JP2014015636A - Hard film, metal mold and tool coated with the hard film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hard film having TiC film excellent in properties such as hardness and elastic modulus as well as adhesion with reduced droplets.SOLUTION: The hard film 112 comprises a metal nitride layer 113, a titanium carbonitride layer 114 and a titanium carbide layer 115 successively laminated from the side of base material 111. The titanium carbide layer 115 has (200) crystal plane and (111) crystal plane and fulfills the conditions of h(200)/h(111)≥1.0, 0<d(200)≤1.5 and 0<d(111)≤1.0, where h(200) and h(111) are peak heights corresponding to each crystal plane obtained by X-ray diffraction of the surface of the titanium carbide layer 115 and d(200) and d(111) are half-peak widths of the peaks corresponding to each crystal plane.

Description

  The present invention relates to a hard coating, a mold having a hard coating, and a tool.

  In recent years, in the field of automobile manufacture, high-tensile steel sheets tend to be frequently used for the purpose of improving safety and reducing the weight of a vehicle body.

  Since a high-tensile steel plate has high tension and high strength, a higher pressing force is required during press forming as compared with conventionally used pressed steel plates. Therefore, in the press working of a high-tensile steel plate, the burden on the press die is remarkably increased, so that there is a problem that the die is easily worn and the die life is short.

  As a method for suppressing the wear of the mold and extending the mold life, a method of increasing the surface hardness of the mold by forming a hard coating on the mold surface is known. Titanium carbide (TiC) coating has high hardness and is expected as a coating formed on the surface of a mold.

  As a method for forming a TiC film, a chemical vapor deposition (CVD) method and a physical vapor deposition (PVD) method are known. A TiC film formed by a CVD method is said to have excellent adhesion. However, in the case of the CVD method, since it is necessary to form a film at a temperature of about 1000 ° C., there is a problem that distortion and thermal deformation occur in the mold base material. The PVD method can form a film at a relatively low temperature, but the adhesion of the TiC film is lower than that of the CVD method.

  As a method of improving the adhesion between the TiC film and the mold base material in the PVD method, there is a method of forming a titanium nitride (TiN) film and a titanium carbonitride (TiCN) film between the TiC film and the mold base material. (For example, refer to Patent Document 1).

JP 2008-207219 A

  However, the coating film formed on the surface of the press mold requires not only adhesion to the mold base material but also characteristics such as hardness and elastic modulus. Although the adhesion between the TiC film and the mold base material is improved by the conventional method, it is required to further improve the hardness, elastic modulus and the like of the outermost TiC film.

  Further, in the case of the PVD method, particles of several μm to several tens of μm called droplets are generated, and a phenomenon of being taken into the film is likely to occur. When droplets are generated, the hardness and elastic modulus of the coating are decreased, and the surface roughness is increased.

  These problems may occur not only in press dies but also in tools that require hardness and wear resistance.

  The present invention solves these problems that may occur when a TiC film is formed using the PVD method, and is excellent not only in adhesion to the base material but also in properties such as hardness and elastic modulus and reducing droplets. An object of the present invention is to realize a hard coating and a mold and a tool having the hard coating.

The hard film according to the present invention includes a metal nitride layer, a titanium carbonitride layer, and a titanium carbide layer that are formed on the surface of the base material and are sequentially provided from the base material side. ) Crystal plane and (111) crystal plane and satisfy the following formulas 1 to 3.
h (200) / h (111) ≧ 1.0 Formula 1
0 <d (200) ≦ 1.5 Formula 2
0 <d (111) ≦ 1.0 Formula 3
However, h (200) is the peak height of the (200) crystal plane obtained when X-ray diffraction is performed on the surface of the TiC layer, and h (111) is the peak height of the (111) crystal plane. D (200) is the half width of the peak of the (200) crystal plane, and d (111) is the half width of the peak of the (111) crystal plane.

  The hard coating of the present invention not only has excellent adhesion to the base material, but also has a high orientation ratio of (200) crystal plane and excellent crystallinity in (200) crystal plane and (111) crystal plane. A TiC film is provided. For this reason, the hardness and elastic modulus of the TiC film are large, and the durability of the mold and the tool can be greatly improved.

