MXPA98007847A - Substrate with a superdured coating containing boron and nitrogen and a method to manufacture elmi - Google Patents

Abstract

A cutting tool includes a substrate (28) and a coating on the substrate (28). The coating includes a base adhesive layer (38) which is on at least a portion of the substrate (28). A first intermediate adhesive layer (40), which includes boron and a first element, which is on the base adhesive layer (38). A second intermediate adhesive layer (42), which includes boron, the first element, and nitrogen, which is on the first intermediate adhesive layer (40). An outer adhesive layer (44), which includes boron and nitrogen, preferably in the form of cubic boron nitride, which is on the second intermediate adhesive layer (42). A wear coating scheme (34) wherein the innermost layer of the wear coating scheme (34) is on the outer adhesive layer (4).

Description

SUBSTRATE WITH A SUPERDURED COATING CONTAINING BORO AND NITROGEN AND A METHOD TO MANUFACTURE THE SAME BACKGROUND OF THE INVENTION The invention pertains to a substrate having an outer layer of a superhard material, as well as a method for manufacturing the same. More specifically, the invention pertains to a cutting tool, as well as a method for manufacturing same, having an external adhesive layer containing boron and nitrogen, which the applicant believes is boron nitride, wherein the crystalline form predominant is that of cubic boron nitride (cBN). As material technology advances, many new materials, including new hard materials, become commercially useful. Such new hard materials include without limitation, ultrafine powdered metals, sintered, metal matrix compositions, heat treated hardened steels (hardness between 50 to 65 Rockwell C), and high temperature alloys. These new materials have combinations of extraordinary properties, such as, for example, hardness, rigidity and wear resistance, which make them very suitable for use in heavy industries, aerospace, transport and consumer products.

In order for these new hard materials to reach their optimum commercial potential, the challenges that these materials present to the currently existing manufacturing and finishing processes must be overcome. One of the reasons for these existing challenges is that these materials are very difficult and expensive to drill, cut and form. These challenges can best be addressed through the use of strong cutting tools, which use a super hard coating. So far, the two main super-cutting commercial cutting tools comprise a polycrystalline diamond cutting tool (PCD) and a polycrystalline cubic boron nitride cutting tool.

