JP2014181388A - Metal product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal product excellent in abrasion resistance.SOLUTION: A metal product has: a base metal in which at least a part of the surface comprises a metal member; and a hard coating which is formed by a PVD method on the surface comprising the metal member, which contains Ti atoms, Si atoms, C atoms and N atoms, and in which the ratio of Si atoms to the total amount of Ti atoms and Si atoms is 10 at% or higher and 25 at% or lower, and the ratio of C atoms to the total amount of C atoms and N atoms is 25 at% or higher and 55 at% or lower.

Description

  The present invention relates to a metal product coated with a hard coating.

  Various compositions of hard coatings for extending the life of metal products represented by tools such as screw punches have been studied. For example, a DLC (diamond-like carbon) film has a low coefficient of friction and excellent performance as a lubricating film, but there are problems in toughness, adhesion, and cost, and it is difficult to expand applications.

  For example, in Patent Document 1, in a stainless steel forging tool composed of a molding part for molding a workpiece and a support part main body of the molding part, the surface of the molding part is coated with a DLC film. A forging tool is disclosed.

Patent Document 2 discloses a vanadium-containing film which is a film coated on a base material made of an iron-based alloy, which is made of V _(1-X) C _X , and X is more than 70 at% and not more than 95 at%. V coatings on ferrous alloy _{substrate, V (1-Y) C} Y coatings (where, Y is 60at% or less than 40 at% in atomic percent) in the after-coated composite film consisting _{of, V (1-X )} a C _X, and X is vanadium coating the coated mold and tool is disclosed or less 70 at% super 95 at%.

JP 2003-112229 A JP 2010-202948 A

Metal products are used by being brought into contact with various target members. Conventionally, wear resistance has been required for the portions in contact with the target members.
An object of this invention is to provide the metal product excellent in abrasion resistance.

In order to achieve the above object, the following invention is provided.
The invention of claim 1
A base material in which at least a part of the surface is made of a metal member;
The surface of the metal member is formed by the PVD method, contains Ti atoms, Si atoms, C atoms, N atoms, and the ratio of the Si atoms to the total amount of Ti atoms and Si atoms is 10 at% or more. A hard coating having a ratio of the C atoms of 25 at% or less and a total amount of the C atoms and N atoms of 25 at% or more and 55 at% or less;
It is a metal product having

The invention of claim 2
2. The metal product according to claim 1, wherein the hardness of the hard coating by a nanoindentation method is 15 GPa or more and 35 GPa or less.

The invention of claim 3
The metal product according to claim 1, wherein the hard coating is a single-layer film.

The invention of claim 4
The metal product according to claim 1, wherein the hard coating is a laminated film of a plurality of layers having different hardnesses.

The invention of claim 5
The said laminated film is a metal product of Claim 4 whose hardness of the outermost layer which comprises outermost surface is lower than the hardness of the lower layer which touches this outermost layer.

The invention of claim 6
6. The metal product according to claim 1, wherein the surface of the hard coating has a friction coefficient of 0.1 or more and 0.4 or less by a ball-on-disk method under the following measurement conditions.
[Measurement condition]
-Opposing material: SUS304 ball of φ6mm-Load: 5N
・ Rotation speed: 10cm / sec
・ Rotating radius: 3mm
・ Friction distance: 1000m
・ Environment: Unlubricated environment

  According to the invention of claim 1, a metal product with improved wear resistance is provided.

  According to the invention of claim 2, a metal product with improved durability is provided.

  According to invention of Claim 3, the metal product with which formation of a hard film is easy is provided.

  According to the invention of claim 4, a metal product having improved durability is provided.

  According to the fifth aspect of the present invention, a metal product having excellent compatibility with the contacted member (target member) is provided.

  According to the invention of claim 6, a metal product with improved wear resistance is provided.

It is the schematic which shows an example of the punch for screw head shaping | molding which is a kind of metal product which concerns on this invention, (A) is a front view, (B) is a left view in (A), (C) is The enlarged view of a protrusion part is represented. It is the schematic which shows an example of the countersunk screw which has the + shaped hole processed with the punch for screw head shaping | molding shown by FIG. 1, (A) is a front view, (B) is the left view in (A). Represents.

