Cutting element formed from composite material of substrate having structured coating and method for manufacturing cutting element

Abstract

The invention relates to a cutting element formed from a composite material of a substrate coated with a structured coating, the composite material comprising a substrate having a surface in contact with the coating. The substrate has a plurality of substrate recesses at least in the region of the substrate surface. The coating extends into the recesses of the substrate and has an inner surface in contact with the substrate and an outer surface opposite the inner surface. The coating includes a plurality of coating recesses at the outer surface that are smaller than the recesses at the surface of the substrate, thereby forming a structured coating. The invention further relates to a method for producing a cutting element.

Description

[0001] This invention relates to a cutting element formed from a composite material of a substrate coated with a structured coating, the composite material comprising a substrate having a surface in contact with the coating. The substrate has a plurality of substrate recesses, at least in a region of its surface. The coating extends into these recesses of the substrate and has an inner surface in contact with the substrate and an outer surface opposite the inner surface. The coating includes a plurality of coating recesses at the outer surface, the plurality of coating recesses being smaller than those at the surface of the substrate, thereby forming a structured coating. Furthermore, this invention relates to a method for manufacturing the cutting element.

[0002] For many engineering applications, the substrate material is coated with a soft or hard material to enhance its properties. For example, a hard coating is applied to increase the wear resistance of the substrate material, or a soft coating is applied to improve its frictional properties. Thus, the substrate material and the coating form a layered composite material with enhanced functional properties.

[0003] For lubrication applications, it is also known to structure the contact surfaces to provide reservoirs for lubricants.

[0004] However, there are many applications that operate without lubricant, such as in cutting processes.

[0005] For such applications, complex material stacks can be used to adjust friction and wear characteristics. For example, for razor blades, a steel substrate with a planar cutting bevel is first coated with a diamond-like carbon (DLC) hard coating to improve wear resistance, followed by a friction-reducing layer of polytetrafluoroethylene (PTFE). Achieving specific trade-offs between wear resistance and friction characteristics using stacks is complex and expensive. Furthermore, different stacks can cause problems due to varying material properties; for example, different Young's moduli can induce shear stresses at the layer interfaces when mechanical deformation is applied to the stack. This can lead to catastrophic failure due to delamination of at least some layers. In addition, stacks can exhibit thermally induced stresses that cause stack deformation, especially when layers are deposited at different temperatures and have different coefficients of thermal expansion.

[0006] Furthermore, all coatings on the cutting edge will increase its radius of curvature, thus reducing its cutting ability. Finally, it should be mentioned that the tribological and wear characteristics of a component composed of layers are always dominated by the final layer exposed to the friction / wear pair. Therefore, for razor blades, the final PTFE layer enhances the tribological properties. Since this layer is soft, it can wear down relatively quickly over time, and the DLC hard coating is then exposed to the friction pair. Unfortunately, the exposed DLC layer exhibits excellent wear resistance, but its tribological properties are worse than those of the PTFE layer. Therefore, although the cutting edge remains undamaged, the blade begins to lose its performance.

[0007] Another technique for optimizing the frictional properties of cutting elements is to reduce the contact surface, as is well-known in cheese knife applications. For safety reasons, adding additional coatings to steel cheese knives is not recommended. Therefore, macroscopically sized holes are introduced into the steel blade body. These holes reduce the contact surface with the cheese, thereby lowering the knife's frictional properties.

[0008] In the absence of lubricants, especially in cutting applications, there is always a need to improve and adjust the friction and wear characteristics of the contact surfaces.

[0009] Therefore, the present invention addresses the aforementioned drawbacks of the prior art and provides a composite material with a substrate coated with a structured coating, wherein the composite material exhibits adjusted frictional and wear characteristics due to the structure of the coating surface.

[0010] This problem is solved by a cutting element formed from a composite material of a substrate coated with a structured coating, having the features of claim 1, and a method for manufacturing the cutting element, having the features of claim 14. Further dependent claims define preferred embodiments.

[0011] The following definitions are used in this application:

[0012] Concave:

[0013] A recess is formed by removing material from the surface of a solid host material (substrate or coating) or by material being missing from the surface and extending below the surface, such that the recess lacks host material, is open to the surrounding environment, and is accessible from the surface; that is, it can be filled with another gaseous, liquid, or solid substance or remain empty. The recess has an opening, a base, and sidewalls. The opening has a periphery located within the host material surface, the base is located within the host material, and the sidewalls are located within the host material and connect the periphery of the opening to the base.

[0014] Protrusion:

[0015] Protrusions are formed by the addition or presence of material on a surface and extend beyond the surface of the solid host material (substrate or coating).

[0016] Maximum inner circle:

[0017] The maximum inner circle is a circle that can be fully fitted into any 2D planar shape (including circles, ellipses, or polygons) with a closed outer perimeter. The maximum inner circle will coincide with the perimeter of the closed 2D planar shape at at least 3 points, and it will not extend beyond the perimeter at any point.

[0018] Depth (of concavity):

[0019] Depth of recess d base It is the vertical distance from the surface of the host material (substrate or coating) to the lowest point on the base of the recess within the host material. The depth d of a pair of recesses. pair-sub and d pair-coat It is the average depth of two adjacent concave parts.

[0020] Width (of the recess):

[0021] Width w of the recess in the substrate and coating sub and w coat These are the diameters of the largest inner circles around the openings of the recesses that can be fully fitted into the surface plane of the host material (substrate or coating). The width w of a pair of recesses... pair-sub and w pair-coat It is the average width of two adjacent concave sections.