(PCBN). The diamond has a Knoop 100 hardness of between about 75 Gpa and about 100 Gpa. The cubic boron nitride has a Knoop 100 hardness of about 45 Gpa. PCBN cutting tools typically find application in the machining of hard ferrous materials. PCD cutting tools have their typical application in the machining of hard non-ferrous alloys and compositions difficult to cut. In the typical polycrystalline cutting tool (PCD or PCBN), the cutting edge comprises a brazed superhard tip on an unfinished part of carbide. The tip comprises diamond crystals with micron-sized cubic boron nitride (cNB), intergrown with a suitable binder and bonded on a cemented carbide support. Unfinished crystals and parts are synthesized and sintered under high pressure-high temperature (HP-HT) conditions such as, for example, 50 kbar and approximately 1500 ° C. The manufacturing process to HP-HT, as well as the finishing process for these tips, each carry high costs. The result is that PCD cutting tools and PCBN cutting tools are very expensive. In addition to the expensive, these cutting tools usually comprise a tool with a single tip, where the tip has relatively few styles with a flat geometry. Although these cutting tools are expensive and come in relatively few styles, up to now they are the best (and sometimes the only) suitable cutting tools to economically machine these new hard and difficult to cut materials. Through the development of techniques for low pressure deposition of the diamond, it is possible to deposit shaped diamond layers (or films) on the substrates of the cutting tool without any significant limitation to the geometry of the cutting tool. Although diamond-coated cutting tools have advantages over PCD cutting tools, there are still some significant limitations related to the use of diamond-coated cutting tools. A major limitation with diamond cutting tools (ie, cutting tools coated with PCD and diamond), is that the diamond is oxidized to carbon dioxide and carbon monoxide during its use at high temperatures. Another major limitation with diamond cutting tools is the high chemical reactivity of the diamond (ie, carbon) with certain materials. More specifically, materials containing one or more of iron, cobalt or nickel, dissolve the carbon atoms in the diamond. These limitations reveal that although diamond cutting tools provide certain advantages, there is a universe of materials that require a cutting tool with super hard coating, but for which the use of a diamond tool is inappropriate. It is very evident that there is a need to provide a cutting tool with a superhard adhesive coating, which overcomes the previous problems with the diamond coated cutting tools. More specifically, there is a need to provide a cutting tool with a superhard adhesive coating, wherein the coating does not rust during its use at high temperature. There is also a need to provide a cutting tool with a superhard adhesive coating, wherein the coating does not react chemically with the materials of the workpiece, which contains any one or more of iron, cobalt, or nickel. A superhard material that becomes inert by the formation of a protective oxide at high temperatures is boron nitride. In addition, boron nitride does not react chemically with any one or more of iron, nickel, or cobalt at typical metalworking temperatures. As a consequence, a workpiece that contains any one or more of the iron, cobalt, or nickel, does not dissolve the boron nitride. These advantageous properties of boron nitride exist with respect to all crystalline forms of boron nitride; however, those forms of boron nitride that exhibit a high hardness to provide a super hard coating, comprise the crystalline forms of cubic boron nitride (cBN) and wurtzitic boron nitride (wBN), where cBN has especially good properties and it is the preferred crystalline form. It should be expected, however, that a coating that is predominantly of cBN will have some other crystalline forms of boron nitride (eg, amorphous boron nitride (aBN) and hexagonal boron nitride (hBN), as well as aBN contained therein and exhibits still excellent hardness, resistance to chemical reactivity, and inerting characteristics.It is evident that a cutting tool coated with boron nitride, especially a cutting tool coated with cBN, would possess highly desirable properties for the machining of new hard materials. It is also evident that a cutting tool coated with boron nitride, especially a cutting tool coated with cBN, would possess highly desirable properties for the machining of new hard materials difficult to cut, containing one or more than iron, cobalt, or nickel. The literature contains a number of articles dealing with erecting a thin film (or layer) of cBN over a substrate in conjunction with the use of interlayers. For example, the article written by Murakawa et al. titled% "C-BN Film Characteristics Made by an Ion-Rectified Electrosurgical Method", pages 1009-1104, suggests two different basic methods for the use of interlayers in the substrate and the external coating of cBN. using a single buffer interlayer, which has a boron and nitrogen gradient, the article suggests the annealing after-treatment of this coating scheme.The other method is to use a titanium interlayer between the previous buffer layer and the substrate. Gissler titled Preparation and Characterization of Cubic Boron Nitride and Metal Boron Nitride Films, "Surface and Interface Analysis, Vol. 22, (1994), pp. 139-148, suggests the sequential deposition of multiple layers of Ti / BN with a subsequent annealing treatment. Gissler's article also suggests the addition of elements to boron and nitrogen, such as, for example, titanium to form a compound of Ti-B-N. However, the reference in Gissler to a coating with the system Ti-B-N-C that has high hardness, is about a coating of TiB2 that does not use interlayers. Mitteier et al., Electronic Deposition of Ultrahard Coatings Within the Ti-BCN System ", Surface and Coatings Technology, 41 (1990), pp. 351-363 The article written by Ikeda et al. Entitled ^ Formation and characterization of films of cubic boron nitride by an ionic sedimentation method enhanced with arc-like plasma ", Surface and Coating Technology, 50 (1991), pp. 33-39, suggests a coating scheme with a titanium base layer, a layer of boron and nitrogen with a concentration gradient that moves from a boron-BN (iBN) rich composition close to the titanium layer, to a constituent of BN near the outer layer, and an external layer of cBN. Ikeda et al. suggest the use of ionic sedimentation techniques to deposit the iBN layer. The patent literature also presents a number of patents that discuss the deposition of a cBN layer on a substrate, in conjunction with the use of interlayers. In this regard, U.S. Patent No. 4,731,303 for a CUBIC BORN NITRIDE COATED MATERIAL AND A METHOD FOR PRODUCING IT FROM Irano et al., Suggests the use of an interlayer of nitrides or nitroxides of any one or more of Al, Ga , In, and TI. U.S. Patent No. 4,892,791 and U.S. Patent No. 5,137,772 for a CUBIC BORN NITRIDE COATED BODY AND A METHOD FOR MANUFACTURING THE SAME from atanabe et al., Each show the use of interlayers including nitrides or borides of carbon dioxide elements. Groups IVb, Illb, Vb, IVa, Va, and Vía. The above documents present various methods for the deposition of a superhard coating containing boron and nitrogen. However, there remains a need to provide a method for depositing such a coating having sufficient thickness to be useful as a cutting tool and as a useful product. Thus it becomes evident that in addition to providing a cutting tool with a super hard coating, it would be desirable to provide a cutting tool with a superhard adhesive coating, which preferably contains boron and nitrogen and, more preferably, contains cBN, in where the coating has sufficient thickness to provide an adequate service life.

BRIEF DESCRIPTION OF THE INVENTION A principal objective of the invention is to provide a substrate with an adhesive coating of a superhard material, which preferably contains boron and nitrogen, and more preferably cBN, wherein the coating has a sufficient thickness to provide a adequate life. Another object of the invention is to provide a cutting tool with an adhesive coating of a superhard material, which preferably contains boron and nitrogen, and more preferably cBN, wherein the coating has a thickness sufficient to provide an adequate shelf life. In one form thereof, the invention is a cutting tool comprising a substrate having a support face and a side face, wherein the support face and the side face intersect to form a cutting edge. There is a coating on the substrate. The coating comprises a base adhesive layer on at least a portion of the substrate; a first intermediate adhesive layer, which includes boron and a first element, on the base adhesive layer; a second intermediate adhesive layer, which includes boron, the first element, and nitrogen, on the first intermediate adhesive layer; an outer adhesive layer, which includes boron and nitrogen, on the second intermediate adhesive layer; and a wear coating scheme, wherein the innermost layer of the wear coating scheme is on the outer adhesive layer. In another form thereof, the invention is a process for the deposition of a coating scheme on a cutting tool including a substrate, wherein the process includes the steps of: depositing a base adhesive layer on the substrate; depositing a first intermediate adhesive layer, which includes boron and a first element on the base adhesive layer; deposit a second • intermediate adhesive layer, which includes boron, the first element, and nitrogen on the first intermediate adhesive layer; depositing an external adhesive layer, which includes boron and nitrogen on the second intermediate adhesive layer; and depositing a wear coating scheme, wherein the innermost layer of the wear coating scheme is on the outer adhesive layer.

