TW202228874A - Wrapping mold for shearing and machining and manufacturing method thereof capable of precisely machining material having high hardness and thinner board thickness - Google Patents

Abstract

The invention provides a wrapping mold for shearing and machining and its manufacturing method for a material, which has high hardness and thinner board thickness, having high durability in the shearing and machining. In the wrapping mold for shearing and machining and its manufacturing method, the wrapping mold for shearing and machining has a hard film comprising AlCrSi nitride on the surface of the mold base material, and the film thickness of the hard film is 0.3 [mu]m to 2.0 [mu]m. The ratio for the film thickness of the hard film of the edge portion of the wrapping mold relative to the film thickness of the hard film of the plane portion of the wrapping mold is 0.6 to 1.4.

Description

Covering die for shearing and method for producing the same

The present invention relates to a covering die for shearing and a manufacturing method thereof.

Conventionally, for plastic working such as forging and stamping, dies using steels represented by tool steels such as cold die steel, hot die steel, and high-speed steel, or cemented carbide as the base material are used. Wear resistance is required. As an effective method for improving the wear resistance, it is known to coat a hard film on the working surface of a mold using a physical vapor deposition (PVD) or chemical vapor deposition (CVD) method.

Among the hard coatings, AlCr nitride (AlCrN) or AlCrSi nitride (AlCrSiN) coatings have high durability even at high temperatures of 1000°C or higher, so various proposals have been proposed for mold applications. For example, as shown in Patent Document 1, the applicant has proposed a covered mold for plastic working, which aims to significantly improve the scratch resistance and wear resistance of the mold working surface, characterized in that the surface of the mold base is covered with Nitride containing AlxCrySiz (where x, y, z represent atomic ratio, x+y+z=100, and x, y, z≠0), and according to Japanese Industrial Standard (JIS)-B The surface roughness of -0601 (2001) is 0.06 μm or less in terms of arithmetic mean roughness Ra, and the maximum height Rz is a hard coating of 1.0 μm or less. In addition, Patent Document 1 also proposes a method for producing a covering mold for plastic working, which covers the surface of a mold base material with a nitride (wherein x includes AlxCrySiz) by a sputtering method using a target. , y, z represent atomic ratios, x+y+z=100, and x, y, z≠0) of the hard coating method, characterized in that the sputtering power input into the target is 5 kW or more, The bias voltage on the mold base material increases toward the negative side above -100 V. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2010-284710

[The problem to be solved by the invention] In precision shearing, in which the quality of the shear surface of the material to be processed must be high-quality, in order to ensure the quality of the shear surface, it is necessary to precisely control the upper die (punch) and lower die ( die) clearance. Among them, when shearing a sheet material of several tens of μm to several hundreds of μm, unless an appropriate gap is set in μm units, a desired sheared plane cannot be obtained, and product defects are likely to occur. Such precision is required, but, on the other hand, the high strength of the material to be processed, such as an amorphous soft magnetic material or a corson alloy, may cause early breakage of the mold. In addition, in order to perform precise and fine shearing, the size of the mold is also reduced, and in the conventional film forming method, it may be difficult to uniformly form a hard film on a small mold. Patent Document 1 is an excellent invention that can improve wear resistance, but it does not deal with the problems that arise when processing a thin and high-hardness material as described above, or when using a small-sized covering mold, and research remains. 's room. Therefore, an object of the present invention is to provide a covering die for shearing, which can be processed with high precision in shearing of a material with high hardness and a thin plate thickness, and a method for producing the same, and also a method for producing the same. Has high durability. [Means of Solving Problems]

The present invention has been made in view of the above-mentioned problems. That is, one aspect of the present invention is a sheathing mold for shearing, which has a hard film containing a nitride of AlCrSi on a surface of a mold base material, and wherein the sheathing mold for shearing has a surface of the hard film. The film thickness is 0.3 μm to 2.0 μm, and the ratio of the film thickness of the hard film covering the edge portion of the mold to the film thickness of the hard film covering the flat surface portion of the mold is 0.60 to 1.40.

