Patent Application Publication No. 10-2016-0111372, anti-friction coating is applied to bearings for internal combustion engines in which a material such as barium sulfate or zinc sulfate is mixed with a binder. However, although such a coating layer reduces friction, the coating method itself is not environmentally friendly, and there is a problem that it is easy to peel off.

Accordingly, an object of the present invention is to design a highly functional coating material having abrasion resistance, high temperature corrosion resistance, low friction, lubricity and light weight suitable for an eco-friendly hybrid vehicle driving part, and to provide a coating method and a coating system according thereto.

In accordance with the above object, the present invention provides a coating film coated with Al-Sn in the final top layer configuration for automobile driving parts, and Al serves as a base material based on lightweight metal components with good toughness and impact resistance for cost reduction. Sn is composed of an alloy-added composition that adds an effect to the low lubrication properties of the coating material. In addition, the material of automobile driving parts is mostly applied as Al alloy-based or steel-based materials, and the same metal component between these parts material-coating material diffuses the Al component of the coating layer into the component material, causing wear of the coating layer of the coated part. And a problem of seizure between metal and metal due to durability problems. In order to prevent the diffusion of such component materials and coating materials, a composite consisting of a NiCr layer as an underlying layer to prevent high coating adhesion between the top layer layer and the component material interface, and to prevent the separation and diffusion precipitation of Al-Sn in the final top layer layer. Provides a coating film. When selecting a coating material that serves as such a diffusion barrier, Ni material is the most suitable considering the economical efficiency and functionality of the material cost, but in theory Ni is classified as a ferromagnetic material, making it difficult to discharge plasma due to the characteristics of the plasma source and material during the sputtering process. There is this. Considering these parts, a coating made of alloys of different types of transition metals or different types of lightweight metals that do not bond with coating films such as Cr, Ti, Cu, etc., which have strong corrosion resistance and excellent mechanical strength based on Ni, and are capable of sputtering discharge. It is a high-end packaging coating that acts as a functional coating layer using a target, that is, a buffer layer for improving adhesion, and a diffusion preventing layer that prevents separation and precipitation of Al-Sn by Al diffusion in the final coating layer.

That is, the present invention,

As a coating material applied to automobile drive parts,

It provides a coating material, characterized in that the Al-Sn is coated in combination.

In the above, it provides a coating material, characterized in that the Ni-Cr, Ni-Ti, or Ni-Cu coating film is formed as a base layer on the substrate and under the Al-Sn.

In the above, it provides a coating material, characterized in that the composition ratio of Al:Sn is 90-50: 10-50 as a weight ratio.

In the above, the base layer provides a coating material, characterized in that consisting of Ni:Cr=80-50:20-50.

About automotive drive parts,

Prepare an Al-Sn alloy target,

By performing pulse sputtering,

It provides a coating method comprising forming an Al-Sn composite coating layer.

In the above, before forming the Al-Sn composite coating layer, a Ni-Cr alloy target is prepared, and a Ni-Cr, Ni-Ti, or Ni-Cu base layer is formed by DC sputtering. do.

In the above, it provides a coating method, characterized in that the composition ratio of Al:Sn in the Al-Sn alloy target is 90-50: 10-50 as a weight ratio.

As a coating material applied to automobile driving parts, ZrO _2, SiO ₂ , Al ₂ O ₃ , Zr _a O _x Si _b O _y , Al _a O _x Si _b O _y , or Zr _a O _x Al _b O _y Si _c It provides a metal-based nanocomposite oxide coating material containing _{O z.}

As a coating material applied to a driving part of an automobile, ZiSi, ZiSiN, and ZiSiO ₂ are sequentially laminated on a substrate.

According to the present invention, due to the high functional coating that combines the ductility, toughness, impact resistance, and light weight of Al and the low friction of Sn, the driving parts of eco-friendly hybrid vehicles have low friction characteristics with a friction coefficient of around 0.1 and near 0.3 um. Showed a low wear depth.

Due to the NiCr diffusion barrier layer, it does not precipitate even if the ratio of Al is increased, and if the Sn composition is increased, the surface roughness can be lowered, thereby improving low friction and lubricity.

