JP2011173244A - Lamination film covering member and method of producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lamination film covering member which is excellent in wear resistance and adhesion property, improves sliding characteristics to reduce attacking properties to a counter member, and prevents the damage of a substrate even in a severe environment, and also to provide a method of producing the lamination film covering member at a low cost. <P>SOLUTION: A plurality of chromium films 2 and a plurality of nitrogen-containing chromium films 3 are alternately and continuously formed in this order on the substrate 1 and, thereafter, a film 4 made of solid lubricant is formed on the outermost surface of the nitrogen-containing chromium films 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a laminated film-coated member and a method for producing the same, and more particularly to a member having a nitrogen-containing chromium film formed as a hard film on a substrate and a method for producing the same.

  Conventionally, nitrogen-containing chromium is produced by physical vapor deposition such as sputtering on the surfaces of sliding parts and machine parts such as automobiles that require wear resistance and seizure resistance, as well as dies used under high surface pressure. A method of forming a film to improve wear resistance and seizure resistance is known (see, for example, Patent Document 1). In addition, a diamond-like carbon lower layer film is formed by a PVD method on a sliding surface of a sliding part such as an automobile, and then a diamond-like carbon upper layer film is formed by a CVD method. A method of forming a diamond-like carbon film having a low thickness has also been proposed (see, for example, Patent Document 2).

JP 11-217666 A (paragraph number 0008-0010) JP 2009-167512 A (paragraph number 0014-0019)

  However, in the conventional method, the surface-treated film is used as a hard film that satisfies all of the wear resistance, adhesion, and sliding characteristics required for the surfaces of sliding parts such as automobiles, machine parts, and dies. It is difficult to form with a simple system, and in order to maximize its capability as a hard coating, it is essential to reinforce the substrate on which the hard coating is formed and to adjust the surface shape of the substrate. It was.

  In addition, the nitrogen-containing chromium film described in Patent Document 1 and the like has an amorphous structure, and thus is chemically stable and excellent in wear resistance and adhesion, but is a hard film. There is a problem of damage to the base material (base material) at the time of destruction of the hard coating in a severe environment.

  In addition, the diamond-like carbon film described in Patent Document 2 has high durability and a low coefficient of friction, but there are problems of adhesion to the base material and damage to the base material when the film is broken. The manufacturing process is complicated and the manufacturing cost is high.

  Therefore, in view of such a conventional problem, the present invention is excellent in wear resistance and adhesion, can improve the sliding characteristics and can reduce the aggression to the mating member, in a harsh environment Another object of the present invention is to provide a multilayer coating member and a method for producing the multilayer coating member at a low cost, which can prevent damage to the substrate.

  As a result of diligent research to solve the above problems, the present inventors formed a nitrogen-containing chromium film on a base material via a chromium film, and formed a film made of a solid lubricant on the nitrogen-containing chromium film. By doing so, it is excellent in wear resistance and adhesion, can improve the sliding characteristics and reduce the aggressiveness to the mating member, can prevent damage to the substrate even in harsh environments, The present inventors have found that a laminated film-coated member can be produced at a low cost and have completed the present invention.

  That is, the laminated film covering member according to the present invention is characterized in that a nitrogen-containing chromium film is formed on a substrate via a chromium film, and a film made of a solid lubricant is formed on the nitrogen-containing chromium film. . In addition, the laminated coating member according to the present invention is characterized in that a plurality of chromium coatings and a plurality of nitrogen-containing chromium coatings are formed on a substrate, and a coating made of a solid lubricant is formed on the outermost surface. In these laminated film-coated members, the fixed lubricant is preferably made of a fluororesin, more preferably polytetrafluoroethylene.

  Also, the method for producing a laminated coating member according to the present invention comprises forming a nitrogen-containing chromium coating on a substrate via a chromium coating, and then applying a solid lubricant on the nitrogen-containing chromium coating and firing. A film comprising a solid lubricant is formed on the nitrogen-containing chromium film. Moreover, the manufacturing method of the laminated film coating | coated member by this invention forms a several chromium film | membrane and several nitrogen-containing chromium film | membrane alternately on a base material in this order, Then, a solid lubricant is apply | coated to an outermost surface, and it bakes. Thus, a film made of a solid lubricant is formed on the outermost surface. In these production methods for laminated film-coated members, the nitrogen-containing chromium film is preferably formed by sputtering in an atmosphere containing argon gas and nitrogen gas using a chromium target. Moreover, it is preferable that a chromium film | membrane is formed by sputtering in argon gas atmosphere using a chromium target. The fixed lubricant is preferably made of a fluorine-based resin, and more preferably made of polytetrafluoroethylene.