[0022] Undercut:

[0023] Undercut refers to the shape of the sidewall of the recess, which has at least one width below the base surface, the at least one width being greater than the width w of the opening of the recess. sub and w coat Maximum width w max At depth d max The diameter of the largest inner circle in the largest periphery of the recess, which can be fully fitted into the recess in a plane parallel to the surface of the host material (substrate), the depth of which is below the surface of the substrate and at the depth d of the base of the recess. base The depth above or at.

[0024] (The spacing between the recesses)

[0025] The spacing s is the distance between any two adjacent recesses, measured between the centers of two adjacent recesses, whereby the center of the recess is defined as the center of the largest inner circle in the periphery of the recess opening at the base surface when fully fitted.

[0026] area:

[0027] The surface of the substrate can be subdivided into multiple smaller areas, which are called regions.

[0028] The term "comprising" in the claims and description of this application is not intended to exclude other components. Within the scope of this invention, the term "consisting of" should be understood as the preferred embodiment of the term "comprising". If a group is defined as "comprising" at least a specific number of components, this should also be understood as the disclosed group preferably "consisting of" those components.

[0029] According to the present invention, a cutting element is provided, which is formed of a composite material of a substrate coated with a structured coating, wherein the composite material comprises or is composed of a substrate having a surface in contact with the coating. The substrate has a plurality of substrate recesses in at least a region of its surface, and the coating extends into the recesses of the substrate. In other words, the cutting element comprises or is composed of a substrate coated with a structured coating, wherein the cutting element comprises or is composed of a substrate having a surface in contact with the coating. The substrate has a plurality of substrate recesses in at least a region of its surface, and the coating extends into the recesses of the substrate, thereby forming protrusions.

[0030] The coating has an inner surface in contact with the substrate and an outer surface opposite the inner surface. The coating includes a plurality of replicated coating recesses on the outer surface, these recesses being smaller than the recesses on the substrate surface, thereby forming a structured coating. The outer surface of the structured coating has a total surface area A. tot Total concave area A r and contact area A c =A tot –A r The condition is A c / A tot The value is in the range of 0.1 to 0.8, preferably 0.3 to 0.7, and more preferably 0.45 to 0.65.

[0031] Such structured surfaces forming the substrate offer the advantage of controllable frictional properties. These properties can be optimized by selecting the width, depth, spacing, and shape of the recesses or protrusions. The distribution can be regular or random.

[0032] Preferably, at least in the region of the composite material, the substrate is removed to expose protrusions, which preferably have a shape opposite to the recesses on the inner surface of the coating.

[0033] According to a preferred embodiment, the substrate recess has a width w in the range of 100 nm to 100 µm, preferably 500 nm to 20 µm. sub and a depth d in the range of 50 nm to 5 µm, preferably 100 nm to 2 µmbase The condition is the ratio w sub / d base The value is in the range of 0.20 to 25, preferably in the range of 1 to 20, and more preferably in the range of 5 to 15.

[0034] Furthermore, preferably, the coating recess has a width w that is preferably in the range of 100 nm to 100 µm, more preferably in the range of 500 nm to 20 µm. coat And preferably a depth d in the range of 10 nm to 4 µm, more preferably 50 nm to 1.5 µm. coat The condition is the ratio w coat / d coat The value is in the range of 0.25 to 25, preferably in the range of 1 to 20, and more preferably in the range of 5 to 15. Preferably, d coat Less than d base .

[0035] According to a preferred embodiment, the base recesses are arranged such that the average width w of any pair of two adjacent base recesses is... pair-sub The ratio w to the distance s between two adjacent concave portions of the same pair pair-sub / s is in the range of 0.1 to 0.95, preferably 0.3 to 0.9, more preferably 0.4 to 0.8, and even more preferably 0.5 to 0.75.

[0036] Furthermore, preferably, the coating recesses are arranged such that the average width w of any pair of two adjacent coating recesses is... pair-coat The ratio w to the distance s between two adjacent concave portions of the same pair pair-coat / s is in the range of 0.1 to 0.95, preferably 0.3 to 0.9, more preferably 0.4 to 0.8, and even more preferably 0.5 to 0.75.

[0037] In a preferred embodiment of the invention, the base recesses are arranged such that the distance s between any pair of two adjacent recesses is equal to the average depth d of the same pair of recesses. pair-sub The ratio s / d pair-sub Preferably in the range of 0.25 to 20, more preferably in the range of 0.5 to 15, and even more preferably in the range of 1 to 12.

[0038] In a preferred embodiment of the invention, the coating recesses are arranged such that the distance s between any pair of two adjacent recesses is equal to the average depth d of the same pair of recesses. pair-coat The ratio s / d pair-coat Preferably in the range of 0.25 to 20, more preferably in the range of 0.5 to 15, and even more preferably in the range of 1 to 12.

[0039] The recesses can be arranged regularly or randomly, so that the spacing s between any pair of base recesses and coating recesses is the same.

[0040] Preferably, the substrate comprises or is composed of a material selected from the group consisting of said material.

[0041] ● Metals, preferably titanium, nickel, chromium, niobium, tungsten, tantalum, molybdenum, vanadium, platinum, germanium, iron and their alloys, especially steel.

[0042] ● Ceramics, wherein the ceramics comprise at least one element selected from the group consisting of: carbon, nitrogen, boron, oxygen, or combinations thereof, preferably silicon carbide, zirconium oxide, aluminum oxide, silicon nitride, boron nitride, tantalum nitride, TiAlN, TiCN, and / or TiB2.

[0043] ● Glass ceramics; preferably aluminum-containing glass ceramics.