  Hereinafter, the metal product according to the present invention will be described in detail.

The metal product according to the present invention has a base material and a hard coating. At least a part of the surface of the base material is made of a metal member. The hard coating is formed on at least the surface made of the metal member. This hard coating is formed by PVD (Physical Vapor Deposition / Physical Vapor Deposition), contains Ti atoms, Si atoms, C atoms, N atoms, and the ratio of the Si atoms to the total amount of Ti atoms and Si atoms. Is 10 at% or more and 25 at% or less (that is, _{x in the} composition “Ti _(1-x) Si _x ” is 0.1 or more and 0.25 or less), and the C atoms with respect to the total amount of the C atoms and N atoms The ratio is 25 at% or more and 55 at% or less (that is, _{y in the} composition “C _y N _(1-y) ” is 0.25 or more and 0.55 or less).

In the metal product according to the present invention, at least a portion that contacts the target member of the base material is formed of the metal member, and the surface of the metal member is covered with the hard coating.
Here, as the metal product in the present invention, for example, a screw head forming punch for forming a + -shaped hole in the screw head, a tool such as a punch used for punching a metal plate, etc .; a pump vane, etc. Machine parts; molds used for bending and drawing of punches, dies, metal plates and the like; dies such as press molds; cutting tools such as drills and end mills.

  Metal products are used in contact with the target member in various modes, such as applying an impact or pressure to various target members. Conventionally, wear resistance is required at the point of contact with the target member. It has been.

  For example, a screw head forming punch, which is a kind of metal product, will be described as an example. 1A and 1B are schematic views showing an example of a screw head forming punch. FIG. 1A is a front view, FIG. 1B is a left side view of FIG. 1A, and FIG. . A screw head forming punch shown in FIG. 1 (hereinafter, also simply referred to as “screw punch”) has a forming portion 2 at an end portion (left side in the figure) of the main body 1, and the forming portion 2 has FIG. As shown in FIG. 2, a protrusion 3 for forming a hole in the screw head is provided at the center. FIG. 1C is an enlarged view of the protrusion 3.

  FIG. 2 is an example of a countersunk screw having a + -shaped hole formed by the screw punch, wherein (A) represents a front view and (B) represents a left side view in (A). The countersunk screw shown in FIG. 2 has a head 6 in which a hole 5 is formed by a screw punch forming part 2 on one side of a main body 4 having a thread formed on the surface thereof.

The screw head 6 is formed by, for example, cold heading, and the hole 5 is formed by hitting with a screw punch at that time. Since the screw punch is repeatedly used for forming the hole 5, chipping or breakage may occur gradually, and it becomes impossible to continue using the screw punch in which chipping or folding occurs. Therefore, a long-life screw punch is required, that is, a screw punch excellent in durability at the protrusion 3 that contacts the screw head 6 is required.
In addition, not only screw punches, but general punches for punching are repeatedly used for punching metal plates and the like, so that they may gradually be chipped or broken, and a punch with excellent durability is required. It is done.

  Further, a press molding die will be described as an example. The mold is filled with a material to be molded, and pressure is applied to the material in a sealed state to perform press molding. Since the mold for press molding is repeatedly used in the above molding, chipping or deformation may occur at the portion where the material is gradually filled, and the press molding mold in which chipping or deformation has occurred may be used. It is impossible to continue. Therefore, there is a demand for a long-life press-molding die, that is, a press-molding die that is excellent in durability at a portion in contact with a material to be filled.

  In addition, a cutting tool such as a drill or an end mill will be described as an example. When cutting a metal such as various steel materials with a cutting tool at high speed and without lubrication, a load is applied to the cutting edge to promote wear of the cutting edge. Sometimes. Further, when the cutting oil is not used, the cutting resistance on the surface of the cutting tool increases, which causes wear damage to the cutting tool. Therefore, a coating film having high hardness and excellent lubricity is required on the cutting tool surface.