Another aspect of the present invention is a method for producing a covered mold for shearing, wherein a hard film containing a nitride of AlCrSi is coated on the surface of a mold base material, and in the method for producing a covered mold for shearing , the hard film is coated on the mold substrate with a film thickness of 0.3 μm to 2.0 μm using high-output pulse sputtering, and a mixed gas of N ₂ and Ar is used during the high-output pulse sputtering, and the flow rate of N ₂ gas is The ratio to the Ar gas flow rate is 0.65 to 1.60. Preferably, the maximum power of the high-output pulse sputtering is 50 kW to 130 kW. [Effect of invention]

ADVANTAGE OF THE INVENTION According to this invention, in the shearing process of the material with high hardness and thin plate thickness, it can process with high precision, and can obtain the covering die for shearing which also has high durability.

Embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments listed here, and can be appropriately combined or improved without departing from the technical idea of the invention. The covering die of the present invention is suitable for use as a die for shearing, and as a specific example, it can be applied to blank processing (cutting, punching, notch processing) using an upper die (punch) and a lower die (die). etc.), punching. Preferably, it is used for the process (fine cutting process) which narrows the clearance gap between an upper die and a lower die, such as fine blanking and fine blanking. The present invention exhibits excellent effects by being particularly suitable for small molds. For example, it is preferable to apply to a die for punching processing having an area of a punch face of 2000 mm ² or less (preferably 1000 mm ² or less, more preferably 500 mm ² or less, and still more preferably 100 mm ² or less). In addition, it is effective for processing thin plates and strip-shaped materials with high hardness and a thickness of 500 μm or less (for example, electrical steel sheets of HV180 or more, amorphous materials, Casson alloys, etc.). More preferably, it is used for a thin plate and a thin strip-shaped material with a thickness of 150 μm or less.

First, the covering die for shearing processing according to the embodiment of the present invention (hereinafter also referred to only as a covering die) will be described. First, the cover mold of the present embodiment has a hard coating including a nitride of AlCrSi (AlCrSiN) on the surface of the mold base material. The damage form of the covering die for shearing is loss due to the detachment of particles of the hard coating. The AlCrSiN film has a finer grain size than the AlCrN film used in the past, and has a granular fracture surface structure. As a result, AlCrSiN suppresses the drop-off of particles of the hard coating, and tends to be superior in wear resistance to that of the AlCrN film. In addition, the hard film of this embodiment is formed into a film at least on the working surface of the mold (the surface that is in contact with the workpiece during machining). A nitride film of AlxCrySiz is preferably used (wherein x, y, and z represent atomic ratios, x+y+z=100, 50<x<75, 20≦y<50, 0<z≦10). Here, the covering mold of the present invention may further have a film having a composition different from that of the above-mentioned hard coating, within the range that does not impair the effect of the present invention. For example, in order to improve the adhesion force, a base film having a thickness of 0.01 μm to 0.1 μm or less may be formed between the base material and the hard film. The base film is preferably a nitride film of one or two or more elements selected from the group 4, 5, and 6 metals of the periodic table, Al, Si, and B.

The thickness of the hard film formed on the mold base material of the present embodiment is 2.0 μm or less. For example, when punching a thin plate-like material with a plate thickness of 50 μm, in general, the upper limit of the gap between the die and the punch is 5 μm, which is 10% of the plate thickness. In such machining with a very small gap, if the hard film covering the mold is too thick, there is a possibility that the machining accuracy will decrease, the material may be abnormally fractured, or the molds will interfere with each other. Therefore, in this embodiment, the hard film is The upper limit of the film thickness was set to 2.0 μm. On the other hand, even if the hard film is too thin, the effect of improving the durability of the mold is not easily obtained, so the lower limit of the film thickness is made 0.3 μm. A preferable upper limit of the film thickness is 1.0 μm, and a more preferable upper limit of the film thickness is 0.6 μm. In addition, the preferable lower limit of the film thickness is 0.5 μm.

