JP5312096B2 - Cutting tools - Google Patents

Description

  The present invention relates to a cutting tool in which a coating layer is formed on the surface of a substrate.

  Cutting tools that perform cutting are used in such a way that when the cutting edge reaches the end of its life, it is replaced with a new cutting edge. Therefore, it is convenient if the used cutting blade and the unused cutting blade can be confirmed at a glance.

For example, in Patent Document 1, a TiN layer having a brass appearance is coated on the outermost layer of a chip plate in which a plurality of coating layers are laminated as a use state display layer, and the underlying layer is black or blackish Al. It is disclosed that an operator can confirm at a glance whether a cutting blade is used or not by arranging the ₂ O ₃ layer as an anti-wear layer.

  Further, the TiN layer is widely used as the first layer of the multilayer coating, and the thickness thereof is often extremely thin. However, for example, as in Patent Document 2, the TiN layer may be formed to be quite thick.

Further, Patent Document 3 describes that the surface of the cermet substrate is a hard nitrided layer, and the appearance color is golden, yellowish brown, reddish brown, etc., so that the corners to be used can be easily identified. There is a description that the surface of the cermet substrate may be further coated with a hard film such as Al ₂ O ₃ .

JP 2002-144108 A Japanese Patent Laid-Open No. 08-267306 JP-A-10-147831

  However, in the method of arranging a brightly colored coating layer on the outermost layer as in Patent Document 1, the use / unused distinction of the cutting blade can be confirmed at a glance, but the cutting edge during the cutting process can be confirmed. It may be difficult to confirm the progress of wear. That is, since the color of the portion where the outermost layer is worn and the underlying layer is exposed and the portion where the welding of the work material is deposited on the surface of the outermost layer is almost the same, the progress of wear is confirmed at a glance. That was difficult. In addition, since the color tone of the base layer and the base is similar, it is difficult to check the exposed state of the base at a glance, and the damaged state is confirmed using a cutting blade after use, under appropriate cutting conditions. It was also difficult to confirm whether it was processed.

  In addition, when a TiN layer is disposed in the underlayer, if the TiN layer is thin, the hardness of the TiN layer may be low, and the thin TiN layer will be worn away quickly, so the exposed portion of the TiN layer is visually confirmed. On the contrary, when the TiN layer is thick as in the cited document 2, there is a problem that the chipping resistance at the cutting edge is low and the tool performance is inferior.

Further, as in Patent Document 3, the surface of the cermet substrate is colored such as a golden color and the surface is covered with a black Al ₂ O ₃ film, but it can be recognized when the golden substrate is exposed, At this timing, the cutting edge was often after the end of its life, and could not be used for life determination.

  An object of this invention is to provide the cutting tool which can confirm the judgment of the lifetime of each cutting blade at a glance during cutting.

The cutting tool of the present invention is formed by forming a coating layer in which a base layer having high lightness and an upper layer having low lightness are laminated on the surface of the base, and the thickness of the base layer in the cutting blade is the above- mentioned in the flank. The thickness of the base layer is 0 to 70%, and the upper layer is present on the cutting blade .

Here, in the color tone in the L ^* a ^* b ^* color system of JIS Z 8729, the lightness difference between the base layer and the upper layer is 15 or more (ΔL ^* ≧ 15 ), and in particular, JIS Z 8729.
In the color tone of the L ^* a ^* b ^* color system, it is desirable that the color difference ((ΔL ^{* 2} + Δa ^{* 2} + Δb ^{* 2} ) ^1/2 ) between the base layer and the upper layer is 40 or more.

Moreover, the underlying layer has a thickness in the flank TiN layer 7～9Myuemu, or the thickness on the flank face that is preferably made of amorphous carbon layer 0.2 to 0.8 [mu] m.

  According to the cutting tool of the present invention, it is possible to accurately determine the life of the cutting blade during cutting without reducing the chipping resistance of the cutting blade. Further, since the state of wear and chipping of the cutting edge that has reached the end of life can be understood well, more optimal cutting conditions can be estimated based on this.

In the color tone of the L ^* a ^* b ^* color system of JIS Z 8729, the lightness difference between the base layer and the upper layer is 15 or more (ΔL ^* ≧ 15 ). In the color tone in the L ^* a ^* b ^* color system, the color difference ((ΔL ^{* 2} + Δa ^{* 2} + Δb ^{* 2} ) ^1/2 ) between the underlayer and the upper layer is 40 or more. It is desirable in that it can be easily visually confirmed when is exposed.

  In addition, when the underlayer is a TiN layer having a flank thickness of 7 to 9 μm, it takes a long time to visually confirm the region where the underlayer is exposed, and when the visual confirmation can be made, it is covered with the cutting blade. Since the layer remains slightly, the life of the cutting blade can be accurately determined. Moreover, when it consists of an amorphous carbon layer with a thickness of 0.2 to 0.8 μm on the flank, the underlayer itself has a high hardness and excellent wear resistance.