  In addition, as with tools such as screw punches and punches for punching, press molds, cutting tools such as drills and end mills, various modes such as applying impacts and applying pressure to various target members, etc. In the metal product used in contact with the target member, wear resistance is required at a location where the metal product is in contact with the target member.

In contrast, the metal product according to the present invention contains Ti atoms, Si atoms, C atoms, and N atoms, and the ratio of the Si atoms to the total amount of the Ti atoms and the Si atoms is 10 at% or more and 25 at% or less. And the hard film whose ratio of the said C atom with respect to the total amount of the said C atom and N atom is 25 at% or more and 55 at% or less is provided.
For example, in the case of the screw punch shown in FIGS. 1 (A) to 1 (C), the protrusion 3 that comes into contact with the screw head 6 when the hole 5 is formed in the screw is formed by at least the hard coating. Covered. Further, in the punch for punching, when the material such as a metal plate is punched, the portion that comes into contact with the material is covered with at least the hard coating, and in the mold, the material to be molded is filled. A portion that comes into contact with the material is at least covered with the hard coating. In a cutting tool such as a drill or an end mill, a portion that comes into contact with the material when cutting a material such as metal is covered with at least the hard coating. Further, in the case of a pump vane, at least a portion of the vane that slides with other members in the pump is covered with the hard coating.
As a result, a metal product having excellent wear resistance and, as a result, excellent durability can be obtained.

  Although the mechanism by which this effect is achieved is not necessarily clear, it is presumed as follows. That is, it is considered that the hard coating in the present invention has a reduced friction coefficient in order to satisfy the above composition. In addition, C atoms contribute particularly to the reduction of the friction coefficient, and the ratio of C atoms to the total amount of C atoms and N atoms is equal to or higher than the above lower limit value to realize a low friction hard coating. Conceivable. And since the location which contacts the object member of a metal product is coat | covered with this low-friction hard film, generation | occurrence | production of the abrasion by contact with an object member is suppressed, and it is estimated that it is excellent in durability as a result. .

  Subsequently, each part which comprises the metal product of this invention is explained in full detail.

[Base material]
As for the base material which comprises the metal product which concerns on this invention, at least one part of the surface is formed with a metal member. In addition, the area | region comprised with this metal member should just contain the location which contacts an object member at least, and the location which does not contact an object member is comprised with other members, even if it is comprised with a metal member. Also good.
Therefore, for example, in the case of the screw punch shown in FIGS. 1 (A) to 1 (C), the protruding portion 3 in the base material of the screw punch is composed of at least a metal member, and the main body 1 is composed of a metal member. Or may be composed of other members. In addition, as a screw punch, it is more preferable that the main body 1 and the protrusion part 3 are integrally shape | molded by the metal member.
In the case of a punch for punching, a portion that comes into contact with the material to be punched when punching a material such as a metal plate is composed of at least a metal member, and in the case of a die, the material to be molded is filled. The portion that comes into contact with the material at the time is made up of at least a metal member, and if it is a cutting tool such as a drill or end mill, the portion that comes into contact with the material when cutting the material such as metal is made up of at least a metal member The Furthermore, if it is a vane for pumps, the part which slides with the other member in the pump of a vane is comprised with a metal member at least. In addition, parts other than the above in metal products such as punches for punching, dies, cutting tools, and vanes for pumps may be composed of metal members or other members. It is preferable that they are integrally formed by the above.

Here, the metal member represents a member made of a metal or an alloy. Examples of the metal and alloy used for the metal member include steel and cemented carbide.
Examples of the steel include known steel materials such as iron containing at least carbon (so-called carbon steel) and compounds containing other alloy elements in the carbon steel (so-called special steel). Examples of the cemented carbide include tungsten carbide.

[Hard coating]
In the metal product according to the present invention, the surface of the metal member in at least a part of the base material is covered with a hard coating.

