JP4848545B2 - Hard coating member and method for producing the same - Google Patents

Description

  The present invention relates to a hard coating member and a method for manufacturing the same, and in particular, a hard coating such as a diamond-like carbon coating is formed on the outermost surface and used for a machine part or a mold. The present invention relates to a member to be manufactured and a manufacturing method thereof.

  A diamond-like carbon (hereinafter referred to as “DLC”) film is a carbon film having characteristics such as high hardness and electrical insulation similar to diamond synthesized by a vapor phase synthesis method. The structure of the DLC film is usually an amorphous structure, and has a diamond bond or a graphite bond. Since the DLD film is hard (for example, micro Vickers hardness Hv1000 to 5000) and excellent in wear resistance, it is used to coat various mechanical parts in addition to recording media for hard disks and magnetic recording heads. ing. In order to improve the adhesion between the DLC film and the base material, a method in which an intermediate layer composed of a titanium carbide layer is interposed between the base material and the DLC film (see, for example, Patent Document 1), the base material does not contain hydrogen. A method of coating with a second DLC film containing hydrogen on the first DLC film (see, for example, Patent Document 2), a gas containing carbon and silicon on a base material coated with a carbon ion implantation layer A method of forming a DLC film using plasma gas (for example, see Patent Document 3), a method of covering a base material with a DLC multilayer film in which soft films and hard films are alternately laminated (for example, see Patent Document 4), etc. Various methods have been proposed.

International Publication WO92 / 006234 (Page 3) JP 2000-128516 A (paragraph numbers 0004-0005) JP 2000-319784 A (paragraph numbers 0008-0009) JP 2004-269991 A (paragraph numbers 0007-0008)

  However, the DLC film is a hard film, and the difference in hardness, thermal expansion coefficient and structure between the base material made of a soft material such as aluminum and the DLC film is very large. In the method, the adhesion between the base material and the DLC film may not be sufficiently improved. Similar problems occur when a base material made of aluminum or an aluminum alloy is coated with a hard film such as a chromium nitride (CrN) film, a titanium nitride (TiN) film, a titanium carbide (TiC) film, or a TiAlN film.

  Accordingly, the present invention provides a hard coating member having good adhesion between a base material made of aluminum or an aluminum alloy and a hard coating such as a DLC coating, and a method for manufacturing the same, in view of such conventional problems. With the goal.

  As a result of diligent research to solve the above problems, the present inventors have processed the surface of a base material made of aluminum or an aluminum alloy to have a maximum surface roughness of 3 μm or less, and a nitrogen-containing chromium film on the base material. After forming the film, by forming a hard film such as a DLC film on the nitrogen-containing chromium film, the adhesion between the base material made of aluminum or an aluminum alloy and the hard film such as a DLC film can be improved. The headline and the present invention were completed.

  That is, in the method for producing a hard film-coated member according to the present invention, the surface of a base material made of aluminum or an aluminum alloy is processed to have a maximum surface roughness of 3 μm or less, and a nitrogen-containing chromium film is formed on the base material. A hard film is formed on the nitrogen-containing chromium film. In this method for producing a hard coating member, it is preferable that the surface has a Vickers hardness Hv of 80 to 200 after the surface of the base material is treated. As the hard film, a diamond-like carbon film, a chromium nitride film, a chromium carbide film, or a TiAlN film can be used. The diamond-like carbon film is preferably formed by sputtering using a carbon target, and the nitrogen-containing chromium film is formed by sputtering in an atmosphere containing argon and nitrogen using a chromium target. Is preferred. Further, it is preferable to form a chromium film on the base material before forming the nitrogen-containing chromium film on the base material, and then form a nitrogen-containing chromium film. In addition, the nitrogen-containing chromium film is a film in which at least one of nitrogen and chromium nitride is dispersed substantially uniformly in the chromium film, or the nitrogen concentration in the central portion in the film thickness direction in the chromium film is higher than the nitrogen concentration on both sides thereof A high film is preferred.

