JP2004169137A - Sliding member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sliding member having excellent load resistance and adhesiveness. <P>SOLUTION: The sliding member having a film on a substrate has, successively from a substrate side, a bond layer, an intermediate layer, a hard bond layer, and a hard carbon film layer on the extreme surface and is characterized in that the Vickers hardness of the intermediate layer is Hv 1,500 to 3,000, that the Vickers hardness of the hard bond layer is Hv 1,000 to 3,000, and that the Vickers hardness of the hard carbon film layer is Hv 1,000 to 5,000. Thereby the hard carbon film layer which has the excellent load resistance and adhesiveness and is applicable under high-load sliding can be provided by inclining a hardness distribution of a depth direction. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sliding member having a hard carbon coating layer.
[0002]
[Prior art]
In recent years, there has been a demand in the industrial world for miniaturization, high performance, and high efficiency of products for the purpose of reducing the burden on the environment. Above all, in a product having a sliding mechanism, there is a demand for a technology with low friction to reduce energy loss and improve performance. A hard carbon coating layer has attracted attention as a new surface modification technology that meets these requirements. The hard carbon coating layer is generally expressed as DLC (Diamond Like Carbon), amorphous carbon, or i-carbon.
The hard carbon coating layer is made of graphite having low friction characteristics and high-altitude diamond, and therefore has both characteristics. The coefficient of friction is as low as 0.05 to 0.2, and it is chemically stable to acids and alkalis. These characteristics change depending on the ratio of graphite to diamond and the hydrogen content depending on the film control method, the type of gas, and the mixing ratio. Recently, DLC for doping metal into the film, DLC for implanting ions, carbon nitride film (CxNy), and the like have been developed.
[0003]
However, since the hard carbon coating layer generally has a very high internal residual stress, it is easily cracked and peeled off, and is inferior in adhesion and resistance to overload. It is also difficult to increase the film thickness. For this reason, it has been difficult to apply the hard carbon coating layer to parts such as automobiles and compressors that slide under a high load.
[0004]
In order to solve this problem, Patent Literature 1 below discloses a technique in which one hard ceramic layer is provided between a substrate and a hard carbon coating layer.
[0005]
[Patent Document 1]
JP 2000-316800 A
[Problems to be solved by the invention]
However, in the above technique, since the hard ceramic layer is formed directly on the base material, there is a problem in adhesion between the base material and the hard ceramic layer. Further, since the hardness distribution in the depth direction is not inclined, the load resistance is not sufficient.
[0007]
It is an object of the present invention to solve the above problems and to provide a sliding member excellent in load resistance and adhesion.
[0008]
[Means for Solving the Problems]
One of the means for achieving the above object is a sliding member having a coating on a base material, wherein an intermediate layer, a hard bond layer, and a topmost hard carbon coating layer are formed from the substrate side. The Vickers hardness of the intermediate layer is Hv 1500 to 3000, the Vickers hardness of the hard bond layer is Hv 1000 to 3000, and the Vickers hardness of the hard carbon coating layer is Hv 1000 to 5000. That is, by inclining the hardness distribution in the depth direction, it is possible to provide a hard carbon coating layer which is excellent in load resistance and adhesion and can be applied under high load sliding.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
[Example 1]
FIG. 1 is a diagram showing a film structure 1 prepared according to the present invention. The film structure of FIG. 1 is a sliding member having a film on a substrate, and has a bond layer 3, an intermediate layer 4, a hard bond layer, and a hard carbon film layer on the outermost surface from the substrate side. ing. Here, the base material 2 is an alloy tool, the bond layer 3 is Cr, the intermediate layer 4 is Cn, the hard bond layer 5 is CrC, and the hard carbon coating layer 6 is DLC.
[0010]
This film forming method will be described. First, the substrate 2 was set in a film forming apparatus, and after vacuum disposal, an oxide film on the substrate surface was removed by Ar ion bombardment. Thereafter, a Cr layer was formed as the bond layer 3, a CrN was formed as the intermediate layer 4, a CrC layer was formed as the hard bond layer 5, and a DLC was formed as the hard carbon coating layer 6 in this order by sputtering. As a sputtering gas and a reactive gas at the time of forming the film structure, Ar gas was used for the Cr layer, N ₂ gas was used for the CrN layer, and CH ₄ gas was used for the CrC layer and the DLC layer. Here, the base material 2 has the same effect with steel materials such as cemented carbide, tool steel, high-speed steel, bearing steel, stainless steel, carbon steel, and Cr—Mo. Excellent in nature. The hard carbon coating layer 6, DLC doped with metal, C _x N _y even the same effect can be obtained, even film formation method ionized evaporation method, a plasma CVD method, the same effect in ion plating to obtain a gas The same effect can be obtained with C ₂ H ₂ and C ₆ H ₆ .
