WO2018155644A1

WO2018155644A1 - Cutting insert and cutting tool provided with same

Info

Publication number: WO2018155644A1
Application number: PCT/JP2018/006771
Authority: WO
Inventors: 涼馬野見山; 綾乃田中
Original assignee: 京セラ株式会社
Priority date: 2017-02-24
Filing date: 2018-02-23
Publication date: 2018-08-30
Also published as: JP6835947B2; JPWO2018155644A1

Abstract

A cutting insert according to the present disclosure is provided with a substrate and a covering layer located on at least part of the substrate. The cutting insert also includes a first surface, a second surface, and a cutting edge located on at least part of a ridge line where the first surface and the second surface intersect. Furthermore, the covering layer exists at least in a first region along the cutting edge on the first surface and a second region along the cutting edge on the second surface, the thickness of the covering layer in the first region is greater than the thickness of the covering layer in the second region, and a ten-point mean roughness in the first region in a direction parallel to the cutting edge is greater than the ten-point mean roughness in the second region in the direction parallel to the cutting edge.

Description

Cutting insert and cutting tool provided with the same

This aspect relates to a cutting insert used in cutting and a cutting tool including the same.

Cutting tools are used when cutting and turning the work material. The cutting tool generally includes a holder having a pocket and a cutting insert attached to the pocket. As a cutting insert, for example, a cutting insert described in Patent Document 1 is known.

The cutting insert described in Patent Document 1 includes a substrate (body) and a coating layer (film) that covers the substrate. Moreover, the cutting insert described in Patent Document 1 has a rake face and a flank face, and has a polygonal plate-like configuration in which cutting edges are formed at portions where these faces intersect.

JP 2013-163264 A

A cutting insert according to one aspect includes a base and a coating layer located on at least a part of the base. Moreover, the cutting insert has a 1st surface, a 2nd surface, and a cutting blade located in at least one part of the ridgeline which the said 1st surface and the said 2nd surface cross | intersect. The covering layer is present at least in a first region along the cutting edge on the first surface and a second region along the cutting edge on the second surface, and the covering layer in the first region When the thickness is C1, the thickness of the coating layer in the second region is C2, the C1 is larger than the C2, the ten-point average roughness in the first region is Rz1a, and the ten-point average in the second region When the roughness is Rz2a, the Rz1a is larger than the Rz2a.

It is a perspective view which shows the cutting insert of one Embodiment. FIG. 2 is a cross-sectional view of the A1-A1 cross section in the cutting insert shown in FIG. It is an enlarged view in area | region A2 shown in FIG. It is a perspective view which shows the cutting tool of one Embodiment.

Hereinafter, a cutting insert according to an embodiment (hereinafter also simply referred to as an insert) will be described in detail with reference to the drawings. However, each drawing referred to below shows only a main member necessary for explaining the present embodiment in a simplified manner for convenience of explanation. Thus, the insert may comprise any component not shown in the referenced figures. Moreover, the dimension of the member in each figure does not represent the dimension of an actual structural member, the dimension ratio of each member, etc. faithfully.

The insert 1 of the present embodiment has a quadrangular plate shape, and has a quadrangular first surface 3 (upper surface in FIG. 1), a second surface 5 (side surface in FIG. 1), a first surface 3 and a second surface 5. And the cutting edge 7 located in at least a part of the ridgeline that intersects. The first surface 3 is a surface called a rake surface. The second surface 5 is a surface called a flank surface.

In the insert 1 of the present embodiment, the entire outer periphery of the first surface 3 may be the cutting edge 7. The insert 1 is not limited to such a configuration. For example, the insert 1 may have only one side of the quadrangular first surface 3 or may have a cutting edge 7 partially.

The first surface 3 has at least a rake surface region, and the first region 3a along the cutting edge 7 on the first surface 3 is at least a rake surface region. The second surface 5 has at least a flank region, and the second region 5a along the cutting edge 7 on the second surface 5 is at least a flank region. In other words, the cutting edge 7 is located at a portion where the rake face area and the flank face area intersect.