  In the present specification, the “nitrogen-containing chromium film” refers to a film in which at least one of nitrogen and chromium nitride is dispersed in the chromium film.

  According to the present invention, it is excellent in wear resistance and adhesion, can improve sliding characteristics and can reduce the attack on the mating member, and can prevent damage to the substrate even in harsh environments The laminated film covering member that can be produced can be manufactured at low cost. This hard film covering member can be used for molds, machine parts, automobile parts and the like.

It is sectional drawing which shows the structure of embodiment of the laminated film coating | coated member by this invention. It is the schematic of the processing apparatus for manufacturing embodiment of the laminated film coating | coated member by this invention. It is the schematic of the high-speed Falex friction abrasion tester used in the Example.

  Embodiments of a laminated film covering member and a method for manufacturing the same according to the present invention will be described below in detail with reference to the accompanying drawings.

  As shown in FIG. 1, an embodiment of a laminated film covering member according to the present invention includes a base material 1, a chromium film (as a stress relaxation layer) and a nitrogen-containing chromium (as a hard layer) on the base material 1. A plurality of chromium films 2 and a plurality of nitrogen-containing chromium films 3 formed so that the films are alternately arranged in this order, and a film 4 made of a solid lubricant formed on the outermost nitrogen-containing chromium film. I have.

  Thus, by forming a film (layer of low friction coefficient) made of a solid lubricant such as a fluororesin on a nitrogen-containing chromium film (hard layer with high mechanical strength), wear resistance and adhesion It is possible to improve the sliding characteristics and reduce the aggressiveness to the mating member, and it is possible to produce a laminated film coated member coated with a film that prevents damage to the base material even in a harsh environment .

  In other words, by forming a hard, high-strength nitrogen-containing chromium film on the substrate, and forming a low-friction coefficient film made of a solid lubricant such as fluororesin on it, it is resistant to wear. And manufacturing a laminated coating member that has excellent adhesion, can improve the sliding characteristics, can reduce the attack on the mating member, and can prevent damage to the substrate even in harsh environments Can do.

  As the fluororesin, it is preferable to use polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), tetrafluoroethylene (TFE) or the like.

  In order to improve the wear resistance, high-temperature oxidation resistance, alkali resistance and releasability of the laminated film covering member, the total thickness of the plurality of nitrogen-containing chromium films is preferably 1 to 30 μm. 1 to 20 μm is more preferable, and 1 to 15 μm is most preferable. In addition, the total thickness of the plurality of chromium films is preferably 0.01 to 10 μm, and more preferably 0.1 to 5 μm.

  The plurality of chromium films and the plurality of nitrogen-containing chromium films can be continuously formed in a processing chamber of a sputtering apparatus using a chromium target. That is, when forming a chromium film as an underlayer, an argon gas atmosphere is formed in the processing chamber, and when forming a nitrogen-containing chromium film, the processing chamber is set to an atmosphere containing argon gas and nitrogen gas, A chromium film and a plurality of nitrogen-containing chromium films can be formed continuously.

  Since this sputtering can be performed by the DC magnetron sputtering method, the film can be formed at a temperature lower than the tempering temperature (about 300 ° C.) of the steel material used as the base material, so that the softening and thermal strain of the steel material are suppressed. It is also more productive than other physical vapor depositions. In addition, in this sputtering, since a lump (droplet) in which the material of the film is melted does not occur as in the case of film formation by an ion plating method, a film having a smooth surface can be formed. Further, since this sputtering forms a chromium film and a nitrogen-containing chromium film, an intermediate layer of other materials can be eliminated, so that a single target is used in a conventional sputtering apparatus to enter the processing chamber. A plurality of chromium films and a plurality of nitrogen-containing chromium films can be formed by switching ON / OFF of introducing nitrogen gas. For this reason, crack propagation is prevented at the interface between the chromium film as the stress relaxation layer and the nitrogen-containing chromium film as the hard layer, and stress is relaxed by the stress relaxation layer while ensuring high hardness and excellent adhesion. The nitrogen-containing chromium film | membrane which has can be obtained. Further, since sputtering can be performed with a constant bias voltage, it is possible to prevent the film from cracking and to prevent the hardness from being lowered even if the stress relaxation layer is sandwiched.

