Hard coating film for a cutting tool

Abstract

A hard coating film for a cutting tool has a first macroscopic surface roughness measured within a range of 100 µm in the direction of the rake face from a cutting edge, which is smaller than a second macroscopic surface roughness measured outside of 100 µm in the direction of the rake face from the cutting edge; a first microscopic surface roughness measured within a range of 100 µm in the direction of the rake face from the cutting edge, which is smaller than a second microscopic surface roughness measured outside of a range of 100 µm in the direction of the rake face from the cutting edge; a third macroscopic surface roughness measured within a range of 100 µm from the cutting edge in the direction of the clearance face, which is smaller than a fourth macroscopic surface roughness measured outside of 100 µm from the cutting edge in the direction of the rake face;and a third microscopic surface roughness measured within 100 µm of the cutting edge in the direction of the clearance face, which is smaller than a fourth microscopic surface roughness measured outside 100 µm of the cutting edge in the direction of the rake face.

Description

Hard film for cutting tools

[0001] The present invention relates to a hard film for a cutting tool, and more particularly, to a hard film having different roughness in an inner range and an outer range centered on a predetermined distance from a cutting edge of the hard film.

[0002]

[0003] In order to improve the cutting performance and extend the life of cutting tools when machining high-hardness workpieces with a hardness of HRC 50 or higher, such as high-hardness steel, and difficult-to-cut materials that cause severe adhesion and chipping, a technology of hard film made of various ceramics on hard substrates such as cemented carbide, cermet, end mills, and drills is being adopted.

[0004] Hard films formed on rigid substrates via deposition techniques pose a risk of delamination due to increased stress within the hard film caused by differences in lattice constants between the hard substrate and the physical vapor deposition process. To address this issue, the adhesion of hard films has been improved through pretreatment, etching, adhesion layers, multilayer thin films, and post-treatment technologies.

[0005] When applying processes such as pretreatment and etching, the specific surface area of ​​the hard base material surface can be increased to increase the adhesion between the base material and the thin film. However, depending on the workpiece, especially when cutting stainless steel and Inconel, the increase in the specific surface area can lead to an increase in the adhesion between the thin film and the workpiece, which can cause a reduction in tool life due to the peeling of the hard film.

[0006] To address these issues, post-treatment processes for hard films have traditionally been employed to reduce tool surface roughness and improve lubricity. However, despite these efforts, the improvement in roughness achieved through post-treatment processes for hard films remains limited, and the additional processes present drawbacks in terms of manufacturing efficiency. Furthermore, even when machining a hard substrate after the hard film has been removed, the high surface area of ​​the hard substrate still increases adhesion, resulting in reduced tool life. This requires improvement. However, excessive reduction in the surface area of ​​the hard substrate can accelerate film removal due to the reduced adhesion between the hard substrate and the hard film.

[0007]

[0008] The purpose of the present invention is to provide a hard film cutting tool having excellent adhesion and wear resistance.

[0009]

[0010] In order to achieve the above purpose, the cutting tool provided in the present invention has a hard film, and the hard film has a first macro roughness (macro_S) which is a macroscopic surface roughness when measuring surface roughness within a range of 100 ㎛ from the edge of the hard film in the direction of the rake surface. aR1 ) is the second macro roughness (macro_S), which is the macroscopic surface roughness when measuring the surface roughness from 100㎛ away in the direction of the rake surface from the above-mentioned line. aR2 ) is smaller than the first micro-roughness (micro_S), which is a microscopic surface roughness when measuring surface roughness within a range of 100㎛ in the direction of the rake surface from the above-mentioned edge. aR1 ) is the second micro-roughness (micro_S), which is the microscopic surface roughness when measuring the surface roughness from 100㎛ away in the direction of the rake surface from the above-mentioned line. aR2 ) is smaller than the third macro roughness (macro_S), which is the macroscopic surface roughness when measuring surface roughness within a range of 100㎛ from the above-mentioned edge toward the flank surface. aF1) is the fourth macro roughness (macro_S), which is the macroscopic surface roughness when measuring the surface roughness from 100㎛ away in the direction of the rake surface from the above-mentioned line. aF2 ) is smaller than the above, and the third micro-roughness (micro_S) is a microscopic surface roughness when measuring surface roughness within a range of 100㎛ from the above-mentioned edge toward the flank surface. aF1 ) is the fourth micro-roughness (micro_S), which is the microscopic surface roughness when measuring the surface roughness from 100㎛ away in the direction of the rake surface from the above-mentioned line. aF2 ) may be smaller.