The covering mold according to the present embodiment is characterized in that the ratio of the film thickness of the hard film covering the edge portion of the mold to the film thickness of the hard film covering the flat surface portion of the mold (hereinafter also simply referred to as film thickness ratio) is 0.60. ~1.40. By having the above-described film thickness ratio, the covering die of the present embodiment can suppress damage to the die during shearing of a high-hardness and thin-plate material, and can perform high-precision machining. When the said film thickness ratio exceeds 1.40, since the film thickness of the edge part of a metal mold|die is too thick, there exists a possibility that a peeling of a film or a chip|tip of a base material may generate|occur|produce by the concentration of shear stress. On the other hand, when the film thickness ratio is less than 0.60, the film thickness of the edge part is very thin with respect to the film thickness of the mold center part, or the film is not formed in the edge part, and the effect of the present invention may not be obtained. The lower limit of the preferable film thickness ratio is 0.65, the lower limit of the preferable film thickness ratio is 0.70, and the lower limit of the preferable film thickness ratio is 0.75. In addition, the upper limit of the preferable film thickness ratio is 1.35, and the upper limit of the preferable film thickness ratio is 1.30. In addition, the "film thickness of the edge part" in this embodiment means the film thickness measured within 5 μm from the edge (blade), and the "film thickness of the flat part" means the thickness of the work surface at least 0.5 mm away from the edge. Film thickness at any location.

In order to further improve the adhesiveness between the substrate and the hard film, the cover mold of the present embodiment preferably has an arithmetic mean roughness Ra of 0.05 μm or less defined in accordance with JIS-B-0601 (2001) on the surface of the substrate. More preferable Ra is 0.02 μm or less, and still more preferable Ra is 0.01 μm or less.

Next, the manufacturing method of the covering die for shearing processing of this invention is demonstrated. The production method of the present invention was carried out to obtain a hard coating having a film thickness of 0.3 μm to 2.0 μm. Furthermore, a coating die for shearing can be effectively obtained in which the ratio of the film thickness of the hard coating on the edge portion of the coating die to the film thickness of the hard coating on the flat surface portion of the coating die is 0.60 to 1.40. (first coating step) In the manufacturing method of this embodiment, the hard film|membrane containing the nitride of AlCrSi is coat|covered on the mold base material by high output pulse sputtering. High output pulse sputtering is, for example, one of physical vapor deposition methods called HiPIMS (High Power Impulse Magnetron Sputtering) or HPPMS (High Power Pulse Magnetron Sputtering). Since the conversion rate is high, it is possible to form a hard film that is dense, has high adhesion to the substrate, and has few droplets (particles attached to the surface of the film). FIG. 1 shows an example of the hard coating of the present embodiment formed by high-output pulse sputtering. 1 , it was confirmed that the hard film 1 formed on the substrate 2 by the high-output pulse sputtering had no droplets on the surface, and a film having a smooth surface could be formed.

In the production method of the present embodiment, a mixed gas of N ₂ and Ar is used as the reaction gas at the time of hard film formation. The film formation method of the AlCrSi nitride film of the present embodiment is performed by the high-output pulse sputtering method using an AlCrSi target and introducing a gas containing N ₂ . Here, in the case of a compound mode in which the AlCrSi target reacts with N ₂ to form nitrides on the target surface, the film formation rate rapidly decreases. Therefore, in this embodiment, the N ₂ gas flow rate is set to the Ar gas flow rate. The ratio was adjusted to 1.60 or less to form a hard coating. By performing film formation at this gas flow rate ratio, it is possible to suppress complete switching to the compound mode during film formation. A preferable upper limit of the ratio of the N ₂ gas flow rate to the Ar gas flow rate is 1.50, more preferably 1.40. On the other hand, when the ratio of the N ₂ gas flow rate to the Ar gas flow rate is too small, there is a possibility that the formation of the hard film on the edge portion of the mold is insufficient. In addition, a large amount of hcp-AlN, which is a fragile phase, is precipitated in the hard coating, and the hardness of the hard coating may decrease. In order to suppress the precipitation of this hcp-AlN and to form a hard coating with a sufficient thickness on the edge of the mold, the ratio of the N ₂ gas flow rate to the Ar gas flow rate in the present invention is 0.65 or more. A preferable lower limit of the ratio of the N ₂ gas flow rate to the Ar gas flow rate is 0.70, more preferably 0.80. Here, in order to perform stable coating, the Ar gas flow rate can be set to 150 ml/min or more. The preferable Ar gas flow rate is 170 ml/min or more, and the more preferable Ar gas flow rate is 190 ml/min or more. In addition to N ₂ gas and Ar gas, Kr gas or the like may be introduced within a range that does not inhibit the effects of the present invention.

The bias voltage at the time of hard coating in the present embodiment is preferably set to -140 V as the lower limit. In the case of less than -140 V, arcing may occur and defects may be generated in the film. On the other hand, when the bias voltage exceeds -60 V, the hardness tends to decrease, so the upper limit is preferably set to -60 V. The lower limit of the better bias voltage is -110 V, and the upper limit of the better bias voltage is -90 V.