1 is a schematic diagram of an eco-friendly hybrid vehicle driving unit and a driving member.
2 is a cross-sectional view showing the configuration of a coating layer formed on a driving member according to the present invention.
3 is a graph of output and sputtering voltage versus applied voltage frequency showing sputtering test results for forming a coating layer according to the coating layer design of the present invention.
4 is a photograph showing target erosion as a result of DC sputtering and pulse sputtering for the coating layer forming process of the present invention.
5 is a photograph showing the surface of the coating layer as a result of DC sputtering and pulse sputtering for the coating layer forming process of the present invention.
6 is a table showing changes in the composition of Al and Sn and coating process conditions in the coating layer according to the present invention.
7 is a photograph showing an erosion state of a target after pulse sputtering according to a composition change of Al and Sn.
8 is a photograph of samples coated by pulse sputtering according to changes in the composition of Al and Sn.
9 is a photograph of the surface analysis of samples coated by pulse sputtering according to changes in the composition of Al and Sn.
10 is a graph of the surface roughness of the coated surfaces of samples according to the composition change of Al and Sn.
11 is a result of surface mapping analysis (EDX) of the coated surfaces of samples according to the composition change of Al and Sn.
12 shows the coating thickness of the samples.
13 to 17 show coating line scanning analysis of samples.
18 shows the micro Vickers hardness of the samples.
19 is a result of evaluating the friction characteristics of samples.
20 to 24 show the evaluation results of the wear characteristics of the samples.
25 and 26 show the depth of wear of the samples.
27 is a cross-sectional view of the configuration of a multilayer coating film as a modified embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of an eco-friendly hybrid vehicle driving unit and a driving member.

Since it is equipped with both an existing internal combustion engine and a battery-driven drive unit, there is a characteristic that the initial drive wear factor increases according to the drive switching. Such driving members include bearings, piston pins, piston rings, worm wheel gears, and the like.

Accordingly, the present invention designed a coating layer having a structure as shown in FIG. 2 having low friction and high hardness characteristics and having adhesion as a coating material capable of improving the abrasion resistance of the driving members as described above.

The coating layer shown in FIG. 2 is an Al-Sn composite coating material and has all of the ductility, toughness, impact resistance, and light weight of Al and the low friction properties of Sn. In addition, such an Al-Sn composite coating material was strongly adhered to the substrate and a NiCr underlayer was formed so as not to cause a problem of precipitation of Sn. As a weight ratio of the Al-Sn composite coating material of the surface layer, Al:Sn=90-50:10-50 can be used. The thickness of the coating layer may be 1 to 2 um of the Al-Sn composite coating layer, and 0.5 to 1.5 um of the underlying layer.

The method of forming the coating layer as described above should be selected in consideration of material properties.

In the present invention, the coating material itself was formed as a target to form a coating layer by sputtering.

3 is a graph of output and sputtering voltage versus applied voltage frequency showing sputtering test results for forming a coating layer according to the coating layer design of the present invention.

With DC power, when Sn exceeds the weight ratio of 50, there is a problem that sputtering discharge does not occur in the target itself. Therefore, sputtering is performed using a pulse voltage. The optimal pulse voltage is a frequency of 150KHz to 350KHz, a voltage of 350 to 390V, and the duty time is set to 1 to 2us.

FIG. 4 is a photograph showing target erosion as a result of DC sputtering and pulse sputtering for the coating layer forming process of the present invention, and FIG. 5 is a photograph showing the surface of the coating layer as a result of DC sputtering and pulse sputtering for the coating layer forming process of the present invention.

As a result of DC sputtering in the above, it can be seen that the target erosion site is formed unevenly, and macroparticles of 2 μm or more are formed even in the surface roughness of the coating layer of the sample. This is achieved by crystal growth of Al. On the other hand, in pulse sputtering, the erosion of the target was uniform, the coating layer also showed a dense structure, and Al particles were formed with less than 1 μm. Therefore, it is preferable to perform the formation of the coating layer by pulse sputtering.

6 is a table showing changes in the composition of Al and Sn and coating process conditions in the coating layer according to the present invention.

Before the coating layer is formed, pre-cleaning treatment is performed with an ion gun, and the underlying layer may be Ni:Cr=80-50:20-50. In the case of this example, a diffusion layer having a composition of NiCr (80:20) was formed, and deposition was performed for about 60 minutes at 10A condition using DC Power. This underlayer prevents the precipitation of Sn and strengthens the adhesion of the Al-Sn composite coating layer.

7 is a photograph showing an erosion state of a target after pulse sputtering according to a composition change of Al and Sn.

In the case of pure Al and pure Sn, the target erosion becomes non-uniform, and in the case of Sn, a molten part appears. According to this, it can be seen that the content of Sn is preferably 10 to 50% by weight.

8 is a photograph of samples coated by pulse sputtering according to the composition change of Al and Sn, and the surface can be observed with the naked eye. Surface structure analysis was conducted to confirm the more reliable coating surface condition.

9 is a photograph of the surface analysis of samples coated by pulse sputtering according to the composition change of Al and Sn, and FIG. 10 is a graph of the surface roughness of the coated surfaces of the samples according to the composition change of Al and Sn.

It can be seen that the higher the Sn composition ratio, the lower the surface roughness. The surface roughness of the sample is 0.31 to 0.40um.

11 is a result of surface mapping analysis (EDX) of the coated surfaces of samples according to the composition change of Al and Sn, and FIG. 12 shows the coating thickness of the samples.

The thickness of the coating layer obtained by coating the targets having each composition for the same period of time is different as shown in FIG. 12. It can be seen that the yield of the alloy target is slightly higher.

