Cutting tool and cutting tool head

Abstract

The present disclosure provides a cutting tool comprising: a tool shank having an axis of rotation, and further comprising a tool head at one end thereof, the tool head comprising a layered body, where the layered body of the tool head comprises a cutting surface formed from polycrystalline CVD diamond, and where the cutting surface comprises a plurality of adjoining peaks, where the adjoining peaks comprise a plurality of adjoining peaks; a sharpness ratio beta of the cutting tool is in a range of about 0.01 to about 1.5, and wherein the sharpness ratio beta is a ratio of an average height H (mm) of the adjoining peaks to an average overlap length L (mm) between two adjacent adjoining peaks.

Description

Technical Field

[0001] The present disclosure relates to a cutting tool and a cutting tool head. In particular, the present disclosure relates to a cutting tool for cutting brittle materials (such as glass). More particularly, the present disclosure relates to a cutting tool comprising a cutting surface formed of polycrystalline CVD diamond, wherein the cutting surface comprises a plurality of satellite peaks (i.e., protrusions) serving as cutting elements. Background Art

[0002] Micro end mills are used for milling operations during the construction of, for example, mobile phone handset housings. The handset housings are typically made of aluminum, polycarbonate, glass or ceramic. One of the prior art is a diamond electroplated micro end mill. In an electroplated tool, hundreds of individual diamond grains are embedded in a binder on the surface of the tool head to provide a large amount of cutting surface and cutting edges. However, a problem with electroplated milling tools is that the diamond grains are easily pulled out of the binder, making the workpiece susceptible to undesirable scratches by bad grains. Another problem is that diamond electroplated tools have a limited tool life, requiring regular tool replacement and increasing the production cost of each required tool. As an alternative, PCD end milling tools can be used. However, such tools require grooves to provide a defined cutting surface, and machining the tool head to form the required grooves is an additional processing step.

[0003] The purpose of the utility model is to solve the above problems of the existing tools, such as abrasive grain extraction, tool life, and the need to form grooves, thereby providing an improved cutting tool and a cutting tool head. Utility Model Content

[0004] According to a first aspect, a cutting tool is provided, the cutting tool comprising: a tool shank having a rotation axis, and further comprising a tool head at one end thereof, the tool head comprising a layer body, wherein the layer body of the tool head comprises a cutting surface formed by polycrystalline CVD diamond, and wherein the cutting surface comprises a plurality of satellite peaks (i.e., protrusions), wherein a sharpness ratio β of the cutting tool is in the range of about 0.01 to about 1.5, wherein the sharpness ratio β is a ratio of an average height H (mm) of a satellite peak (i.e., protrusion) to an average overlapping length L (mm) between two adjacent satellite peaks (i.e., protrusions).

[0005] β = H / L Equation 1

[0006] In the present disclosure, the term "satellite peak" and the term "protrusion" are considered to be fully interchangeable and synonymous. "Satium peak" means a body protruding from and integrally formed with a polycrystalline CVD diamond cutting surface as described herein, in other words, a protrusion.

[0007] As an option, the sharpness ratio β of the cutting tool is in the range of about 0.01 to about 0.5, optionally about 0.01 to about 1.

[0008] As an option, the satellite peaks (ie, protrusions) have an average height H (mm) of about 0.005 mm to about 0.025 mm.

[0009] As an option, the average overlap length L (mm) between two adjacent satellite peaks (ie, protrusions) is about 0.02 mm to about 1 mm.

[0010] As an option, the satellite peaks (ie, protrusions) have an average diameter D of about 0.005 mm to about 0.025 mm.

[0011] As an option, the area density C of the satellite peaks (ie, protrusions) is about 50 per mm 2 About 1000 per mm 2 .

[0012] As an option, CD ≥ 1 (ie, C times D is greater than or equal to 1), where C is the area density (per mm2) of satellite peaks (ie, protrusions). 2 ) and D is the average diameter (mm) of the satellite peaks (ie, protrusions).

[0013] As an option, the satellite peak (ie the protrusion) is continuously curved.

[0014] As an option, the tool head comprises at least one further layer, wherein the layers are axially displaced from each other and separated by a non-cutting portion of the tool head.

