# US 7,883,775 B2 · Diamond film coated tool and process for producing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,883,775 B2 - Document ID: US7883775B2 - Status: Granted - Kind: B2 - Application number: 10/566,633 - Filed: 2003-11-12 - Published: 2006-09-28 - Granted: 2011-02-08 - Earliest claimed: 2003-07-31 - Assignees: A.L.M.T. Corp.; Sumitomo Electric Industries, Ltd. - Inventors: Katsuo Kazahaya; Shigetaka Kawai; Yasushi Matsumoto; Keiji Ishibashi; Takahiro Imai - Web page: https://patentgrep.com/patent/US7883775B2 ## CPC - C23C 16/27: Diamond only - B23G 5/06: Taps (chucks therefor B23B31/00) - C23C 16/0218: {in a reactive atmosphere (C23C16/0227 takes precedence)} - B23G 2200/26: Coatings of tools - B23G 2225/08: Cermets - B23G 2225/16: Diamond - B23G 2225/28: Hard metal, i.e. cemented carbides - Y10T 428/30: Self-sustaining carbon mass or layer with impregnant or other layer - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - B23G: THREAD CUTTING; WORKING OF SCREWS, BOLT HEADS, OR NUTS, IN CONJUNCTION THEREWITH (making helical grooves by turning B23B5/48, by milling B23C3/32, by forging, pressing, or hammering B21K1/56, by grinding B24B19/02; arrangements for copying or controlling B23Q; thread-forming by corrugating tubes B21D15/04, by rolling B21H3/02) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The invention provides a diamond coated tool having an excellent cutting performance, wear resistance, adhesion resistance and work surface roughness in combination and a method of producing such a tool. A diamond coated tool comprising a substrate and a diamond coating formed on the surface of the substrate, wherein said substrate is made of a cemented carbide or a cermet, diamond grains constituting a growth surface of said diamond coating has an average grain size of about 1.5 micrometers or below, said diamond coating has a thickness ranging from about 0.1 micrometer to 20 micrometers, and said diamond coating has an average surface roughness Ra ranging from about 0.01 micrometer to 0.2 micrometer. Such a diamond coated tool can be obtained by carburizing the substrate consisting of a cemented carbide or a cermet, and growing up a diamond coating thereon. ## Claims ### Claim 1 A diamond coated tool comprising: a substrate; and a polycrystalline diamond coating formed on a surface of the substrate, wherein said substrate is made of a cemented carbide or a cermet, said polycrystalline diamond coating is an aggregate of secondary diamond grains, each of which includes an aggregate of primary diamond fine grains, the primary diamond fine grains having a first crystal structure and the secondary diamond grains having a second crystal structure different from the first crystal structure, said secondary diamond grains constituting a growth surface of said polycrystalline diamond coating has an average grain size of about 1.5 micrometers or below, grain boundaries are formed between each of said secondary diamond grains, said primary diamond fine grains are elongated in a growth direction of said polycrystalline diamond coating, said primary diamond fine grains have a major axis diameter ranging from 0.01 micrometer to 1 micrometer, said polycrystalline diamond coating has a thickness ranging from about 0.1 micrometer to 20 micrometers, and said polycrystalline diamond coating has an average surface roughness Ra ranging from about 0.01 micrometer to 0.2 micrometer. ### Claim 2 (depends on 1) The diamond coated tool according to claim 1, wherein: said diamond fine grains are disposed as elongated fine grains extending longitudinally in a growth direction of the diamond coating in cross-section thereof and have a minor axis diameter in the range of about 0.001 micrometer to 0.1 micrometer. ### Claim 3 (depends on 2) The diamond coated tool according to claim 2, wherein said diamond fine grains have an aspect ratio ranging from about 2 to 20. ### Claim 4 (depends on 1) The diamond coated tool according to claim 1, wherein said diamond coating satisfies the relationship between the peak height D for diamond and the peak height G for graphite or an amorphous carbon in a Raman spectroscopic analysis: about 0.5≦D/G≦about 5. ### Claim 5 (depends on 1) The diamond coated tool according to claim 1, wherein said diamond coating has a ratio I220/It not smaller than about 0.6, where I220 is a peak intensity of the diamond crystal face (220) and It is a total of peak intensities of diamond crystal faces (111), (220), (311), (400) and (331) as observed in X-ray diffractometry of said diamond coating. ### Claim 6 (depends on 1) The diamond coated tool according to claim 1, wherein said diamond coating has a hydrogen content in the range of about 1% to 5% by atomic ratio (at %). ### Claim 7 (depends on 1) The diamond coated tool according to claim 1, wherein said diamond coating is formed as a single layer in a cross-sectional zone of about 70% of its thickness above the substrate surface. ### Claim 8 (depends on 1) The diamond coated tool according to claim 1, wherein said substrate comprises a cemented carbide containing about 0.1 mass % to 6 mass % of Co. ### Claim 9 (depends on 8) The diamond coated tool according to claim 8, wherein said substrate having its Co content partially substituted with Cr has a magnitude of saturation magnetization not smaller than 1,900×(binding phase content of alloy (by mass %))/100×0.93 (G-cm3/g) but not greater than 2,023×(binding phase content of alloy (by mass %))/100 (G-cm3/g). ### Claim 10 (depends on 8) The diamond coated tool according to claim 8, wherein said diamond coating is formed partially on the substrate surface, and said substrate has a magnitude of saturation magnetization Ms satisfying the following condition A in its area that is at least about 5 mm apart outside from the outer border of the diamond coating along the substrate surface: A: 1,900×(binding content of alloy (mass %))/100 (G-cm3/g)≦Ms≦2,023×(binding content of alloy (mass %))/100 (G-cm3/g). ### Claim 11 (depends on 8) The diamond coated tool according to claim 8, wherein: said substrate has its Co content partially substituted with Cr; said diamond coating is formed partially on the substrate surface; and said substrate has a magnitude of saturation magnetization Ms satisfying the following condition B in its area that is at least about 5 mm apart outside from the outer border of the diamond coating along the substrate surface: B: 1,900×(binding content of alloy (mass %))/100×0.93 (G-cm3/g)≦Ms≦2,023×(binding content of alloy (mass %))/100 (G-cm3/g). ### Claim 12 (depends on 1) The diamond coated tool according to claim 1, wherein said substrate has a magnitude of saturation magnetization not smaller than 1,900×(binding phase content of alloy (by mass %)) /100(G-cm3/g) but not greater than 2,023×(binding phase content of alloy (by mass %)) /100(G-cm3/g). ### Claim 13 (depends on 1) The diamond coated tool according to claim 1, wherein said diamond coating has surface unevenness in the range of about 15 nm to 200 nm in RMS (root mean square) value as measured by an atomic force microscope. ### Claim 14 (depends on 1) The diamond coated tool according to claim 1, wherein said substrate has in its outer zone closer to its surface a composition having a binding phase content lower than that in its inner area inside the outer zone, and the outer zone ranges from about 1 micrometer to 20 micrometers in depth. ### Claim 15 (depends on 1) The diamond coated tool according to claim 1, wherein diamond coating is provided as it is produced through a vapor-phase synthesis process.