[0044] ● Composite materials made of ceramic materials in a metal matrix (cermet).

[0045] ● Hard metals, preferably sintered carbide hard metals, such as tungsten carbide or titanium carbide bonded to cobalt or nickel.

[0046] ● Monocrystalline silicon or germanium, preferably having crystal planes parallel to the first surface, with wafer orientation. <100> , <110> , <111> or <211> ,

[0047] ● Glass or sapphire

[0048] ● Polycrystalline or amorphous silicon or germanium

[0049] ●Single-crystal or polycrystalline diamond, diamond-like carbon (DLC), diamond carbon, and

[0050] ● Their combination.

[0051] More preferably, the substrate comprises silicon, steel, and combinations thereof, or is composed of silicon, steel, and combinations thereof.

[0052] The steel used for the base material is preferably selected from the group consisting of: 1095, 12C27, 14C28N, 154CM, 3Cr13MoV, 4034, 40X10C2M, 4116, 420, 440A, 440B, 440C, 5160, 5Cr15MoV, 8Cr13MoV, 95X18, 9Cr18MoV, Acuto+, ATS-34, AUS-4, AUS-6 (=6A), AUS-8 (=8A), C75, CPM-10V, CPM-3V, CPM-D2, CPM-M4, CPM-S-30V, CPM-S-35VN, CPM-S-60V, CPM-154, Cronidur-30, CTS 204P, CTS 20CP, CTS40CP, CTS B52, CTS B75P, CTS BD-1, CTS BD-30P, CTS XHP, D2, Elmax, GIN-1, H1, N690, N695, Niolox (1.4153), Nitro-B, S70, SGPS, SK-5, Sleipner, T6MoV, VG-10, VG-2, X-15T.N., X50CrMoV15, ZDP-189.

[0053] Martensitic stainless steel substrates are preferred for manufacturing cutting components, such as knives, scalpels, and razor blades, due to their high hardness and good corrosion resistance. Specifically, high-carbon martensitic stainless steel bars containing approximately 13% Cr by mass are preferred as razor blade materials.

[0054] The substrate material preferably has a coefficient of thermal expansion of 0.9 ppm / K to 20 ppm / K (at 20°C), more preferably 1 ppm / K to 15 ppm / K, and even more preferably 2 ppm / K to 5 ppm / K.

[0055] The substrate preferably has a Young's modulus of 50 GPa to 1000 GPa, more preferably 75 GPa to 800 GPa, and even more preferably 100 GPa to 400 GPa.

[0056] Preferably, the coating comprises or is composed of a material selected from the group consisting of hard materials (hard coatings), such as...

[0057] ●Oxides, nitrides, carbides, and borides, preferably aluminum nitride, chromium nitride, titanium nitride, titanium carbon nitride, titanium aluminum nitride, and cubic boron nitride.

[0058] ●Boron, aluminum, magnesium

[0059] ● Carbon, preferably diamond, nanodiamond, microcrystalline diamond, polycrystalline diamond, single-crystal diamond, diamond-like carbon (DLC), or tetrahedral amorphous carbon.

[0060] In addition, all materials referenced in VDI Guide 2840 can be selected as hard coating materials.

[0061] Alternatively, preferably, the coating comprises or is composed of a material selected from the group consisting of soft materials (soft coatings) such as low-friction materials, preferably selected from polymers, especially fluoropolymers (preferably polytetrafluoroethylene (PTFE)), silicone polymers (preferably silicone), parylene, polysilazane, polyvinylpyrrolidone, polyethylene, polypropylene, polymethyl methacrylate, graphite, and combinations thereof.

[0062] Particularly preferred are hard coating materials made of nanodiamond and / or multilayers of nanodiamond and coarse-grained polycrystalline diamond. Compared to single-crystal diamond, the production of nanodiamond can be accomplished more easily and economically. Furthermore, nanodiamond layers are more uniform in grain size distribution than coarse-grained polycrystalline diamond layers, and the material also exhibits lower intrinsic stress. Therefore, macroscopic deformation of cutting elements made of nanodiamond is unlikely.

[0063] Preferably, the substrate is coated with more than one coating, i.e., the coating is a first coating deposited on the substrate at least in a region, and at least one additional coating is deposited on the first coating at least in a region. Preferably, the second coating is deposited on the first coating at least in a region or on the outer surface of the first coating.

[0064] Preferably, the hard coating has an elastic modulus (Young's modulus) of less than 1200 GPa, more preferably less than 900 GPa, more preferably less than 750 GPa, and even more preferably 50 GPa to 500 GPa. Due to the low elastic modulus, the hard coating becomes more flexible and elastic. The Young's modulus for diamond materials is determined according to the method disclosed in Markus Mohr et al., “Young's modulus, fracture strength, and Poisson's ratio of nanocrystalline diamond films,” J. Appl. Phys. 116, 124308 (2014), particularly under paragraph III.B. Static measurement of Young's modulus.

[0065] The hard coating has a transverse fracture stress σ0 of 1 GPa to 15 GPa, preferably 2.5 GPa to 10 GPa, and more preferably 5 GPa to 8 GPa.

[0066] For the definition of transverse fracture stress σ0, please refer to the following references:

[0067] ●R. Morrell et al., Int. Journal of Refractory Metals & Hard Materials, 28 (2010), pp. 508-515

[0068] ● R. Danzer et al., in: "Technische keramische Werkstoffe" published by J. Kriegesmann, HvB Press, Ellerau, ISBN 978-3-938595-00-8, Chapter 6.2.3.1 "Der4-Kugelversuch zur Ermittlung der biaxialen Biegefestigkeit spröder Werkstoffe".