In yet another form thereof, the invention is a substrate with a coating on at least a portion thereof. The coating comprises a base adhesive layer which is on at least a portion of the substrate; a first intermediate adhesive layer, which includes boron and a first element, which is on the basic adhesive layer; a second intermediate adhesive layer, which includes boron, the first element, and nitrogen, which is on the first intermediate adhesive layer; an external adhesive layer, which includes boron and nitrogen, ie on the second intermediate adhesive layer; and a wear coating scheme, wherein the innermost layer of the coating scheme is on the outer adhesive layer.

BRIEF DESCRIPTION OF THE DRAWINGS The following is a brief description of the drawings forming part of the present patent application: Figure 1 is an isometric view of a specific embodiment of a cutting tool of the present invention; Figure 2 is a cross-sectional view of the cutting tool of Figure 1, taken along line 2-2 to illustrate the coating scheme of this specific embodiment; and Figure 3 is a schematic mechanical view of an apparatus for practicing the method of the invention.

DETAILED DESCRIPTION Referring to the drawings, Figures 1 and 2 illustrate a first specific embodiment of the invention, which is a cutting tool (generally designated 20). The cutting tool 20 has a support face 22 and a side face 24, which intersect to form a cutting edge 26. The coating scheme of the first specific embodiment (20) is generally representative of the sample that was part of a current test, that is, Test No. 1, set forth hereinafter. The cutting tool 20 further includes a substrate 28 on which there is a multilayer coating scheme illustrated in brackets as 30. All samples used in Test No. 1 had substrates of tungsten carbide cemented with cobalt. However, the samples used show that in Test No. 2, ceramic substrates were also included in the actual tests. With respect to the type of substrate material, the substrate may comprise metals, ceramics, polymers, compositions of combinations thereof and combinations thereof. The metals can be elements, alloys and / or intermetallics. The metals include the elements of Groups 2-14 of the IUPAC. Ceramics include borides, carbides, nitrides, oxides, their mixtures, their solid solutions and combinations thereof. The polymers include polymers based on organic and / or inorganic compounds that retain the desired metallic and / or physical properties, after the coating scheme has been applied to a portion thereof. The compositions include metal matrix compositions (MMC), ceramic matrix compositions (CMC), polymer matrix compositions (PMC), and combinations thereof. Preferred compositions include cements, cemented carbides, and in particular, tungsten carbides cemented with cobalt, the compositions may include substrates with diamond tip or diamond coating, PCBN, or PCD. Other typical materials include a material based on tungsten carbide with other carbides (eg, TaC, NbC, TiC, VC), present as simple carbides or in solid solution. In the case of the cemented carbides, the amount of cobalt binder can range from about 0.2 weight percent to about 20 weight percent, although the most typical range is between about 5 weight percent and about 16 weight percent. percent in weight. It should be appreciated that other binder materials may be suitable for such use. In addition to cobalt and cobalt alloys, suitable metal binders include nickel, nickel / iron alloys, iron alloys and any combination of the above materials (i.e., cobalt, cobalt alloys, nickel, nickel alloys, iron and / or iron alloys). It should further be appreciated that a substrate with binder (cobalt) enrichment near the surface of the substrate, as described in Reissue of US Patent No. 34,180 to Nemeth et al., For ENRICHED CEMENTED CARBIDE BODY PREFERABLY WITH BINDER AND MANUFACTURING METHOD (granted to the beneficiary of the present patent application), may be appropriate for the treatment with the coating scheme. The multilayer coating scheme 30 includes an adhesive coating scheme illustrated in square brackets such as 32, and a wear coating scheme illustrated in brackets as 34. The total thickness of the multilayer coating scheme should range from about 1 icometer ( μm) and 5 μm or more, and preferably, the total thickness should range from about 3 μm to about 5 μm. Referring to the specific coating scheme of FIGURES 1 and 2, the adhesive coating scheme 32 comprises a base adhesive layer 38, which is close to the surface of the substrate 28. The base adhesive layer 38 comprises metallic titanium. However, it should be appreciated that the base addition may comprise (or include) aluminum, magnesium, zirconium or hafnium. The thickness of the base layer 38 ranges from about 0.001 μm (10 Angstroms) (Á) to about 1 μm (10,000 A), where typical thickness is about 0.1 μm (1000 μ). A first intermediate adhesive layer 40 is on the base layer 38. The first intermediate layer 40 contains boron and carbon. The atomic ratio of the boron and carbon atoms (B: C) is between about 2.7 to about 3.3. The thickness of the first intermediate layer 40 ranges from about 0.001 μm (10 Angstroms) (Á) to about 1 μm (10,000 Á), where the typical thickness is about 0.2 μm (2000 Á). The second intermediate adhesion layer 42 is on the first intermediate layer 40. The second intermediate layer 42 contains boron, carbon and nitrogen. The atomic ratio of boron-nitrogen (B: N) ranges from 29:71 to 54:46 (preferably 29:71 and 41:59), where the atomic percent for carbon fluctuates between about 11 percent and approximately 26 percent. In other words, the atomic ratio of nitrogen to carbon (N: C) ranges from about 74:26 to about 89:11, where the atomic percent of boron is between about 29 percent and about 54 percent. The thickness of the second intermediate layer 42 ranges from about 0.001 μm (10 Angstroms) (Á) to about 1 μm (10,000 Á), where the typical thickness is about 0.2 μm (2000 Á). An outer adhesive layer 44 is on top of the second intermediate adhesive layer 42. The outer adhesive layer 44 comprises boron and nitrogen in an atomic ratio of between about 0.6 to about 5.7, that is, the atomic percent for Boron is between approximately 38 percent and approximately 85 percent. The thickness of the external adhesive layer 44 ranges from about 0.1 μm (1000 Angstroms) (Á) to about 2 μm (20,000 Á), where the typical thickness is about 1 μm (10,000 μm).