  The hard coating of the present invention may have a hardness of 30 GPa or more and an elastic modulus of 310 GPa or more.

The hard coating of the present invention may have 90 droplets / mm ² or less of droplets having an area on the surface of 5 μm ² or more.

  In the hard coating of the present invention, the metal nitride layer may be a titanium nitride layer or a chromium nitride layer, or may be a chromium nitride layer and a titanium nitride layer sequentially provided from the base material side.

  The press die of the present invention has the hard coating of the present invention.

  The tool of the present invention has the hard coating of the present invention.

  According to the hard coating, the mold and the tool having the hard coating according to the present invention, the hard coating and the TiC film having excellent properties such as hardness and elastic modulus as well as adhesion to the base material and reduced droplets are included. Molds and tools can be realized.

It is sectional drawing which shows a part of press die of this embodiment. It is sectional drawing which shows a part of press die of this embodiment. It is a figure which shows the coordinate system for evaluating magnetic field distribution. It is a figure which shows the metal mold | die used for a bead pull-out test. It is a figure which shows the implementation method of a bead pull-out test. It is a figure which shows the measurement model of magnetic field distribution.

  In the following embodiments, a press mold will be described as an example, but the hard coating of the present embodiment can be formed not only on the surface of the press mold but also on the surface of a tool or the like. .

  FIG. 1 shows a cross-sectional configuration of a press mold according to the present embodiment. In the press mold of this embodiment, a hard coating 112 is formed on the surface of a mold base material 111.

  As the mold base material 111, various materials conventionally used as a press mold can be used. Specifically, die steels such as SKD11 and SKD61, high speed steels such as SKH51, various tool steels such as SK5 and SKS3, carbide materials, and stainless steel materials such as SUS440C, SUS420J2, and SUS304 can be used. Among these, a die steel such as SKD11 and a high speed steel such as SKH51 in which secondary hardening occurs due to high-temperature tempering are particularly preferable from the viewpoint of obtaining high hardness and improving wear resistance by strengthening backup force.

  The surface of the mold base 111 on which the hard coating 112 is formed preferably has an arithmetic average surface roughness Ra of 0.1 μm or less. Since the hard coating 112 formed by the physical vapor deposition (PVD) method is a dense and highly smooth coating, the surface state of the surface of the mold base 111 is easily reflected as the surface state of the hard coating 112. For this reason, by making the surface roughness of the mold base material 111 into such a range, the slipperiness on the surface of the hard coating 112 can be further improved.

  As shown in FIG. 1, the hard coating 112 has a metal nitride layer 113, a titanium nitride carbide (TiCN) layer 114, and a titanium carbide (TiC) layer 115 that are sequentially formed from the mold base material 111 side. . The metal nitride layer 113 can be a titanium nitride (TiN) layer, a chromium nitride (CrN) layer, or the like.

By providing the metal nitride layer 113 on the mold base material 111 side and providing the TiCN layer 114 between the metal nitride layer 113 and the TiC layer 115, the adhesion of the hard coating 112 as a whole is improved. The TiCN layer 114 between the metal nitride layer 113 and the TiC layer 115 is TiC _x N _y (where x + y = 1, x <1, x gradually increases so as to approach 1 as the distance from the TiN layer surface increases. ). By making the TiCN layer 114 a layer having a gradient composition in which the ratio of C and N gradually changes, the adhesion between the metal nitride layer 113 and the TiC layer 115 can be further improved.

  The metal nitride layer 113 may be a laminate of a CrN layer 113a and a TiC layer 113b that are sequentially formed from the mold base material 111 side as shown in FIG.

  The thickness of the hard coating 112 is not particularly limited, but is preferably 12 μm or less, and more preferably 8 μm or less from the viewpoint of maintaining a higher adhesive force while maintaining the internal stress balance of the coating. Further, the total thickness of the metal nitride layer 113 and the TiCN layer 114 is preferably about 2 μm to 8 μm, and preferably about 3 to 5 μm from the viewpoint of keeping the adhesion of the hard coating 112 higher. More preferred. Further, the total thickness of the metal nitride layer 113 and the TiCN layer 114 is preferably about 2 μm to 8 μm, and preferably about 3 to 5 μm from the viewpoint of keeping the adhesion of the hard coating 112 higher. More preferred. The thickness of the TiC layer 115 is not particularly limited, but is preferably 1 μm or more.