[0011] In addition, in the cutting tool according to the present invention, the first macro roughness (macro_S aR1 ) is 0.1㎛≤macro_S aR1 ≤0.3㎛ range and the first micro-roughness (micro_S aR1 ) is 0.05㎛≤micro_S aR1 ≤0.2㎛ range, and the second macroscopic roughness (macro_S aR2 ) is 0.2㎛≤macro_S aR2 ≤0.4㎛ range and the second micro-roughness (micro_S aR2 ) is 0.1㎛≤micro_S aR1 ≤0.25㎛ range, and the third macroscopic roughness (macro_S aF1 ) is 0.15㎛≤macro_S aF1 ≤0.35㎛ range and the third micro-roughness (micro_S aF1 ) is 0.1㎛≤micro_S aR1 ≤0.25㎛ range, and the fourth macroscopic roughness (macro_S aF2 ) is 0.25㎛≤macro_S aR2 ≤0.5㎛ range and the fourth micro-roughness (micro_S aF2 ) is 0.15㎛≤micro_S aR1 It can be in the range of ≤0.35㎛.

[0012] Additionally, in the cutting tool according to the present invention, the first to fourth macro roughnesses and the first to fourth micro roughnesses may increase obliquely as they get farther away from the cutting edge.

[0013] In addition, in the cutting tool according to the present invention, the hard film has a composition satisfying the chemical formula 1 below and may be formed of one or more layers.

[0014] [Chemical Formula 1] Al (1-a-b-c) Ti a Cr b Me c N(0≤a≤0.6, 0≤b≤0.5, 0≤c≤0.15, and must contain at least one of Ti or Cr, and Me is at least one of Ta, Hf, Nb, Zr, V, Y, W, Mo, Si, B)

[0015] Additionally, in the cutting tool according to the present invention, the thickness of the hard film may be in the range of 0.02 to 20 μm.

[0016]

[0017] According to the present invention, a cutting tool having excellent adhesion of a hard film and excellent welding resistance can be provided. Furthermore, the process efficiency in manufacturing a cutting tool having a hard film can be improved.

[0018]

[0019] Figure 1 is a cross-sectional schematic diagram illustrating a cutting tool having a hard film according to the present invention.

[0020] Figure 2 is a schematic diagram explaining the macro-roughness and micro-roughness in a hard film according to the present invention.

[0021]

[0022] In the following description of the present invention, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present invention. Furthermore, when a part is said to "include" a component, unless otherwise specifically stated, this does not exclude other components, but rather implies the inclusion of additional components.