TO). The multilayer wear coating scheme 34 is on the adhesive coating scheme 32. In this specific embodiment, there is a sequence for the basic wear coating scheme. However, the applicant contemplates that multiple sequences of the basic wear coating scheme can be deposited to treat certain applications. By deposition of multiple sequences of the wear coating scheme, the total thickness of the total coating can be increased to a desired thickness. Referring to the wear coating scheme 34, the wear base layer 48 is on the external adhesive layer 44. The wear base layer 48 comprises boron, carbon and nitrogen. The atomic ratio of boron-nitrogen (B: N) ranges from 29:71 to 54:46 (preferably 29:71 and 41:59), where the atomic percent for carbon fluctuates between about 11 percent and approximately 26 percent. In other words, the atomic ratio of nitrogen to carbon (N: C) ranges from about 74:26 to about 89:11, where the atomic percent of boron is between about 29 percent and about 54 percent. The thickness of the wear base layer 48 ranges from about 0.001 μm (10 Angstroms) (Á) to about 1 μm (10,000 Á), where the typical thickness is about 0.2 μm (2000 Á). The outer wear layer 50 comprises boron and nitrogen in an atomic ratio of between about 0.6 to about 5.7, that is, the atomic percent of boron is between about 38 percent and about 85 percent. The thickness of the wear layer 50 ranges from approximately 0.1 μm (1000 Angstroms) (Á) and approximately 2 μm (20,000 Á), in where the typical thickness is approximately 1 μm (10,000 Á). A cutting tool at least partially coated with the current coating scheme can be advantageously used in so-called "hard turning" or "hard machining" to displace the grinding. Hard turning can include the process of cutting hardened alloys, including ferrous alloys such as steels, to a final or finished form. The hardened alloy can be accurately cut from at least about ± 0.0127 mm (0.0005 inches), preferably at least about ± 0.0076 (0.0003 inches) and finished better than about 20 microns rms above the center of a lathe or turning. Cutting speeds, feeding and cutting depth (DOC) can include whatever is compatible to achieve the desired results. The cutting speed can range from about 50 to 300 meters / minute, preferably 75 to 200 meters / minute, and more preferably at about 80 to 150 meters / minute. Similarly, the feed may fluctuate from about 0.05 to 1 mm / revolution, preferably from about 0.1 to 0.6 mm / revolution, and more preferably from about 0.3 to 0.6 mm / revolution. In addition, the DOC can range from about 0.05 to 1 mm, preferably from about 0.1 to 0.25 mm, and more preferably from about 0.1 to 0.3 mm. The above cutting parameters can be used with or without a cutting or cooling fluid. The total thickness of the total multilayer coating scheme 30 should range from about 1 micrometer (μm) to about 5 μm or more with the preferred range between about 3 μm and about 5 μm. As can be appreciated, the ability to deposit multiple sequences of the wear coating scheme provides the ability to deposit coatings with a selected total thickness. By achieving the desired total thickness of the coating on the cutting tool 30, there is greater expectation of a satisfactory service life of the cutting tool 30. With respect to the method of applying those coating layers, it would be expected that numerous deposition techniques would provide adequate results . Typical processes for the application of cBN coatings include the techniques of PVD assisted by ion beams, ion implantation of nitrogen, chemical transport of plasma, electrodeposition by radio frequency, ionic sedimentation, CVD by plasma rf, and CVD by electronic cyclotron resonance . The applicant also considers that the techniques of electronic deposition by unbalanced magnetron (UBN), could provide adequate results. The representative techniques of cBN synthesis by CVD include, for example, those described in 'Deposition of Cubic BN over Interlayers of Diamonds', NASA Tech Briefs, Vol. 18, No. 8, 53, Z. Song, F. Zhang, Y. Guo, &G. Chin, X? TEXTURIZED GROWTH OF A CUBIC BORO NITRIDE FILM ON NICKEL SUBSTRATES "Applied Physics Letter", Vol. 65, No. 21, 1994, pp. 2669-2671; Khur, S. Reinke, &W Kulisch. * DEPOSITION OF CUBIC BORO NITRIDE WITH AN INDUCTIVELY COUPLED PLASMA "Surface and Coating Technology, Vol. 74-75, 1995, p. 806-812; and Murakawa & S. Watanabe, * THE SYNTHESIS OF CUBIC BN FILMS USING A DISCHARGE OF HOT CATHODIC PLASMA IN A PARALLEL MAGNETIC FIELD ", Coating Technology, Vol. 43, 1990, pp. 128-136. The techniques representative of the synthesis of cBN by PVD include, for example, those described in M. Mieno &T. Yosida, 'PREPARATION OF CUBIC BORO NITRIDE FILMS BY ELECTRONIC DEPOSITION, "Japanese Journal of Applied Physics, Vol. 29, No. 7, July 1990, pp. . L1175-L117; Kester et al., 'CONTROL OF PHASE OF SMALL FILMS OF BORO NITRIDE', Journal of Applied Physics, Vol. 72, No. 2 (July 1990); Wada et al., 'FORMATION OF CBN FILMS BY DEPOSITION HELPED BY AN IONIC BEAM, "Journal of Vacuum Science Technology, Vol. 10, No. 3 (May / June 1992), Ikeda et al.,' TRAINING CUBIC BORO NITRIDE FILMS BY A METHOD OF IONIC SEDIMENTATION INDUCED BY A PLASMA SIMILAR TO AN ARC ", Journal of Vacuum Science Technology, Vol. 8, No. 4 (July / August 1990); and T. Ikeda, T. Satou, & H. Stoh, 'FORMATION AND CHARACTERIZATION OF CUBIC BORO NITRIDE FILMS BY AN IONED SEDIMENTATION METHOD IMPROVED WITH A PLASMA SIMILAR TO AN ARC ", Surface and Coating Technology, Vol. 50, 1991, pp. 33-39. Specifically used for Tests No. 1 and 2, was a PVD process by electron beam with the help of an ion beam to form the nitrogen-containing layers.A PVD technique is set forth in the US patent application entitled COATING CONTAINING BORO. AND NITROGEN AND METHOD TO MANUFACTURE IT by Aharon Inspektor (the applicant of the present patent application), which was filed on the same date as the present patent application and granted to Kennametal Inc. (the same beneficiary as the assignee of the present patent application). The above patent application entitled COATING CONTAINING BORO AND NITROGEN AND METHOD OF MANUFACTURING IT, by Aharon Inspektor, is hereby