[0015] As an option, at least one of the at least one further layer comprises a cutting surface formed of polycrystalline CVD diamond, wherein the cutting surface is as defined herein.

[0016] As an option, each layer body comprises a cutting surface formed of polycrystalline CVD diamond, wherein the cutting surface is as defined herein.

[0017] As an option, the tool comprises at least two layers.

[0018] As an option, the tool comprises at least three layers.

[0019] As an option, at least one layer body is configured for an operation selected from any one of rough machining, semi-finishing, and finishing.

[0020] As an option, two or more layers are configured for the same operation, such as roughing, semi-finishing, finishing.

[0021] As an option, each layer is configured differently from the remaining layers.

[0022] As an option, at least one layer has a diameter that is different from the other layers.

[0023] As an option, the tool head is cylindrical and non-tubular.

[0024] As an option, the overall height of the tool head does not exceed 12 mm.

[0025] As an option, the overall height of the tool head is not less than 0.5 mm.

[0026] As an option, the outer diameter of the tool shank is selected from any one of not more than 15 mm, not more than 10 mm, and not less than 6 mm.

[0027] As an option, the tool shank and / or the tool head comprises cemented carbide.

[0028] As an option, at least one layer of the tool head comprises cemented carbide.

[0029] The material to be cut may optionally include any one of glass, ceramic, polymer, composite material, metallic material and metal-ceramic composite material.

[0030] The tool handle may optionally further include a conduit for delivering compressed air to the tool head to expel spent cutting media.

[0031] According to a second aspect, there is provided a method of manufacturing a cutting tool head, the method comprising the following steps:

[0032] a. Provide disc-shaped blanks;

[0033] b. machining at least one precursor tool head from a disc machine;

[0034] c. forming a layer body in a precursor tool head to thereby form a tool head comprising a layer body; and

[0035] d. Using chemical vapor deposition to deposit polycrystalline diamond on a layer body of a tool head to form a cutting surface of polycrystalline CVD diamond on the layer body, wherein the cutting surface includes a plurality of satellite peaks (i.e., protrusions), wherein the sharpness ratio β of the cutting tool is in the range of 0.01 to 1.5, wherein the sharpness ratio β is the ratio of the average height H (mm) of the satellite peaks (i.e., protrusions) to the average overlapping length L (mm) between two adjacent satellite peaks (i.e., protrusions).

[0036] As an option, a laser is used to form the layer in the precursor tool head.

[0037] As an option, the method further includes repeating step c as needed to thereby form a tool head comprising at least two layers, each layer comprising a cutting surface formed from polycrystalline CVD diamond, wherein the cutting surface comprises a plurality of satellite peaks (i.e., protrusions), wherein the layers are axially displaced from each other and separated by a non-cutting portion of the tool head.

[0038] As an option, the method further comprises repeating step c as needed to thereby form a tool head comprising a plurality of layers.

[0039] As an option, the method further includes repeating steps c and d as needed to thereby form a tool head comprising at least two layers, each layer comprising a cutting surface formed of polycrystalline CVD diamond, wherein the cutting surface comprises a plurality of satellite peaks (i.e., protrusions), wherein the layers are axially displaced from each other and separated by a non-cutting portion of the tool head.

[0040] As an option, the method further includes repeating steps c and d as needed to thereby form a tool head comprising at least two layers, wherein at least one layer comprises a cutting surface formed of polycrystalline CVD diamond, wherein the cutting surface comprises a plurality of satellite peaks (i.e., protrusions), wherein the layers are axially displaced from each other and separated by a non-cutting portion of the tool head.

[0041] As an option, the method further includes repeating step c as needed to thereby form a tool head comprising a plurality of layers, wherein at least two of the plurality of layers comprise cutting surfaces formed from polycrystalline CVD diamond, wherein the cutting surface comprises a plurality of satellite peaks (i.e., protrusions), wherein the layers are axially displaced from one another and separated by a non-cutting portion of the tool head.

[0042] As an option, the chemical vapor deposition of polycrystalline diamond comprises hot-filament chemical vapor deposition.

