Abstract: The cemented carbide of the present disclosure is a cemented carbide comprising a first phase composed of a tungsten carbide particle and a second phase comprising cobalt as a main component, wherein a total content of the first phase and the second phase in the cemented carbide is 97% by volume or more, an average value of an equivalent circle diameter of the tungsten carbide particle is 0.8 ?m or less, a cobalt content of the cemented carbide is 3% by mass or more and 10% by mass or less, a vanadium content of the cemented carbide is 0.01% by mass or more and 0.30% by mass or less, and a maximum value of the vanadium content in an interface region between a (0001) crystal plane of the tungsten carbide particle and the second phase is 15 atomic % or less.

Abstract: A cemented carbide consists of: a first phase consisting of a plurality of tungsten carbide grains; and a second phase including cobalt, an average value of equivalent circle diameters of the tungsten carbide grains is 0.5 ?m to 1.2 ?m, on number basis, the tungsten carbide grains include less than or equal to 13% of first tungsten carbide grains each having an equivalent circle diameter of less than or equal to 0.3 ?m, on number basis, the tungsten carbide grains include less than or equal to 12% of second tungsten carbide grains each having an equivalent circle diameter of more than 1.3 ?m, in a histogram indicating a distribution of the equivalent circle diameters of the tungsten carbide grains. Fmax/Fmin is less than or equal to 7.0, Fmax/Fmin being a ratio of a maximum frequency Fmax to a minimum frequency Fmin.

Abstract: A cemented carbide consists of: a first phase consisting of a plurality of tungsten carbide grains; and a second phase including cobalt, an average value of equivalent circle diameters of the tungsten carbide grains is 0.5 ?m to 1.2 ?m, on number basis, the tungsten carbide grains include less than or equal to 13% of first tungsten carbide grains each having an equivalent circle diameter of less than or equal to 0.3 ?m, on number basis, the tungsten carbide grains include less than or equal to 12% of second tungsten carbide grains each having an equivalent circle diameter of more than 1.3 ?m, in a histogram indicating a distribution of the equivalent circle diameters of the tungsten carbide grains, Fmax/Fmin is less than or equal to 7.0, Fmax/Fmin being a ratio of a maximum frequency Fmax to a minimum frequency Fmin.

Abstract: A rod includes a first rod section occupying a predetermined region in a longitudinal direction, and a second rod section occupying a region different from the first rod section in the longitudinal direction. The first rod section has composition including A% by mass of cobalt, 0 to 1% by mass of chromium, 0 to 0.5% by mass of vanadium, and remainder of tungsten carbide and unavoidable impurities. The second rod section has composition including B% by mass of cobalt, 0 to 1% by mass of chromium, 0 to 0.5% by mass of vanadium, and remainder of tungsten carbide and unavoidable impurities. Contents of cobalt in the first rod section and the second rod section satisfy a relationship of 1% by mass?B<A?20% by mass. The second rod section has a length of 10 to 1000% with respect to the first rod section in the longitudinal direction.

Abstract: A lightweight material for decorative parts having a silver metallic color tone is provided. The material includes a sintered body including a main hard phase composed of a solid solution formed of titanium carbonitride and titanium carbide; a main binder phase composed of nickel; a first additive material composed of at least one selected from the group consisting of molybdenum carbide, niobium carbide, tungsten carbide, and tantalum carbide; a second additive material composed of at least one of chromium and chromium carbide; and the balance being incidental impurities. The N content in the sintered body is 2.0% to 6.0% by mass. The color tone of the sintered body satisfies L*=9 to 14, a*=?2 to 3, and b*=?6 to 0, which are values of the L*a*b* color system measured with a spectrophotometric colorimeter.

Abstract: A lightweight material for decorative parts having a silver metallic color tone is provided. The material includes a sintered body including a main hard phase composed of a solid solution formed of titanium carbonitride and titanium carbide; a main binder phase composed of nickel; a first additive material composed of at least one selected from the group consisting of molybdenum carbide, niobium carbide, tungsten carbide, and tantalum carbide; a second additive material composed of at least one of chromium and chromium carbide; and the balance being incidental impurities. The N content in the sintered body is 2.0% to 6.0% by mass. The color tone of the sintered body satisfies L*=9 to 14, a*=?2 to 3, and b*=?6 to 0, which are values of the L*a*b* color system measured with a spectrophotometric colorimeter.

Abstract: The invention is to prolong the life time of tools dramatically by (1) considerably improving the flaking resistance of the coating layer at the time of cutting, (2) increasing the wear resistance and crater resistance of the coating layer itself, and (3) enhancing the breakage strength of the coating layer in comparison with the conventional coating cutting tools. In order to achieve the object, the coated cemented carbide of the invention has the following structure in the coating layer on the surface of the cemented carbides: The outer layer has an Al2O3 layer practically having an &agr;-type crystal structure. The Al2O3 layer has a region where &agr;-type and &kgr;-type crystal grains coexist in the first row of the crystal grains that grow on the inner layer. In addition to that, the crystal grains of &agr;-Al2O3 in the region include no pores.