incorporated by reference. The description of the equipment and specific procedure that was used to carry out the current tests, i.e., Tests Nos. 1 and 2, are set forth hereinafter. The appropriate equipment would be an AIRCO TEMESCAL FC 1800 fast-cycle electron beam evaporation unit (e-beam), with a high-vacuum chamber cooled by water at 20 ° C, equipped with a four-cavity beam cannon and used a substrate holder deflected by radio frequency (RF). The unit would also include a residual gas analyzer (IQ 200 of Inficon), a quartz lamp to heat the chamber, an ion source (a type of endless ion canyon without a Mark I grid from Commonwealt Scientific Corp. of Alexandria, Virginia), a Faraday cage (interconnected to an IQ 6000 of Inficon), and filaments (or an additional quartz lamp), for additional heating of the substrate. Although this specific arrangement used a single ion gun, the Applicant contemplates that two ion guns may be suitable for the deposition of the coating scheme. Figure 4 depicts a substrate holder 100, an electron beam 102 for creating a vapor from a source of material 104, the Faraday cage 106, and an ion source 108. The angle was measured between the plane (112) of the substrate holder 100 and a line perpendicular to the surface of the steam source and substantially parallel to the observation line of the steam source. The angle ß was measured between the plane (112) of the substrate holder 106 and the observation line (110) of the ion source (108). The distance between the surface of the material source 104 and the plane (112) of the substrate was identified as "di." The distance between the ion source 108 and the plane (112) of the substrate holder 100 was identified as' d2. " Referring to the calibration of the equipment as described in Figure 4, the operating parameters comprised an angle that is between approximately 45 degrees and approximately 75 degrees, the angle ß is between approximately 65 degrees and approximately 80 degrees, the distance is approximately 444 mm, the distance d2 is approximately between 90 mm and approximately 165 mm. Samples for Test No. 1 comprised a total of eight samples of cutting tool, where four of the cutting tools had a tungsten carbide substrate cemented with cobalt (WC-Co) (ie, Composition No. 1), with the following composition and basic properties: between about 5.4 and 5.9 weight percent cobalt, between about 1.4 to about 2.4 weight percent tantalum, no more than 0.2 weight percent titanium, no more about 0.3 weight percent niobium, and the rest tungsten carbide. For Composition No. 1, the average grain size of the tungsten carbide is about 1-4 micrometers (μm), the specific gravity is between about 14.80 and about 15.10 grams per cubic centimeter (gm / cc), the hardness Rockwell A is between about 92.4 and about 93.0, the magnetic saturation is between about 85 and about 98 percent, wherein 100 percent is equal to about 202 microtesla cubic meter per kilogram of cobalt (μTm3 / kg) (approximately 160 gauss cubic centimeter per gram of cobalt (gauss-cm3 / gm)), and the coercive force is between approximately 230 and approximately 320 oersteds. The other four cutting tools had a tungsten carbide substrate cemented with cobalt (ie, Composition No. 2) with the following composition and basic properties: between about 5.7 and 6.3 weight percent cobalt, no more than about 0.1 weight percent tantalum, no more than 0.1 weight percent titanium, no more than about 0.1 weight percent niobium, between about 0.3 and about 0.5 weight percent chromium, and rest of tungsten carbide. For Composition No. 1, the average grain size of the tungsten carbide is about 1-5 micrometers (μm), the specific gravity is between about 14. 80 and approximately 15.00 grams per cubic centimeter (gm / cc), the Rockwell A hardness is between about 92.6 and about 93.4, the magnetic saturation is between about 83 and about 95 percent, where 100 percent is equal to about 202 microtesla cubic meter per kilogram of cobalt (μTm3 / kg) (approximately 160 gauss cubic centimeter per gram of cobalt (gauss-cmVgm), and the coercive force is between approximately 250 and approximately 320. Samples for Test No. 2 comprised a total of ten cutting tools, where two of the cutting tools had a tungsten carbide substrate cemented with cobalt (WC-Co) of Composition No. 1. Six of the cutting tools had a tungsten carbide substrate cemented with cobalt of the composition No. 2. Two of the cutting tools had a SiAlON ceramic substrate. The ceramic substrate SiAlOn comprised a ceramic of SiAlOn and Si-Silon of double silicon aluminum oxynitride, made substantially by the methods of US Pat. No. 4,563,433 and having a density of about 3.26 g / cm.sup.3, a hardness of Knoop 200g of approximately 18 GPa, a fracture strength (K? C) of approximately 6.5 MPa m1 / 2, an elastic modulus of approximately 304 GPa, a cutting modulus of approximately 119 GPa, a volumetric modulus of approximately 227 GPa, a poission ratio of approximately 0.27, a tensile strength of approximately 450 MPa, a transverse rupture strength of approximately 745 MPa, a final compressive strength of approximately 3.75 GPa. The first step of Tests Nos. 1 and 2 was the step of cleaning the substrate. The purpose of this step was to clean the relevant environment (including the volume near the surface of the substrate) and the surface of the substrate. Referring to the measurement units used in Tables I through XIII, the gas flow was measured in standard cubic centimeters per cubic centimeter (sccm), the pressure was measured in Pascal (Pa), the temperature was measured in degrees Celsius (° C). C), the ion beam energy was measured in electron volts (eV), the range of the electron beam was measured in a percentage (%) of the maximum power range, and the evaporation rates were measured between the plane of the source of vaporization and the substrate holder (in a position approximately 254 mm from the surface of the vaporization source and approximately 165 mm away from the center of the vaporization source), in nanometers per second (nm / sec). Table I below sets out the parameters for the cleaning step for Tests Nos. 1 and 2.