  1 and 2 clearly show the boundaries between the layers constituting the hard coating 112, but the boundaries between the layers may not be clearly specified depending on the manufacturing method, film thickness, and the like. In the TiCN layer 114, it is preferable that the ratio of C and N is continuously changed because peeling in the film is less likely to occur. However, it may change stepwise.

  The durability of the press mold greatly varies depending on the characteristics of the TiC layer 115 provided on the outermost surface of the hard coating 112. The characteristics of the TiC film are affected by the crystal plane of TiC. The inventors of the present application examined the influence of the crystal orientation ratio ((200) / (111)) and crystallinity of the (200) plane to the (111) plane on the hardness and elastic modulus of the TiC film. As a result, it was found that the hardness and elastic modulus of the TiC film increase when (200) / (111) is large and the crystallinity of the (200) plane and (200) plane is good.

  Specifically, by forming the TiC layer 115 satisfying the following formulas 1 to 3, the hardness and elastic modulus of the TiC layer 115 can be greatly improved, and the durability of the press mold can be improved.

h (200) / h (111) ≧ 1.0 Formula 1
0 <d (200) ≦ 1.5 Formula 2
0 <d (111) ≦ 1.0 Formula 3
However, h (200) is the peak height of the crystal plane obtained by (200) X-ray analysis, h (111) is the peak height of the (111) crystal plane, and d (200) is (200). The half width of the peak of the crystal plane, and d (111) is the half width of the peak of the (111) crystal plane. h (200), h (111), d (200), and d (111) can be obtained by the X-ray diffraction method described in detail in Examples.

  The larger h (200) / h (111) is better. Specifically, h (200) / h (111) is preferably 1.2 or more, and more preferably 1.5 or more. The upper limit is not particularly limited. d (200) is preferably 1.2 or less, and more preferably 1.0 or less. d (111) is preferably 0.9 or less, and more preferably 0.5 or less. The lower limit of the half width is not particularly limited, but theoretically becomes larger than 0.

  In order to exhibit sufficient durability as a press mold, the TiC layer 115 preferably has sufficient hardness and elastic modulus. Specifically, the hardness of the TiC layer 115 is preferably 30 GPa or more. The elastic modulus of the TiC layer 115 is preferably 280 GPa or more, more preferably 290 GPa or more, and further preferably 300 GPa or more. The hardness and elastic modulus can be measured by the nanoindentation method described in detail in the examples.

  In addition, the surface of the TiC layer 115 is preferably sufficiently smooth. Specifically, the maximum roughness on the surface of the TiC layer 115 is preferably less than 10 nm, more preferably 8 nm or less, and further preferably 5 nm or less. The maximum roughness can be measured by a method using a scanning probe microscope (SPM) described in detail in Examples.

Furthermore, it is preferable that the TiC layer 115 has as few droplets as possible. Specifically, the number of droplets having an area per 1 mm ^{2 of the} TiC layer 115 of 5 μm ² or more is preferably 90 or less, more preferably 70 or less, and further preferably 50 or less. preferable. The number of droplets can be measured by a method using a stereomicroscope described in detail in the examples.

  The hard coating 112 preferably has sufficient adhesion to the mold base material 111. Specifically, the scratch strength of the hard coating 112 is preferably greater than 30N, more preferably 35N or more, and even more preferably 40N or more. The scratch strength can be measured by a scratch test described in detail in Examples.

  The mold on which the hard coating 112 is formed preferably has sufficient bead drawing characteristics. Specifically, the bead drawing break pressure load is preferably greater than 30 kN, more preferably 31 N or more, and even more preferably 33 kN or more. The bead pull breaking pressure load can be measured by a bead pull test described in detail in the examples.

  The hard coating 112 is formed under the condition that the mold base 111 is not exposed to a high temperature in order to suppress the occurrence of distortion and deformation of the mold base 111 due to heat. It is preferable that the mold base material 111 formed of high-speed steel or die steel can be formed at a temperature lower than the tempering temperature. Therefore, the hard coating 112 is formed by a physical vapor deposition (PVD) method. In particular, a cathodic arc ion plating method using a cathodic arc apparatus as an ion source is preferable.