This hard film is formed by a PVD (Physical Vapor Deposition / physical vapor deposition) method, and contains Ti atoms, Si atoms, C atoms, and N atoms as its composition.
The ratio of Si atoms to the total amount of Ti atoms and Si atoms is 10 at% or more and 25 at% or less (that is, _{x in the} composition “Ti _(1-x) Si _x ” is 0.1 or more and 0.25 or less). . Further, the Si atom ratio is more preferably 10 at% or more and 15 at% or less.
Further, the content of Si atoms is preferably less than 15 at% with respect to the total amount of Si atoms and Ti atoms. By setting it to a range of less than 15 at%, it is presumed that the crystal structure of the hard coating is refined and high hardness of 28 GPa or more can be expressed.
Moreover, since the crystal structure will change if the amount of Si atoms exceeds the upper limit, it cannot be suitably used as a hard coating.

The ratio of C atoms to the total amount of C atoms and N atoms is 25 at% or more and 55 at% or less (that is, _{y in the} composition “C _y N _(1-y) ” is 0.25 or more and 0.55 or less). .
When the ratio of C atoms is lower than the lower limit, the hard coating cannot be reduced in friction, resulting in a problem that the durability of the metal product is inferior.

Moreover, the ratio which each of Ti atom, Si atom, C atom, and N atom occupies in all the elements which comprise the hard film in this invention has the following ranges.
Ti atom: 34.5 at% or more and 45 at% or less
(More preferably 37.5 at% or more and 45 at% or less)
Si atom: 5 at% or more and 12.5 at% or less
(More preferably, 5 at% or more and 7.5 at% or less)
C atom: 12.5 at% to 35 at% N atom: 15 at% to 41.5 at%
(More preferably 15 at% or more and 37.5 at% or less)

The ratio of Si atoms to the total amount of Ti atoms and Si atoms, the ratio of C atoms to the total amount of C atoms and N atoms, and each of Ti atom, Si atom, C atom, and N atom in the hard coating The ratio is measured with an electron probe microanalyzer (EPMA: Electron Probe Micro Analyzer).
Specifically, JXA-8500F (FE-EPMA) manufactured by JEOL Ltd. is used, acceleration voltage: 10 kV, irradiation current: 5 × 10 ⁻⁸ A, analysis region: φ50 μm, standard data used: Ti (pure Ti), It is measured under the measurement conditions of Si (pure Si), C (Glass Carbon), N (AlN), and O (SiO ₂ ). Although the measurement results may include O atoms, the detection of the O atoms is caused by residual gas in the furnace when the hard film is formed and is not present in the hard film. Calculation is made so that the total number of atoms excluding O atoms is 100%.

-Friction coefficient It is preferable that the friction coefficient of the surface of the hard coating in this invention is low, and specifically, it is preferable that the friction coefficient by the ball on disk method on the following measurement conditions is 0.4 or less. The lower limit is not particularly limited, but is preferably 0.1 or more, for example.

  The friction coefficient is measured by a ball on disk method. Specifically, a “tribometer” manufactured by CSM Instruments (Switzerland) is used as a measuring device, a test piece is set in the measuring device, a SUS304 ball of φ6 mm is set in a holder as a counterpart material, a load: 5 N, Measured under conditions of rotational speed: 10 cm / sec, rotational radius: 3 mm, friction distance: 1000 m, unlubricated environment.

  The friction coefficient of the hard coating is controlled by the ratio of C atoms to the total amount of C atoms and N atoms, the proportion of C atoms in all the elements constituting the hard coating, and the like.

-Hardness It is preferable that the hardness by the nano indentation method of the hard film in this invention is 15 GPa or more and 35 GPa or less.