[0069] Therefore, the transverse fracture stress σ0 is determined through statistical evaluation of fracture tests, such as the B3B load test according to the details of the aforementioned literature. Thus, it is defined as the fracture stress with a fracture probability of 63%.

[0070] Due to the extremely high transverse fracture stress of the hard coating material, the detachment of individual microcrystals from the hard coating is almost completely suppressed.

[0071] The hard coating preferably has a hardness of 20 GPa to 100 GPa, more preferably 25 GPa to 50 GPa. The hardness is determined by nanoindentation (Yeon-Gil Jung et al., J. Mater. Res., Vol. 19, No. 10, p. 3076).

[0072] Contact surface A c The hard coating preferably has an average surface roughness R of 1 nm to 100 nm, more preferably 5 nm to 50 nm, and even more preferably 10 nm to 20 nm. A .

[0073] For nanodiamond hard coatings, the average grain size d of the nanodiamond is... 50 Preferably, the average grain size is 1 nm to 100 nm, more preferably 5 nm to 90 nm, even more preferably 7 nm to 30 nm, and most preferably 10 nm to 20 nm. 50It is the diameter when 50% of the second material consists of smaller particles. Average particle size d 50 The average grain size d of the diamond film can be determined using X-ray diffraction or transmission electron microscopy and grain counting. For coarse-grained polycrystalline diamond, the average grain size d of the diamond film is... 50 Preferably, it is in the range of greater than 100 nm to 1500 µm.

[0074] The hard coating preferably has a coefficient of thermal expansion of 0.9 ppm / K to 8 ppm / K (at 20°C), more preferably 0.95 ppm / K to 5 ppm / K, and even more preferably 1.0 ppm / K to 3 ppm / K.

[0075] The periphery of the recessed opening can be of any shape, but the preferred shape of the recessed opening is without corners, that is, the periphery of the recessed opening is a closed continuous line without any singularities. Preferably, the recess has a circular or elliptical shape, but it can also be a linear shape.

[0076] The recess preferably includes undercut sidewalls, meaning that the recess has at least one width below the substrate surface, which is greater than the width w of the recess opening. sub This improves the mechanical interlocking between the coating and the substrate material because some of the coating material will fill the undercut in the substrate material, thus residing below the first surface of the substrate. This increases the adhesion between the substrate and the coating because separation of the coating from the substrate material would require breaking down some of the substrate material near the first surface.

[0077] Preferably, the coating has a thickness T of 100 nm to 50 µm, more preferably 150 nm to 20 µm, and even more preferably 200 nm to 15 µm. c .

[0078] The substrate has a thickness T of preferably 20µm to 2000µm, more preferably 30µm to 1000µm, and even more preferably 50µm to 400µm. s .

[0079] According to a preferred embodiment, the composite material has a total thickness T of 25µm to 2050µm, preferably 35µm to 1000µm, and more preferably 55µm to 400µm. tot .

[0080] Preferably, the depth d of the recess in the substrate base With the thickness T of the coating c The ratio d base / T c The value is in the range of 0.01 to 15, preferably 0.1 to 5, and more preferably 0.5 to 2.

[0081] Further preferably, the depth d of the recess in the coating coat With the thickness T of the coating c The ratio d coat / T c It is in the range of 0.01 to 5, preferably 0.02 to 1, and more preferably 0.05 to 0.5.

[0082] According to another aspect of the invention, a cutting element having a cutting edge is provided, the cutting element being formed from a composite material as described above. The cutting element is preferably a knife blade, razor blade, surgical scalpel, knife, mechanical blade in a slitting, bursting, or crashing cutting system, scissors, or a shearing cutting system.

[0083] Preferably, the region where the substrate is removed to expose the protrusion, which is a recessed reverse structure, is the region of the cutting edge of the cutting element, preferably a region extending up to 200µm from the cutting edge.

[0084] A cutting edge can be manufactured by partially removing the substrate material until only the coating material (preferably a hard coating) remains, and then forming the cutting edge in a self-supporting coating. If the substrate material contains recesses on its surface, the coating includes protrusions formed during the coating process as the coating material fills the recesses in the substrate material. These protrusions mirror the shape and distribution of the recesses formed on the surface of the substrate material prior to coating deposition and reduce the surface contact area to adjust frictional properties. The coating includes multiple coating recesses at the coating surface that have been transferred from multiple recesses on the substrate surface and reduce the surface contact area to adjust frictional properties.

[0085] According to another aspect of the invention, a cutting element with a cutting edge is also provided, the cutting element being formed from a composite material of a substrate coated with a structured coating, the composite material comprising a substrate having a surface in contact with the coating, wherein the composite material comprises or is composed of a substrate having a surface in contact with the coating, wherein the substrate has a plurality of substrate recesses at least in a region of the substrate surface, and the coating extends into the recesses of the substrate. The coating has an inner surface in contact with the substrate and an outer surface opposite to the inner surface. Furthermore, the composite material includes a region in which the substrate is removed to expose protrusions, these protrusions preferably having a shape opposite to the recesses at the inner surface of the coating. The cutting element includes a cutting bevel and a cutting element body, wherein the cutting bevel is at least partially located in the region of the composite material in which the substrate is removed and in the coating having exposed protrusions on the cutting bevel.

[0086] According to another aspect of the present invention, a method for manufacturing a cutting element is provided, the method comprising the following steps:

[0087] a) Provide a substrate having a first surface,

[0088] b) Form an etch mask with openings on the surface of the substrate.