  The film forming apparatus includes, for example, a chamber, a cathode, an anode, and a work holder provided in the chamber. The cathode is a target holder, and a target is fixed on the surface thereof. The anode is provided so as to surround the cathode. The work holder is a rotary table, and a work (substrate) is placed on the work holder. A heater is installed in the chamber, and the placed workpiece can be heated to an arbitrary temperature.

  An arc power source is connected between the cathode and the anode, and arc discharge can be generated between the cathode and the anode. A bias power source is connected to the work holder, and a bias voltage can be applied to the work. By generating arc discharge, the target can be evaporated and ionized. Ions can be accelerated by a bias voltage applied to the workpiece and deposited on the surface of the workpiece.

  The cathode is provided with a magnet or an electromagnetic coil which is a magnetic force generation source. Magnetic lines of force extending from the cathode to the workpiece are formed by a magnet or electromagnetic coil. A part of the electrons (e) generated by the arc discharge moves so as to be wound around the magnetic field lines, and the electrons introduced into the chamber are turned into plasma by colliding with the gas molecules in the chamber. Since the magnetic lines of force extend to the workpiece, the generated ions can efficiently reach the workpiece. If the target is titanium and nitrogen gas is introduced into the chamber, a TiN film can be formed. If the inside of the chamber is a mixed gas of nitrogen gas and hydrocarbon gas, a TiCN film can be formed. If the inside of the chamber is a hydrocarbon gas, a TiC film can be formed. If the target is chromium and nitrogen gas is introduced into the chamber, a CrN film can be formed.

  In order to form a film having a high density on the surface of the workpiece, it is important to supply sufficient energy for forming a stable atomic arrangement to the atoms supplied to the surface of the workpiece. As a method for supplying sufficient energy to atoms on the surface of the workpiece, it is conceivable to increase the temperature of the workpiece. However, in the case of a press die, it is necessary to suppress thermal deformation or the like of a workpiece that is a die base material, and it is difficult to sufficiently raise the temperature of the workpiece. As a method of supplying sufficient energy other than heating the workpiece, it is conceivable to increase the energy of ions that reach the workpiece. As a method for increasing the energy of ions reaching the workpiece, it is conceivable to increase the strength of the magnetic field (vertical magnetic field) from the cathode toward the workpiece. By increasing the strength of the vertical magnetic field, the density of ions reaching the workpiece is improved, and the substrate current density, which is an index of the energy of ions reaching the workpiece, is also increased.

  Thus, in the film formation, it is preferable to increase the magnetic field strength from the center of the target to the workpiece direction. However, the generated magnetic field lines have the property of returning to the opposite pole side. This tendency becomes more conspicuous as the position is more outward from the center of the magnetic force generation source, and the magnetic lines of force try to return to the opposite pole with a short trajectory. Accordingly, the amount of ions reaching the workpiece decreases from the workpiece direction around the target, and the substrate current density cannot be increased.

  The inventors of the present application have found that the magnetic flux density in the workpiece direction is improved 2 to 4 times by controlling the horizontal magnetic field. Consider a coordinate system as shown in FIG. 3 in which the direction orthogonal to the main surface of the target and extending toward the workpiece is the X direction (vertical direction) and the radial direction of the target is the r direction (horizontal direction). Assume that the center of the target is X = 0, r = 0, the radius of the target is R, and the workpiece is on the plus side of X. When the magnetic flux density at the position of X = 2R and r = 2R is 1.8 mT or more and 10 mT or less, the vector ratio of the r-direction magnetic force vector (r-component magnetic force vector) to the X-direction magnetic force vector (X-component magnetic force vector) (| If Z / r |) is 2.5 or less, ions generated from the cathode can be guided in the work direction without diffusing. As a result, the substrate current density can be increased, and a coating film having a high density can be formed. Further, h (200) / h (111) can be increased and the values of d (200) and d (111) can be suppressed to be small.