[0023] A hard film cutting tool according to the present invention includes a hard base material and a hard film formed on the hard base material. In the hard film, when surface roughness is measured within a range of 100 ㎛ from the edge of the hard film in the direction of the rake surface, the macroscopic surface roughness is referred to as a first macro roughness (macro_S aR1 ), when measuring the surface roughness from 100㎛ away from the above-mentioned edge in the direction of the rake surface, the macroscopic surface roughness is referred to as the second macroscopic roughness (macro_S aR2 ), when measuring surface roughness within a range of 100㎛ from the above-mentioned guideline in the direction of the rake surface, the microscopic surface roughness is referred to as the first micro-roughness (micro_S aR1 ), when measuring the surface roughness from 100㎛ away from the above-mentioned guideline in the direction of the rake surface, the microscopic surface roughness is called the second micro roughness (micro_S aR2 ), when measuring surface roughness within a range of 100㎛ from the above-mentioned edge toward the flank surface, the macroscopic surface roughness is referred to as the third macroscopic roughness (macro_S aF1 ), when measuring the surface roughness from 100㎛ away from the above-mentioned edge in the direction of the rake surface, the macroscopic surface roughness is referred to as the fourth macro roughness (macro_S aF2 ), when measuring surface roughness within a range of 100㎛ from the above-mentioned edge toward the flank surface, the microscopic surface roughness is called the third micro-roughness (micro_S aF1 ), when measuring the surface roughness from 100㎛ away from the above-mentioned guideline in the direction of the rake surface, the microscopic surface roughness is called the fourth micro roughness (micro_S aF2), the first macroscopic illuminance is smaller than the second macroscopic illuminance, the first microscopic illuminance is smaller than the second microscopic illuminance, the third macroscopic illuminance is smaller than the fourth macroscopic illuminance, and the third microscopic illuminance is smaller than the fourth microscopic illuminance.

[0024] The roughness of a hard film is greatly affected by the roughness of the base material. If the roughness of the base material is high, the bonding strength between the hard film and the base material increases, but there is a problem that the possibility of adhesion with the workpiece increases. In order to harmonize the conflicting relationships in the characteristics of the hard film according to the roughness of the hard film, the hard film according to the present invention has a low surface roughness in a part close to the edge center, thereby improving welding resistance and enabling uniform nucleation and growth in the hard film, thereby relieving stress and improving chipping resistance against intermittent impact during cutting. In addition, the hard film in an area far from the edge center has a higher surface roughness than that at the edge center, thereby increasing the bonding strength of the hard film. In particular, considering that peeling and tearing of the hard film occur intensively during cutting in areas exceeding 100㎛ from the cutting edge, by providing an appropriate surface roughness in these areas, a high bonding force between the base material and the hard film can be maintained, and sufficient peeling resistance can be provided.

[0025] To this end, the macro-roughness in the area within 100 ㎛ from the edge center on both the rake face and the flank face becomes smaller than the macro-roughness in the area 100 ㎛ away from the edge center. Similarly, the micro-roughness in the area within 100 ㎛ from the edge center becomes smaller than in the area 100 ㎛ away from the edge center.

[0026] In this specification, roughness refers to the arithmetic mean height specified in ISO 25178. Roughness is generally expressed by adopting one of several parameters specified in ISO 4287 and ISO 25178. However, since these parameters alone cannot distinguish the overall morphological changes of the surface, it is easy to make errors in expressing roughness. For example, cemented carbide is made through the process of mixing hard particles and binder powder, pressing, and liquid sintering. During sintering, the binder liquefies and then solidifies again, showing irregular wavy roughness on the surface of the hard gas. Meanwhile, hard particles with an angular polygonal shape are fixed to the binder and protrude irregularly along the surface, showing fine roughness. Therefore, in order to measure the surface roughness of hard substrates such as superalloys and cermets more accurately, it is necessary to distinguish between macroroughness, which indicates roughness including changes in the overall shape of the surface, and microroughness, which indicates roughness caused by hard particles protruding along the surface. In order to measure macroroughness and microroughness separately, a micro 3D roughness measuring device using a laser confocal and a white light interferometer and analysis software were used, and in the present invention, the VK-X3050 equipment and its own analysis software from Keyence were used. In this specification, macroroughness means the arithmetic mean height shown without additional correction after measurement, and microroughness means the arithmetic mean height after removing irregular waves or large-scale components using the correction function (L-filter) of the analysis software after measurement. This correction means correction using a filter corresponding to the cut-off value specified in JIS B0633-2001.