In the hard coating according to the present invention, the ratio of C atoms to the total amount of C atoms and N atoms is controlled within the above-described range, that is, it contains a relatively large amount of C atoms. Here, it is known that a film generally formed by the PVD method becomes a hard film as the proportion of C atoms increases. However, the present inventors have adjusted the bias voltage applied when the film is formed by the PVD method, even if it is a hard film of the present invention containing a relatively large amount of C atoms. It has been found that the hardness can be further adjusted. The reason why the hardness of the hard coating can be adjusted by the bias voltage is considered to be that crystal growth can be controlled by changing the bias voltage.
Therefore, in the present invention, the hardness of the hard film is in a harder direction or softer in spite of the hard film in which the ratio of C atoms is in the above-mentioned range and contains a relatively large amount of C atoms. You can also adjust the direction.

In addition, since a hard film can be softened to some extent, high toughness can be obtained and impact resistance can be improved, and as a result, durability can be improved. On the other hand, deformation resistance can be obtained by hardening to some extent, and as a result, durability can be improved.
In the case of obtaining a harder film in order to obtain deformation resistance, the hardness is more preferably 30 GPa or more and 35 GPa or less.
On the other hand, when the toughness is obtained and a softer film is obtained, the hardness is more preferably 10 GPa or more and 20 GPa or less.

  The hardness is measured by a nanoindentation method. Specifically, the product name Nanohardness tester manufactured by CSM Instruments (Switzerland) is used as a measuring device, and the measurement condition is adjusted to a load of 5 mN.

  The hardness of the hard coating is the ratio of C atoms to the total amount of C atoms and N atoms, the proportion of C atoms in all elements constituting the hard coating, and the bias voltage applied when the hard coating is formed by the PVD method. Controlled by etc. That is, the higher the C atom ratio and ratio, the harder the film, and the higher the bias voltage, the harder the film.

-Hard coating mode (single layer film)
The hard coating in the present invention may be a single-layer film consisting of one layer. A single layer film can be easily formed.

-Formation method of a single layer film | membrane Here, the formation method by PVD method in case a hard film is a single layer film | membrane is demonstrated.
The hard coating in the present invention may be formed by any method as long as it is a PVD method, and examples thereof include an ion plating method, a sputtering method, a vapor deposition method, and the like. It is preferable because it can be mentioned.

In particular, the cathode arc discharge method is preferable, and when a cathode target to which a plurality of metal elements are added is melted by arc discharge, the difference between the target composition and the formed film composition is relatively small.
A target containing Ti and Si is set as an evaporation source of the metal component, and molding is performed while N ₂ gas and CH ₄ gas are allowed to flow as reaction gases, and the coating substrate temperature, reaction gas pressure, and applied bias voltage are adjusted. The ratio of C atoms to N atoms in the hard coating is adjusted by adjusting the flow rates of the reaction gas N ₂ gas and CH ₄ gas.

  In addition, as a bias voltage applied when forming a film by the PVD method, for example, when a hard film having a ratio of C atoms to a total amount of C atoms and N atoms of 30 at% or more is targeted, deformation resistance In the case of obtaining a harder film in view of the properties, it is preferably −100V. On the other hand, in the case of obtaining a softer film in order to obtain the toughness, it is preferably −50V.

-Hard coating mode (laminate film)
The hard film in the present invention may be a laminated film composed of a plurality of layers having different hardnesses. By comprising a plurality of layers having different hardnesses, durability is improved by a synergistic effect of high toughness due to the softer layer and deformation resistance due to the harder layer.
Further, when a ceramic film, which is a single-layer brittle material, is formed as a coating, for example, when a load is applied, breakage may progress all at once and the film may peel off. However, in the present invention, by forming a laminated film composed of a plurality of layers having different hardnesses as described above as a hard film, the destruction of the film remains between the laminations, and the wear of the film is also suppressed, so that the durability is improved. improves.

  In the case of a laminated film, the hardness of the outermost layer constituting the outermost surface of the hard coating is preferably lower than the hardness of the lower layer (second layer from the outermost surface) in contact with the outermost layer. Since the hardness of the outermost layer is lower than the hardness of the lower layer in contact with the outermost layer, the compatibility with the contacted member (target member) in contact with the metal product according to the present invention is excellent.