In FIG. 1, the boundary between the first region 3a and the other region on the first surface 3 and the boundary between the second region 5a and the other region on the first surface 3 are indicated by a one-dot chain line. In FIG. 1, since an example in which all of the ridge lines where the first surface 3 and the second surface 5 intersect is the cutting edge 7, an annular one-dot chain line along the cutting edge 7 is shown on the first surface 3. Has been.

The size of the insert 1 is not particularly limited. For example, in the present embodiment, the length of one side of the first surface 3 is set to about 3 to 20 mm. The height from the first surface 3 to the surface (the lower surface in FIG. 1) located on the opposite side of the first surface 3 is set to about 5 to 20 mm.

2 and 3, the insert 1 according to the present embodiment includes a square plate-shaped base 9 and a coating layer 11 that covers the surface of the base 9. The coating layer 11 may cover the entire surface of the substrate 9 or may cover only a part thereof. When only a part is covered, it can also be said that the covering layer 11 is located on at least a part of the substrate 9.

The covering layer 11 in the present embodiment is present at least in the first region 3 a along the cutting edge 7 on the first surface 3 and the second region 5 a along the cutting edge 7 on the second surface 5. FIG. 1 shows an example in which the coating layer 11 is present on the entire first surface 3 including the first region 3a and the entire second surface 5 including the second region 5a.

The thickness of the coating layer 11 in this embodiment is not constant, and the thickness of the coating layer 11 in the first region 3a is different from the thickness of the coating layer 11 in the second region 5a. Specifically, when the thickness of the coating layer 11 in the first region 3a is C1, and the thickness of the coating layer 11 in the second region 5a is C2, C1 is larger than C2.

Note that C1 is an average value of the thickness of the coating layer 11 in the first region 3a. C2 is an average value of the thickness of the coating layer 11 in the second region 5a.

C1 of the thickness of the coating layer 11 in the first region 3a is an average value of the thickness of the coating layer 11 in the range of 0.3 to 1.0 mm from the cutting edge 7. The thickness C2 of the coating layer 11 in the second region 5a is an average value of the thickness of the coating layer 11 in the range of 0.05 to 1.0 mm from the cutting edge 7.

The thickness of the coating layer 11 in the first region 3a is the distance from the first surface 3 to the coating layer 11 in the cross section as shown in FIG. 3, and in calculating the average value, the n number is 3 or more. And Further, the thickness of the coating layer 11 in the second region 3b is the distance from the second surface 5 to the coating layer 11 in the cross section as shown in FIG. 3 or more.

Since the thickness C1 of the coating layer 11 in the first region 3a is relatively larger than C2, the durability of the insert 1 is enhanced. Since the chips of the work material flow on the first region 3a during the cutting process, the portion of the coating layer 11 located in the first region 3a is relatively easily worn. Since the thickness C1 of the covering layer 11 in the first region 3a is relatively larger than C2, the base 9 is hardly exposed.

In the second region 5a, since the thickness C2 of the coating layer 11 is relatively smaller than C1, the possibility of the coating layer 11 peeling off in the second region 5a is reduced. Since a cutting load is applied to the second region 5a at a relatively small angle at the time of cutting, a shearing force is easily applied to the coating layer 11 in the second region 5a. Since the thickness C2 of the coating layer 11 in the second region 5a is relatively smaller than C1, the coating layer 11 in the second region 5a is hardly sheared.

Further, the surface roughness of the coating layer 11 in the present embodiment is not constant, and the surface roughness of the coating layer 11 in the first region 3a and the surface roughness of the coating layer 11 in the second region 5a are different from each other. Specifically, when the ten-point average roughness of the coating layer 11 in the first region 3a is Rz1a and the ten-point average roughness of the coating layer 11 in the second region 5a is Rz2a, Rz1a is larger than Rz2a.

Since the surface roughness of the first region 3a is relatively large, the area where chips come into contact with the rake face region during cutting can be reduced. Therefore, an excessively large friction coefficient can be avoided and the amount of heat generated can be kept small. Thereby, the coating layer 11 becomes difficult to deteriorate in the rake face region.