  The hard coating member according to the present invention has a nitrogen-containing chromium coating formed on a base material made of aluminum or an aluminum alloy having a maximum surface roughness of 3 μm or less, and the hard coating is formed on the nitrogen-containing chromium coating. It is characterized by being. In this hard film-coated member, the Vickers hardness Hv of the surface of the base material is preferably 80 to 200. As the hard film, a diamond-like carbon film, a chromium nitride film, a chromium carbide film, or a TiAlN film can be used. Further, it is preferable that a chromium film is formed between the base material and the nitrogen-containing chromium film. In addition, the nitrogen-containing chromium film is a film in which at least one of nitrogen and chromium nitride is dispersed substantially uniformly in the chromium film, or the nitrogen concentration in the central portion in the film thickness direction in the chromium film is higher than the nitrogen concentration on both sides thereof A high film is preferred. Furthermore, the thickness of the nitrogen-containing chromium film is preferably 25 μm or less, and more preferably 10 μm or less.

  ADVANTAGE OF THE INVENTION According to this invention, the hard film coating | coated member with favorable adhesiveness of hard films, such as a base material consisting of aluminum or aluminum alloy, and a DLC film, can be manufactured.

  In the embodiment of the method for producing a hard film-coated member according to the present invention, the maximum surface roughness of the base material is set to 3 μm or less by treating the surface of the base material made of aluminum or aluminum alloy, preferably the surface Vickers. After setting the hardness Hv to 80 to 200 and forming a nitrogen-containing chromium film on the base material, a hard film such as a DLC film is formed on the nitrogen-containing chromium film. In addition to the DLC film, the hard film includes a chromium nitride (CrN) film having a Vickers hardness of Hv 2000 to 2200, a titanium nitride (TiN) film of Hv 2000 to 2500, a titanium carbide (TiC) film of around Hv 3000, and TiAlN of Hv 2300 to 2800. A hard film such as a film can be used.

  The adhesion strength between the base material and the film varies depending on the surface roughness of the base material, and the maximum surface roughness Rmax is preferably 3 μm or less, more preferably 1 μm or less. When the maximum surface roughness Rmax exceeds 3 μm, the adhesion strength between the base material and the film is remarkably reduced, and the strength is less than half in the scratch test compared to the case where the maximum surface roughness Rmax is 1 μm (less than half May peel off under load). Hard coatings such as nitrogen-containing chromium coatings and DLC coatings are easily formed following the shape of the irregularities on the surface of the base material, and the surface roughness of the base material appears almost as it is on the surface roughness of the hard coating. However, when the base material is made of a soft metal such as aluminum or an aluminum alloy, it is difficult to reduce the maximum surface roughness Rmax of the base material to 3 μm or less with abrasive paper or the like, and the polishing material bites into the base material. Therefore, it is preferable that the maximum surface roughness Rmax of the base material is 3 μm or less by lapping, electrolytic polishing, or the like.

  In general, the Vickers hardness Hv of aluminum or an aluminum alloy is about 20 to 200, and the Vickers hardness Hv (about 500 to 700) of a metal such as tool steel or low carbon steel used as a material for machine members. The hardness is remarkably lower than that. In particular, the Vickers hardness Hv of pure aluminum (JIS1000 series) is about 20 to 120, and the Vickers hardness Hv of aluminum alloys (such as Al-Cu series, Al-Mn-Cu series, Al-Si series, Al-Mg series) is The Vickers hardness Hv varies depending on the composition and processing history. In general, when the film formed on the base material is relatively thin, the characteristics of the film are greatly influenced by the hardness (strength) of the base material, and the higher the Vickers hardness Hv of the base material, the better the adhesion between the base material and the film. To do. In particular, when aluminum or an aluminum alloy is used as the base material of the mechanical member, the Vickers hardness Hv needs to be 80 or more, and is preferably 100 to 200.

  The embodiment of the hard coating member according to the present invention can be manufactured using 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 base material 20 made of aluminum or an aluminum alloy as a member to be processed placed on the turntable 16 via a jig 18, and a target as an evaporation source disposed so as to surround the base material 20 22, DC sputtering power supply 24 connected to each of these targets 22, DC ion bombardment and bias power supply 26 connected to the rotary table 16, and argon gas and nitrogen gas are introduced into the vacuum processing chamber 12. A gas introduction pipe 28 is provided.