[0089] c) Using reactive ion etching or wet chemical etching, the substrate is etched through openings in an etching mask to form multiple recesses on the first surface of the substrate.

[0090] d) Optionally, remove the etch mask from the substrate.

[0091] e) A coating is deposited onto the substrate surface and into multiple recesses, thereby transferring the substrate recesses to coating recesses on the outer surface of the coating, which are smaller than the substrate recesses, thus forming a structured coating.

[0092] f) Etch the substrate to expose the protrusions on the inner surface of the coating to form the cutting bevel of the cutting element.

[0093] In a preferred embodiment, after step c), the etch mask is removed from the substrate.

[0094] The following figures and examples further illustrate the invention, showing specific embodiments according to the invention. However, these specific embodiments should not be construed as limiting the invention in any way with respect to the claims as described in the general part of the specification.

[0095] Figure 1a and Figure 1b The top view, cross-sectional view, and enlarged cross-sectional view of the recess are shown respectively.

[0096] Figure 2 A cross-sectional view of the composite material of the present invention is shown.

[0097] Figure 3 It is a top view of the base on the surface.

[0098] Figure 4 This is a cross-sectional view of the substrate of the present invention.

[0099] Figures 5a to 5c These are scanning electron microscope (SEM) images of the substrate and coating surfaces according to the present invention.

[0100] Figure 6 shows an alternative concave shape according to the invention.

[0101] Figure 7 This is a schematic diagram of the process steps according to the method of the present invention.

[0102] Figures 8a to 8d This is a schematic diagram of depositing a coating onto a substrate material according to the present invention.

[0103] Figure 9 Schematic top and side views of the cutting elements at different stages during the process according to the invention are shown.

[0104] Figure 10 A schematic cross-sectional view of a cutting element formed in a hard coating is shown.

[0105] Figures 11a to 11c SEM images of perspective views of cut elements with circular recesses at different scales are shown.

[0106] Figures 12a to 12b SEM images of perspective views of cut elements with linearly shaped recesses at different scales are shown.

[0107] Figures 13a to 13b Scanned electron photographs at different magnifications of the cross-section in the perspective view of the cut element are shown. List of reference numerals

[0108] 10 Composite Materials

[0109] 110 interface

[0110] 20. Substrate (material)

[0111] 200 substrate surface

[0112] 205 substrate back surface

[0113] 210 photoresist

[0114] 220 photoresist area

[0115] 230 Unprotected Areas

[0116] 240 areas with recesses

[0117] 250 areas without recesses

[0118] 30 coating layers

[0119] 300 Coated Surface

[0120] 305 coating inner surface

[0121] 320 protrusions

[0122] 330 coated recess

[0123] 40, 40', 40'', 40'''' recess

[0124] 410 concave opening

[0125] 415 sidewall

[0126] 420 concave base

[0127] 460° recessed opening perimeter

[0128] 462 Maximum perimeter of the concave part

[0129] 470 maximum inner circle

[0130] 472 concave center

[0131] 480 bottom cut

[0132] 600 cutting elements

[0133] 610 cutting blade

[0134] 620 cutting bevel

[0135] 630 Cutting Component Body

[0136] Figure 1a A top view of a recess 40 in a base 20 is shown. The recess 40 has an opening 410 with an opening perimeter 460, both of which lie within the surface 200 of the base 20. The opening perimeter 460 can be of any shape, but a preferred shape for the recess opening 410 is without corners; that is, the recess opening perimeter 460 is a closed continuous line without any singularities. The width w of the recess... sub It is the diameter of the largest inner circle 470 that can be fully fitted into the perimeter 460 of the opening 410, such as Figure 1a As shown by the dotted lines. The circumference of the largest inner circle 470 may coincide with the periphery 460 of the recess opening 410, but may not extend beyond the periphery 460 of the recess opening 410. The center of the largest inner circle 470 defines the recess center 472 of the recess.

[0137] Figure 1b Showing from Figure 1a A cross-sectional view of a recess 40 in a base 20. The recess 40 includes an opening in a surface 200 of the base 20, a base 420, and a sidewall 415 located within the base 20. The opening has a width w defined by a maximum inner circle 470. sub .

[0138] As can be seen from the enlarged view of sidewall 415, sidewall 415 has an undercut 480. This results in the width of recess 40 at a depth below the base surface 200 being greater than the width w of the opening of recess 40 at the base surface 200. sub The width of the recess 40 at any depth below the base surface 200 is defined by the diameter of the largest inner circle, which can be completely placed within the periphery of the recess at that depth below the base surface 200, whereby the periphery lies in a plane parallel to the base surface at that depth.

[0139] Figure 2A cross-sectional view of a composite material 10 including a substrate material 20 and a coating 30 is shown. The substrate material 20 is made of silicon. The substrate material 20 has a surface 200. The substrate material 20 includes a plurality of recesses 40, which are provided according to the description below and Figure 7 The method illustrated in the figure is etched into surface 200. Each recess 40 has a width of w at surface 200. sub The opening. Furthermore, each recess 40 has a depth d below the surface 200. max The maximum width w is located at the point. max Adjacent recesses 40 are separated by a spacing s. The coating 30 is composed of nanodiamond. As described below and... Figure 7 The method illustrated herein involves depositing a coating 30 onto a structured surface 200 of a substrate material 20. The coating 30 has a coating thickness T measured from the substrate surface 200. c .

[0140] Figure 3 A top view of the surface 200 of the substrate material 20 is shown. The substrate material 20 includes a plurality of recesses 40, which are provided according to the description below and Figure 7 The method illustrated in the figure is etched into surface 200. Each recess 40 has a width of w at surface 200. sub The opening 410 and the recess opening perimeter 460 surrounding the opening 410 of the recess 40. Furthermore, the maximum depth d of each recess 40 below the surface 200. max The maximum width w is located at the point. max Adjacent recesses 40 are separated by a distance s.