It is a schematic perspective view about the throw away tip which is a suitable example of the cutting tool of the present invention. It is a schematic sectional drawing about the cutting edge vicinity of the throw away tip of FIG. It is a schematic sectional drawing about the cutting edge vicinity of the end mill which is the other suitable example of the cutting tool of this invention.

  An example of a throw-away tip which is a preferred example of the cutting tool of the present invention will be described with reference to FIG. 1 which is a schematic perspective view and FIG. 2 which is a schematic cross-sectional view of the first embodiment.

  A throw-away tip (hereinafter simply abbreviated as “tip”) 1 in FIGS. 1 and 2 has a substantially flat plate shape, and an intersecting ridge line portion between a main surface which is a rake face 5 and a side face which is a flank face 6 is a cutting edge. 7 is used.

  Further, as shown in the cross-sectional view of FIG. 2, the chip 1 has two or more coating layers 3 (3 L, 3 U) formed on the surface of the base 2. And about two layers with the most different colors (the color difference is the largest) among the some coating layers 3, the coating layer 3 formed in the base | substrate 2 side is the base layer 3L, and the coating layer formed in the side far from the base | substrate 2 3 is identified as the upper layer 3U. When the coating layer 3 is composed of three or more layers, the cross section of the coating layer 3 is exposed, or the coating layer 3 is polished obliquely and the exposed surface is observed visually or with a microscope. After confirming the color of each layer, the base layer 3L and the top layer 3U are specified.

Here, according to the present embodiment, the brightness of the underlying layer 3L high and low together lightness of upper base layer 3U, and the thickness t _f of the underlayer 3L in the thickness t _e can flank of the underlayer 3L in cutting consisting 0% to 70% of the thickness _{(t e / t f = 0~0.7} ) against.

  Thereby, the lifetime of the cutting blade 7 during cutting can be accurately determined without reducing the fracture resistance of the cutting blade 7. Moreover, since the state of wear and chipping of the cutting edge 7 which has reached the end of life can be understood well, more optimal cutting conditions can be estimated based on this.

In addition, in the color tone of the L ^* a ^* b ^* color system of JIS Z 8729, the brightness difference between the base layer 3L and the upper layer 3U is 15 or more (ΔL ^* ≧ 15 ). In the color tone in the L ^* a ^* b ^* color system, the color difference ((ΔL ^{* 2} + Δa ^{* 2} + Δb ^{* 2} ) ^1/2 ) between the base layer 3L and the upper layer 3U is 40 or more. It is desirable in that visual confirmation when 3L is exposed is easy.

Here, it is desirable that the base layer 3 </ b ^> L exhibits a color with a lightness L ^* of 40 or more and a saturation (c ^* = (a ^{* 2} + b ^{* 2} ) ^1/2 ) of 30 or more.

In addition, when the underlayer 3L is made of a TiN layer having a thickness t _{f of 7} to 9 μm on the flank 6, the time during which the region where the underlayer 3L is exposed can be visually confirmed becomes long and can be visually confirmed. Since the coating layer 3 remains slightly on the cutting edge 7, the life of the cutting edge 7 can be accurately determined. Further, if the thickness t _f in the flank 6 is made of amorphous carbon layer 0.2~0.8μm, since the hardness of the underlayer 3L itself is excellent in wear resistance is high, the coating layer It is also desirable to improve the wear resistance of No. 3.

The upper layer 3U can be made of a blackish material having a lightness L ^* of 20 or less and a saturation (c ^* = (a ^{* 2} + b ^{* 2} ) ^1/2 ) of 10 or less. For example, Al ₂ O ₃ layer, TiC layer, TiCN layer, Ti _1-a-b Al _a M _b (C _x N _1-x ) (where M is a periodic table group 4, 5, 6 element, rare earth element excluding Ti, and 1 or more selected from Si, and 0 ≦ a <1, 0 ≦ b ≦ 1, and 0 ≦ x ≦ 1) Blackish amorphous material having different film forming conditions from the layer, diamond layer, and underlayer 3L A carbon layer, a cBN layer or a metal layer is preferred.

Here, the thickness of the coating layer 3 on the flank 6 in the present invention is measured at a position spaced by a distance of 0.2 mm from the tip position of the cutting edge 7 because it is used for determining the life of the cutting edge 7. If the base layer 3L having a predetermined thickness is covered at this position, the base layer 3L is exposed with a width visible from the tip of the cutting blade 7 and can be easily confirmed.
Further, as the shape of the cutting tool, even in a cutting tool having a rotating shaft such as the drill or the end mill 8 shown in FIG. 3, the cutting tool 9 has a straight line A passing from the tip of the cutting edge 9 to the rotation center (center of the base 10). The thickness of the flank 11 is measured at a position parallel to the center of rotation of 0.2 mm. In the figure, 13 indicates a rake face.

  Moreover, the base | substrates 2 and 10 which comprise the chip | tip 1 consist of hard sintered bodies, such as a cemented carbide alloy, a cermet, ceramics, diamond, cBN, for example.