  The base material 20 is coated with a nitrogen-containing chromium film using a chromium target as the target 22 of the processing apparatus 10, and then the target 22 is changed and coated with a hard film. When a DLC film is formed as the hard film, a carbon target is used as the target 22. The nitrogen-containing chromium film may be a film in which nitrogen or chromium nitride is almost uniformly dispersed in the chromium film (hereinafter referred to as “nitrogen-containing chromium film I”), or the nitrogen concentration in the central portion in the film thickness direction in the chromium film. May be a film (hereinafter referred to as “nitrogen-containing chromium film II”) having a higher nitrogen concentration on both sides. Hereinafter, a method for forming the nitrogen-containing chromium film and the hard film will be described in detail.

(Method for forming nitrogen-containing chromium film I)
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. And nitrogen gas are introduced to create a sputtering atmosphere in the vacuum processing chamber 12. If necessary, it is preferable to activate the surface of the base material 20 by performing ion bombardment before sputtering.

Next, a high voltage of the sputtering power source 22 is applied to the target 22 to generate 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. Struck against the surface of the base material 20, the surface of the base material 20 was dotted with Cr _X N _Y crystals containing 50 to 99 chromium atoms and 50 to 1 nitrogen atoms per 100 atoms as a chromium film containing nitrogen. A film is formed. In this sputtering, in order to make the thickness of the film uniform and to maintain the temperature of the base material 20 below the tempering temperature, the distance between the target 22 and the base material 20 is preferably maintained at 70 mm, for example. .

  Sputtering is performed without introducing nitrogen gas to form a chromium film having a thickness of 3 μm or less, preferably 1 μm or less on the base material 20, and then nitrogen gas is introduced to perform sputtering to form a nitrogen-containing chromium film I. It may be formed. If the nitrogen-containing chromium film is formed through the chromium film in this way, the adhesion between the base material 20 and a hard film such as a DLC film can be further improved.

(Method for forming nitrogen-containing chromium film II)
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. Is introduced into the vacuum processing chamber 12 to form a sputtering atmosphere. If necessary, it is preferable to activate the surface of the base material 20 with argon ions by performing ion bombardment in an argon gas atmosphere before performing sputtering.

  Next, a high voltage of the sputtering power source 24 is applied to the target 22 to generate glow discharge (low temperature plasma) in the vicinity of the target 22. Thereby, the argon gas in the discharge region is ionized and collides with the target 22 at a high speed, and chromium atoms are knocked out of the target 22 by this collision.

  When the introduction of nitrogen gas into the vacuum processing chamber 12 via the gas introduction pipe 28 is started after a predetermined time has elapsed from the start of sputtering or from the start of sputtering, the chromium atoms knocked out from the target 22 are When the nitrogen concentration in the atmosphere in the vacuum processing chamber 12 is zero, chromium alone, and after nitrogen gas is introduced into the atmosphere in the vacuum processing chamber 12, the surface of the base material 20 together with the nitrogen atoms in the atmosphere It is struck and deposited.

  This nitrogen-containing chromium coating II has a structure in which nitrogen is dissolved in chromium, a structure in which chromium nitride is dispersed in chromium, or a structure in which nitrogen is dissolved in chromium and chromium nitride is dispersed. However, the adjustment of the structure can be performed by controlling the nitrogen concentration in the atmosphere in the vacuum processing chamber 12 during sputtering. The nitrogen concentration in the atmosphere is controlled by the gas introduction pipe 28. This can be done by controlling the supply amount of nitrogen gas introduced into the vacuum processing chamber 12 via If the supply amount of nitrogen gas is increased to increase the nitrogen concentration in the atmosphere, the amount of nitrogen that combines with the chromium atoms knocked out of the target 22 and deposits on the surface of the base material 20 increases. If the supply amount of nitrogen gas is reduced to lower the nitrogen concentration in the atmosphere, the amount of nitrogen contained in the nitrogen-containing chromium film II is reduced. Therefore, supply of nitrogen gas so that the nitrogen concentration in the atmosphere at the intermediate point of sputtering is higher than the other points and the nitrogen concentration in the atmosphere at the start and end points of sputtering is lower than the nitrogen concentration at the intermediate point. If the amount is controlled, it is possible to form a nitrogen-containing chromium coating II in which the nitrogen concentration in the central portion in the film thickness direction in the chromium coating is higher than the nitrogen concentration in the portions on both sides. Specifically, it is preferable to increase the nitrogen concentration in the atmosphere from the start time of sputtering to the intermediate time point of sputtering, and to decrease the nitrogen concentration in the atmosphere from the intermediate time point of sputtering to the end time of sputtering. Note that the nitrogen gas may not be supplied at the start of sputtering.