[0043] According to a third aspect, there is provided use of a cutting tool as described herein in a method of cutting (eg grinding) a brittle material (eg any of glass, ceramics, polymers, composites, metallic materials and metal-ceramic composites). BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which:

[0045] Figure 1 is a perspective view of a tool according to the utility model, the tool having a first embodiment of a tool head;

[0046] Figure 2 yes Figure 1 A front view of the tool;

[0047] Figure 3 yes Figure 2 An enlarged view of the X portion;

[0048] Figure 4 is a schematic outline view of a CVD diamond cutting surface, which shows how the height H of the protrusions is determined;

[0049] Figure 5 is a schematic plan view of a CVD diamond cutting surface, which shows how to determine the overlap length L (mm) between two adjacent satellite peaks (ie, protrusions);

[0050] Figure 6 is a schematic plan view of a CVD diamond cutting surface showing how to determine the area density C of satellite peaks (i.e., protrusions);

[0051] Figure 7 yes Figure 6 and illustrates how to determine the diameter D of the satellite peak (i.e., protrusion);

[0052] Figure 8 is a front view of a second embodiment of a tool head;

[0053] Fig. 9 is a front view of a third embodiment of a tool head;

[0054] Fig.10 is a front view of a fourth embodiment of a tool head;

[0055] Fig.11 yes Fig. 9 Annotated version of the tool header.

[0056] In the embodiments, like parts are denoted by the same reference numerals, and further description is omitted for the sake of brevity. DETAILED DESCRIPTION

[0057] The following description relates to cutting glass by way of example, but it should be understood that the same tool configuration can be used to cut (e.g., grind) other types of materials (e.g., other types of brittle materials). A non-limiting list of materials that can be cut includes glass, ceramics, polymers, composites, metallic materials, and metal-ceramic composites.

[0058] First reference Figures 1 to 3 , a cutting tool is generally indicated at 10. The tool comprises a tool shank 12 having a longitudinal axis of rotation 14, and further comprises a tool head 16 at one end of the shank 12. The tool head 16 comprises at least one layer 18 (i.e., a platform or flat surface). Additional layers are axially displaced with respect to the initial layer. Thus a tool with multiple layers has layers that are coaxially aligned and adjacent to each other.

[0059] The cutting surface of the tool head 16 is formed of chemical vapor deposition (CVD) polycrystalline diamond (PCD). The cutting surface includes a plurality of satellite peaks (i.e., protrusions). These satellite peaks (i.e., protrusions) originate from the CVD polycrystalline diamond cutting surface and are integral with the CVD polycrystalline diamond cutting surface. The satellite peaks (i.e., protrusions) achieve a function similar to that of the diamond abrasive grains embedded in the conventional diamond electroplating tool described above, i.e., the satellite peaks serve as cutting elements. Since the satellite peaks (i.e., protrusions) are part of the CVD diamond coating, they are not easily pulled out of the binder. In addition, compared to the conventional PCD tool described above, these satellite peaks (i.e., protrusions) eliminate the need to machine grooves on the tool head, because the satellite peaks act as cutting elements, thereby eliminating a processing step when the tool head is manufactured. The cutting tool disclosed herein is therefore an improvement compared to conventional end mills.

[0060] The tool head is used as a substrate for the polycrystalline CVD diamond coating. Thus, the tool head may be formed from or include any suitable substrate for a CVD coating of polycrystalline diamond. For example, the tool head may be formed from or include metal carbides such as tungsten carbide, silicon carbide and / or silicon nitride.

[0061] The number average height H of the satellite peak (i.e., protrusion) can be about 0.005 mm to about 0.025 mm, alternatively about 0.010 mm to about 0.020 mm, alternatively about 0.015 mm to about 0.020 mm. The number average height H of the satellite peak (i.e., protrusion) is measured according to methods known to those skilled in the art, for example, using a scanning electron microscope (SEM). An example method is as follows: Take an SEM image perpendicular to the cutting surface so that the complete outline of the satellite peak (i.e., protrusion) is visible. Then measure the distance from the base to the tip of the satellite peak (i.e., protrusion) in a direction perpendicular to the cutting surface, such as Figure 4 This process is performed for at least 100 satellite peaks (ie, protrusions) to obtain the number average (ie, mean) height H of the satellite peaks (ie, protrusions).