  The embodiment of the laminated film covering member according to the present invention can be manufactured using, for example, the processing apparatus 10 shown in FIG. The processing apparatus 10 includes a vacuum processing chamber 12, a vacuum pump 14 for reducing the pressure in the vacuum processing chamber 12 to form a vacuum, and a rotary table 16 disposed at the center of the bottom of the vacuum processing chamber 12. A substrate 20 as a member to be processed placed on the turntable 16 via a jig 18; a target 22 as an evaporation source disposed so as to surround the substrate 20; and these targets 22 A DC sputtering power source 24 connected to each of these, a DC ion bombard and bias power source 26 connected to the rotary table 16, and a gas introduction pipe 28 for introducing argon gas and nitrogen gas into the vacuum processing chamber 12. And. Hereinafter, a method for producing an embodiment of a laminated coating member according to the present invention using this processing apparatus 10 will be described.

(Ion bombarding process)
First, a chromium target is used as the target 22 of the processing apparatus 10, the vacuum pump 14 is operated to evacuate the vacuum processing chamber 12, and then argon gas is introduced into the vacuum processing chamber 12 through the gas introduction pipe 28. Then, the inside of the vacuum processing chamber 12 is made an argon gas atmosphere, and ion bombarding is performed to activate the surface of the substrate 20.

(Chromium film formation process)
Next, the introduction of the argon gas is temporarily stopped, the inside of the vacuum processing chamber 12 is evacuated, and then the argon gas is introduced into the vacuum processing chamber 12 through the gas introduction pipe 28 so that the inside of the vacuum processing chamber 12 is argon gas. Make the atmosphere. Thereafter, a predetermined voltage of the sputtering power supply 24 is applied to the target 22 to cause glow discharge (low temperature plasma) in the vicinity of the target 22. As a result, the argon gas in the discharge region is ionized and collides with the target 22 at a high speed. As a result of this collision, chromium atoms are struck out from the target 22, and the chrome atoms are struck against the surface of the substrate 20. A chromium film as a stress relaxation layer is formed on the surface of 20.

(Nitrogen-containing chromium film forming process)
Next, after evacuating the inside of the vacuum processing chamber 12, argon gas and nitrogen gas are introduced into the vacuum processing chamber 12 through the gas introduction pipe 28, and the inside of the vacuum processing chamber 12 is brought to an atmosphere of argon gas and nitrogen gas. To do. Thereafter, a predetermined voltage of the sputtering power supply 24 is applied to the target 22 to cause glow discharge (low temperature plasma) in the vicinity of the target 22. As a result, the argon gas in the discharge region is ionized and collides with the target 22 at a high speed, and this collision expels chromium atoms from the target 22, and these chromium atoms together with nitrogen atoms in the atmosphere in the vacuum processing chamber 12. A chromium film (hard layer) containing nitrogen is formed on the surface of the chromium film on the substrate 20 by being struck against the surface of the chromium film on the substrate 20.

  Furthermore, the chromium film forming step and the nitrogen-containing chromium film forming step are repeated to form a plurality of chromium films and a plurality of nitrogen-containing chromium films so that the chromium films and the nitrogen-containing chromium films are alternately arranged.

  In the sputtering in the chromium film forming process and the nitrogen-containing chromium film forming process, the target 22 is used in order to make the thickness of each film uniform and to keep the temperature of the substrate 20 below the tempering temperature. It is preferable to keep the distance between the substrate 20 and the substrate 20 at, for example, 70 to 80 mm.

(Film formation process consisting of solid lubricant)
Next, the base material 20 in which the chromium film and the nitrogen-containing chromium film are alternately formed is taken out from the processing apparatus 10, and a solid lubricant made of a fluorine-based resin such as polytetrafluoroethylene on the outermost nitrogen-containing chromium film. After spraying with a spray gun to a predetermined thickness, it is fired at a temperature of 260 to 340 ° C. for about 0.1 to 3 hours. Thereby, a film made of a solid lubricant is formed on the nitrogen-containing chromium film. The thickness of the film made of the solid lubricant is preferably 1 to 10 μm, and more preferably 1 to 6 μm.

  Examples of the laminated film-coated member and the method for producing the same according to the present invention will be described in detail below.