-Formation method of laminated film Formation of a laminated film is performed according to formation of the above-mentioned single layer film. In addition, as a method of laminating layers having different hardness by the PVD method, a method of changing the flow rate of the reaction gas in the middle of forming a coating, a method of changing the bias voltage to be applied, and the like can be given. Layers of different hardness are laminated from the time of switching.

  When laminating a plurality of layers having different hardnesses, it is preferable that the number of laminations is large from the viewpoint of suppressing the progress of the destruction of the coating. For example, it is preferable to laminate two to ten layers.

-Film thickness of hard coating Although the thickness of the hard coating in this invention is not specifically limited, 1 micrometer or more and 20 micrometers or less are preferable, and 2 micrometers or more and 10 micrometers or less are more preferable.

-Formation of nitride layer In the metal product of the present invention, before forming the hard coating on the base material, a nitride layer is formed on the surface made of a metal member, and the hard coating is formed via the nitride layer. It may be formed.

The nitride layer, for example, holds the base metal member at a temperature of 300 ° C. or more and 650 ° C. or less, and uses NH ₃ gas and H ₂ gas to form 0.001 mA / cm ² or more and 2.0 mA on the surface of the metal member. It is formed by performing glow discharge with a current density of / cm ² or less and ion nitriding.

  By interposing the nitrogen layer, only the nitride layer is cured while taking advantage of the toughness of the base material. This buffers the load received by the hard coating formed on the nitride layer, and as a result, improves the adhesion of the hard coating and makes it possible to fully exhibit the properties of the hard coating.

  Examples will be described below, but the present invention is not limited to these examples.

<Example 1>
・ Preparation of base material First, as a screw punch (base material), a finish punch for a brand name JISM4 flat head screw made by Nissei Seimitsu Kogyo Co., Ltd. having the shape shown in FIG. 1 (A) to FIG. 1 (C) Prepared a screw punch made of steel members.
Moreover, the following test pieces were prepared as film characteristic evaluation test pieces.
(Test piece 1) Flat test piece of SKH51 material 20 mm square, thickness 2 mm and mirror polished on one side (Test piece 2) φ6 mm SKH51 material drill (test piece 3) For cold forging of SKH51 material with φ15 mm and length 60 mm Press punch (test piece 4) SKD11 die with an outer diameter of 36 mm, an inner diameter of 10.5 mm, and a thickness of 7 mm

Formation of Nitride Layer First, a nitride layer is formed on the test piece for film characteristic evaluation of (test piece 1, 3, 4) excluding the molding part 2 including the protruding part 3 of the screw punch and (test piece 2) SKH51 material drill. Formed. The treatment was performed using a radical nitriding apparatus, and NH ₃ and H ₂ as reaction gases were mixed at a predetermined gas ratio, and the treatment was performed for 3 hours under the condition that the heater heating temperature was 500 ° C. or less.

Formation of Hard Film Next, a screw punch having a nitride layer formed thereon, a test piece for evaluating film characteristics of (test pieces 1, 3, 4), and a film characteristic evaluation of having no nitride layer formed (test piece 2) The test piece is placed in an arc ion plating apparatus (AIP-S20 manufactured by Kobe Steel), subjected to bombardment treatment with Ar ions, a TiSi target that is an evaporation source of metal components, and N ₂ gas that is a reaction gas. And a CH ₄ gas were introduced, and a hard coating was formed under the conditions of a coating substrate temperature of 400 ° C. and a chamber pressure of 5 Pa.
At this time, the flow rate of N ₂ gas was adjusted to 290 ml / min, the flow rate of CH ₄ gas was adjusted to 290 ml / min, and the bias voltage was adjusted to 50V.
The thickness of the hard coating obtained was 2.2 μm.

In this way, a screw punch having a nitride layer and a single layer hard coating formed on the molded part 2, and a film characteristic evaluation test of the nitride layer and a single layer hard coating (test pieces 1, 3, 4). A test piece for film characteristic evaluation of a piece and a hard coating consisting of a single layer (test piece 2) was prepared.
About the obtained screw punch and the test piece for film property evaluation of (Test pieces 1 to 4), the respective proportions of Ti atom, Si atom, C atom, and N atom in all elements constituting the hard coating by the above-described method The ratio of Si atoms to the total amount of Ti atoms and Si atoms (Si / (Ti + Si)), the ratio of C atoms to the total amount of C atoms and N atoms (C / (C + N)), by the ball-on-disk method The coefficient of friction and hardness by the nanoindentation method were measured. The results are shown in Table 1 below.