[0011]
The thickness of the film structure produced this time is as follows: the bond layer 3 has a Cr layer of 0.5 μm, the intermediate layer 4 has a CrN layer of 3.0 μm, the hard bond layer 5 has a CrC layer of 0.4 μm, and the hard carbon coating layer 6 has a DLC of 1.5 μm. It is. The thickness of the bond layer 3 is 0.01 μm or less, the thickness of the intermediate layer 4 is 0.5 μm or less, the thickness of the hard bond layer 5 is 0.1 μm or less, and the thickness of the hard carbon coating layer 6 is 0.1 μm or less. In the case of (1), it is difficult to use the film because the film thickness is too small to exert an effect on the improvement of the load resistance and the film thickness is difficult to control. Conversely, when the thickness of the bond layer 3 is 0.5 μm or more, the thickness of the intermediate layer 4 is 30 μm or more, the thickness of the hard bond layer is 5.0 μm or more, and the thickness of the hard carbon coating layer is 5 μm or more, Since the residual stress of each layer is increased and cracking or peeling is likely to occur, load resistance and adhesion are reduced.
[0012]
In order to examine the superiority of the film structure 1, as a comparative structure, a film structure 7, a film structure 8, a film structure 9, a film structure 10, a film structure 11, a film structure 12, and a film structure 13 were manufactured, and a comparative study was performed. went. 2 to 8 show the respective film structures.
[0013]
9 to 16 show hardness distributions of the film structure 1 of the present example and the comparative structures 7 to 13. Among these film structures, the film structures 1 and 7 have the most gradient hardness distribution, and it can be seen that the film structure has the most durable structure under high load sliding.
[0014]
FIG. 17 shows the load resistance evaluation results of the film structure 1 of this example and the comparative structures 7 to 13 by an indenter indentation test. Among these film structures, the film structures 1 and 7 have the largest indentation loads, indicating that they have excellent load resistance. This is because the higher the hardness of the layer immediately below the DLC and the more the hardness distribution in the depth direction is inclined, the better the load resistance.
[0015]
FIG. 18 shows the adhesion evaluation results of the film structure 1 of this example and the comparative structures 7 to 13 by a scratch test. Among these film structures, the film structures 1 and 7 have the largest critical load (the load at which the film has peeled), and it can be seen that the film structures 1 and 7 have the most excellent adhesion. This is because by providing Cr, which is an active metal, between the base material and CrN, or by providing CrC between CrN and DLC, a strong bond is formed at the interface between the layers and the adhesion is excellent. Another factor is that an oxide film cannot be formed between the layers by performing a continuous process in which only the gas is changed.
[0016]
FIG. 19 shows the results of evaluating the corrosion resistance of the film structures 1 and 7 to 13 by a polarization test. Among these film structures, the film structures 1 and 7 have the highest pitting corrosion potential, and it can be seen that the film structures have the highest corrosion resistance. This is because by providing CrN and CrC having high corrosion resistance on the substrate having the lowest corrosion resistance, the barrier effect of the corrosive liquid is increased.
[0017]
From the above, it can be seen that the film structure 1 is a film structure excellent in load resistance, adhesion and corrosion resistance.
[0018]
[Example 2]
Investigation was performed in the same manner as in Example 1 using the film structure 1 and using Ti for the bond layer 3.
[0019]
As a film forming method, the substrate 2 was set in a film forming apparatus, and after evacuation, an oxide film on the substrate surface was removed by Ar ion bombardment. Thereafter, a film structure was formed by a sputtering method in the order of a Ti layer as the bond layer 3, a CrN layer as the intermediate layer 4, a CrC layer as the hard bond layer 5, and a DLC as the hard carbon coating layer 6. As a sputtering gas and a reactive gas at the time of forming the film structure, an Ar gas was used for the Ti layer, an N ₂ gas was used for the CrN layer, and a CH ₄ gas was used for the CrC layer and the DLC layer.
[0020]
The thickness of the film structure manufactured this time is as follows: Ti layer 0.5 μm as the bond layer 3, CrN layer 3.0 μm as the intermediate layer 4, CrC layer 0.4 μm as the hard bond layer 5, and DLC 1.5 μm as the hard carbon coating layer 6. It is.