Abstract: A coated hard metal for a cutting tool is excellent in wear resistance and chipping resistance. The coated hard metal includes a hard coating layer on a surface of a base material of cemented carbide or cermet. The hard coating layer includes an inner layer (2) on the base material (1), an intermediate layer (3) on the inner layer (2) and an outer layer (4) on the intermediate layer (3). The inner layer (2) consists of a carbide, a nitride, a carbo-nitride, a carbo-oxide, a carbonitrogen oxide or a boronitride of Ti. The intermediate layer (3) consists of Al2O3 or ZrO2. The outer layer (4) consists of a carbide, a nitride, a carbo-nitride, a carbo-oxide, a carbonitrogen oxide or a boronitride of Ti. The thickness of the inner layer (2) is 0.1 to 5 &mgr;m, the thickness of the intermediate layer (3) is 5 to 50 &mgr;m in the case of it being an Al2O3 layer and 0.5 to 20 &mgr;m in the case of it being a ZrO2 layer, and the thickness of the outer layer (4) is 5 to 100 &mgr;m.

Abstract: A coated cemented carbide member includes a cemented carbide base material containing a binder metal of at least one iron family metal and a hard phase, and a coating layer provided on the surface of the cemented carbide base material. The hard phase contains at least one metal component selected from carbides, nitrides, carbo-nitrides and carbonic nitrides of Zr and/or Hf and WC. A layer consisting of only WC and an, iron family metal or a binder phase enriched layer or a low hardness layer is provided on an outermost surface of each insert edge portion of the cemented carbide base material. The coating layer is a single or multiple layer consisting of at least one metal component selected from carbides, nitrides, carbo-nitrides, oxides and borides of metals belonging to the groups IVB, VB and VIB of the periodic table. Due to this structure, it is possible to improve chipping resistance with no deterioration of wear resistance in the coated cemented carbide member to be used, for example, as a cutting tool.

Abstract: This invention relates to a coated cutting tool suitable for high speed cutting working and a process for the production of the same. The feature of the present invention consists in a coated cutting tool comprising a coating layer consisting of an inner layer and outer layer on a surface of a substrate consisting of a cemented carbide such as tungsten carbide-based cemented carbide, etc., the inner layer being composed of a mono-layer of titanium carbonitride in contact with the substrate, a double layer of titanium nitride of 0.1 to 2 .mu.m in thickness, in contact with the substrate, and titanium carbonitride directly above it or a multi-layer provided thereon consisting of titanium carbide, etc., in which the chlorine content in the inner layer is at most 0.

Abstract: A coated hard metal for a cutting tool is excellent in wear resistance and chipping resistance. The coated hard metal includes a hard coating layer on a surface of a base material of cemented carbide or cermet. The hard coating layer includes an inner layer (2) on the base material (1), an intermediate layer (3) on the inner layer (2) and an outer layer (4) on the intermediate layer (3). The inner layer (2) consists of a carbide, a nitride, a carbo-nitride, a carbo-oxide, a carbonitrogen oxide or a boronitride of Ti. The intermediate layer (3) consists of Al.sub.2 O.sub.3 or ZrO.sub.2. The outer layer (4) consists of a carbide, a nitride, a carbo-nitride, a carbo-oxide, a carbonitrogen oxide or a boronitride of Ti. The thickness of the inner layer (2) is 0.1 to 5 .mu.m, the thickness of the intermediate layer (3) is 5 to 50 .mu.m in the case of it being an Al.sub.2 O.sub.3 layer and 0.5 to 20 .mu.m in the case of it being a ZrO.sub.2 layer, and the thickness of the outer layer (4) is 5 to 100 .mu.m.

Abstract: A coated cemented carbide member includes a cemented carbide base material containing a binder metal of at least one iron family metal and a hard phase, and a coating layer provided on the surface of the cemented carbide base material. The hard phase contains at least one metal component selected from carbides, nitrides, carbo-nitrides and carbonic nitrides of Zr and/or Hf and WC. A layer consisting of only WC and an iron family metal or a binder phase enriched layer or a low hardness layer is provided on an outermost surface of each insert edge portion of the cemented carbide base material. The coating layer is a single or multiple layer consisting of at least one metal component selected from carbides, nitrides, carbo-nitrides, oxides and borides of metals belonging to the groups IVB, VB and VIB of the periodic table. Due to this structure, it is possible to improve chipping resistance with no deterioration of wear resistance in the coated cemented carbide member to be used, for example, as a cutting tool.

Abstract: A coated cemented carbide comprising: a substrate comprising a WC-based cemented carbide containing 4 to 10 wt. % of Co as a binder phase; based on a ratio in a mirror-polished texture of a cross section of the cemented carbide, 70% or more of WC crystals as a hard phase being classified into either of a group of fine particles A having a particle size of from 0.1 to 1 .mu.m and a group of coarse particles B having a particle size of from 3 to 10 .mu.m, the area ratio S.sub.A /S.sub.B of the fine particles A to the coarse particles B being in a range of from 0.22 to 0.45; and a coating layer disposed on a surface of the cemented carbide and having a total thickness in a range of from 5 to 100 .mu.m. The coating layer comprises at least one layer comprising at least one selected from the group consisting of: carbides, nitrides, carbonitrides, oxycarbides, and boronitrides of Ti, Zr, and/or Hf; and at least one layer comprising at least one selected from the group consisting of: Al.sub.2 O.sub.

Abstract: Coated cemented carbides used for cutting tool and having improved resistance to chipping without sacrificing resistance to wear.They comprise a substrate comprising WC, at least one iron-family metal forming a binder phase and a hard phase in which a hard phase comprising at least one element selected from the group consisting of carbides, nitrides and carbonitrides of metal containing Zr and/or Hf as a main component coexists with a hard phase comprising at least one element selected from the group consisting of carbides, nitrides and carbonitrides of metal containing Ti as a main component, and at least one coating layer formed on said substrate, said coating layer comprising at least one element selected from the group consisting of a carbide, nitride, oxide and boride of a metal that belongs to the IVa, Va and VIs groups and aluminum oxide.