The cathode current value is preferably higher, preferably 120 A or more, more preferably 130 A or more, and even more preferably 140 A or more. The higher the cathode current, the greater the effect of directing the ions generated from the cathode toward the workpiece without diffusing, and the amount of ions generated relative to the amount of droplets generated is relatively large, and the proportion of droplets occupying the film Can be suppressed. On the other hand, it is preferable not to make the cathode current too high in order to suppress the temperature rise of the workpiece to 500 ° C. or less. For this reason, the cathode current is preferably 300 A or less, and more preferably 280 A or less. The current density of the workpiece is determined by the energy of ions reaching the workpiece, but is preferably higher. Specifically, it is preferably 1.0 mA / cm ² or more, and more preferably 1.2 mA / cm ² or more.

  It is expected that the higher the pressure in the chamber, the higher the ion density and h (200) / h (111) will be. However, in order to suppress the decrease in d (200) and d (111), it is preferable not to make it too high. For this reason, the pressure in the chamber is preferably 2.0 Pa or more, and more preferably 2.5 Pa or more. Moreover, 3.5 Pa or less is preferable and 3.0 Pa or less is more preferable.

The hydrocarbon gas introduced into the chamber when forming the TiC layer is not particularly limited, but methane (CH ₄ ), ethane (C ₂ H ₆ ), propane (C ₃ H ₈ ), butane (C ₄ H) _10), pentane (C ₅ H _12), hexane (C ₆ H _14), heptane (C ₇ H _16), octane (C ₈ H _18), nonane (C ₉ H _20), decane (C ₁₀ H ₂₂₎ alkane can be represented by C _n H _{n + 2} of the formula such as, ethylene (C ₂ H _4), propylene (C ₃ H _6), butene (C ₄ H _8), pentene (C ₅ H _10), hexene (C _{6 H 12) C n H 2n} (n alkenes that can be represented by the chemical formula of ≧ 2), acetylene such (C ₂ H _2), propyne _{(C 3 H 4) C n} H 2n (n ≧ 2) of the formula such as in alkynes can be expressed, and benzene (C ₆ H _6), toluene _{(C 6 H 5 CH 3)} , dimethylbenzene _{C 6 H 4 C 2 H 6} ), can be used aromatic hydrocarbons such as trimethylbenzene _{(C 6 H 3 C 3 H} 9). These hydrocarbons may be used alone or in combination.

  In the present embodiment, an example in which the base material is a die base material of a press mold is shown. However, the base material is a base for cold forming tools such as punches, drills, end mills, taps, and rolling dies, cutters, cutting blades, punching tools, and processing devices that require wear resistance and hardness. It may be a material. The hard coating of this embodiment that can be formed without exposing the base material to a high temperature is also very useful for a base material such as a tool that adjusts the hardness by quenching or the like. By forming the hard film of the present embodiment on the surface of the base material of the tool, a tool that hardly peels off the coating and hardly wears out can be realized.

(Evaluation method)
-Crystal structure-
The crystal structure of the coating was measured using an X-ray diffractometer (Rigaku Corporation: RINT2500 VHF). An X-ray diffraction spectrum was measured with an X-ray incident angle of 2 ° and a diffraction angle (2θ) of 20 ° to 120 °. Copper was used for the target. The peak intensity of the (200) plane of TiC was h (200), the half width was d (200), the peak intensity of the (111) plane was h (111), and the half width was d (111).

-Physical properties-
The hardness and elastic modulus (Young's modulus) of the coating were measured with a nanoindentation device (Hysitron: TI-950 Triboindenter). The diamond indenter was a triangular pyramid Berkovich type with a ridge angle of 115 °, the indentation load of the diamond indenter was 1000 μN, the load-displacement curve was obtained, and the hardness and elastic modulus were calculated from the obtained load-displacement curve.

−Roughness shape−
The roughness of the coating was measured using a nanoindentation device (Hysitron: TI-950 Triboindenter) as a scanning probe microscope. The sample was lapped with diamond having a particle diameter of 1 to 10 μm after film formation at a probe load of 70 nN, and scanned at a scan speed of 0.01 to 3 Hz. A reciprocating scan was performed in the range of 10 μm, and the maximum roughness was obtained from the average value of the forward and return paths.