In the production method of the present embodiment, it is preferable that the maximum power input into the target be 50 kW to 130 kW. By setting the maximum power input to the target high in this way, a dense film structure can be easily obtained, the adhesion to the substrate can be improved, and the effect of keeping the film surface smoother can also be obtained. In addition, the maximum power shown here is calculated using the following calculation formula from the average power thrown into a target. Maximum power (kW) = average power (kW) × period (μs) / pulse width (μs) Period (μs)=1000×1000/Frequency (Hz)

In the manufacturing method of this embodiment, in order to further improve the adhesiveness of a hard coating film and a base material, a base film may be formed on a base material before covering a hard coating film. As the base film, a nitride film of one or two or more elements selected from metals of Group 4, Group 5, and Group 6 of the periodic table, Al, Si, and B can be used, and the film thickness can be set to a thickness of 0.01 μm to 0.1 μm. within the range. [Example]

(Example 1) As the base material, three small punch faces with dimensions of 1 mm × 1 mm (made of cemented carbide), 2 mm × 2 mm (made of cemented carbide), and 4 mm × 4 mm (made of high-speed steel) were prepared. shower. Samples No. 1 to No. 6, which are examples of the present invention, used a high-output pulse sputtering (HiPIMS) apparatus as a coating apparatus, and No. 7 to No. 9, which were comparative examples, used a direct-current magnetron sputtering (direct-current magnetron sputtering). current magnetron sputtering, DCMS) as the cladding device. The coating apparatuses used in the examples of the present invention and the comparative examples have a rotating mechanism that revolves while the provided punch is rotating, and the target is fixed to the side surface side of the punch. All of the samples No. 1 to No. 9 used Ti as a target for forming a base film, and used AlCrSi as a target for forming a hard film. Before coating the base film on the substrate, the surface of the substrate was ground to an average roughness Ra of 0.05 μm and Rz of 0.1 μm, degreased and cleaned, and fixed on the substrate holder. Then, the substrate was heated to around 500° C. by a heater for heating provided in the chamber, and held for 120 minutes. Next, Ar gas was introduced, a bias voltage of -200 V was applied to the substrate, and plasma cleaning treatment (Ar ion etching) was performed for 15 minutes. Then, the base material after the cleaning treatment was covered with a base film of TiN, and then the film was formed under the conditions shown in Table 1 to prepare samples No. 1 to No. 6 as examples of the present invention and comparative examples. of sample Nos. 7 to 9.

[Table 1] Sample No. Film formation method Ar flow (ml/min) N ₂ flow (ml/min) N ₂ /Ar Film thickness (μm) Bias Voltage (V) Pulse width (μs) Frequency (Hz) Average power (kW) Maximum power (kW) Remark 1,2,3 HiPIMS 200 160 0.80 1.0 -100 50 1000 1→3 ^{※ 1} 60 Example of the present invention 4,5,6 HiPIMS 200 264 1.32 1→6 ^{※ 2} 120 Example of the present invention 7,8,9 DCMS 300 170 0.57 - - 4 4 Comparative example *1: Increase the output from 1 kW to 3 kW at 0.5 kW/10 s, and keep it fixed from 3 kW *2: Increase the output from 1 kW to 6 kW at 0.5 kW/10 s, and keep it constant from 6 kW

Next, the surface analysis by EPMA was performed about the produced sample Nos. 1 to 3 and No. 7 to 9, and the measurement of the film thickness ratio was performed for the sample Nos. 1 to 9. FIG. 2( a ) is a schematic diagram showing the observed portion of the film thickness by EPMA. As shown in FIG. 2( a ), surface analysis was performed on the front end side surface portion of the sample, and the film thickness distribution was observed from the distribution of the Cr component. In samples No. 1, No. 2, No. 7, and No. 8 with small sample sizes, the W component was also measured in order to confirm the presence or absence of exposure of the cemented carbide as the base material. In addition, for the film thickness measurement, as shown in FIG. 2( b ), the center of the sample was cut, and the tip portion of the sample was measured from a photograph obtained by a scanning electron microscope (SEM) at a magnification of 10,000 times. The film thickness of the upper surface part and the edge part and the side surface part of two parts (parts (1)-(7) of FIG.2(c)). In addition, the position of each edge part about 5 micrometers from an edge was measured on the sample upper surface side and the sample side surface side. After the measurement, the film thickness of the upper surface portion (4) was used as the film thickness of the flat portion, and the ratio of the film thickness of each measurement site to the film thickness of the flat portion was calculated. The EPMA analysis results are shown in FIG. 3 , and the film thickness ratios are shown in Table 2.