Table I Parameters for Cleaning the Substrate For Tests Nos. 1 and 2, the next step involved the deposition of a thin layer of metallic titanium directly on the surface of the substrate. The purpose of this step was to prepare (or condition) the surface of the substrate for the deposition of the subsequent layers. Titanium is a reactive metal called "eliminator" of gaseous waste. In other words, titanium reacts with oxygen and other contaminants in the chamber or on the surface of the substrate to form titanium compounds, and consequently, remove contaminants. The applicant contemplates that other metals such as, for example, magnesium, aluminum, zirconium or hafnium, could also function to prepare the substrate for the deposition of the coating. Table II below shows the parameters for the deposition of this basic titanium adhesive layer.

Table II Parameters for the Deposition of the Titanium Basic Adhesive Layer For Tests Nos. 1 and 2, after the deposition of the basic titanium adhesive layer, the next step in the deposition of the adhesive coating scheme, comprised the deposition on the titanium layer of the first intermediate adhesive layer, which it contained boron and carbon. In this regard, the parameters for the deposition of the first intermediate adhesive layer are set forth in Table III below.

Table III Parameters for the Deposition of the First Intermediate Adhesive Layer of Boron-Carbon For Tests Nos. 1 and 2, after the deposition of the first intermediate adhesive layer (containing boron and carbon), the next step in the deposition of the adhesive coating scheme comprised the deposition on the first intermediate adhesive layer of the second intermediate adhesive layer, which contains boron, nitrogen and carbon. In this regard, Table IV below sets forth the parameters for the deposition of the second intermediate adhesive layer via Tests Nos. 1 and 2.

Table IV Parameters for the Deposition of the Second Intermediate Adhesive Layer of Boron-Carbon-Nitrogen Table IV (Continued) Parameters for the Deposition of the Second Intermediate Adhesive Layer of Boron-Carbon-Nitrogen % for Tests Nos. 1 and 2, after the deposition of the second intermediate adhesive layer, the next step in the deposition of the adhesive coating scheme, comprised the deposition of the external adhesive layer containing boron and nitrogen (more preferable in the form of cBN). Table V below shows the parameters for the deposition of this layer according to Tests Nos. 1 and 2.