[0027] These surface roughnesses by region are explained through FIGS. 1 and 2. The macro-roughness and micro-roughness in a range (21) within 100 ㎛ from the edge (40) on the rake surface (20) are smaller than the macro-roughness and micro-roughness in a range (22) outside 100 ㎛ from the edge (40), respectively. On the other hand, the macro-roughness and micro-roughness in a range (31) within 100 ㎛ from the edge (40) on the flank surface (30) are smaller than the macro-roughness and micro-roughness in a range (32) outside 100 ㎛ from the edge (40), respectively.

[0028] Macro-roughness and micro-roughness are shown in Fig. 2. Fig. 2(a) shows the surface roughness in the range (21, 31) within 100 ㎛ from the edge (40), and Fig. 2(b) shows the surface roughness in the range (22, 32) outside 100 ㎛ from the edge (40). The dotted line shows the macro-roughness, and the solid line shows the micro-roughness. As can be compared in Fig. 2(a) and Fig. 2(b), the surface roughness in the range (21, 31) within 100 ㎛ from the edge (40) is smaller in both macro-roughness and micro-roughness than the surface roughness in the range (22, 32) outside 100 ㎛.

[0029] Meanwhile, in the cutting tool according to the present invention, the first macro roughness (macro_S aR1 ) is 0.1㎛≤macro_S aR1 ≤0.3㎛ range, and the first micro-roughness (micro_S aR1 ) is 0.05㎛≤micro_S aR1 ≤0.2㎛ range, and the second macroscopic roughness (macro_S aR2 ) is 0.2㎛≤macro_S aR2 ≤0.4㎛ range, and the second micro-roughness (micro_S aR2 ) is 0.1㎛≤micro_S aR1 ≤0.25㎛ range, and the third macroscopic roughness (macro_S aF1 ) is 0.15㎛≤macro_S aF1 ≤0.35㎛ range, and the third micro-roughness (micro_S aF1) is 0.1㎛≤micro_S aR1 ≤0.25㎛ range, and the fourth macroscopic roughness (macro_S aF2 ) is 0.25㎛≤macro_S aR2 ≤0.5㎛ range, and the fourth micro-roughness (micro_S aF2 ) is 0.15㎛≤micro_S aR1 It can be in the range of ≤0.35㎛.

[0030] The first to fourth macro-roughnesses and the first to fourth micro-roughnesses are not only comparable to each other, but also have a certain range of surface roughness, which allows for the harmonious maintenance of adhesion resistance, chipping resistance, and bonding strength of a hard film.

[0031] To this end, the first macro-roughness on the lake surface may be smaller than the second macro-roughness, while the first macro-roughness may be in the range of 0.1 to 0.3 μm and the second macro-roughness may be in the range of 0.2 to 0.4 μm. The third macro-roughness on the flank surface may be smaller than the fourth macro-roughness, while the third macro-roughness may be in the range of 0.15 to 0.35 μm and the fourth macro-roughness may be in the range of 0.25 to 0.5 μm.

[0032] Additionally, on the lake surface, the first microroughness may be smaller than the second microroughness, while the range of the first microroughness may be 0.05 to 0.2 μm and the range of the second microroughness may be 0.1 to 0.25 μm. On the flank surface, the third microroughness may be smaller than the fourth microroughness, while the range of the third microroughness may be 0.1 to 0.25 μm and the range of the fourth microroughness may be 0.15 to 0.35 μm.

[0033] If the macroscopic roughness falls below a certain range, the bonding strength of the hard film may be compromised, while if it exceeds this range, adhesion and chipping resistance may deteriorate. To address this, the first and third macroscopic roughnesses must be lower than the second and fourth macroscopic roughnesses, respectively, while remaining within a certain range.

[0034] The reason why the roughness range on the flank surface is larger than that on the rake surface is because the adhesion of the hard film on the flank surface is required to be slightly greater. On the rake surface, chip adhesion occurs during the process of the machined chip being swept away, and the hard film is torn off when the adhered chip is removed, so it is important to suppress chip adhesion itself as a top priority. On the flank surface, wear and tear due to direct contact with the workpiece occur actively, so the adhesion of the hard film is given slightly greater priority along with wear resistance.