  In this way, a nitrogen-containing chromium film II is formed on the base material 20 in which the nitrogen concentration in the central portion in the film thickness direction in the chromium film is higher than the nitrogen concentration in the both sides. The sputtering time can be appropriately set according to the type of the base material 20 and the required film thickness, and can be set to 0.5 to 15 hours, for example.

  Further, in the nitrogen-containing chromium film II, the hardness is highest in the central portion in the film thickness direction due to the difference in nitrogen content in the film thickness direction, for example, Hv 800 to 2000, preferably about Hv 1700, and the base material 20 side and the surface The hardness is low on the side, for example, Hv 500 to 1000, preferably about 500 on the base material 20 side, and Hv 1000 to 1900 on the surface side, preferably about Hv1000. Therefore, it is considered that the toughness of the film is improved by making the hardness of the entire film lower than that of the highest hardness part and suppressing the generation of chromium nitride (CrN) which is a ceramic.

  Furthermore, since the chromium content is higher on the base material 20 side of the nitrogen-containing chromium coating II than the central portion in the film thickness direction, the adhesion between the coating and the base material 20 is improved. Further, by reducing the difference between the coefficient of thermal expansion at the interface of the nitrogen-containing chromium film II with the base material 20 and the coefficient of thermal expansion of the base material 20, that is, the chromium at the interface with the base material 20 of the nitrogen-containing chromium film II. By increasing the content and gradually increasing the nitrogen content toward the center in the film thickness direction, it is considered that the generation of thermal stress can be reduced and the adhesion strength can be increased.

  Also, wear resistance is maintained by gradually changing the nitrogen concentration during film formation to reduce (relax) the stress caused by the difference between the coefficient of thermal expansion at the contact surface with the base material 20 and the coefficient of thermal expansion inside the film. However, it is considered that the thermal shock resistance can be improved.

  Further, in the nitrogen-containing chromium film II, the surface nitrogen content is higher than the nitrogen content in the contact surface with the base material 20, and therefore the hardness on the film surface side is higher than the hardness on the base material 20 side.

For example, the atmosphere is set so that the partial pressure of argon gas in the atmosphere in the vacuum processing chamber 12 is about 1.2 × 10 ⁻³ torr and the partial pressure of nitrogen gas is about 0 to 0.5 × 10 ⁻³ torr. By changing the nitrogen concentration (nitrogen gas supply amount), a layer on the base material 20 side having a nitrogen concentration of 0 to 0.6 atomic% and Hv of 500 to 1000 can be formed at the initial stage of sputtering. In the middle period, a central layer in the film thickness direction having a nitrogen concentration of 0.5 to 6.0 atomic% and Hv of 800 to 2000 can be formed. In the final stage of sputtering, a nitrogen concentration of 0.3 to 5.0 atomic%, A layer on the surface side of Hv 1000 to 1900 can be formed. The nitrogen concentration in the nitrogen-containing chromium film II thus formed can be measured by applying a normal physical analysis method, for example, using glow discharge luminescence surface analysis (GDS). It can be carried out by sputtering with argon in the film thickness direction from the surface and measuring the nitrogen content in the film thickness direction.

  Further, the thickness of the nitrogen-containing chromium film II can be set to about several μm to a maximum of 100 μm including a portion where the nitrogen content is zero. However, if the nitrogen-containing chromium coating II is too thick, the coating tends to crack due to the stress of the coating, and the thermal stress may increase due to the difference in thermal expansion coefficient with the base material. The upper limit of the film thickness is preferably about 25 μm. In the case of a mechanical member that requires good wear resistance, the film thickness is 5 to 25 μm, preferably about 10 to 15 μm, and more preferably about 10 μm.