[0062] The average overlap length L between two adjacent satellite peaks (i.e., protrusions) may be about 0.02 mm to about 1 mm, alternatively about 0.05 mm to about 1 mm, alternatively about 0.1 mm to about 1 mm, alternatively about 0.1 mm to about 0.75 mm, alternatively about 0.2 mm to about 0.5 mm. The average overlap length L between two adjacent satellite peaks (i.e., protrusions) is measured according to methods known to those skilled in the art, for example, using a SEM. An example method is as follows: Take an SEM image perpendicular to the cut surface so that the satellite peaks (i.e., protrusions) are visible from above, i.e., provide a Figure 5A plan view of the cutting surface depicted in the schematic diagram in FIG. Then the straight-line distance from the center of one satellite peak (i.e., protrusion) to the center of the adjacent satellite peak (i.e., protrusion) is measured, as Figure 5 Then, this process is repeated for each satellite peak (ie, protrusion) in the image (at least 100 satellite peaks (ie, protrusions)) to obtain the number average (ie mean) overlap length L between two adjacent satellite peaks (ie, protrusions).

[0063] The sharpness ratio β of the cutting tool is calculated by the ratio of the average height H of the satellite peak (i.e., protrusion) to the average overlap length L between two adjacent satellite peaks (i.e., protrusions). The desired sharpness ratio β depends on the type of material to be cut. In order to efficiently cut brittle materials (such as glass), it has been found that the sharpness ratio β should be in the range of about 0.01 to about 1.5, optionally about 0.01 to about 1.25, optionally about 0.01 to about 1, optionally about 0.01 to about 0.75, optionally about 0.01 to about 0.5, optionally about 0.05 to about 0.25, optionally about 0.10 to about 0.25, optionally about 0.15 to about 0.25.

[0064] The area density C of the satellite peaks (ie, protrusions) may be about 50 per mm 2 About 1000 per mm 2 , optionally about 100 per mm 2 About 900 per mm 2 , optionally about 100 per mm 2 About 800 per mm 2 , optionally about 200 per mm 2 About 700 per mm 2 , optionally about 300 per mm 2 About 600 per mm 2 , optionally about 400 per mm 2 About 500 per mm 2 The area density C of satellite peaks (ie protrusions) can also be measured using methods known to those skilled in the art, for example, using SEM. Figure 6 An example method is schematically depicted in FIG. 1 . For example, an SEM image of a plan view of a cut surface is obtained by measuring the average overlap length L between two adjacent satellite peaks (i.e., protrusions). A square region with a side length P (containing at least 100 satellite peaks (i.e., protrusions)) is identified (e.g. Figure 6 ), and count the number of satellite peaks (i.e., protrusions) within a square area or a partial square area. Then the number of satellite peaks (i.e., protrusions) per unit area is obtained by dividing the number of satellite peaks (i.e., protrusions) by the square of the side length P of the square, thereby calculating the area density C of the satellite peaks (i.e., protrusions). In the present disclosure, the area density is expressed as per mm 2, i.e. mm -2 Expressed as a unit.

[0065] From the same SEM image, the average diameter D of the satellite peaks (i.e., protrusions) can be measured. This is obtained by measuring the diameter of each satellite peak (i.e., protrusion) in a square area along the longest axis of the satellite peak (e.g., Figure 7 The average diameter D of the satellite peaks (i.e., protrusions) is about 0.005 mm to about 0.025 mm, optionally about 0.010 mm to about 0.020 mm, optionally about 0.010 mm to about 0.015 mm.

[0066] If the area density C (per mm 2 ) and the average diameter D (mm) of the satellite peaks (i.e., protrusions) is greater than or equal to one (i.e., CD ≥ 1), the coating design is particularly suitable for cutting brittle materials. 2 ) multiplied by the average diameter D (mm) of the satellite peaks (i.e., protrusions) is less than one, the coating design may not be suitable for cutting brittle materials.

[0067] In some embodiments, the satellite peak (i.e., protrusion) can be continuously curved. For example, the satellite peak (i.e., protrusion) can be substantially dome-shaped, or the satellite peak (i.e., protrusion) can be substantially elliptical, semi-elliptical, spherical, hemispherical, oval and / or semi-oval.