Further, since the surface roughness Rz2a of the second region 5a is relatively smaller than Rz1a, the surface roughness of the finished surface is excessive even when the flank region is in contact with the finished surface of the work material. Deterioration is avoided.

As described above, according to the cutting insert 1 of the present embodiment, when the average value of the thickness of the coating layer 11 in the first region 3a is C1, and the average value of the thickness of the coating layer 11 in the second region 5a is C2. , C1 is larger than C2, and when the ten-point average roughness of the coating layer 11 in the first region 3a is Rz1a and the ten-point average roughness of the coating layer 11 in the second region 5a is Rz2a, Rz1a is Rz2a. Bigger than. Thereby, the coating layer 11 is hard to peel off, the durability of the insert 1 is good, and the surface state of the finished surface can be made good.

The thickness C1 of the coating layer 11 in the first region 3a is not limited to a specific thickness. The thickness C1 of the covering layer 11 in the first region 3a can be set to about 1.5 to 4 μm, for example. Further, the thickness C2 of the covering layer 11 in the second region 5a is not limited to a specific thickness. The thickness C2 of the covering layer 11 in the second region 5a can be set to about 0.5 to 1.5 μm, for example.

In addition, since the thickness of the coating layer 11 is very thin with respect to the size of the insert 1 as described above, the size of the base 9 substantially matches the size of the insert 1. Therefore, description of the specific size of the base 9 is omitted.

The ten-point average roughness Rz1a of the coating layer 11 in the first region 3a is not limited to a specific value, but can be set to about 1.0 to 3.0 μm, for example. Further, the ten-point average roughness Rz2a of the coating layer 11 in the second region 5a is not limited to a specific value, but can be set to about 0.1 to 1.0 μm, for example.

In this embodiment, the ten-point average roughness Rz1a of the first region 3a and the ten-point average roughness Rz2a of the second region 5a are measured according to JISB0601-2001 standard except that the cutoff value is fixed to 0.08 mm. Accordingly, the surface shapes of the first region 3a and the second region 5a may be measured. For the measurement, for example, a contact type surface roughness measuring machine using a stylus or a non-contact type surface roughness measuring machine using a laser may be used. Based on the measured results, the ten-point average roughness Rz1a of the first region 3a and the ten-point average roughness Rz2a of the second region 5a may be calculated. In addition, Rz1a and Rz2a shall be measured along the direction parallel to the cutting edge 7, respectively. Rz1a and Rz2a may be measured in the measurement ranges of C1 and C2, respectively.

The ten-point average roughness Rz1a in the first region 3a is different from the ten-point average roughness Rz2a in the second region 5a, while the ten-point average roughness in the portion corresponding to the first region 3a in the base 9 However, in the case where the ten-point average roughness in the portion corresponding to the second region 5a in the base body 9 is substantially the same, the variation in the bonding property between the base body 9 and the covering layer 11 is small. It is difficult to peel off. In such a case, the ten-point average roughness of the substrate 9 can be set to about 1.0 to 1.4 μm, for example.

When the ten-point average roughness of the coating layer 11 in the cutting edge 7 is Rz3, Rz1a may be larger than Rz3, in other words, Rz3 may be smaller than Rz1a. In such a case, it is possible to reduce the risk of the cutting edge 7 being chipped during the cutting process. Therefore, the durability of the insert 1 can be increased.

Further, Rz3 may be smaller than Rz1a and equivalent to Rz2a. In such a case, the surface state of the finished surface can be improved while reducing the risk of the cutting edge 7 being chipped during cutting. However, it is not necessarily exactly the same that Rz3 is equivalent to Rz2a, and the ratio Rz2a / Rz3 of Rz2a and Rz3 may be 0.9 to 1.2.

In order to measure the ten-point average roughness Rz3 of the cutting edge 7, the insert 1 is placed in the direction in which the second surface 5 is the front, and the unevenness of the cutting edge 7 is observed. That is, a surface roughness measuring machine may be used similarly to the measurement of the ten-point average roughness of the first region 3a and the second region 5a, but the insert 1 is placed in a direction in which the second surface 5 faces the front. The ten-point average roughness Rz3 of the cutting blade 7 may be measured by performing image analysis of the photograph taken.