Table V Parameters for the Deposition of the External Adhesive Layer of Boron-Nitrogen Table V (Continued) Parameters for the Deposition of the External Adhesive Layer of Boron-Nitrogen For Tests Nos. 1 and 2, the deposition of the external adhesive layer completes the deposition of the adhesive coating scheme. Referring now to the adhesive coating scheme, the above tests show that the first intermediate adhesive layer and the second intermediate adhesive layer have two elements in common; namely, boron and carbon. However, the applicant does not intend that the scope of the invention be limited to those common elements. Although the first intermediate adhesive layer and the second intermediate adhesive layer have two elements in common, the applicant contemplates that only at least one element is common between those two layers. The applicant further contemplates that other elements, as well as a plurality of elements, may be common between the first and second intermediate adhesive layers. For example, the first intermediate adhesive layer may contain three elements (other than boron and carbon) that are common to the constituents of the second intermediate adhesive layer. Samples from the specific tests also show that the second intermediate adhesive layer and the outer adhesive layer have two elements in common; namely, boron and nitrogen. However, the applicant does not intend that the scope of the invention be limited to those common elements. Although the second intermediate adhesive layer and the outer adhesive layer have two elements in common, the applicant contemplates that only at least one element is common between those two layers. The applicant further contemplates that there may be other elements, as well as a plurality of elements, which are common between the second intermediate adhesive layer and the external adhesive layer. For example, the second intermediate adhesive layer may contain three elements (other than boron and nitrogen), which are common to the constituents of the external adhesive layer. The specific embodiments of the first intermediate adhesive layer, the second intermediate adhesive layer and the outer adhesive layer, reveal that there is a common element between the three; namely, boron is the common element. The applicant does not intend to limit the scope of the invention to a coating scheme in which there is an element common to all those layers (ie, the first intermediate adhesive layer, the second intermediate adhesive layer and the external adhesive layer). Furthermore, the applicant does not intend to limit the scope of the invention to a coating scheme in which boron is the only common element. The applicant contemplates that there may be one or more elements (other than boron), which are common to the first intermediate adhesive layer, the second intermediate adhesive layer and the external adhesive layer. Referring now to the deposition of the multilayer wear coating scheme, this coating scheme was the following sequence of steps, after completing the adhesive coating scheme. The multilayer wear coating scheme was different for each of the tests, so that for easier understanding, the multilayer wear coating scheme for each test is discussed below.

Multiple Layer Wear Coating Scheme for Test No. 1 Referring to the multi-layer wear coating for Test 1, the base wear layer contained boron, carbon and nitrogen. The parameters for the deposition of this layer are shown in Table VI.

Table VI Parameters of Test No. 1 for Deposition of the Layer of Boron-Carbon-Nitrogen Based Wear After the deposition of the wear base layer, the next step was the deposition of the outer wear layer. The outer wear layer contained boron and nitrogen. The parameters for the deposition of this layer are set forth in Table VII below.

Table VII Parameters of Test No. 1 for the Deposition of the Boron-Nitrogen Outer Wear Layer This completed the deposition of the total coating scheme for Test No. 1. The total coating scheme for the samples of Test No. 1 thus comprised an adhesive coating scheme and a wear coating scheme. The adhesive coating scheme comprised the following layers: Ti / B-C / B-C-N / B-N. The wear coating scheme comprised the following layers: B-C-N and B-N.

Multiple Layer Wear Coating for Test No. 1 For samples made according to Test No. 2, the basic wear layer comprised titanium, boron and nitrogen. The parameters for the deposition of this layer are set forth in Table VIII below.

Table VIII Parameters of Test No. 2 for the Deposition of the Basic Layer of Ti-Anio-Boron-Nitrogen Wear The next step involved the deposition of the outer wear layer, which contained boron and nitrogen. The parameters for the deposition of this layer are shown in Table IX.

Table IX Parameters of Test No. 2 for the Deposition of the Outer Wear Layer of Boron-Ni The deposition of the external wear layer completed the total coating scheme for the No. 2 test. The total coating scheme comprised an adhesive coating comprising four layers (Ti / BC / B-CN / BN) and a coating scheme which comprises a base layer containing titanium, boron and nitrogen and an outer layer containing boron and nitrogen. The materials of the steam source that could be used during the different steps of the deposition would include titanium, boron carbide, titanium boride (TiB2) and boron. The titanium and the boron carbide would each comprise 99.9 percent by weight (% by weight) of commercially available materials, while the boron and the titanium boride would comprise 99.5% by weight of commercially available material. Samples from Tests Nos. 1 and 2 reveal that there are two elements in common between the outer adhesive layer and the wear base layer. For the samples of Test No. 1, the common elements are boron and nitrogen. For the samples of Test No. 2, the common elements are also boron and nitrogen. Although not a requirement of the coating scheme, the Applicant contemplates that for the preferred coating scheme, there is at least one element in common between the outer adhesive layer and the wear base layer. The samples from Tests No. 1 and 2 also reveal that there are two elements in common between the outer wear layer and the wear base layer. For the samples of both Tests Nos. 1 and 2, the common elements between those layers are boron and nitrogen. Although not a requirement of the coating scheme, the applicant contemplates that for the preferred coating scheme there is at least one element in common between the outer wear layer and the wear base layer. Although the samples of Tests Nos. 1 and 2 do not show the presence of intermediate layers between the wear base layer and the outer layer, the Applicant contemplates that one or more intermediate layers may be useful. further, although the samples of the Essays Nos. 1 and 2 do not show a repeatable wear lining scheme, the Applicant contemplates that the wear lining scheme may be repeated one or more times to achieve a full lining of sufficient thickness. In this regard, the total thickness of the coating (ie, the combined thickness of the adhesive coating scheme and the wear coating scheme) should range from about 1 μm to about 5 μm or more, with the preferred range for thickness total coating being between about 3 μm and about 5 μm. The above-described versions of the present invention have many advantages, including allowing the use of a coating containing boron and nitrogen, preferably cBN, with tools such as, for example, cutting inserts to form chips, for drilling, turning, grinding , and / or forming hard materials, difficult to cut, and indexable tools, as well as not indexable. In addition, these tools can be used to machine metals, ceramics, polymers, compositions of combinations thereof, and combinations thereof. In particular, these tools can be used to cut, drill and form materials that are incompatible with diamond, such as, iron-based alloys, nickel-based alloys, cobalt-coating alloys, titanium-based alloys, steels hardened, hard cast iron, soft cast iron, and sintered irons. Although the present invention has been described in considerable detail and with reference to certain preferred versions thereof, other versions are possible. Examples include: coatings on the parts useful for such applications, such as TAB binders for electronic applications, dies and punches; coatings on tips of mining tools, construction tools, tools to drill the earth, tools for rock drilling; thin coatings on the sliders used in resistive magneto computer disk drives (MR); and transparent coatings on barcode scanning windows. All patents and other documents identified in this application are hereby incorporated by reference. Other embodiments of the invention will be apparent to those skilled in the art, from consideration of the specification or practice of the invention described herein. It is intended that the specification and assays described herein be considered as illustrative only, with the true scope and spirit of the invention being those indicated by the following claims.