[0021]
Even when Ti was used for the bond layer 3, the hardness distribution was graded almost in the same manner as in Example 1, and almost the same indentation load, critical load, and pitting potential were exhibited.
[0022]
From the above, it can be seen that even when Ti is used for the bond layer 3, the film structure is excellent in load resistance, adhesion and corrosion resistance as in Example 1.
[0023]
The same comparative study was performed using W, Al, Zn, Fe, and Si for the bond layer 3. As a result, the result was almost the same as when Cr and Ti were used.
[0024]
[Example 3]
Using the film structure 1 and using the TiN for the intermediate layer 4, the same study as in Example 1 was conducted.
[0025]
As a film forming method, the substrate 2 was set in a film forming apparatus, and after evacuation, an oxide film on the substrate surface was removed by Ar ion bombardment. Thereafter, a film structure was formed by a sputtering method in the order of a Cr layer as the bond layer 3, a TiN layer as the intermediate layer 4, a CrC layer as the hard bond layer 5, and a DLC as the hard carbon coating layer 6. As a sputtering gas and a reactive gas at the time of forming the film structure, an Ar gas was used for the Ti layer, an N ₂ gas was used for the CrN layer, and a CH ₄ gas was used for the CrC layer and the DLC layer.
[0026]
The thickness of the film structure manufactured this time is as follows: a 0.5 μm Cr layer as the bond layer 3, a 3.0 μm TiN layer as the intermediate layer 4, a 0.4 μm CrC layer as the hard bond layer 5, and a 1.5 μm DLC as the hard carbon coating layer 6. It is.
[0027]
Even when TiN was used for the intermediate layer 4, the hardness distribution was graded almost similarly to Example 1, and almost the same indentation load, critical load, and pitting potential were exhibited.
[0028]
From the above, it can be seen that, even when TiN is used for the intermediate layer 4, the film structure is excellent in load resistance, adhesion and corrosion resistance as in Example 1.
[0029]
The same comparative study was performed using TiAlN, TiCN, and TiC for the intermediate layer 4. As a result, the result was almost the same as when CrN and TiN were used.
[0030]
From the above, CrN, TiN, TiAlN, TiCN, and TiC can be used for the intermediate layer 4. When TiCN or TiC is used for the intermediate layer 4, Ti is used for the bond layer 3, and when CrN is used for the intermediate layer 4, Cr can be used for the bond layer 3. Cost reduction is possible.
[0031]
[Example 4]
Investigation was performed in the same manner as in Example 1, using the film structure 1 and using TiC for the hard bond layer 5.
[0032]
As a film forming method, the substrate 2 was set in a film forming apparatus, and after evacuation, an oxide film on the substrate surface was removed by Ar ion bombardment. Thereafter, a film structure was formed by a sputtering method in the order of a Cr layer as the bond layer 3, a CrN layer as the intermediate layer 4, a TiC layer as the hard bond layer 5, and a DLC as the hard carbon coating layer 6. As a sputtering gas and a reactive gas during the formation of the film structure, an Ar gas was used for the Cr layer, an N ₂ gas was used for the CrN layer, and a CH ₄ gas was used for the TiC layer and the DLC layer.
[0033]
The thickness of the film structure produced this time is as follows: the bond layer 3 has a Cr layer of 0.5 μm, the intermediate layer 4 has a CrN layer of 3.0 μm, the hard bond layer 5 has a TiC layer of 0.3 μm, and the hard carbon coating layer 6 has a DLC of 1.5 μm. It is.
[0034]
Even when the CrC layer was used for the hard bond layer 5, the hardness distribution was inclined almost in the same manner as in Example 1, and almost the same indentation load, critical load, and pitting potential were exhibited.
[0035]
From the above, it can be seen that, even when the TiC layer is used for the hard bond layer 5, the film structure is excellent in load resistance, adhesion and corrosion resistance as in Example 1.
[0036]
Similar comparison was made using WC, AlC, FeC, and SiC for the hard bond layer 5. As a result, the result was almost the same as when CrC and TiC were used.
[0037]
Further, the same comparative study was performed using an inclined layer composed of a carbide layer and a metal layer, which can be produced by adjusting the gas amount. As a result, the result was almost the same as when CrC and TiC were used.
[0038]
From the above, as the hard bond layer 5, a gradient layer including CrC, TiC, WC, AlC, FeC, SiC, a carbide layer, and a metal layer can be used. Also, by combining with the main metal of the intermediate layer 4, the film can be formed only by changing the gas, so that the cost can be reduced.
[0039]
[Example 5]
Investigation was performed in the same manner as in Example 1 using the film structure 1 and using hard Cr for the hard bond layer 5.