[0035] In the hard film of the cutting tool according to the present invention, the first to fourth macro-roughnesses and the first to fourth micro-roughnesses may increase in a slope as they get farther away from the cutting edge.

[0036] The closer to the center of the weld, the smaller the surface roughness for adhesion and chipping resistance, and the farther away, the surface roughness gradually increases, thereby securing the bonding strength between the hard film and the base material.

[0037] Meanwhile, in the cutting tool according to the present invention, the hard film has a composition satisfying the chemical formula 1 below and may be formed of one or more layers.

[0038] [Chemical Formula 1] Al (1-a-b-c) Ti a Cr b Me c N(0≤a≤0.6, 0≤b≤0.5, 0≤c≤0.15, and must contain at least one of Ti or Cr, and Me is at least one of Ta, Hf, Nb, Zr, V, Y, W, Mo, Si, B)

[0039] Nitride films containing Al and Ti or Cr are known to have excellent wear resistance, heat resistance, and chipping resistance. In addition to Al, Ti, and Cr, these hard films may contain any one of the following metal elements: Ta, Hf, Nb, Zr, V, Y, W, Mo, Si, and B. By controlling these metal elements, the wear resistance, chipping resistance, and heat resistance of the hard film can be significantly improved.

[0040] In the hard film, a, b, and c determine the composition ratio of the metal elements Al, Ti, Cr, and Me. When the composition of Al is large, wear resistance, oxidation resistance, and lubrication are better, but when the Al content is too high, there is a problem of increased chipping, so it is preferable that the contents of Ti and Cr be 0≤a≤0.6 and 0≤b≤0.5.

[0041] Other elements such as Ta and Hf can be added to improve the chipping resistance, heat resistance, and wear resistance of the hard film, but if the content is high, it can cause an increase in residual stress due to an increase in the amorphous phase. Therefore, it is preferable that the content of Me, an other element, be 0 to 0.15.

[0042] In addition, the thickness of the hard film in the cutting tool according to the present invention may be in the range of 0.02 to 20 μm. If the thickness of the hard film is less than 0.02 μm, it is difficult to provide sufficient wear resistance, and if it exceeds 20 μm, internal stress increases, which may actually increase chipping.

[0043]

[0044] Hereinafter, to explain the present invention in more detail, preferred embodiments according to the present invention will be described in more detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein.

[0045]

[0046] [Example]

[0047] Manufacturing of hard films

[0048] After applying a microblast honing process or a diagonal brush honing process and a polishing process to a hard base material made of a superalloy, a hard film was formed using an arc ion plating method, which is a physical vapor deposition (PVD) method.

[0049] In the hard base material polishing process, a paste containing diamond particles of 1 to 5 μm in size was used, and arc targets of TiAl, AlCr, TiAlSi, and AlCrSi were used as targets for coating the hard film.

[0050] The hard substrate was wet microblasted and washed with ultrapure water, and then mounted along the circumference at a predetermined radial distance from the center axis on the rotary table in a dry state in the coating furnace. The initial vacuum pressure in the coating furnace was 8.5ⅹ10 -5 The pressure was reduced to below 10 Torr, the temperature was heated to 400 to 600°C, and then a pulse bias voltage of -400 to -200 V was applied to the rotating base material on the rotary table under an Ar gas atmosphere to perform ion bombardment for 30 to 90 minutes. The gas pressure for coating was maintained at 50 mTorr or less, preferably 40 mTorr or less, to form a film.

[0051] In more detail, films were formed using TiAl, AlCr, TiAlSi and AlCrSi targets under conditions of bias voltage of -100 to -30 V, arc current of 100 to 150 A, N2 injected as a reaction gas and pressure of 20 to 40 mtorr. Coating conditions may vary depending on equipment characteristics and conditions.