[0141] Figure 4 A cross-sectional view of the substrate material 20 is shown. The substrate material 20 includes a plurality of recesses 40, which are provided according to the description below and Figure 7 The method illustrated is used to etch into surface 200. Each recess 40 has an opening at surface 200, a sidewall 415, and a depth d below surface 200. base The base of the location is 420.

[0142] As can be seen from the enlarged view of the sidewall 415 of the recess 40, the opening periphery 460 is located around the opening of the recess 40. Furthermore, the maximum depth d of each recess 40 below the surface 200... max It has a maximum perimeter of 462. The maximum inner circle that can be fully fitted into the opening perimeter 460 defines the surface width w. sub And can be fully fitted into the maximum inner circle of the maximum perimeter 462, which limits the maximum width w. max w max Subtract w sub The difference corresponds to twice the width of the overhang h. Depth dmax The depth d of the concave portion is greater than zero but less than or equal to 40. base This means a maximum perimeter of 462 and therefore a maximum width of w. max It is located below the surface 200 of the base 20 to form an undercut 480. Adjacent recesses 40 are separated by a distance s.

[0143] Figure 5a A scanning electron micrograph (SEM) of the surface 200 of the substrate material 20, comprising a plurality of circular recesses 40, is shown. As can be inferred from the scale bar, in this example, the opening width w of the recesses 40 is... sub It is approximately 10µm.

[0144] Figure 5b A cross-sectional SEM image of the substrate material 20, including multiple circular recesses 40 with undercuts of 480, is shown. As can be seen from the scale and measurements, in this example, the opening width w of the recesses 40 is... sub It is approximately 10µm, and the depth of the recess is d. base It is approximately 1µm.

[0145] Figure 5c A perspective SEM image of composite material 10 is shown, which includes a coating 30 and a substrate material 20 having a plurality of recesses 40, wherein the coating has been partially removed. After the coating is deposited onto the substrate surface containing the plurality of recesses, these recesses are transferred to the surface of the coating 300 and a plurality of coating recesses 330 are formed.

[0146] Figure 6a and Figure 6b Two alternative enlarged views of the sidewall 415 of the recess 40 are shown.

[0147] like Figure 6a As can be seen, the recess 40 has an undercut 480 with straight sidewalls 430, which increase the width of the recess from the opening toward the base 420. An opening periphery 460 is located around the opening of the recess 40, and a maximum periphery 462 is located at a maximum depth d below the surface 200. max In this example, the maximum depth is equal to the depth d of the recess. base The maximum inner circle within 460 degrees of the opening perimeter defines the surface width w. sub And fully assembled into the maximum inner circle of the maximum perimeter 462, defining the maximum width w. max 432. w max Subtract w sub The difference corresponds to twice the width of the overhang h.

[0148] like Figure 6bAs can be seen, the recess 40 has an undercut 480, which has sidewalls 415 of different shapes. An opening periphery 460 is located around the opening of the recess 40, and a maximum periphery 462 is located at the maximum depth d below the surface 200. max Location. Depth d max The depth d of the concave portion is greater than zero but less than or equal to 40. base This means a maximum perimeter of 462 and therefore a maximum width of w. max It is located between the base surface 200 and the recessed base 420.

[0149] The maximum inner circle defining the surface width w is fully fitted into the opening perimeter 460. sub And fully assembled into the maximum inner circle of the maximum perimeter 462, defining the maximum width w. max w max Subtract w sub The difference corresponds to twice the width of the overhang h.

[0150] To form an undercut of 480, if a depth d exists... max The width w of the recess at that depth max Width greater than the opening of the recess sub If there is an overhang h greater than zero, then the sidewall 415 of the recess 40 can have any shape. Example

[0151] The method of the present invention for manufacturing composite materials with a substrate having a structured coating is described in... Figure 7 The diagram is shown and explained in detail below.

[0152] Process step a) shows the starting point, providing a single-crystal silicon wafer as a substrate.

[0153] After carefully cleaning the substrate surface 200 in step b), a photoresist 210 providing reasonable selectivity to the reactant etch gas composition is deposited by spin coating or spraying to achieve reasonable thickness (e.g., 1 µm to 2 µm) and uniformity. For reasonable resolution and selectivity, standard photoresists used in semiconductor manufacturing are recommended.

[0154] The photoresist is dried / pre-baked according to the recommended parameters provided by the photoresist manufacturer. To pattern the photoresist, a photomask and UV exposure equipment are required. The photoresist is exposed through the photoresist mask, and the exposed photoresist areas 220 are developed according to the recommended parameters provided by the photoresist manufacturer.

[0155] After development, post-baking is recommended to increase the selectivity of subsequent etching processes. The treatment of the photoresist is schematically shown in process step b).

[0156] Using photoresist 210 as a mask with sufficient stability to the reactants, the recess 40 is formed by isotropic etching of the unprotected region 230 on the substrate. If a small recess depth is required, dry etching processes such as (D)RIE or ICP are advantageous. In the case of a silicon substrate, a DRIE adaptation process, alternating sidewall passivation, and isotropic etching steps can be used. Details can be found, for example, MD Henry, “ICP Etching of silicon for micro and nanoscale devices,” Thesis California Institute of Technology, May 19, 2010. Such steps allow for precise control over the desired shape of the sidewalls 415 and the undercut 480. This method is illustrated in process step c).