[0040]
As a film forming method, the substrate 2 was set in a film forming apparatus, and after evacuation, an oxide film on the substrate surface was removed by Ar ion bombardment. Thereafter, a film structure was formed by a sputtering method in the order of a Cr layer as the bond layer 3, a CrN layer as the intermediate layer 4, a hard Cr layer as the hard bond layer 5, and a DLC as the hard carbon coating layer 6. As a sputtering gas and a reactive gas during the formation of the film structure, an Ar gas was used for the Cr layer and the hard Cr layer, an N ₂ gas was used for the CrN layer, and a CH ₄ gas was used for the DLC layer. The degree of vacuum at the time of forming the hard Cr layer was 1 Pa.
[0041]
The thickness of the film structure manufactured this time is 0.5 μm for the Cr layer as the bond layer 3, 3.0 μm for the CrN layer as the intermediate layer 4, 0.3 μm for the hard bond layer 5, and 0.3 μm for the hard bond coat layer 6. 5 μm.
[0042]
In order to examine the effect of the hard bond layer 5, a comparative study was performed with the CrC layer used in Example 1. As a result, the hardness distribution was inclined almost in the same manner as in Example 1, and almost the same indentation load, critical load, and pitting potential were exhibited.
[0043]
From the above, it can be seen that, even when the hard Cr layer is used for the hard bond layer 5, the film structure is excellent in load resistance, adhesion and corrosion resistance as in Example 1.
[0044]
The same comparative study was performed using hard Ti, W, Al, Zn, Fe, and Si for the hard bond layer 5. As a result, the result was almost the same as when CrC or hard Cr was used.
[0045]
From the above, for the hard bond layer 5, hard Cr, Ti, W, Al, Zn, Fe, and Si can be used. Also, by combining with the main metal of the intermediate layer 4, the film can be formed only by changing the gas, so that the cost can be reduced.
[0046]
[Example 6]
FIG. 20 shows a film structure 14 manufactured according to this example. The effect of the diffusion hardened layer 15 was examined using the film structure 14.
[0047]
As a film forming method, the substrate 2 was set in a film forming apparatus, and after vacuum evacuation, ion nitriding was performed at 410 ° C. × 00 h to form a diffusion hardened layer 15. Thereafter, a film structure was formed by a sputtering method in the order of a Cr layer as the bond layer 3, a CrN layer as the intermediate layer 4, a CrC layer as the hard bond layer 5, and a DLC as the hard carbon coating layer 6. As a sputtering gas and a reactive gas at the time of forming the film structure, an Ar gas was used for the Cr layer, an N ₂ gas was used for the CrN layer, and a CH ₄ gas was used for the CrC and DLC layers.
[0048]
The thickness of the film structure manufactured this time is 0.5 μm of the Cr layer as the bond layer 3, 3.0 μm of the CrN layer as the intermediate layer 4, 0.3 μm of CrC as the hard bond layer 5, and 1.5 μm of DLC as the hard carbon coating layer 6. .
[0049]
In order to examine the effect of the diffusion hardened layer 15, a comparative study was performed with the film structure 1 used in Example 1.
[0050]
FIG. 21 shows the hardness distribution. It can be seen that the hardness distribution is inclined more than the film structure 1.
[0051]
FIG. 22 shows the results of the load resistance evaluation by the indenter indentation test. Since the critical indentation load almost similar to that of the film structure 1 is shown, it is understood that the load resistance is excellent.
[0052]
FIG. 23 shows the results of the evaluation of adhesion by the scratch test. Since the critical load is almost the same as that of the film structure 1, it is understood that the adhesiveness is excellent.
[0053]
FIG. 24 shows the results of the corrosion resistance evaluation by the polarization test. Since the pitting potential is almost the same as that of the film structure 1, it is understood that the film has excellent corrosion resistance.
[0054]
From the above, it is understood that the film structure 14 on which the diffusion hardened layer 15 is formed is a film structure excellent in load resistance, adhesion, and corrosion resistance, similarly to the film structure 1.
[0055]
According to the above, a bond layer, an intermediate layer, and a hard bond layer are formed on a base material, and a hard carbon coating layer is further formed thereon, and the hardness distribution in the depth direction is graded, so that the resistance is improved. It is possible to provide a hard carbon coating layer which is excellent in loadability and adhesion and can be applied under high load sliding.
[0056]
【The invention's effect】
As described above, it is possible to provide a sliding member excellent in load resistance and adhesion.