The ten-point average roughness Rz3 of the coating layer 11 in the cutting edge 7 may be 0.1 to 1.0 μm.

The configuration of the cutting blade 7 is not particularly limited, but FIG. 1 shows a configuration in which the cutting blade 7 has a main cutting blade 13 and a wiper blade 15. For example, when the first surface 3 is viewed from the front, the main cutting edge 13 and the wiper blade 15 are respectively positioned on the sides of the first surface 3, the main cutting edge 13 has a linear shape, and the wiper blade 15. Is a gentle convex curve shape. Here, the gentle convex curve shape means that the curve shape is convex outward, and the radius of curvature of the curve is larger than the maximum width of the first surface 3. .

The main cutting edge 13 functions as a main cutting edge 7 that cuts the work material during cutting. Further, the wiper blade 15 functions as the cutting blade 7 that enhances the smoothness of the finished surface of the work material during cutting. For this reason, the insert 1 is usually used for cutting with the main cutting edge 13 inclined with respect to the finished surface and the wiper blade 15 parallel to the finished surface.

Here, when the thickness of the coating layer 11 in the main cutting edge 13 is C31, and the thickness of the coating layer 11 in the wiper blade 15 is C32, if C31 is larger than C32, the smoothness of the finished surface at the time of cutting is improved. In the wiper blade 15 for increasing, film peeling hardly occurs and the processed surface becomes good.

The thickness C31 of the coating layer 11 in the main cutting edge 13 is not limited to a specific thickness, but can be set to about 1.5 to 4.0 μm, for example. Further, the thickness C32 of the coating layer 11 in the wiper blade 15 is not limited to a specific thickness, but can be set to about 0.5 to 1.5 μm, for example.

In addition, the thickness of the coating layer 11 in the main cutting edge 13 or the wiper blade 15 is the distance from the intersection of the first surface 3 and the second surface 5 to the coating layer 11 in the cross section as shown in FIG. That is. When the example shown in FIG. 3 is a cross section including the main cutting edge 13, it is a portion indicated by a symbol C <b> 31 and an arrow, specifically, a corner portion where the first surface 3 and the second surface 5 intersect with each other. In the coating layer 11, it is the distance from the corner where two surfaces intersect. Further, even when the first surface 3 and the second surface 5 of the base 9 intersect with each other so as to have an R portion, the thickness calculation method is the same.

Furthermore, in this embodiment, when the ten-point average roughness of the coating layer 11 in the main cutting edge 13 is Rz31 and the ten-point average roughness of the coating layer 11 in the wiper blade 15 is Rz32, Rz31 is larger than Rz32. It may be. As described above, the wiper blade 15 functions as the cutting blade 7 that improves the smoothness of the finished surface of the work material during cutting. When the ten-point average roughness of the coating layer 11 in the main cutting blade 13 and the wiper blade 15 is the above relationship, the surface roughness of the wiper blade 15 is particularly small, so that the smoothness of the finished surface is further increased. Enhanced.

When the ten-point average roughness Rz31 of the coating layer 11 in the main cutting edge 13 and the ten-point average roughness Rz32 in the wiper blade 15 are compared, Rz31 which is the ten-point average roughness in the main cutting edge 13 is relative. May be large. Rz32 and Rz31 may be smaller than Rz1a.

Rz31 may be 0.1 to 1.0 μm. Rz32 may be 0.1 to 0.7 μm.

When the ten-point average roughness of the coating layer 11 in the direction perpendicular to the cutting edge 7 in the second region 5a is Rz2b, Rz2a may be smaller than Rz2b.

Rz2a may be 0.1 to 1.0 μm. Rz2b may be 0.5 to 1.4 μm.