  The thickness of the nitrogen-containing chromium film II in the thickness direction central portion (portion having a Vickers hardness Hv of about 1700 (Hv1700 ± 150)) is preferably 1.0 to 4.5 μm, preferably 1.5 to More preferably, it is 3 μm. Further, the thickness of the portion of the interface with the base material of the nitrogen-containing chromium film II (the portion where the Vickers hardness Hv is 500 to 600) is preferably 0.3 μm to 2 μm, and preferably 0.5 to 1.5 μm. More preferably. Furthermore, the thickness of the portion on the surface side of the nitrogen-containing chromium film II (the portion where the Vickers hardness Hv is 1000 ± 150) is preferably 3 to 5 μm. Between these parts of the nitrogen-containing chromium film II, there is preferably a part where the Vickers hardness increases or decreases.

(Hard film formation)
As described above, after the base material 20 is coated with the nitrogen-containing chromium film I or II, ion etching is performed. Next, when a DLC film is formed as a hard film, a carbon target is used as the chromium target 22 of the processing apparatus 10, the vacuum pump 14 is operated, the vacuum processing chamber 12 is evacuated, and then the gas is discharged. Argon gas (or argon gas and nitrogen gas) is introduced into the vacuum processing chamber 12 through the introduction pipe 28 to make the inside of the vacuum processing chamber 12 a sputtering atmosphere.

  Next, a high voltage of the sputtering power source 22 is applied to the target 22 to generate 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 carbon atoms are knocked out of the target 22 by this collision, and the carbon atoms are released into the vacuum processing chamber 12 (argon gas and nitrogen gas). Is introduced into the surface of the nitrogen-containing chromium film on the base material 20 to form a DLC film containing nitrogen on the surface of the nitrogen-containing chromium film on the base material 20. The

  In this way, it is possible to manufacture a hard film-coated member in which the base material 20 is coated with a nitrogen-containing chromium film and the nitrogen-containing chromium film is coated with a DLC film. It is preferable to adjust the hardness of the DLC film by adjusting the bias voltage so that the hardness of the interface with the nitrogen-containing chromium film is equal to that of the nitrogen-containing chromium film. For example, the hardness of the surface of the nitrogen-containing chromium film is preferably Hv 800 to 1300, and a DLC film of Hv 1000 to 1300 is preferably formed thereon.

  Identification of carbon in the DLC film can be performed by Raman spectroscopy. The micro Vickers hardness of the film can be measured by a usual method after polishing the cross section of the film and pressing an indenter on the cross section. When the film is thin and the hardness of the cross section of the film cannot be measured, the hardness of the cross section of the film having a thickness that can be measured by increasing the film formation time under the same conditions may be measured.

  In the case of forming a CrN film as a hard film, the CrN film is formed by the same method as the method for forming the nitrogen-containing chromium film I described above, except that the flow rate of the nitrogen gas introduced into the vacuum processing chamber 12 is changed. Can be formed. In this case, it is preferable to first introduce only argon gas into the vacuum processing chamber 12 and form a chromium film by sputtering, and then introduce nitrogen to form a CrN film.

  When a TiN film is formed as the hard film, the TiN film can be formed by the same method as the method for forming the nitrogen-containing chromium film I described above except that a titanium target is used. In this case, only argon gas is first introduced into the vacuum processing chamber 12 and a titanium film having a thickness of about 0.5 to 1 μm is formed by sputtering, and then nitrogen is introduced and about 1.5 to 5 μm is introduced. It is preferable to form a TiN film having a thickness.

Moreover, when forming a TiC film as a hard film, a titanium target is used in the same manner as the TiN film, and a hydrocarbon gas such as acetylene (C ₂ H ₂ ) or methane is introduced instead of nitrogen. A TiC film can be formed by the same method as the TiN film forming method described above.

  When a TiAlN film is formed as the hard film, the TiAlN film can be formed by the same method as the method for forming the nitrogen-containing chromium film I described above except that a TiAl target is used. In this case, first, only an argon gas is introduced into the vacuum processing chamber 12 to form a TiAl film, and then nitrogen is introduced to form a TiAlN film. The total film thickness of the TiAl film and the TiAlN film is 2 to 2. The thickness is preferably 5 μm.