−Scratch characteristics−
The scratch properties of the coating were measured with a scratch tester (CSEM Co .: Revetest Scratch Tester). The test was performed in accordance with the Japan Society of Mechanical Engineers standard JSME S010 (1996).

-Bead pulling characteristics-
The bead pulling characteristics of the press mold on which the film was formed were measured as follows. A press mold 310 including a male mold 311 and a female mold 312 shown in FIG. 4 was prepared. As shown in FIG. 5, a steel plate 315 made of a high-tensile steel material SPFC980Y (100k class high tensile) of 20 × 300 × 1.4 mm was sandwiched between press dies 310. The press mold 310 sandwiching the steel plate 315 was set in a small press machine, and one end of the sandwiched steel plate 315 was pulled at a constant speed of 500 mm / min while gradually pressurizing. The pressurizing load P of the small press when the steel plate 315 broke was taken as the breaking pressurizing load.

-Droplet-
The droplets on the coating surface were measured visually using a stereomicroscope (Leica: M165C). The measurement range was 1.6 mm × 1 mm, and those with a projected area of 5 μm ² or more were counted as droplets.

-Magnetic field distribution-
As shown in FIG. 6, the distribution of the magnetic field in the target was determined by measuring the magnetic fields in the X axis, Y axis, and Z axis with a gauss meter (manufactured by Electronic Magnetic Industry: GM-301). X, Y, and Z component magnetic force vectors were calculated from the measured values. The Z-axis component was replaced with the r-direction component. Since the proportion of the Y component is 3% or less, the magnetic flux density B was set to ((X component magnetic force vector) ² + (r component magnetic force vector) ² ) ^0.5 .

Example 1
First, a set of a male side die base material and a female side die base material made of SKD11 having the shape and dimensions shown in FIG. 6 and having a mirror-finished surface of about Ra = 0.05 μm was prepared.

A coating film was formed on the surfaces of the male side die base material and the female side die base material by an arc ion plating method using a film forming apparatus using arc ion plating. Specifically, first, the male mold base and the female mold base were placed on the work holder of the film forming apparatus. Pure titanium (JIS type 2) was used as a target. Subsequently, the pressure in the chamber was reduced to 3 × 10 ⁻³ Pa. The temperature of the male side mold base material and the female side mold base material was set to 450 ° C. by a heater. Subsequently, while supplying argon (Ar) gas from the gas inlet, the pressure in the chamber is maintained at a predetermined pressure by exhausting, and argon bombarding is performed by discharging between the workpiece and the chamber, and gold The surface of the mold base material was cleaned.

  Next, after the supply of Ar gas was stopped, the supply gas was changed to nitrogen gas, and the pressure was maintained at 2.7 Pa. At the same time, arc discharge was generated to evaporate the target made of Ti. The evaporated Ti and nitrogen were ionized by arc discharge and supplied toward the male mold base and the female mold base to which a bias voltage was applied, and a TiN layer was formed on each surface. After the formation of the TiN layer, the supply gas was gradually switched from nitrogen gas to methane gas to form a TiCN layer. After the TiCN layer was formed, the supply gas was changed to only methane gas, and the TiC layer was formed. The obtained coating had a TiN layer thickness of about 1 μm, a TiCN layer thickness of about 2 μm, and a TiC layer thickness of about 1 μm.

  The cathode current during film formation was 160 A. The X component magnetic force vector was 1.3 mT, the Y component magnetic force vector was 0 mT, the Z component (r direction component) magnetic force vector was 2.7 mT, the magnetic flux density was 3.0 mT, and the vector ratio was 2.08. The positive value of the magnetic force vector represents the N pole, and the negative value represents the S pole.

The work-side current density when forming the TiC layer was 1.3 mA / cm ² . H (200) / h (111) of the obtained film was 2.4, d (200) was 0.94, and d (111) was 0.38. The hardness was 34.5 GPa, the elastic modulus was 315.8 GPa, and the maximum roughness was 4 nm. The load at which film peeling occurred in the scratch test was 41.3 N, and the breaking load in the bead pull-out test was 33 kN. The number of droplets was 38 / mm ² .