[0068] Figure 3 A first embodiment of a tool head 16 is shown. The tool head 16 comprises three layers 18a, 18b, 18c and a notch element 22. The layer 18a corresponds to the layer closest to the handle, the layer 18c corresponds to the layer farthest from the handle, and the layer 18b corresponds to the layer axially intermediate the layers 18a and 18c. Each layer 18 is separated from an adjacent layer 18 by a non-cutting portion 17 of the tool head 16.

[0069] The notch element 22 is configured to cut a correspondingly shaped notch in a workpiece, such as a microphone aperture in a mobile phone handset housing. By way of example only, the notch element 22 may have a diameter of up to 1 mm and a height of up to 1 mm. The notch element 22 is entirely optional and may be omitted.

[0070] exist Figure 8 , an exemplary tool head 24 is shown. In this example, only a single layer 18a is provided.

[0071] Now go to Fig. 9, another embodiment of the tool head 26 is shown. In this embodiment, three layers 18a, 18b, 18c are provided again, each of which is separated from an adjacent layer by a non-cutting portion. Each of the three layers 18a, 18b and 18c is configured for a finishing operation. However, all three layers can be configured for roughing, or alternatively, all three layers can be configured for semi-finishing. The advantage of configuring all layers for the same cutting (e.g., grinding) operation is that it extends the service life of the tool by "n" times, where "n" is the number of layers. As the first layer (regardless of which layer may be used first) wears, the spindle can then be appropriately extended or retracted to move one of the other layers into place. This is repeated as needed and when needed, depending on the number of layers 18 provided. Since the wear rate for all three layers is the same, the operating life of the tool is maximized.

[0072] In another embodiment, three layers 18a, 18b, 18c are again provided, each layer being separated from an adjacent layer by a non-cutting portion 17, such as Fig. 9 . The first layer 18a and the second layer 18b are each configured for a semi-finishing cutting operation. Only the third layer 18c is configured for a finishing cutting operation. One of the advantages of this configuration is that, unlike the examples given in the preceding paragraphs, it does not require additional tool changes between cutting operations. The tool has multifunctionality and can be used for more than one specific cutting operation, thereby reducing machine downtime and maximizing operating equipment efficiency. A tool that is configured for more than one type of cutting operation can be considered a "multi-purpose tool."

[0073] The inventors have found that the layer farthest from the shank 12 is subjected to the greatest forces and the greatest moments during use, and therefore will in principle wear at the greatest rate. Larger moments also result in lower stability and higher vibrations. It is important to consider that the wear patterns for different cutting operations are also different. For example, during finishing, the wear tends to be entirely abrasive, while during semi-finishing, debris may also occur. All of these factors may lead to premature failure of the tool. Therefore, it is important to consider the relative positioning of the layers 18 and their configuration for a particular cutting operation.

[0074] It is preferred to place the layer configured for finishing operations farthest from the shank, since finishing operations require less force and produce less wear. By placing the two layers configured for semi-finishing closer to the shank, the wear rates on the three layers 18 are balanced and the life of the three layers 18 is maximized. Moreover, by having a larger number of layers for semi-finishing and roughing, since the probability of failure due to chips is higher in these cutting operations, the tool provides operational redundancy and enables rapid replacement with subsequent layers, thereby minimizing machine downtime.

[0075] Since a finishing operation produces half the wear of a semi-finishing process, a layer configured for finishing has approximately twice the life of a layer configured for semi-finishing. Therefore, it is an optimal ratio to use twice as many layers for semi-finishing cutting operations as for finishing operations. As an example, for a tool having a total of six layers, four of these layers would be used for semi-finishing and two of these layers would be used for finishing. Continuing with the example, for a tool having a total of twelve layers, eight of these layers would be used for semi-finishing and four of these layers would be used for finishing.

[0076] In another embodiment (not shown), the layers 18 may all be configured specifically for roughing operations. In another embodiment (not shown), not all layers include cutting surfaces formed of polycrystalline CVD diamond as disclosed herein. It is contemplated that different layers of the tool may include different cutting surfaces that are suitable, for example, for cutting different materials or performing different operations, thereby increasing machining efficiency. In another embodiment (not shown), all layers include cutting surfaces formed of polycrystalline CVD diamond as disclosed herein.

[0077] In another embodiment (not shown), substantially all of the tool head is coated with polycrystalline CVD diamond.In another embodiment (not shown), only the cutting surface(s) of the tool head is coated with polycrystalline CVD diamond.