[Brief description of the drawings]
FIG. 1 is a diagram showing a film structure 1.
FIG. 2 is a view showing a film structure 7;
FIG. 3 is a view showing a film structure 8;
FIG. 4 is a view showing a film structure 9;
FIG. 5 is a view showing a film structure 10;
FIG. 6 is a view showing a film structure 11;
FIG. 7 is a view showing a film structure 12;
FIG. 8 is a view showing a film structure 13;
FIG. 9 is a diagram showing a hardness distribution of a film structure 1;
FIG. 10 is a diagram showing a hardness distribution of a film structure 7;
FIG. 11 is a diagram showing a hardness distribution of a film structure 8;
FIG. 12 is a diagram showing a hardness distribution of a film structure 9;
FIG. 13 is a diagram showing a hardness distribution of the film structure 10;
FIG. 14 is a diagram showing a hardness distribution of a film structure 11;
FIG. 15 is a diagram showing a hardness distribution of a film structure 12;
FIG. 16 is a diagram showing a hardness distribution of a film structure 13;
FIG. 17 is a diagram showing load resistance of the film structures 1 and 7 to 13.
FIG. 18 is a diagram showing the adhesion between film structures 1 and 7 to 13.
FIG. 19 is a diagram showing the corrosion resistance of film structures 1, 7 to 13.
FIG. 20 is a view showing a film structure 14;
FIG. 21 is a diagram showing a hardness distribution of a film structure 14;
FIG. 22 is a diagram showing the load resistance of the film structures 1, 13, and 14.
FIG. 23 is a diagram showing the adhesiveness of film structures 1, 13, and 14.
FIG. 24 is a view showing the corrosion resistance of the film structures 1, 13, and 14.
[Explanation of symbols]
1, 7, 8, 9, 10, 11, 12, 13, 14 ... film structure, 2 ... base material, 3 ... bond layer, 4 ... intermediate layer, 5 ... hard bond layer, 6 ... hard carbon coating, 15 ... Diffusion hardened layer.

Claims (9)

A sliding member having a coating on a substrate,
From the substrate side, having a bond layer, an intermediate layer, a hard bond layer, and a hard carbon coating layer on the outermost surface,
The Vickers hardness of the intermediate layer is Hv 1500 to 3000,
The Vickers hardness of the hard bond layer is Hv1000-3000,
A sliding member, wherein the Vickers hardness of the hard carbon coating layer is Hv1000-5000. A sliding member having a coating on a substrate subjected to a diffusion hardening treatment,
From the substrate side, an intermediate layer, a hard bond layer, and an outermost hard carbon coating layer,
The Vickers hardness of the substrate is Hv500 to 1500,
The Vickers hardness of the intermediate layer is Hv 1500 to 3000,
A sliding member, wherein the Vickers hardness of the hard carbon coating layer is Hv1000-5000. A sliding member having a coating on a substrate,
From the substrate side, an intermediate layer, a hard bond layer, and an outermost hard carbon coating layer,
The Vickers hardness of the intermediate layer is Hv 1500 to 3000,
The Vickers hardness of the hard bond layer is Hv1000-3000,
A sliding member, wherein the Vickers hardness of the hard carbon coating layer is Hv1000-5000. The thickness of the bond layer is 0.01 μm to 0.5 μm,
The thickness of the intermediate layer is 0.5 μm to 30 μm,
The thickness of the hard bond layer is 0.1 μm to 5.0 μm,
The sliding member according to claim 1, wherein the thickness of the hard carbon coating layer is 0.1 m to 5 m. 2. The slide according to claim 1, wherein the bond layer is a metal layer made of one of Cr, Ti, W, Al, Zn, Fe, and Si, a carbide layer containing these elements, or an inclined layer made of a metal layer. Moving member. The sliding member according to any one of claims 1 to 3, wherein the intermediate layer is a layer made of CrN, TiN, TiAlN, TiCN, and TiC. 4. The hard bond layer according to claim 1, wherein the hard bond layer is a metal layer made of one of Cr, Ti, W, Al, Zn, Fe, and Si, and is formed in a vacuum of 1 Pa or less. Either sliding member. 4. The hard bond layer according to claim 1, wherein the hard bond layer is a carbide layer of Cr, Ti, W, Al, Zn, Fe, Si, and TiAl, or an inclined layer formed of the carbide layer or the metal layer. The sliding member as described in the above. The sliding member according to any one of claims 1 to 3, wherein the hard carbon coating layer is a layer made of diamond-like carbon, diamond-like carbon containing metal, and carbon nitride.

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