(Example 2)
A film was formed in the same manner as in Example 1 except that the pressure in the chamber was 3.0 Pa. The work-side current density when forming the TiC layer was 1.0 mA / cm ² . H (200) / h (111) of the obtained film was 1.2, d (200) was 1.1, and d (111) was 0.90. The hardness was 30.3 GPa, the elastic modulus was 290.0 GPa, and the maximum roughness was 8 nm.

(Comparative Example 1)
The cathode voltage during film formation is 150 A, the X component magnetic force vector is 0.6 mT, the Y component magnetic force vector is 0.1 mT, the Z component magnetic force vector is 1.6 mT, the magnetic flux density is 1.7 mT, and the vector ratio is It was set to 2.67. Other conditions were the same as in Example 1 to form a film. The work-side current density when forming the TiC layer was 0.5 mA / cm ² . H (200) / h (111) of the obtained film was 0.8, d (200) was 1.7, and d (111) was 1.6. The hardness was 29.8 GPa, the elastic modulus was 277.5 GPa, and the maximum roughness was 16 nm. The load at which film peeling occurred in the scratch test was 29.6 N, and the breaking load in the bead pull-out test was 30 kN. The number of droplets was 95 / mm ² .

(Comparative Example 2)
A coating was formed in the same manner as in Comparative Example 1 except that the pressure in the chamber was 4.0 Pa and the cathode voltage was 160 A. The work-side current density when forming the TiC layer was 0.6 mA / cm ² . H (200) / h (111) of the obtained film was 0.90, d (200) was 2.2, and d (111) was 2.0. The hardness was 13.3 GPa, the elastic modulus was 130.0 GPa, and the maximum roughness was 11 nm.

(Comparative Example 3)
A coating was formed in the same manner as in Example 1 except that the pressure in the chamber was 3.5 Pa and the cathode current was 160 A. The work-side current density when forming the TiC layer was 0.8 mA / cm ² . H (200) / h (111) of the obtained coating was 1.0, d (200) was 1.3, and d (111) was 1.1. The hardness was 22.1 GPa, the elastic modulus was 199.2 GPa, and the maximum roughness was 10 nm.

  The evaluation results in each example and embodiment are summarized in Table 1. In Examples 1 and 2 in which a film having a large h (200) / h (111) and a small d (200) and d (111) was formed, the hardness and elastic modulus were larger than those of the comparative example, and the press mold Suitable as The maximum roughness was also reduced. Furthermore, there were few droplets and the results of the scratch test and bead pull-out test were also excellent.

  The hard coating according to the present invention, a mold and a tool having a hard coating, not only have excellent adhesion between the hard coating and the base material, but also have excellent properties such as hardness and elastic modulus. It is useful in the field of

111 Mold base material 112 Coating 113 Metal nitride layer 113a CrN layer 113b TiN layer 114 TiCN layer 115 TiC layer 310 Pressing die 311 Male die 312 Female die 315 Steel plate

Claims (7)

A metal nitride layer formed on the surface of the base material and sequentially provided from the base material side, a titanium carbonitride layer, and a titanium carbide layer,
The titanium carbide layer has a (200) crystal plane and a (111) crystal plane, and satisfies the following formulas 1 to 3.
h (200) / h (111) ≧ 1.0 Formula 1
0 <d (200) ≦ 1.5 Formula 2
0 <d (111) ≦ 1.0 Formula 3
However, h (200) is the peak height of the (200) crystal plane obtained when X-ray diffraction is performed on the surface of the titanium carbide layer, and h (111) is the (111) crystal plane. The peak height, d (200) is the half width of the peak of the (200) crystal plane, and d (111) is the half width of the peak of the (111) crystal plane.   The hard film according to claim 1, wherein the hardness is 30 GPa or more and the elastic modulus is 310 GPa or more. 3. The hard coating according to claim 1, wherein the number of droplets having an area of 5 μm ² or more on the surface is 90 / mm ² or less.   The hard film according to any one of claims 1 to 3, wherein the metal nitride layer is a titanium nitride layer or a chromium nitride layer.   The hard film according to any one of claims 1 to 3, wherein the metal nitride layer is a chromium nitride layer and a titanium nitride layer provided in order from the base material side.   A press mold, wherein the hard film according to any one of claims 1 to 5 is provided.   A tool provided with the hard coating film according to any one of claims 1 to 5.

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