<Example 2>
In the formation of the hard coating of Example 1, a screw punch and a test piece were formed in the same manner as in Example 1 except that the flow rate of N ₂ gas was changed to 440 ml / min and the flow rate of CH ₄ gas was changed to 220 ml / min. 1-4) The test piece for film | membrane characteristic evaluation was produced.

<Comparative Example 1>
In the formation of the hard coating of Example 1, the screw punch and the test piece were made in the same manner as in Example 1 except that the flow rate of N ₂ gas was changed to 600 ml / min and the flow rate of CH ₄ gas was changed to 150 ml / min. 1-4) The test piece for film | membrane characteristic evaluation was produced.

<Comparative example 2>
In the formation of the hard coating of Example 1, the screw punch and the test piece were made in the same manner as in Example 1 except that the flow rate of N ₂ gas was changed to 670 ml / min and the flow rate of CH ₄ gas was changed to 80 ml / min. 1-4) The test piece for film | membrane characteristic evaluation was produced.

<Comparative Example 3>
In the formation of the hard coating of Example 1, a screw punch and a test piece were formed in the same manner as in Example 1 except that the flow rate of N ₂ gas was changed to 750 ml / min and the flow rate of CH ₄ gas was changed to 0 ml / min. 1-4) The test piece for film | membrane characteristic evaluation was produced.

〔Evaluation test〕
Ball-on-disk wear test The lubricity and wear resistance of the hard coating were evaluated by a ball-on-disk wear test.
The test used a “tribometer” manufactured by CSM Instruments (Switzerland). A test piece was set on a testing machine, and a SUS304 ball having a diameter of 6 mm was set on a holder. The test was performed in a non-lubricated environment under a load of 5 N, a rotation speed of 10 cm / sec, a rotation radius of 3 mm, a friction distance of 1000 m.
The result obtained by the above test is whether or not adhesion has occurred in the wear mark of the test piece after the 1000 m test, and the friction coefficient is lower than the friction coefficient (0.5 to 0.6) between general steel materials. It was evaluated according to the following evaluation criteria whether it was 0.8 or more which means the occurrence of adhesion.
◎: No adhesion, stable frictional behavior with a friction coefficient of 0.5 or less ○: No adhesion, stable frictional behavior exceeding 0.5 and less than 0.8, but △: Friction coefficient is More than 0.5 and less than 0.8, and adhesion occurred in the middle of the test. X: The coefficient of friction was 0.8 or more, and adhesion occurred.

-Drill cutting test Using the test piece of the drill of (Test piece 2), the drill cutting performance in the hard coating was evaluated by the following test.
The test method was evaluated by the number of holes formed by drilling. The cutting conditions were such that the work material was SUS plate thickness 2T, cutting speed 50 m / min, feed 0.2 mm / RPM, and through hole.

-Mold processing performance test (rear extrusion press test)
Using the test piece of the cold forging press punch described above (Test piece 3), the die processing performance of the hard coating was evaluated by the following test.
The test method uses a cold forging press knuckle joint type 160t press machine, the pre-working dimensions of SS400 (bonded product) as the work material, diameter 19.7 mm, height 14.0 mm, A shot press was performed with the test punches that had been coated in the examples and comparative examples, rolled to a thickness of 5 mm at the bottom, and this test was repeated 150 shots. The presence or absence of peeling of the coating applied to the test punch after the shot press was confirmed.
The results obtained from the above tests were evaluated according to the following evaluation criteria.
A: 150 shots could be processed. No scratches were found on the punch surface even after processing. ○: 150 shots could be processed. After processing, peeling of the film was observed on the punch surface. ×: 150 shots could not be processed, and punch galling occurred midway

-Mold processing performance test (deep drawing press test)
The die processing performance of the hard coating was evaluated by the following test using the test piece of the die of (Test piece 4).
In the test method, the performance of the die coated with the film was evaluated by the number of products formed by aluminum drawing. The material to be processed was A1100 aluminum plate thickness 0.4T, the cutting oil was a highly viscous press oil, and the processing speed was 30 spm. The number of processing was set at a constant of 30,000.