[Example 1]
First, as a base material, a cylindrical Fabry pin with a diameter of 6.5 mm, which was mirror-polished after carburizing, quenching and tempering the steel type SCM415, was prepared. This base material is put into a vacuum processing chamber of a processing apparatus (DC magnetron sputtering apparatus) using a chrome target and evacuated to an ultimate vacuum of 5 × 10 ⁻⁴ Pa or less, and then the pressure in the vacuum processing chamber is 5 × 10 ⁻ Argon gas was introduced into a vacuum processing chamber under control of an argon gas atmosphere of ¹ Pa, and ion bombarding was performed at 1000 V × 2 A for about 180 minutes to activate the surface of the substrate.

  Next, the introduction of the argon gas is temporarily stopped, the vacuum processing chamber is evacuated and evacuated, and then the argon gas is evacuated so that the partial pressure of the argon gas in the atmosphere in the vacuum processing chamber becomes 0.061 Pa. While being introduced, the input power was 4 kW, the bias voltage was −100 V, and sputtering was performed for 30 seconds to form a chromium film having a thickness of about 40 nm (about Vickers hardness HV500) on the substrate (chromium film formation step).

  Next, after evacuating and vacuuming the vacuum processing chamber, the argon gas is introduced into the vacuum processing chamber so that the partial pressure of the argon gas in the atmosphere in the vacuum processing chamber becomes 0.042 Pa, and the nitrogen gas is separated. While introducing nitrogen gas into the vacuum processing chamber so that the pressure becomes 0.054 Pa, sputtering was performed for 60 seconds with an input power of 4 kW and a bias voltage of −100 V, and a nitrogen-containing chromium having a thickness of about 80 nm on the substrate. A film was formed (nitrogen-containing chromium film forming step).

  Further, the chromium film forming step and the nitrogen-containing chromium forming step are alternately repeated, so that 40 layers each of a chromium film having a thickness of about 40 nm and a nitrogen-containing chromium film having a thickness of about 80 nm (total 80 layers, total film thickness). 4.8 μm) alternately formed (nitrogen-containing chromium film forming step).

  Next, the base material on which the chromium film and the nitrogen-containing chromium film are alternately formed is taken out of the processing apparatus, and based on the dry coating and baking method, the surface of the outermost nitrogen-containing chromium film is solid lubricated with polytetrafluoroethylene. The coating was made of a solid lubricant on the nitrogen-containing chromium coating by applying the agent and baking the solid lubricant by holding at 300 ° C. for about 2 hours.

  Observation of the surface of the thus obtained multilayer coating member (cylindrical multilayer coating coated Fabypin) with a scanning electron microscope (SEM) confirmed the solid lubricant formed on the entire surface of the nitrogen-containing chromium coating. It was done. Moreover, when the cross section of the obtained laminated film coating | coated member was observed by SEM, the layer of the solid lubricant about 2 micrometers thick was confirmed.

  In addition, in order to evaluate the load bearing performance and sliding characteristics of the obtained multilayer coating coated Fabry pin, the multilayer coating coated Fabry pin 110 is connected to the rotary drive 112 of the high-speed Falex frictional wear tester as shown in FIG. The upper part of the substrate is fixed, and the side surface is sandwiched between the V-grooves of a pair of V-blocks (blocks with V-grooves SCM 415 subjected to carburizing, quenching and tempering) 111, and the multilayer coating coated Fabry pins 110 are rotated by the rotary drive 112. Then, the load applied to the V block (indicated by the arrow L in the figure) was increased, and a non-lubricated frictional wear test was performed. Then, the appearance of the laminated film-coated Fabry pins and the V block after the test was observed. In this test, the sliding speed was 0.1 m / s, the maximum load at the end of the test was 20000 N (maximum load of the testing machine), and the friction coefficient μ at the end of the test was 0.021 as an evaluation of the sliding characteristics. It was. Further, in the observation of the appearance of the fabric pin (base material) after the test was completed, no seizure or damage was observed, and no damage to the nitrogen-containing chromium film was observed.

[Example 2]
Sputtering of the chromium film forming process is performed for 45 seconds to form a chromium film having a thickness of about 60 nm on the substrate, and sputtering of the nitrogen-containing chromium film forming process is performed for 90 seconds to contain nitrogen having a thickness of about 120 nm on the substrate. A chromium film is formed, and this chromium film forming process and the nitrogen-containing chromium film forming process are alternately repeated to obtain a chromium film 40 layer having a thickness of about 60 nm and a nitrogen-containing chromium film 39 layer having a thickness of about 120 nm (79 layers in total). Layer and a total film thickness of about 7.08 μm), and a multilayer film was formed in the same manner as in Example 1 except that a solid lubricant composed of polytetrafluoroethylene was applied to the surface of the outermost chromium film. A covering member was produced.