[Table 2] Sample No. Sample size substrate Film thickness (μm) at measurement site (4) Ratio of film thickness at each measurement site to film thickness (4) Remark (1) (2) (3) Side (3) Upper surface (4) (5) Upper surface (5) Side (6) (7) 1 1mm×1mm Cemented carbide 0.8 0.89 0.93 0.96 1.15 1.00 1.02 0.98 0.95 0.89 Example of the present invention 2 2mm×2mm Cemented carbide 0.8 0.92 0.90 1.29 1.27 1.00 1.19 1.23 0.92 0.91 3 4mm×4mm high speed steel 0.8 0.90 1.04 1.24 1.08 1.00 1.10 1.03 0.85 0.85 4 1mm×1mm Cemented carbide 1.1 0.94 0.98 0.92 1.12 1.00 1.15 1.05 1.00 0.97 5 2mm×2mm Cemented carbide 0.9 1.02 1.03 1.12 1.10 1.00 1.18 1.10 1.05 1.01 6 4mm×4mm high speed steel 1.0 1.02 1.00 1.16 1.16 1.00 1.18 1.16 0.96 0.98 7 1mm×1mm Cemented carbide 0.9 0.67 0.31 0.20 0.42 1.00 0.55 0.00 0.00 0.72 Comparative example 8 2mm×2mm Cemented carbide 0.9 0.71 0.40 0.39 0.55 1.00 0.45 0.34 0.30 0.71 9 4mm×4mm high speed steel 0.9 0.77 0.40 0.48 0.63 1.00 0.67 0.40 0.58 0.62

According to the EPMA surface analysis results of FIG. 3 , the Cr components of the samples No. 1 to No. 3, which are examples of the present invention, are uniformly distributed in the base material, and the Cr component is the base material component in the sample No. 1 and the sample No. 2. W was also not confirmed, so it was confirmed that there was no exposure of the substrate, and uniform film formation was possible. On the other hand, in the samples No. 7 to No. 9, which are comparative examples, there are portions where the film is very thin at the front end portion of the base material, or where the film is not formed and the base material is almost exposed. Furthermore, in the value of the film thickness ratio, the film thickness difference of the edge part, the side surface part, and the upper surface part of the example of this invention was small, and showed a very favorable value. On the other hand, it was confirmed that the film thickness of the edge part and the side part of the comparative example was thinner than the film thickness of the upper surface part, and the edge part of the sample No. 7 did not form a film, and it was confirmed that a defect was likely to occur during actual processing.

(Example 2) Next, the shapes of Example 1 and the mold were changed, and the film thickness distribution was investigated. A test piece simulating a precision machining die (die) having an upper surface of a complicated shape shown in FIG. 4 was prepared, and the target was set on the upper surface side of the die. Sample No. 10, which is an example of the present invention, was produced under the same conditions as Sample Nos. 4 to 6 in Example 1, and Comparative Examples were produced under the same conditions as Sample Nos. 7 to 9 in Example 1. The sample No.11. The prepared samples were cut along AA' and BB' shown in Fig. 4. For the AA' cut surface (Fig. 5) and the BB' cut surface (Fig. 6), respectively The film thicknesses of the upper surface portion and the two edge portions of the sample were measured using a photograph at a magnification of 10,000 times obtained by a scanning electron microscope (SEM). In addition, similarly to Example 1, the position of each edge part about 5 micrometers from an edge was measured on the sample upper surface side and the sample side surface side. After the measurement, the upper surface portion ( 12 ) on the AA' cut surface is a flat portion, and the upper surface portion ( 15 ) on the BB' cut surface is a flat portion, and the film thickness of each measurement site is calculated relative to the flat surface. The ratio of the film thickness of the part. The results are shown in Table 3 and Table 4.