The second region 5a may come into contact with the finished surface during cutting. At this time, even if the surface shape of the coating layer 11 in the direction parallel to the cutting edge 7 is transferred to the finished surface, the smoothness of the finished surface is impaired because Rz2a is relatively smaller than Rz2b. Can be avoided. Further, since Rz2b is relatively larger than Rz2a, the contact area of the second region 5a with the finished surface can be reduced even when the second region 5a is in contact with the finished surface. Therefore, it is easy to avoid that the finished surface is denatured by frictional heat or the like.

When the residual stress in the covering layer 11 is a compressive stress, it is a case where a part of the covering layer 11 is temporarily damaged, such as when the covering layer 11 is partially peeled off or when the covering layer 11 is cracked. However, this damage is difficult to progress. Thereby, it is avoided that durability of insert 1 falls greatly.

Whether the residual stress in the coating layer 11 is a compressive stress may be determined based on, for example, measurement using a 2D method. Specifically, each of the first surface 3 and the second surface 5 that is 1 mm or more away from the cutting edge 7 is set as a measurement position. X-ray diffraction peaks are measured at these positions. Regarding the crystal structure specified from the measurement result, the residual stress of the coating layer 11 is confirmed by checking how the 2θ value in the measurement result is deviated from the reference 2θ value described in the JCPDS card. Can be specified.

The insert 1 of the present embodiment has a square plate shape as shown in FIG. 1, but the shape of the insert 1 is not limited to such a shape. For example, the upper surface may be a triangle, a hexagon, or a circle instead of a rectangle.

The insert 1 of this embodiment may have a through-hole 17 as shown in FIG. The through-hole 17 in the present embodiment is formed from the first surface 3 to a surface located on the opposite side of the first surface 3, and is open on these surfaces. The through hole 17 can be used for attaching a screw or a clamp member when holding the insert 1 in the holder. The through hole 17 may be configured to open in regions located on opposite sides of the second surface 5.

Examples of the material of the substrate 9 include inorganic materials such as cemented carbide, cermet, and ceramics. Examples of the composition of the cemented carbide include WC (tungsten carbide) -Co, WC-TiC (titanium carbide) -Co, and WC-TiC-TaC (tantalum carbide) -Co. Here, WC, TiC and TaC are hard particles, and Co is a binder phase. A cermet is a sintered composite material in which a metal is combined with a ceramic component. Specifically, the cermet includes a compound mainly composed of TiC or TiN (titanium nitride). The material of the base 9 is not limited to these.

Examples of the material of the coating layer 11 include titanium carbide, nitride, oxide, carbonate, nitride oxide, carbonitride, and carbonitride. The covering layer 11 may contain only one of the above materials, or may contain a plurality. Moreover, the coating layer 11 may be comprised by only one layer, and the structure by which the several layer was laminated | stacked may be sufficient. The material of the covering layer 11 is not limited to these.

The coating layer 11 can be positioned on the substrate 9 by using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. For example, when the coating layer 11 is formed using the above-described vapor deposition method with the base 9 held on the inner peripheral surface of the through hole 17, the entire surface of the base 9 excluding the inner peripheral surface of the through hole 17. The covering layer 11 can be positioned so as to cover the surface.

The thickness of the coating layer 11 can be appropriately adjusted by polishing treatment. For example, the portion of the coating layer 11 that is desired to be thickened may be masked, and the portion that is desired to be thinned may be exposed to be subjected to blasting. Moreover, when it grind | polishes using a brush and an abrasive | polishing agent, a grinding | polishing damage | wound is formed in the surface of the coating layer 11 along the rotation direction of a brush. By utilizing this, the ten-point average roughness in the direction parallel to the cutting edge 7 and the ten-point average roughness in the direction perpendicular to the cutting edge 7 can be made different.

In order to set the residual stress in the coating layer 11 to compressive stress, for example, the coating film 11 may be formed by the PVD method and formed under a high bias condition of 75 to 200V. Further, as another method of using the residual stress in the coating layer 11 as a compressive stress, the coating film 11 having a smaller thermal expansion coefficient than that of the substrate 9 may be formed by a CVD method.