  When the surface of this multilayer coating member was observed with an SEM, a solid lubricant formed on almost the entire surface was confirmed, and when a cross section of the multilayer coating member was observed with an SEM, a solid lubricant layer having a thickness of about 3 μm was observed. Was confirmed.

  Further, when the load bearing performance and sliding characteristics of the obtained laminated coating coated Fabry pin were evaluated by the same method as in Example 1, the maximum load at the end of the test was 20000 N, and the friction coefficient μ at the end of the test was 0. 0.023. Further, in the observation of the appearance of the Fabry pin after the test was completed, no seizure or damage was observed, and no damage to the laminated film was observed.

[Comparative Example 1]
A laminated film coated member (cylindrical laminated film coated Fabry pin) was prepared by the same method as in Example 1 except that a film made of a solid lubricant was not formed on the nitrogen-containing chromium film, and the load bearing performance And the sliding characteristics were evaluated. In this test, the maximum load at the end of the test was 5519 N, and the friction coefficient μ at the end of the test was 0.282. Further, in the observation of the external appearance after completion of the test, the nitrogen-containing chromium film was broken, deformation of the Fabry pin (base material) due to plastic flow was observed, and galling and adhesion were also observed.

[Comparative Example 2]
The load bearing performance and sliding characteristics of the same Fabry pin as in Example 1 (cylindrical type Fabry pin with a diameter of 6.5 mm, which was carburized, quenched and tempered into steel type SCM415) were evaluated by the same method as in Example 1. As a result, the maximum load at the end of the test was 4837 N, and the friction coefficient μ at the end of the test was 0.336. Further, in the observation of the appearance of the Fabry pin after the test was completed, deformation due to plastic flow was observed, and seizure was observed.

DESCRIPTION OF SYMBOLS 1 Base material 2 Chromium film | membrane 3 Nitrogen-containing chromium film | membrane 4 Film | membrane consisting of a solid lubricant 10 Processing apparatus 12 Vacuum processing chamber 14 Vacuum pump 16 Rotary table 18 Jig 20 Base material 22 Target 24 Sputter power supply 26 Ion bombard and bias power supply 28 Gas Introducing pipe 110 Laminated coating coated Fabry pin 111 V block 112 Rotating drive 113 Pin

Claims (10)

A laminated film-coated member, wherein a nitrogen-containing chromium film is formed on a substrate via a chromium film, and a film made of a solid lubricant is formed on the nitrogen-containing chromium film. A laminated film-coated member, wherein a plurality of chromium films and a plurality of nitrogen-containing chromium films are formed on a substrate, and a film made of a solid lubricant is formed on the outermost surface. The laminated coating member according to claim 1 or 2, wherein the fixed lubricant is made of a fluorine resin. The laminated coating member according to claim 1 or 2, wherein the fixed lubricant is made of polytetrafluoroethylene. After forming a nitrogen-containing chromium film on the substrate via a chromium film, a solid lubricant is applied onto the nitrogen-containing chromium film and baked to form a film made of the solid lubricant on the nitrogen-containing chromium film. A method for producing a laminated film-coated member, which is characterized in that it is formed. A plurality of chromium films and a plurality of nitrogen-containing chromium films are alternately formed on the substrate in this order, and then a solid lubricant is applied to the outermost surface and fired to form a film made of a solid lubricant on the outermost surface. A method for producing a laminated coating member, characterized in that: The said nitrogen-containing chromium membrane | film | coat is formed by sputtering in the atmosphere containing argon gas and nitrogen gas using a chromium target, The manufacture of the laminated film coating | coated member of Claim 5 or 6 characterized by the above-mentioned. Method. The method for producing a laminated film-coated member according to any one of claims 5 to 7, wherein the chromium film is formed by sputtering in an argon gas atmosphere using a chromium target. The method for producing a laminated film-coated member according to any one of claims 5 to 8, wherein the fixed lubricant is made of a fluororesin. The method for manufacturing a laminated film-coated member according to any one of claims 5 to 8, wherein the fixed lubricant is made of polytetrafluoroethylene.

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