  In addition, a nitrogen-containing chromium film II having various thicknesses is formed on a base material, and a DLC film having a thickness of 5 μm is formed. The adhesion strength between these films and the base material is examined by a scratch test. When the dynamic characteristics were examined, it was found that when the thickness of the nitrogen-containing chromium film II was 5 to 25 μm, the adhesion strength was hardly changed, but there was a great difference in the sliding characteristics. That is, when the base material is made of a soft metal such as aluminum or an aluminum alloy, the adhesion and slidability are excellent when the film thickness of the nitrogen-containing chromium film II is 5 to 15 μm. It was further improved when the thickness was 11.5 μm, and best when the thickness was about 10 μm. That is, when the base material is made of tool steel or low carbon steel, it is preferable that the nitrogen-containing chromium film II has a relatively thick thickness of about 20 to 30 μm, but the base material is made of aluminum or an aluminum alloy. In this case, it is preferable that the nitrogen-containing chromium film II has a relatively thin thickness of about 10 μm.

  The Vickers hardness Hv of the film can be measured by a normal method using a micro Vickers hardness meter, pressing an indenter with a load of about 25 g on the cross section of the polished film. When the film is thin and the cross-sectional hardness cannot be measured, the cross-sectional hardness of the film thickened to a measurable level can be measured by extending the film formation time under the same film formation conditions as that part.

  Examples of the hard film-coated member and the manufacturing method thereof according to the present invention will be described in detail below.

[Example 1]
First, the surface of the base material 20 made of aluminum was lapped to make the maximum surface roughness 1.1 μm. The Vickers hardness Hv of the surface of the base material 20 after the lapping treatment was about 110. A base material 20 made of aluminum thus lapped is prepared, and the base material 20 is placed in the vacuum processing chamber 12 of the processing apparatus 10 that uses a chromium target as the target 22, and the inside of the vacuum processing chamber 12 is 2 × 10 ^−. The surface of the base material 20 was activated by performing ion bombardment treatment at 1250 V × 0.01 mA for about 40 minutes in an argon gas atmosphere of ² torr.

Next, after the vacuum processing chamber 12 is evacuated and evacuated, the argon gas partial pressure in the atmosphere in the vacuum processing chamber 12 is 1.2 × 10 ⁻³ torr, the bias voltage is −100 V, and sputtering is performed. After about 7 minutes, a chromium film having a hardness of about Hv 700 and a thickness of less than 1 μm was formed on the base material 20.

Subsequently, nitrogen gas is introduced into the vacuum processing chamber 12, and the partial pressure of argon gas in the atmosphere in the vacuum processing chamber 12 is 1.2 × 10 ⁻³ torr, and the partial pressure of nitrogen gas is 0.2 ×. Sputtering was performed for about 93 minutes at 10 ⁻³ torr and a bias voltage of −100 V, and a nitrogen-containing chromium film I having a hardness of about Hv 1700 and a thickness of 15 μm was formed on the chromium film.

After the base material 20 thus formed with the nitrogen-containing chromium film I is placed in the processing apparatus 10 using a carbon target as the target 22, the inside of the vacuum processing chamber 12 is evacuated and depressurized to 8 × 10 ⁻³ Pa. Ion bombarding was performed at −1000 V × 0.1 A for 3 hours.

Finally, the partial pressure of argon gas in the vacuum processing chamber 12 is 1.2 × 10 ⁻³ torr, the partial pressure of nitrogen gas is 0.6 × 10 ⁻³ torr, the bias voltage is −150 V, DC discharge (1 The DLC film having a thickness of 5 μm was formed on the nitrogen-containing chromium film I by performing the sputtering process using the plasma generated on the target 22 by .4 kW) for 4 hours.

[Comparative Example 1]
A DLC film having a thickness of 5 μm was formed on the base material 20 by the same method as in Example 1 except that the nitrogen-containing chromium film I was not formed.

[Example 2]
After activating the surface of the base material 20 as in Example 1, the partial pressure of argon gas in the atmosphere in the vacuum processing chamber 12 of the processing apparatus 10 that uses a chromium target as the target 22 is 1.2 × 10 ^−. Sputtering was performed for 7 minutes at ³ torr and a bias voltage of −100 V, and a chromium film having a hardness of about Hv 700 and a thickness of less than 1 μm was formed on the base material 20.