[0052] Comparative examples and examples of the present invention were manufactured under the above conditions, and hard films having a thickness ranging from 3.0 to 3.5 ㎛ were formed as in Comparative Examples 1 and 2 and Example 1 using TiAl (composition ratio 50:50) and TiAlSi (composition ratio 30:60:10) targets, and hard films having a thickness ranging from 3.5 to 4.0 ㎛ were formed as in Comparative Examples 4 and 5 and Example 2 using TiAl (composition ratio 50:50), AlCr (composition ratio 70:30) and AlCrSi (composition ratio 60:30:10) targets. In the corresponding rake surface and flank surface, a macro roughness (macro_S) of about 100 ㎛ from the edge was formed. a ), micro-roughness (micro_S a ) Information about this is shown in Table 1 below.

[0053]

[0054] Surface plank surface macro roughness (㎛) micro roughness (㎛) macro roughness (㎛) micro roughness (㎛) macro_S aR1 macro_S aR2 micro_S aR1 micro_S aR2 macro_S aF1 macro_S aF2 micro_S aF1 micro_S aF2 Comparative Example 10.4370.4830.3200.3040.4710.4590.3170.322 Comparative Example 20.0830.0780.0490.0470.1120.1250.0890.099 Comparative Example 30.4540.4390.3460.3530.5200.5380.3680.320 Comparative Example 40.1070.0900.0440.0580.1340.1020.0940.095 Exemplary Example 10.2140.2890.1230.1880.2400.3790.1760.226 Exemplary Example 20.2220.3010.1400.2150.2670.3940.2000.253

[0055] As confirmed in Table 1 above, Examples 1 and 2 have lower roughness overall compared to Comparative Examples 1 and 3, and higher roughness overall compared to Comparative Examples 2 and 4. In addition, the roughness within 100 μm from the edge has a lower value than the roughness outside 100 μm.

[0056] Cutting performance evaluation

[0057] In order to evaluate the adhesion, peeling, and chipping resistance of the cutting tools manufactured as shown in Table 1 above, a milling test was performed and the evaluation was conducted under the following conditions.

[0058] 1) Evaluation of adhesion and chipping resistance

[0059] Workpiece material: GCD600

[0060] Sample Model Number: SNMX1206ANN-MF (Comparative Examples 1-2, Example 1)

[0061] Cutting speed: 150 m / min

[0062] Cutting feed: 0.2mm / tooth

[0063] Cutting depth: 2mm

[0064] When machining spheroidal graphite cast iron, the main types of wear are generally mechanical frictional wear and tear, as well as chipping and tearing caused by repeated adhesion and shedding of chips, and the adhesion resistance and chipping resistance of cutting tools have a significant impact on cutting performance.

[0065] (2) Evaluation of peeling and chipping resistance

[0066] Workpiece material: STD11

[0067] Sample Model Number: ADKT170608PESR-MM (Comparative Examples 3-4, Example 2)

[0068] Cutting speed: 120 m / min

[0069] Cutting feed: 0.2mm / tooth

[0070] Cutting depth: 5mm

[0071] When machining high-hardness steel, excessive wear and chipping due to tearing are generally the main types of wear, and the peeling resistance and chipping resistance of cutting tools have a significant impact on cutting performance.

[0072] Classification GCD600 Machining Results STD11 Machining Results Machining Length (mm) Wear Type Machining Length (mm) Wear Type Comparative Example 1 1500 Thermal Cracks, Chipping -- Comparative Example 2 2700 Thin Film Peeling, Excessive Wear -- Comparative Example 3 -- 9000 Excessive Wear, Comparative Example 4 -- 6900 Thin Film Peeling, Chipping Example 1 4200 Normal Wear -- Example 2 -- 15000 Normal Wear

[0073] As confirmed in Table 2 above, the cutting tools of the examples had overall superior cutting performance compared to the cutting tools of the comparative examples. In the case of comparative examples 2 and 4, although the roughness of the cutting tools was the lowest, the adhesion between the hard base material and the hard film decreased, resulting in a decrease in tool life. Therefore, as in the examples, it was confirmed that by having an appropriate roughness range for each section of the cutting tool, the welding resistance, peeling resistance, and chipping resistance were improved, and the tool life was improved along with stable processing in the form of normal wear.