  An example of a method for manufacturing the throw-away tip will be described.

  First, a base is prepared, and a base layer 3L is formed on the surface of the base by a thin film forming method. As the thin film forming method, it is desirable to use either a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method.

  Next, part or all of the underlying layer 3L is removed from the formed underlying layer 3L by the cutting blade 7. As a method for removing the underlayer 3L, a method of removing the chip from the film forming apparatus and polishing it may be used. When the underlayer 3L is formed by the PVD method, the film formation is continued. Then, the base layer 3L in the cutting blade 7 can be thinned by performing bombardment in the film forming apparatus. In this bombardment process, it is necessary to perform the process under such a condition that only the cutting edge 7 is selectively removed by the edge effect.

  And about the chip | tip which made the base layer 3L thin in the cutting blade 7, the chip | tip 1 can be manufactured by forming the upper layer 3U into a film using the thin film formation method mentioned above.

  Instead of the method of removing the base layer 3L from the cutting blade 7 after forming the base layer 3L as described above, the base layer 3 is masked by masking the cutting blade 7 when forming the base layer 3L. A method of preventing 3L from being formed may also be used.

WC powder, Co powder, Cr ₃ C ₂ powder and VC powder are mixed, pressed into a tip shape of a throw-away tip for grooving (Kyocera throw-away tip model number GMM3020-040MW), fired and ground, Honed. Thereafter, a coating layer having a thickness shown in Table 1 is formed by the PVD method. After the treatment shown in Table 1, the thickness of the base layer in the cutting blade is reduced to the thickness shown in Table 1, an upper layer of the thickness shown in Table 1 is formed. Membranes were used to make chips (Sample Nos. 1-6).

And this chip | tip is mounted | worn to a holder and sample No. For chips other than 3, cutting tests were performed under the following conditions to evaluate the cutting performance. When the front flank wear amount reached 0.2 mm, the life was judged.
Cutting method: Grooving work material: SNCM439
Cutting speed: 200 m / min Feed: 0.1 mm / rev
Cutting depth: 2.0mm
Cutting state: wet evaluation method: Every time cutting was performed for 10 minutes, the exposed state of the underlayer was visually confirmed on the flank surface near the cutting edge, and the ease of confirmation was evaluated. Moreover, the cutting time which was able to cut with this cutting blade was confirmed.
Sample No. The chip 3 was subjected to a cutting test under the following conditions to evaluate the cutting performance.
Cutting method: Shoulder work material: A7075
Cutting speed: 170 m / min Feed: 0.03 mm / tooth
Cutting depth: 3.0mm
Cutting state: Dry evaluation method: Every 10 minutes of cutting, the exposed state of the underlying layer was visually confirmed on the flank surface near the cutting edge, and the ease of confirmation was evaluated. Moreover, the cutting time which was able to cut with this cutting blade was confirmed.
The results are shown in Table 2.

  As is clear from the results in Tables 1 and 2, the upper layer has a higher brightness than the lower layer. 4, sample no. Compared with 1 to 3, it was difficult to visually check the wear state due to the influence of welding or the like. In addition, Sample No. in which the thickness of the foundation layer at the cutting edge exceeds 70% of the thickness of the foundation layer at the flank face. In Nos. 5 and 6, the cutting edge was defective, In No. 6, the exposure of the underlayer could not be confirmed during the cutting evaluation.

  On the other hand, in accordance with the present invention, the sample No. 1 in which the lightness of the underlayer is higher than the lightness of the upper layer and the thickness of the underlayer at the cutting edge is 0 to 70% of the thickness at the flank. In each of 1-3, the wear state of the cutting edge could be easily confirmed visually during cutting, and the chipping resistance of the cutting edge was also good.

1 Throw away tip (chip)
2, 10 Substrate 3, 12 Coating layer 3L, 12L Underlayer 3U, 12U Upper layer 5, 13 Rake face 6, 11 Flank 7, 9 Cutting edge 8 End mill

Claims (4)

On the surface of the substrate, a high lightness underlayer, made by forming a coating layer formed by laminating an upper low brightness formations, and the thickness of the underlying layer in the thickness flank of the underlying layer in the cutting edge A cutting tool having a thickness of 0 to 70% and the upper layer being present on the cutting edge. The color difference in the L ^* a ^* b ^* color system of JIS Z 8729, wherein the lightness difference between the underlayer and the upper layer is 15 or more (ΔL ^* ≧ 15 ). Cutting tools. In the color tone of JIS Z 8729 in the L ^* a ^* b ^* color system, the color difference ((ΔL ^{* 2} + Δa ^{* 2} + Δb ^{* 2} ) ^1/2 ) between the base layer and the upper layer is 40 or more. The cutting tool according to claim 1 or 2, wherein The underlayer claims 1 to 3 thickness in the flank TiN layer 7～9Myuemu, or the thickness of the flank, characterized in that it consists of an amorphous carbon layer 0.2~0.8μm The cutting tool of any one of.

Images