[table 3] Sample No. Film thickness (μm) at measurement site (12) Ratio of film thickness at each measurement site to film thickness (12) Remark (11)Side (11) Upper surface (12) (13) Upper surface (13)Side 10 0.8 0.87 1.15 1.00 1.06 0.86 Example of the present invention 11 0.9 0.64 0.91 1.00 0.78 0.00 Comparative example

[Table 4] Sample No. Film thickness (μm) at measurement site (15) Ratio of film thickness at each measurement site to film thickness (15) Remark (14)Side (14) Upper surface (15) (16) Upper surface (16)Side 10 0.9 0.95 1.14 1.00 1.01 0.66 Example of the present invention 11 1.0 0.89 0.88 1.00 0.96 0.00 Comparative example

As shown in the results in Tables 3 and 4, it was confirmed that even if the sample No. 10, which is an example of the present invention, has a more complicated shape than that of Example 1, the film thickness ratio does not become too small or too large, and even at the edge portion A hard coating can also be formed with a film thickness equivalent to that of the flat portion. On the other hand, in the sample No. 11 as a comparative example, there are parts (the side of the measurement part (13) and the side of the measurement part (16)) where the hard coating cannot be formed in the edge part, and there is a possibility that the part cannot be formed when it is used for processing. A substrate chipping or hard film peeling occurs in the film portion.

(Example 3) Next, the influence of the gas flow rate on the hard coating was confirmed. A test piece made of cemented carbide was prepared, and the surface of the base material was mirror-finished. A high-power pulse sputtering apparatus was used as a coating apparatus, Ti was prepared as a target for base film formation, and AlCrSi was prepared as a target for hard film formation. Plasma cleaning was carried out under the same conditions as in the example of the present invention in Example 1. After the substrate after the plasma cleaning treatment was coated with a TiN base film, a hard film was coated under the conditions shown in Table 5 to prepare the present invention. Samples of Inventive Examples and Comparative Examples.

[table 5] Sample No. Ar flow (ml/min) N ₂ flow (ml/min) N ₂ /Ar Film thickness (μm) Bias Voltage (V) Average power (kW) Maximum power (kW) Remark 12 200 264 1.32 1.9 -100 1→6 ^※ 120 Example of the present invention 13 200 160 0.80 1.9 14 250 160 0.64 2.0 Comparative example 15 300 160 0.53 1.9 16 300 140 0.47 1.3 ※: The output is increased from 1 kW to 6 kW at 0.5 kW/10 s, and the output is kept constant from 6 kW

The hardness and crystal structure of the obtained samples No. 12 to No. 16 were measured. The hardness is determined by selecting a region where the maximum indentation depth is less than about 1/10 of the layer thickness in the polished surface of the film using a nanoindentation device manufactured by Elionix Co., Ltd., and measuring 10 points. The average of the values was taken as the hardness. The measurement conditions were an indentation load: 9.8 mN, a maximum load holding time: 1 second, and a removal rate after a heavy load: 0.49 mN/sec. In addition, X-ray diffraction was used for the measurement of the crystal structure. Specifically, an X-ray diffraction apparatus (model: RINT2500PC) manufactured by Rigaku Co., Ltd. was used, at tube voltage: 40 kV, tube current: 200 mA, X-ray source: Cokα (λ=0.17902 nm), 2θ: 30 It implements under the measurement conditions of ° to 70°. The measurement results are shown in FIGS. 7 and 8 . It was confirmed that the samples No. 12 and No. 13, which are examples of the present invention, have hardness superior to other comparative examples. In addition, according to the XRD measurement results, the samples No. 12 and No. 13, which are examples of the present invention, have no peaks in the vicinity of hcp-AlN (100), which is a fragile phase. A peak was confirmed near AlN (100).

Next, in order to evaluate the durability of the hard coating, a scratch test was performed. In the comparative example, a hydrogen-free diamond-like carbon film previously used for shear processing applications was used. The testing machine was a scratch testing machine (REVETEST) manufactured by CSM Corporation, and the measurement conditions were set to measurement load: 0 N to 120 N, scratch speed: 10 mm/min, scratch distance: 10 mm, AE sensitivity: 5, indenter : Rockwell, diamond, tip radius: 200 μm, hardware setting: Fn contact 0.9 N, Fn speed: 5 N/s, Fn removal speed: 10 N/s, approach speed: 2%/s. The results are shown in Figure 9. In the sample of the comparative example, peeling of the film occurred at a scratch distance of about 5 mm, but in the example of the present invention, the destruction of the film was not confirmed in the test. From the above, it was confirmed that even when the covering mold of the present invention is applied to a shearing application, it has good adhesion and good durability.