Claims (19)

CHAPTER CLAIMING Having described the invention, it is considered as a novelty and, therefore, the content is claimed in the following:

1. A cutting tool, characterized in that it comprises: a substrate having a support face and a side face, wherein the support face and the side face intersect to form a cutting edge; and a coating on the substrate, the coating comprises: a base adhesive layer, the base adhesive layer being on at least a portion of the substrate; a first intermediate adhesive layer including boron and a first element, the first intermediate adhesive layer being on the base adhesive layer; a second intermediate adhesive layer including boron, the first element, and nitrogen, the second intermediate adhesive layer being on the first intermediate adhesive layer; an external adhesive layer including boron and nitrogen, the outer adhesive layer is on the second intermediate adhesive layer; and a wear coating scheme, the innermost layer of the wear coating scheme is on the outer adhesive layer.

The cutting tool according to claim 1, characterized in that the base adhesive layer includes a reactive metal, the reactive metal is selected from the group consisting of titanium, zirconium, hafnium, magnesium, and aluminum.

3. The cutting tool according to claim 1, characterized in that the first element is carbon.

The cutting tool according to claim 1, characterized in that the coating scheme comprises a basic wear layer on the external adhesive layer.

The cutting tool according to claim 4, characterized in that the wear coating scheme further comprises an external wear layer on the base wear layer.

The cutting tool according to claim 5, characterized in that the first element is carbon; the base wear layer comprises boron, nitrogen, and carbon; and the external wear layer comprises boron and nitrogen.

7. The cutting tool according to claim 1, characterized in that the first intermediate adhesive layer and the second intermediate adhesive layer have at least one element in common.

The cutting tool according to claim 1, characterized in that the second intermediate adhesive layer and the outer adhesive layer have at least one element in common.

The cutting tool according to claim 1, characterized in that the first intermediate adhesive layer, the second intermediate adhesive layer and the outer adhesive layer have at least one element in common.

10. A process for the deposition of a coating scheme on a cutting tool, including a substrate, the process is characterized in that it comprises the steps of: depositing a base adhesive layer on the substrate; depositing a first intermediate adhesive layer including boron and a first element on the base adhesive layer; depositing a second intermediate adhesive layer including boron, the first element, and nitrogen on the first intermediate adhesive layer; depositing an external adhesive layer including boron and nitrogen on the second intermediate adhesive layer; and depositing a wear coating scheme, wherein the innermost layer of the wear coating scheme is on the outer adhesive layer.

The process according to claim 10, characterized in that the base adhesive layer includes a reactive metal, the reactive metal is selected from the group consisting of titanium, zirconium, hafnium, magnesium, and aluminum.

12. The process according to claim 10, characterized in that the first element is carbon.

13. The process in accordance with the claim 10, characterized in that the step of depositing the wear coating scheme includes depositing a base wear layer on the external adhesive layer.

The process according to claim 13, characterized in that the deposit of the wear coating scheme further comprises depositing an outer wear layer on the base wear layer.

15. The process according to claim 14, characterized in that the base wear layer comprises boron, nitrogen, and carbon; and the external wear layer comprises boron and nitrogen.

16. A substrate with a. coating on at least a part thereof, the coating is characterized in that it comprises: a base adhesive layer, the base adhesive layer is on at least a portion of the substrate; a first intermediate adhesive layer including boron and a first element, the first intermediate adhesive layer being on the base adhesive layer; a second intermediate adhesive layer including boron, the first element, and nitrogen, the second intermediate adhesive layer being on the first intermediate adhesive layer; an external adhesive layer including boron and nitrogen, the outer adhesive layer is on the second intermediate adhesive layer; and a wear coating scheme, the innermost layer of the wear coating scheme is on the outer adhesive layer.

The substrate according to claim 16, characterized in that the base adhesive layer includes a reactive metal, the reactive metal is selected from the group consisting of titanium, zirconium, hafnium, magnesium, and aluminum, and the first element is carbon.

18. The substrate according to claim 16, characterized in that the wear coating scheme comprises a base wear layer on the external adhesive layer.

19. The substrate according to claim 18, characterized in that the wear coating scheme further comprises an outer wear layer on the base wear layer.