Subsequently, after changing the partial pressure of argon gas in the atmosphere in the vacuum processing chamber 12 to 1.2 × 10 ⁻³ torr and changing the partial pressure of nitrogen gas to 0 to 0.5 × 10 ⁻³ torr, 0 is obtained. Sputtering was performed at a bias voltage of −100 V for about 180 minutes while changing to 15 × 10 ⁻³ torr. A 20 μm nitrogen-containing chromium film II was formed on the base material 20. That is, by first setting the partial pressure of nitrogen gas to 0 torr and forming a Cr film on the interface with the base material, the partial pressure of nitrogen gas is increased to 0.5 × 10 ⁻³ torr by 88 minutes. By gradually increasing the hardness of the nitrogen-containing chromium film II, forming an intermediate layer of the nitrogen-containing chromium film II, and then gradually reducing the partial pressure of nitrogen gas to 0.15 × 10 ⁻³ torr in 88 minutes The hardness of the nitrogen-containing chromium film II was gradually lowered to form a layer on the surface side of the nitrogen-containing chromium film II.

Next, after the vacuum processing chamber 12 is evacuated and evacuated, the argon gas partial pressure in the atmosphere in the vacuum processing chamber 12 is 1.2 × 10 ⁻³ torr, the bias voltage is −100 V, and sputtering is performed. After about 7 minutes, a chromium film having a hardness of about Hv 700 and a thickness of less than 1 μm was formed on the base material 20.

Subsequently, nitrogen gas is introduced into the vacuum processing chamber 12, the partial pressure of argon gas in the atmosphere in the vacuum processing chamber 12 is set to 1.2 × 10 ⁻³ torr, and the partial pressure of nitrogen gas is set to 0 to 2. While changing to 2 × 10 ⁻³ torr, the bias voltage was set to −100 V and sputtering was performed for about 75 minutes to form a chromium nitride (CrN) film having a thickness of 5 μm on the chromium film. That is, the partial pressure of nitrogen gas is set to 0 to 1.0 × 10 ⁻³ torr in the first 10 minutes to form a layer on the interface side with the base material of the CrN film, and then the partial pressure of nitrogen gas is set to 1 in 20 minutes. The intermediate layer of the CrN film is formed by increasing to .5 × 10 ⁻³ torr, and then the partial pressure of the nitrogen gas is increased to 2.2 × 10 ⁻³ torr in 45 minutes. A surface side layer was formed.

[Comparative Example 2]
A CrN film having a thickness of 5 μm was formed on the base material 20 by the same method as in Example 2 except that the nitrogen-containing chromium film II was not formed.

[Example 3]
After forming a nitrogen-containing chromium film II having a thickness of 20 μm on the base material 20 by the same method as in Example 2, a DLC film having a thickness of 5 μm was formed by the same method as in Example 1.

[Example 4]
By lapping the surface of the base material 20 made of an aluminum alloy (Al—Cu system) and setting the maximum surface roughness to 0.9 μm (surface Vickers hardness Hv is 180), the same method as in Example 3 is used. A nitrogen-containing chromium film II having a thickness of 20 μm and a DLC film having a thickness of 5 μm were formed on the base material 20.

[Example 5]
The nitrogen-containing chromium film II and the DLC film were formed in the same manner as in Example 3 except that the film formation time of the nitrogen-containing chromium film II was halved and the film thickness of the nitrogen-containing chromium film II was 10 μm. .

[Comparative Example 3]
A nitrogen-containing chromium film II and a DLC film were formed in the same manner as in Example 3 using the same base material (maximum surface roughness 5 μm) as in Example 1 except that the lapping treatment was not performed.

  Thus, the adhesiveness of the hard film coating | coated member of Examples 1-5 and Comparative Examples 1-3 which were manufactured in this way was evaluated. This adhesion was evaluated by scratching the film with a diamond indenter (0.2 mmR) at a load rate of 100 N / min and a scratch rate of 10 mm / min using a scratch tester. As a result, in Example 1, there was no peeling of the film from the base material up to 50N and no turning (breaking) of the film around the scratch, and in Examples 2 to 5, peeling of the film from the base material and coating of the film even at 100N or more. Although there was no turning, in Comparative Examples 1 to 3, there were peeling of the film from the base material and turning of the film at 25N, 28N and 48N, respectively.