(Example 4) Next, the punching test using the dies of the example of the present invention and the comparative example was implemented. The base material of the punch used was made of cemented carbide, the size of the punch face was 2 mm×2 mm, and the corner R portion with a curvature radius of 0.2 mm was formed at the four corners of the punch. Figure 10 shows a schematic view of the front end of the punch. The punch of sample No. 17, which is an example of the present invention, was coated with the same hard film as Nos. 4 to 6 of Example 1, and the punch of sample No. 18, which was a comparative example, was coated with the same hard film as that of Example 1. Sample Nos. 7 to 9 have the same hard coatings. In addition, as the punch of the sample No. 19 of the previous example, a punch coated with a 0.3 μm hydrogen-free diamond-like carbon film was also prepared. The die was coated with a hard coating made of cemented carbide and the same as that of Sample Nos. 4 to 6 of Example 1 in any of the examples of the present invention, the comparative examples, and the previous examples. A Carson alloy with a thickness of 0.1 mm and a hardness of 160 to 210 HV was prepared as the workpiece to be processed, and 400,000 punches were performed using a punching machine under the conditions of a punching speed of 800 spm, a gap of 5 μm, and a punch insertion length of 1 mm. punching process. Then, with respect to the processed punch, two parts of the corner R portion where damage is particularly likely to occur were observed using a scanning electron microscope (C and D in FIG. 10 ). The observation photo is shown in Figure 11.

From the results of FIG. 11 , the punch of Sample No. 17, which is an example of the present invention, has little damage even after punching of 400,000 punches, and is in a state in which further processing can be continued. On the other hand, in the sample No. 18 as a comparative example, a large damage was confirmed in the corner R part D, and in the sample No. 19 as a conventional example, a large damage was confirmed in the corner R part C. Therefore, when the punches of the comparative example and the previous example are continuously processed, there is a possibility that burrs or shape accuracy may be reduced in the workpiece at an early stage.

1: Hard film 2: Substrate C, D: corner R

FIG. 1 is a scanning electron microscope photograph showing an example of the hard coating of the present invention. FIGS. 2( a ) to 2 ( c ) are schematic diagrams showing the measurement method of the sample. FIG. 3 is a diagram showing the results of surface analysis by an electron probe microanalyzer (EPMA) according to an example of the present invention and a comparative example. FIG. 4 is a schematic diagram showing the shape of a sample in an example. FIG. 5 is a cross-sectional view taken along line AA′ of FIG. 4 . FIG. 6 is a cross-sectional view taken along line BB′ of FIG. 4 . FIG. 7 is a graph showing the hardness measurement results of the examples of the present invention and the comparative examples. FIG. 8 is a graph showing the results of X-ray diffraction (XRD) measurement of examples of the present invention and comparative examples. FIGS. 9( a ) and 9 ( b ) are diagrams showing scratch test results of the examples of the present invention and the comparative examples. Fig. 10 is a schematic view of the front end portion of the punch used in the examples. Fig. 11 is an enlarged photograph of the corner portion of the punch after the punching test.

1: Hard film

2: Substrate

Claims (3)

A covering mold for shearing, comprising a hard film of nitride of AlCrSi on the surface of a mold base material, and wherein the covering mold for shearing, The thickness of the hard coating is 0.3 μm to 2.0 μm, The ratio of the film thickness of the hard coating in the edge portion of the covering mold to the film thickness of the hard coating in the flat surface portion of the covering mold is 0.60 to 1.40. A method for manufacturing a sheathed mold for shearing processing, wherein a hard film containing a nitride of AlCrSi is coated on the surface of a mold base material, and in the method for manufacturing a sheathed mold for shearing processing, high-output pulse sputtering is used method to coat the hard film on the mold base material with a film thickness of 0.3 μm to 2.0 μm, and use a mixed gas of N ₂ and Ar during the high-output pulse sputtering, and the flow rate of N ₂ gas is relative to the flow rate of Ar gas The ratio is 0.65 to 1.60. The manufacturing method of the covering mold for shearing according to claim 2, wherein the maximum power at the time of hard film covering by the high-output pulse sputtering is 50 kW to 130 kW.

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