# US 7,744,056 B2 · Hard-material-coated member excellent in durability > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,744,056 B2 - Document ID: US7744056B2 - Status: Granted - Kind: B2 - Application number: 11/860,951 - Filed: 2007-09-25 - Published: 2008-03-27 - Granted: 2010-06-29 - Earliest claimed: 2006-09-27 - Assignees: Hitachi Metals, Ltd. - Inventors: Kenichi Inoue; Fumiaki Honda - Web page: https://patentgrep.com/patent/US7744056B2 ## CPC - C23C 14/0664: {Carbonitrides} - C23C 14/024: {Deposition of sublayers, e.g. to promote adhesion of the coating (C23C14/027 takes precedence)} - C23C 14/0635: {Carbides} - C23C 14/0641: {Nitrides (C23C14/0617 takes precedence)} - C23C 30/005: {on hard metal substrates} - 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) ## Abstract There is provided a hard-material-coated member which is suitable as a long-life mold for plastic working of metals and which has a metal as base material and coating layers formed at least on its working plane by physical vapor deposition. At least three layers, i.e., a layer a) as the outermost layer, a layer c) just above the base material and a layer b) between layer a) and the layer c) are formed as coating layers. The hardness values of these layers in terms of hardness symbol HV 0.025 are as follows: 2500>(the hardness of the layer a)>1000, 3500>(the hardness of the layer b)>2300, 2500>(the hardness of the layer c)>1000, (500+the hardness of the layer a)<(the hardness of the layer b), and (500+the hardness of the layer c)<(the hardness of the layer b); the thickness of the layer b) is smaller than that of the layer c); and the total thickness of the coating layers is 5 to 15 μm. ## Claims ### Claim 1 A hard-material-coated member with an excellent durability comprising a metal as base material and having coating layers formed at least on its working plane by physical vapor deposition, wherein at least three layers, i.e., a layer a as the outermost layer, a layer c just above the base material and a layer b between the layer a and the layer c are formed as the coating layers, where each of the three layers a, b and c contains a compound composed mainly of a metal common to the three layers; the hardness values of these layers in terms of hardness symbol HV 0.025 are as follows: 2500>(the hardness of the layer a)>1000, 3500>(the hardness of the layer b)>2300, 2500>(the hardness of the layer c)>1000, (500+the hardness of the layer a)<(the hardness of the layer b), and (500+the hardness of the layer c)<(the hardness of the layer b); the thickness of the layer b is smaller than that of the layer c; and the total thickness of the coating layers is 5 to 15 μm. ### Claim 2 (depends on 1) A hard-material-coated member with an excellent durability according to claim 1, wherein each of the layer a and the layer c consists of any of a nitride, a carbide or a carbonitride, the metal element portion of which is composed mainly of Ti or Cr, and the layer b consists of any of a nitride, a carbide or a carbonitride, the metal element portion of which is composed mainly of one or more elements selected from Ti or Cr. ### Claim 3 (depends on 1) A hard-material-coated member with an excellent durability according to claim 1, wherein the thickness of the layer a is 1 to 5 μm, the thickness of the layer b is 1 to 5 μM, and the thickness of the layer c is 2 to 7 μm. ### Claim 4 (depends on 1) A hard-material-coated member with an excellent durability according to claim 1, wherein the base material having the coating layers formed thereon has a hardness at a depth of 25 μm from the outermost surface of the base material which is higher than that at a depth of 500 μm from said outermost surface by 100 or more in terms of hardness symbol HV 0.2. ### Claim 5 (depends on 1) A hard-material-coated member with an excellent durability according to claim 1, which is a mold for plastic working. ### Claim 6 (depends on 1) A hard-material-coated member with an excellent durability according to claim 1, which is a member for casting. ### Claim 7 (depends on 2) A hard-material-coated member with an excellent durability according to claim 2, which is a mold for plastic working. ### Claim 8 (depends on 3) A hard-material-coated member with an excellent durability according to claim 3, which is a mold for plastic working. ### Claim 9 (depends on 4) A hard-material-coated member with an excellent durability according to claim 4, which is a mold for plastic working. ### Claim 10 (depends on 2) A hard-material-coated member with an excellent durability according to claim 2, which is a member for casting. ### Claim 11 (depends on 3) A hard-material-coated member with an excellent durability according to claim 3, which is a member for casting. ### Claim 12 (depends on 4) A hard-material-coated member with an excellent durability according to claim 4, which is a member for casting.