[0157] After the recess 40 is formed, the photoresist 210 is removed using a solution recommended by the photoresist manufacturer, as shown in process step d).

[0158] The coating process is performed on a planar silicon substrate (e.g., a wafer) coated with a 10µm thick nanodiamond CVD film. Since diamond growth or deposition does not spontaneously begin on a clean silicon surface, a nucleation step (not shown) must be performed beforehand. Here, an aqueous nucleation slurry containing purified diamond particles (seeds) is used. The seed size should be much smaller than the recess depth d. base To achieve high nucleation density, the nucleation process is performed by immersing the silicon wafer in a slurry, followed by water-based rinsing and drying steps.

[0159] After nucleation, the wafer is placed in, for example, a hot-filament CVD system, and the growth process begins. Hot-filament CVD growth of diamond is known to be fairly isotropic because it does not involve ion bombardment. Therefore, the recessed silicon surface is either overgrown or covered, and the remaining diamond growth surface becomes smoother as the diamond film thickness increases, such as... Figure 5c The image is shown in a cross-sectional SEM photograph. Process step e) schematically illustrates the final result.

[0160] Figures 8a to 8d The stage of depositing a coating onto a structured substrate 20, which includes a plurality of recesses (40, 40, 40'', 40''') of different widths, is illustrated to illustrate the selection of the correct recess width w. sub and ratio w sub / d base The importance of this ratio. It has been found that the deposition rate strongly depends on this ratio w. sub / d baseFurthermore, the deposition rate at the base of the recess at 420° is typically lower than the growth rate at the coating surface at 300°, resulting in different coating thicknesses T. c-surf and T c-base (See) Figure 8a As the coating thickness increases ( Figure 8b , Figure 8c , Figure 8d Before the recess is filled with the coating material, the coating at the coating surface 300 can form a continuous layer, resulting in the formation of cavities 340 in the coating 30. These cavities are undesirable because they reduce the adhesion between the substrate material 20 and the coating 30. Understanding the deposition rate allows for the selection of the correct ratio w between the recess width and the recess depth. sub / d base For the CVD growth of nanodiamonds, w is preferred. sub / d base The ratio is in the range of 1 to 20. The resulting concave portion has a width w. coat and depth d coat This depends on the base width w sub Depth d base and coating thickness T c .

[0161] Figure 9 Schematic top and cross-sectional views of a cutting element at different stages during the composite material and cutting element manufacturing process are shown. A cutting element 600, having a cutting edge 610 and a cutting element body 620, is manufactured from a layered composite material 10, whereby a coating 30 comprises a hard coating selected from the materials disclosed above. The cutting edge 610 can be manufactured by partially removing the substrate material 20 until only the coating 30 remains and subsequently forming the cutting edge 610 in the unsupported portion of the coating. If the substrate material 20 includes recesses 40 on its surface 200, the coating 30 includes protrusions 320 formed during the coating process when the coating material fills the recesses 40 in the substrate material 20. These protrusions 320 mirror the shape and distribution of the recesses 40 formed in the surface 200 of the substrate material 20 prior to the deposition of the coating 30. However, in the case where the cutting edge 610 is formed in the unsupported coating 30 by partially removing the substrate material 20, it is desirable that the cutting edge 610 not have protrusions 320. The protrusions 320 on the cutting edge 610 can cause the cutting edge 610 to become jagged and the cutting bevel 620 to become rough, which can lead to poor cutting performance and instability of the cutting blade 600. Therefore, it is desirable to avoid the protrusions 320 at the cutting edge 610, which requires that no recesses 40 be formed on the surface 200 of the substrate 20 in the area where the substrate 20 will be removed after the coating process to form the cutting bevel 620 with the cutting edge 610.

[0162] Figure 10 An optional cutting edge forming process is shown on a substrate surface 200, which has been configured to include a plurality of recesses 40, such that a cutting element 600 having a cutting bevel 620 including protrusions 320 and a cutting element body 630 having a coating surface 300 including coating recesses 330 can be realized.

[0163] Figure 10 The initial stage a) in the middle corresponds to Figure 7 Step e), wherein the thickness T c Coating 30 has been deposited onto a substrate with a thickness of T. s The coating 30 includes a plurality of coating recesses 330 at a coating surface 300, which are transferred from the plurality of recesses 40 on the surface 200 of the substrate 20 and will reduce the contact area of ​​the coating surface to adjust the friction characteristics. In addition, the coating 30 includes protrusions 320 at an inner coating surface 305 that fill the recesses 40 in the substrate 20.

[0164] Figure 11 shows electron microscope images of the cutting element 600 at three different magnifications. After the substrate material 20 is removed, the inner coating surface 305 is exposed on the cutting bevel 620 formed in the coating 30. Multiple circular protrusions 320 can be seen on the inner coating surface 305 of the cutting bevel 620.

[0165] Figure 12 shows electron microscope images of the cutting element 600 at two different magnifications. After the substrate material 20 is removed, the inner coating surface 305 is exposed to the cutting bevel 620 formed in the coating 30. In this case, multiple linear protrusions 320 can be seen on the inner coating surface 305 of the cutting bevel 620.

[0166] Figure 13 shows scanning electron photographs of the cross-section at different magnifications in a perspective view of the cutting element according to the present invention. The width w of the circular recess 40... sub The diameter is approximately 10µm, the spacing s is 15µm, and the depth d of the recess is... max It is approximately 1µm. The recess 330 and the protrusion 320 originate from the recess 40.