  According to the present invention, the difference in hardness or thermal expansion coefficient between the base material made of aluminum or an aluminum alloy and a hard film such as a DLC film is smaller than the difference in hardness or thermal expansion coefficient between the base material and nitrogen. The nitrogen-containing chromium film, which is contained but basically made of metal, is formed on the base material, and then a hard film such as a DLC film is formed thereon, thereby improving the adhesion between the base material and the hard film. Can be improved. In addition, if a chromium film softer than the nitrogen-containing chromium film is formed between the base material and the nitrogen-containing chromium film, the difference in hardness and thermal expansion coefficient between the nitrogen-containing chromium film and the hard film is small. The adhesion of the hard film can be further improved. Further, the adhesion between the base material and the hard coating can be further improved by adjusting the nitrogen concentration in the nitrogen-containing chromium coating and the hardness of the hard coating.

  The hard-coated member according to the present invention is lightweight and has excellent wear resistance, slidability, and adhesion properties, and therefore is used as a material for automotive parts and compressor parts such as air conditioners. be able to.

It is the schematic of the processing apparatus for manufacturing embodiment of the hard film coating | coated member by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Processing apparatus 12 Vacuum processing chamber 14 Vacuum pump 16 Rotary table 18 Jig 20 Base material 22 Target 24 Sputtering power supply 26 Ion bombardment and bias power supply 28 Gas introduction pipe

Claims (15)

Polishing the surface of a base material made of aluminum or aluminum alloy to a maximum surface roughness of 3 μm or less, forming a nitrogen-containing chromium film on the base material, and then forming a hard film on the nitrogen-containing chromium film A method for producing a hard film-coated member, characterized by: The method for producing a hard film-coated member according to claim 1, wherein the polishing is performed by lapping or electrolytic polishing. The method for producing a hard film-coated member according to claim 1 or 2 , wherein the Vickers hardness Hv of the surface after treating the surface of the base material is 100 to 200. The method for producing a hard film-coated member according to any one of claims 1 to 3, wherein the hard film is a diamond-like carbon film, a chromium nitride film, a chromium carbide film, or a TiAlN film. The method for producing a hard film-coated member according to claim 4 , wherein the diamond-like carbon film is formed by sputtering using a carbon target. The hard film-coated member according to any one of claims 1 to 5 , wherein the nitrogen-containing chromium film is formed by sputtering in an atmosphere containing argon and nitrogen using a chromium target. Production method. Before forming a nitrogen-containing chromium film on the base material, a chromium film is formed on the base material, then, and forming the nitrogen-containing chromium film, any one of claims 1 to 6 The manufacturing method of the hard-film coating | coated member as described in 2 .. The production of a hard film-coated member according to any one of claims 1 to 7 , wherein the nitrogen-containing chromium film is a film in which at least one of nitrogen and chromium nitride is substantially uniformly dispersed in the chromium film. Method. It said nitrogen-containing chromium film, characterized in that the nitrogen concentration in the film thickness direction center portion in the chrome surface has a high film than the nitrogen concentration of the portion of the both sides, rigid according to any one of claims 1 to 7 A method for producing a film-coated member. A nitrogen-containing chromium film is formed on a base material made of aluminum or an aluminum alloy having a maximum surface roughness of 3 μm or less and a surface Vickers hardness Hv of 100 to 200 , and a hard film is formed on the nitrogen-containing chromium film. A hard coating member characterized by being formed. The hard coating member according to claim 10 , wherein the hard coating is a diamond-like carbon coating, a chromium nitride coating, a chromium carbide coating, or a TiAlN coating. The hard film covering member according to claim 10 or 11 , wherein a chromium film is formed between the base material and the nitrogen-containing chromium film. The hard film-coated member according to any one of claims 10 to 12, wherein the nitrogen-containing chromium film is a film in which at least one of nitrogen and chromium nitride is dispersed substantially uniformly in the chromium film. The hard coating according to any one of claims 10 to 12, wherein the nitrogen-containing chromium coating is a coating in which the nitrogen concentration in the central portion in the film thickness direction in the chromium coating is higher than the nitrogen concentration in the portions on both sides thereof. Film covering member. The hard film-coated member according to any one of claims 10 to 14, wherein the nitrogen-containing chromium film has a thickness of 25 µm or less.

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