-Punch life test Using the above-mentioned screw punch, a hole was formed in a screw having no + -shaped hole formed in the countersunk head portion by the following test, and the number until the life was confirmed.
The test method evaluated the critical life by biting with a Shimada double header (NS41) with a rotation speed of 160 rpm, a screw wire material SUSXM7, a wire diameter of 3.45 mm, and a lubricating oil Naniwa-Lube.

<Example 3>
In the formation of the hard coating of Example 1, a screw punch and a test piece for evaluating film characteristics of (Test pieces 1 to 4) were prepared by the same method as in Example 1 except that the bias voltage was changed to 100V.

<Example 4>
In the formation of the hard coating film of Example 1, a screw punch and a test piece for evaluating film properties of (Test pieces 1 to 4) were prepared in the same manner as in Example 1 except that the bias voltage was changed to 200V.

<Example 5>
In the formation of the hard coating of Example 2, a screw punch and a test piece for evaluating film properties of (Test pieces 1 to 4) were prepared by the same method as in Example 2 except that the bias voltage was changed to 100V.

<Example 6>
In the formation of the hard coating film of Example 2, a screw punch and a test piece for evaluating film properties of (Test pieces 1 to 4) were prepared in the same manner as in Example 2 except that the bias voltage was changed to 200V.

  The evaluation test was also performed on the above example in the same manner as in Example 1.

<Example 7>
Except that the formation of the hard coating was changed as follows, a screw punch and a test piece for evaluating film properties of (test pieces 1 to 4) were prepared in the same manner as in Example 1.
-Formation of hard film (laminated film) The hard film of Example 2 and the hard film of Example 5 were alternately laminated 5 times, and then the outermost layer was coated with the hard film of Example 1. The film thickness of the obtained film was 2.6 μm as a whole.

  As a result of conducting a ball-on-disk wear test with the coating of Example 7, the friction coefficient was 0.2, no adhesion was seen, and the wear state was stable.

  The evaluation test was also performed on the above example in the same manner as in Example 1.

DESCRIPTION OF SYMBOLS 1 Main body 2 Molding part 3 Protrusion part 4 Main body 5 Hole 6 Head

Claims (6)

A base material in which at least a part of the surface is made of a metal member;
The surface of the metal member is formed by the PVD method, contains Ti atoms, Si atoms, C atoms, N atoms, and the ratio of the Si atoms to the total amount of Ti atoms and Si atoms is 10 at% or more. A hard coating having a ratio of the C atoms of 25 at% or less and a total amount of the C atoms and N atoms of 25 at% or more and 55 at% or less;
Having metal products.   The metal product according to claim 1, wherein the hardness of the hard coating by a nanoindentation method is 15 GPa or more and 35 GPa or less.   The metal product according to claim 1, wherein the hard coating is a single-layer film.   The metal product according to claim 1 or 2, wherein the hard coating is a laminated film of a plurality of layers having different hardnesses.   The metal product according to claim 4, wherein the laminated film has a hardness of an outermost layer constituting an outermost surface lower than a hardness of a lower layer in contact with the outermost layer. The metal product according to any one of claims 1 to 5, wherein the surface of the hard coating has a coefficient of friction of 0.1 or more and 0.4 or less by a ball-on-disk method under the following measurement conditions.
[Measurement condition]
-Opposing material: SUS304 ball of φ6mm-Load: 5N
・ Rotation speed: 10cm / sec
・ Rotating radius: 3mm
・ Friction distance: 1000m
・ Environment: Unlubricated environment

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