Claims

1. A cutting element (600), said cutting element being formed of a composite material (10) having a substrate (20) with a structured coating (30). The composite material includes a substrate (20) having a surface in contact with the coating (30) or is composed of the substrate. The substrate (20) has a plurality of substrate recesses (40, 40', 40'', 40''') in at least a region of the substrate surface (200), and the coating (30) extends into the recesses (40, 40', 40'', 40''') of the substrate (20), and The coating (30) has an inner surface (305) in contact with the substrate and a surface (300) opposite to the inner surface, and The coating (30) includes a plurality of coating recesses (330) at the surface (300), the plurality of coating recesses being smaller than the recesses (40, 40', 40'', 40''') at the surface of the substrate (200), thereby forming a structured coating (30). The structured coating (300) has a total surface area A. tot Total concave area A r and contact area A c =A tot - A r The condition is Ac / A tot It is in the range of 0.1 to 0.

8.

2. The cutting element according to claim 1, Its features At least in the region of the composite material, the substrate (20) is removed to expose a protrusion (320), which preferably has a shape opposite to the recess (40, 40', 40'', 40''') at the surface of the substrate.

3. The cutting element according to any one of claims 1 or 2, Its features The substrate recess (40, 40', 40'', 40''') has a width w in the range of 100 nm to 100 µm, preferably 500 nm to 20 µm. sub and a depth d in the range of 50 nm to 5 µm, preferably 100 nm to 2 µm base The condition is the ratio w sub / d base The value is in the range of 0.20 to 25, preferably in the range of 1 to 20, and more preferably in the range of 5 to 15. And / or The coating recess (330) has a width w in the range of 100 nm to 100 µm, preferably 500 nm to 20 µm. coat and a depth d in the range of 50 nm to 5 µm, preferably 100 nm to 2 µm coat The condition is the ratio w coat / d coat The value is in the range of 0.25 to 25, preferably in the range of 1 to 20, and more preferably in the range of 5 to 15.

4. The cutting element according to claim 3, Its features d coat Less than d base .

5. The cutting element according to any one of claims 1 to 4, Its features A c / A tot It is in the range of 0.3 to 0.7, and preferably 0.45 to 0.

65.

6. The cutting element according to any one of claims 1 to 5, Its features The base recesses (40, 40', 40'', 40''') are arranged such that the distance s between any pair of two adjacent recesses is equal to the average depth d of the same pair of recesses. pair The ratio s / d pair The value is in the range of 0.25 to 20, preferably in the range of 0.5 to 15, and more preferably in the range of 1 to 12.

7. The cutting element according to any one of claims 1 to 6, Its features The coating (30) is a first coating deposited on the substrate at least in a region, and at least one additional coating deposited on the first coating at least in a region, preferably a second coating deposited on the first coating at least in a region or on the outer surface of the first coating.

8. The cutting element according to any one of claims 1 to 7, Its features The recess (40, 40', 40'', 40''') has a circular, elliptical, or linear shape. Preferably, the recess has a recess opening perimeter, which is a closed continuous line without any singularities.

9. The cutting element according to any one of claims 1 to 8, Its features The coating (30) has a thickness T of 100 nm to 50 µm, preferably 150 nm to 20 µm, and more preferably 200 nm to 15 µm. c And / or The substrate (20) has a thickness T of 20µm to 2000µm, preferably 30µm to 1000µm, and more preferably 50µm to 400µm. s And / or The composite material (10) has a total thickness T of 25µm to 2050µm, preferably 35µm to 1000µm, and more preferably 55µm to 400µm. tot .

10. The cutting element according to any one of claims 1 to 9, Its features The depth d of the base recess (40, 40', 40'', 40''') base The thickness T of the coating (30) c The ratio d base / T c The value is in the range of 0.01 to 15, preferably 0.1 to 5, and more preferably 0.5 to 2. And / or The depth d of the coating recess (330) coat The thickness T of the coating (30) c The ratio d coat / T c It is in the range of 0.01 to 5, preferably 0.02 to 1, and more preferably 0.05 to 0.

5.

11. The cutting element according to any one of the preceding claims, Its features The cutting element is selected from the group consisting of: knife blades, razor blades, surgical scalpels, knives, mechanical tools in cutting, punching and impact cutting systems, scissors or shearing cutting systems.

12. The cutting element according to claim 11, Its features The region of the composite material (10) in which the substrate (20) is removed to expose the protrusion (320) which is the opposite structure of the recess (40, 40', 40'', 40''') is the region of the cut bevel.

13. The cutting element according to claim 11 or 12, Its features The cutting element (600) includes a cutting bevel (620) and a cutting element body (630), wherein the cutting bevel (620) is at least partially located in the region of the composite material (10) where the substrate (20) is removed to expose the inner coating surface (305).

14. A method for manufacturing a cut element (600), the method comprising the steps of: ● Provide a substrate (20) having a surface (200). ● An etching mask with an opening is formed on the surface of the substrate (200). ● The substrate (20) is etched through the opening in the etching mask using reactive ion etching or wet chemical etching to form a plurality of substrate recesses (40, 40', 40'', 40''') on the substrate surface (200). ● Optionally, the etch mask can be removed from the substrate (20). ● A coating (20) is deposited onto the substrate surface (200) and into the plurality of recesses (40, 40', 40'', 40'''), thereby transferring the substrate recesses (40, 40', 40'', 40''') into coating recesses (330) on the coating surface (300), the coating recesses being smaller than the substrate recesses (40, 40', 40'', 40'''), thereby forming a structured coating (30). ● Etch the substrate (20) to expose the protrusion (320) at the inner coating surface (305) to form the cutting bevel (620) of the cutting element (600).

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