Next, a cutting tool 101 according to an embodiment will be described with reference to the drawings. As shown in FIG. 4, the cutting tool 101 of the present embodiment is a rod-like body extending from a first end (upper end in FIG. 4) to a second end (lower end in FIG. 4), and has a pocket on the first end side. The holder 105 having 103 and the above-described insert 1 located in the pocket 103 are provided.

The pocket 103 is a portion to which the insert 1 is mounted, and has a seating surface parallel to the lower surface of the holder 105 and a restraining side surface inclined with respect to the seating surface. Further, the pocket 103 is opened on the first end side of the holder 105.

The insert 1 is located in the pocket 103. At this time, the lower surface of the insert 1 may be in direct contact with the pocket 103, or a sheet may be sandwiched between the insert 1 and the pocket 103.

The insert 1 is mounted such that a portion used as the cutting edge 7 on the ridge line where the first surface and the second surface intersect protrude from the holder 105 outward. In the present embodiment, the insert 1 is attached to the holder 105 with a fixing screw 107. That is, the insert screw 1 is inserted into the through hole of the insert 1, the tip of the fix screw 107 is inserted into a screw hole (not shown) formed in the pocket 103, and the screw portions are screwed together to insert 1. Is mounted on the holder 105.

As the holder 105, steel, cast iron or the like can be used. In particular, it is preferable to use steel having high toughness among these members.

In the present embodiment, a cutting tool used for so-called turning is illustrated. Examples of the turning process include an inner diameter process, an outer diameter process, and a grooving process. The cutting tool is not limited to that used for turning. For example, you may use the insert 1 of said embodiment for the cutting tool used for a turning process.

DESCRIPTION OF SYMBOLS 1 ... Insert 3 ... 1st surface 3a ... 1st area | region 5 ... 2nd surface 5a ... 2nd area | region 7 ... Cutting blade 9 ... Base | substrate 11 ... Covering layer DESCRIPTION OF SYMBOLS 13 ... Main cutting blade 15 ... Wiper blade 17 ... Through-hole 101 ... Cutting tool 103 ... Pocket 105 ... Holder 107 ... Fixing screw C1 ... Cover in 1st area | region Layer thickness C2 ... thickness of the coating layer in the second region

Claims

A cutting insert comprising a substrate and a coating layer located on at least a part of the substrate,
The cutting insert has a first surface, a second surface, and a cutting edge located on at least a part of a ridge line intersecting the first surface and the second surface,
The covering layer is present at least in a first region along the cutting edge on the first surface and a second region along the cutting edge on the second surface,
When the thickness of the coating layer in the first region is C1, and the thickness of the coating layer in the second region is C2, the C1 is larger than the C2,
When the ten-point average roughness in the direction parallel to the cutting edge in the first region is Rz1a, and the ten-point average roughness in the direction parallel to the cutting edge in the second region is Rz2a, the Rz1a is A cutting insert that is larger than Rz2a.
2. The cutting insert according to claim 1, wherein the Rz1a is 1.0 to 3.0 μm, and the Rz2a is 0.1 to 1.0 μm.
The cutting insert according to claim 1 or 2, wherein the Rz1a is larger than the Rz3 when the ten-point average roughness of the cutting edge is Rz3.
4. The cutting insert according to claim 3, wherein the Rz3 is 0.1 to 1.0 μm.
The cutting blade has a main cutting blade and a wiper blade,
The C31 is larger than the C32 when the thickness of the coating layer on the main cutting edge is C31 and the thickness of the coating layer on the wiper blade is C32. Cutting insert according to one.
The cutting insert according to claim 5, wherein Rz31 is larger than Rz32 when the ten-point average roughness of the main cutting edge is Rz31 and the ten-point average roughness of the wiper blade is Rz32.
The Rz2a is smaller than the Rz2b when the ten-point average roughness in the direction orthogonal to the cutting edge in the second region is Rz2b. Cutting inserts.
The cutting insert according to any one of claims 1 to 7, wherein the residual stress in the coating layer is a compressive stress.
A holder having a pocket on the tip side;
A cutting tool comprising the cutting insert according to any one of claims 1 to 8, which is located in the pocket.