13 to 17 show coating line scanning analysis of samples.

18 shows the micro Vickers hardness of the samples.

Here, in the case of a pure Sn target, the target melting phenomenon occurs after discharging, so it is difficult to say that it is accurate data. In general, as the Sn content increases, the micro-Vickers hardness decreases, showing 100 to 260 Hv. As a result, it can be seen that the AlSn composite coating material has some degree of excellent hardness.

19 is a result of evaluating the friction characteristics of samples.

The coating material of AlSn (80:20) exhibited a lower coefficient of friction than pure Al and pure Sn, and exhibited a coefficient of friction of less than 0.1 (near 0.08), indicating excellent low friction characteristics.

20 to 24 show the evaluation results of the wear characteristics of the samples.

Here, it can be seen that the coating material wear characteristics of AlSn (80:20) and AlSn (50:50) are excellent.

25 and 26 show the depth of wear of the samples.

The wear depth was also lower in AlSn composites than in pure Al and pure Sn.

As described above, by applying the AlSn composite coating material to the eco-friendly hybrid driving member, it is possible to obtain wear resistance and low friction, thereby obtaining life and stability.

Although the above embodiment was made for a bearing, it is not limited thereto and may be implemented on various driving members.

In addition, metal-based or alloy-based nanocomposite oxides, that is, ZrO _2, SiO ₂ , Al ₂ O ₃ , Zr _a O _x Si _b O _y , Al _a O _x Si _b O _y , Zr _a O _x Al _b O _y Si _{Metal-based nanocomposite oxide coating materials such as c} O _z can also be applied by a sputtering process that supplies oxygen to an alloy target or a pure metal target. By forming a thin film thickness of tens or hundreds of nanometers, it is possible to overcome brittleness and improve low friction and wear resistance in an engine oil environment, grease or non-lubricating environment such as a drive shaft of an electric vehicle motor. In addition, in the case of a coating film using an alloying target that forms an oxide such as Si rather than a single metal target, an amorphous metal nanocomposite oxide can be formed, so that the brittleness of the ceramic coating layer against impact can be compensated for dozens or hundreds. It is also possible to form a thick film rather than a nano-thick metal composite oxide layer.

Recently, engine parts of nanocomposite nitride ZrCuSiN coating material applied parts are being applied as a new technology using ZrCuSi-based alloyed coating targets, but due to the influence of Cu, heat resistance and corrosion resistance are insufficient, and low friction in engine parts applied with existing CrN coating. It is reported that there is no significant difference in characteristics. Considering these characteristics, there is a limit to application to next-generation high-power-based eco-friendly combustion engines or electric drive parts. Therefore, in the case of the metal-based nanocomposite oxide coating material mentioned above, the high hardness and low strength of the ceramic structure by supplementing brittleness. It is possible to apply a multifunctional coating film that is based on frictional properties and has added high-temperature stability, heat resistance, and oxidation resistance.

In addition, the formation of a nanocomposite coating film of a metal-based oxide using reactive sputtering having a base layer using a metal or alloy target may be composed of multiple layers to improve durability. In other words, as an underlying layer on the first component material, 0.5um to 2.0um buffer layer is deposited through pure sputtering with the same coating target composition, and in the second step, a metal nanocomposite nitride layer that serves as a buffer layer for buffering and impact resistance and reinforcement using the same target. Formation of 1.0um~3.0um in the final layer, multifunctional high-temperature wear resistance using a metal or alloy target, and application of a metal nanocomposite multi-coating layer by depositing a coating film within 50nm~1000nm of the low-friction metal nanocomposite oxide layer is also possible. .

In the above, the alloy may be manufactured by a casting or sintering method, and the target of this embodiment is manufactured by a sintering method.

In the case of sintering, a coating target can be manufactured by sintering general sintering or alloying powder (atomizing method).

The rights of the present invention are not limited to the embodiments described above, but are described in the claims.

It is defined by what has been defined, and it is apparent that a person of ordinary skill in the field of the present invention can make various modifications and adaptations within the scope of the rights described in the claims.

Claims (9)

delete delete delete delete About automotive drive parts,
Prepare an Al-Sn alloy target and a Ni-Cr alloy target,
DC sputtering was performed on the Ni-Cr alloy target to form a Ni-Cr base layer,
Pulse sputtering is performed on the Al-Sn alloy target to form an Al-Sn composite coating layer on the Ni-Cr underlayer,
In the Ni-Cr alloy target, the composition ratio of Ni:Cr is a weight ratio, and Ni:Cr=80-50: 20-50,
The composition ratio of Al:Sn in the Al-Sn alloy target is 90-50:10-50 as a weight ratio,
The coating method, characterized in that the formation of the Al-Sn composite coating layer is performed by performing pulse sputtering using a pulse voltage of a frequency of 150KHz to 350KHz.











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