[0078] In an embodiment, the tool head does not include any grooves. In another embodiment, the tool head is substantially free of grooves.

[0079] Since layers configured for roughing experience more wear than layers configured for semi-finishing, the proportion of layers configured for roughing will be at least twice the number of layers configured for semi-finishing, typically three to four times. For example, a single tool configured for all three cutting (e.g., grinding) operations may have a total of nine layers, such as six layers for roughing, two layers for semi-finishing, and one layer for finishing.

[0080] Now go to Fig.10 , shows another embodiment of a tool head 28. In this embodiment, two layers 18a and 18b are provided, each layer being separated from an adjacent layer by a non-cutting portion, and the tool head is provided with a notch element 22.

[0081] In any of the above embodiments, the tool shank 12 may include a metal carbide (e.g., tungsten carbide), although other suitable materials are contemplated, such as silicon carbide and silicon nitride. Optionally, the tool shank 12 includes a conduit (not shown) for delivering compressed air to the tool head to expel spent cutting media from the cutting surface.

[0082] In any of the above embodiments, the tool head 16 may be cylindrical and non-tubular.

[0083] refer to Fig.11 , the total height of the tool head 16 is indicated by 36, and the total height is the sum of the height 38 of the layer body portion 32 and the height 40 of the upper portion 34. Optionally, the height 36 of the tool head 16 is 0.5 mm to 12 mm. Optionally, the height 36 of the tool head 16 is 1 mm to 10 mm. Optionally, the height 36 of the tool head 16 is 6 mm. The height 38 of the layer body portion 32 can be in the range of 0.5 mm to 6 mm, for example, 2.5 mm. Optionally, the height 36 of the tool head 16 does not exceed 12 mm.

[0084] The outer diameter of the tool 10 is indicated at 42 and is the largest, outermost diameter of any layer 18 and handle 12. The individual layers 18 may have different diameters from one another, depending on, for example, which cutting (e.g., grinding) operation they are configured for. Alternatively, all layers 18 will have the same diameter.

[0085] Preferably, the outer diameter of the tool 10, 24, 26, 28 does not exceed 15 mm. Optionally, the outer diameter 42 of the tool is 10 mm. In one example of a tool, the overall height of the tool including the tool handle 12 and the tool head 16 may be about 200 mm.

[0086] The height 44 of each layer 18 (measured axially, the same as the previous height measurement) depends on the number of layers 18 and the height 38 of the substrate. As an example, for a tool head 16 (having a tool head height 36 of 6 mm), the height 38 of the layer portion is 2.5 mm, and for three layers, the height 44 of each layer is 0.6 mm to 0.7 mm.

[0087] The above parameters, i.e. the sharpness ratio β of the cutting surface of the layer or each layer, the average height H (mm) of the satellite peaks (i.e., protrusions), the average overlap length L (mm) between two adjacent satellite peaks (i.e., protrusions), the average diameter D of the satellite peaks (i.e., protrusions), and the area density C of the satellite peaks (i.e., protrusions) are optimized in the case of cutting glass or other similar brittle materials depending on the cutting operation intended for roughing, semi-finishing, or finishing. Roughing cutting operations are generally intended to prepare the surface of the workpiece before finishing operations. The goal is to bring the size to a "rough" size of the final size. How this may look is not important, because the main goal is to quickly remove a relatively large amount of material. Semi-finishing cutting operations are typically the next stage after roughing. The goal is to obtain a size that is closer to the final size. Finishing cutting operations are the final stage of machining a workpiece. The minimum amount of workpiece material is removed, the workpiece is machined to a certain size, the final size is obtained, and sometimes the surface is further refined.

[0088] One of the methods of manufacturing a tool head is as follows: a carbide disc-shaped blank is provided and a precursor tool head is machined from the disc. A layer body is formed in the precursor tool head, for example using a laser. This step is repeated as required, for example to form a tool head comprising at least two layers, and wherein the layers are axially displaced from each other and separated by a non-cutting portion of the tool head. Finally, polycrystalline diamond is deposited on the tool head, for example using chemical vapor deposition to deposit polycrystalline diamond on the layers. Typically, hot wire CVD is used, but other forms of CVD, such as microwave plasma CVD, may also be used. A final finishing operation may be required on the deposited diamond layer on the tool head.