Claims

1. Includes a hard base material and a hard film formed on the hard base material, The above hard film is, When measuring surface roughness within a range of 100㎛ from the edge of the hard film in the direction of the rake surface, the first macro roughness (macro_S) is the macroscopic surface roughness. aR1 ) is the second macro roughness (macro_S), which is the macroscopic surface roughness when measuring the surface roughness from 100㎛ away in the direction of the rake surface from the above-mentioned line. aR2 ) smaller than When measuring surface roughness within a range of 100㎛ in the direction of the rake surface from the above-mentioned guide line, the first micro-roughness (micro_S) which is a microscopic surface roughness aR1 ) is the second micro-roughness (micro_S), which is the microscopic surface roughness when measuring the surface roughness from 100㎛ away in the direction of the rake surface from the above-mentioned line. aR2 ) smaller than When measuring surface roughness within a range of 100㎛ in the direction of the flank from the above-mentioned line, the third macro roughness (macro_S) is the macroscopic surface roughness. aF1 ) is the fourth macro roughness (macro_S), which is the macroscopic surface roughness when measuring the surface roughness from 100㎛ away in the direction of the rake surface from the above-mentioned line. aF2 ) smaller than When measuring surface roughness within a range of 100㎛ from the above-mentioned line toward the flank surface, the third micro-roughness (micro_S) is a microscopic surface roughness. aF1 ) is the fourth micro-roughness (micro_S), which is the microscopic surface roughness when measuring the surface roughness from 100㎛ away in the direction of the rake surface from the above-mentioned line. aF2 ) smaller than the cutting tool.

2. In paragraph 1, The first macroscopic roughness (macro_S) aR1 ) is 0.1㎛≤macro_S aR1 ≤0.3㎛ range, and the first micro-roughness (micro_S aR1 ) is 0.05㎛≤micro_S aR1 ≤0.2㎛ range, The second macroscopic roughness (macro_S) aR2 ) is 0.2㎛≤macro_S aR2 ≤0.4㎛ range, and the second micro-roughness (micro_S aR2 ) is 0.1㎛≤micro_S aR1 ≤0.25㎛ range, The third macroscopic roughness (macro_S) aF1 ) is 0.15㎛≤macro_S aF1 ≤0.35㎛ range, and the third micro-roughness (micro_S aF1 ) is 0.1㎛≤micro_S aR1 ≤0.25㎛ range, The fourth macroscopic roughness (macro_S) aF2 ) is 0.25㎛≤macro_S aR2 ≤0.5㎛ range, and the fourth micro-roughness (micro_S aF2 ) is 0.15㎛≤micro_S aR1 Cutting tool with a range of ≤0.35㎛.

3. In paragraph 1, A cutting tool, wherein the first to fourth macro roughnesses and the first to fourth micro roughnesses increase obliquely as they get farther away from the cutting edge.

4. In paragraph 1, A cutting tool in which the above hard film has a composition satisfying the chemical formula 1 below and is composed of one or more layers. [Chemical Formula 1] Al (1-a-b-c) Ti a Cr b Me c N(0≤a≤0.6, 0≤b≤0.5, 0≤c≤0.15, and must contain at least one of Ti or Cr, and Me is at least one of Ta, Hf, Nb, Zr, V, Y, W, Mo, Si, B) 5. In paragraph 1, A cutting tool having a thickness of the above hard film in the range of 0.02 to 20㎛.

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