[0089] The cutting tool and the cutting tool head of the utility model can be used for cutting brittle materials, which can be any one of glass, ceramics, polymers, composite materials, metal materials and metal-ceramic composite materials.

[0090] In summary, the inventors have designed a cutting tool and a cutting tool head that maximizes tool life and improves cost / benefit performance. This is accomplished by using a tool head as described herein, the tool head comprising a layer body having a CVD diamond cutting surface, the CVD diamond cutting surface comprising a plurality of satellite peaks (i.e., protrusions).

[0091] While the invention has been particularly shown and described with reference to the embodiments, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the scope of the invention as defined by the appended claims.

Claims

1. A cutting tool, characterized in that: The cutting tool comprises: A tool shank having a rotation axis and further comprising a tool head at one end thereof, the tool head comprising a layer body, wherein the layer body of the tool head comprises a cutting surface formed of polycrystalline CVD diamond, and wherein the cutting surface comprises a plurality of satellite peaks, wherein the sharpness ratio β of the cutting tool is in the range of about 0.01 to about 1.5, The sharpness ratio β is the ratio of the average height H mm of the satellite peaks to the average overlapping length L mm between two adjacent satellite peaks.

2. The cutting tool according to claim 1, wherein: The satellite peak has an average height H mm of about 0.005 mm to about 0.025 mm.

3. The cutting tool according to claim 1 or claim 2, wherein: The average overlap length L mm between two adjacent satellite peaks is about 0.02 mm to about 1 mm.

4. The cutting tool according to claim 1, wherein: The satellite peak has an average diameter D of about 0.005 mm to about 0.025 mm.

5. The cutting tool according to claim 1, wherein: The area density C of the satellite peak is about 50 per mm 2 About 1000 per mm 2 .

6. The cutting tool according to claim 1, wherein: CD ≥ 1, where C is the area density of the satellite peak per mm 2 And D is the average diameter of the satellite peaks in mm.

7. The cutting tool according to claim 1, wherein: The satellite peak is continuously curved.

8. The cutting tool according to claim 1, wherein: The tool head comprises at least one further layer, wherein the layers are axially displaced from each other and separated by a non-cutting portion of the tool head.

9. The cutting tool according to claim 8, wherein: At least one of the at least one further layer comprises a cutting surface formed of polycrystalline CVD diamond, wherein the cutting surface comprises a plurality of satellite peaks as defined in claim 1 .

10. The cutting tool according to claim 8, wherein: Each layer body comprises a cutting surface formed of polycrystalline CVD diamond, wherein the cutting surface comprises a plurality of satellite peaks as defined in claim 1 .

11. The cutting tool according to any one of claims 8 to 10, wherein: The tool comprises at least two layers.

12. The cutting tool according to any one of claims 8 to 10, wherein: The tool comprises at least three layers.

13. The cutting tool according to any one of claims 8 to 10, wherein: At least one layer is configured for an operation selected from any one of rough machining, semi-finishing, or finishing.

14. The cutting tool according to any one of claims 8 to 10, wherein: Two or more layers are configured for the same operation.

15. The cutting tool according to any one of claims 8 to 10, wherein: Each layer is configured differently from the remaining layers.

16. The cutting tool according to any one of claims 8 to 10, wherein: At least one layer has a diameter that is different from the other layers.

17. The cutting tool according to claim 1, wherein: The tool head is cylindrical and non-tubular.

18. The cutting tool according to claim 1, wherein: The tool head has an overall height of no more than 12 mm and / or wherein the tool head has an overall height of no less than 0.5 mm.

19. The cutting tool according to claim 1, wherein: The outer diameter of the tool handle is selected from any one of not more than 15 mm, not more than 10 mm, and not less than 6 mm.

20. The cutting tool according to claim 1, wherein: The tool shank and / or the tool head comprises cemented carbide.

21. The cutting tool according to claim 1, wherein: The cutting tool is used for cutting brittle materials.

22. The cutting tool according to claim 21, wherein: The brittle material is any one of glass, ceramic, polymer, composite material, metal material and metal-ceramic composite material.

Images