Abstract: There is provided a joined product suitable as a cutting tool that is fit for high-speed cutting, CVD coating process and the like, and does not cause a reduction in joint strength of a joining layer even if a high temperature exceeding a temperature at which a brazing filler forms the liquid phase is reached during cutting. Specifically, the joined product includes a cemented carbide sintered compact serving as a first material to be joined and a cBN sintered compact or a diamond sintered compact serving as a second material to be joined. The first material to be joined and the second material to be joined are joined by a joining material that does not form a liquid phase at a temperature lower than 1000° C. and that is placed between the first material to be joined and the second material to be joined. The joining is performed by resistance heating and pressing at a pressure of 0.1 to 200 MPa.

Abstract: There is provided a joined product suitable as a cutting tool that is fit for high-speed cutting, CVD coating process and the like, and does not cause a reduction in joint strength of a joining layer even if a high temperature exceeding a temperature at which a brazing filler forms the liquid phase is reached during cutting. Specifically, the joined product includes a cemented carbide sintered compact serving as a first material to be joined and a cBN sintered compact or a diamond sintered compact serving as a second material to be joined. The first material to be joined and the second material to be joined are joined by a joining material that does not form a liquid phase at a temperature lower than 1000° C. and that is placed between the first material to be joined and the second material to be joined. The joining is performed by resistance heating and pressing at a pressure of 0.1 to 200 MPa.

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: In a coated hard tool, a hard coating is formed on a hard base material, wherein the coating includes ten or more sublayers of types A and B stacked alternately. In the sublayer of type A, a plurality of secondary sublayers of different types each having a thickness of 1 to 50 nm are stacked periodically and repeatedly, while the sublayer of type B is formed of a single layer. The sublayers each have a thickness of 100 to 1000 nm. Each sublayer contains at least one compound selected from a nitride, a carbide, a nitrided carbide and an oxide containing at least one element selected from elements of periodic group 4A, elements of periodic group 5A, Al and B.

Abstract: A nitrogen-containing sintered alloy includes at least 75 and not more than 95 percent by weight of a hard phase containing Ti, a group 6A metal and WC in a prescribed composition, and at least 5 and not more than 25 percent by weight of a binder phase containing Ni, Co and unavoidable impurities. The alloy contains at least 5 and not more than 60 percent by weight of a carbide, nitride or carbonitride of Ti, and at least 30 and not more than 70 percent by weight of a carbide of a metal belonging to the group 6A of the periodic table. The atomic ratio of nitrogen/(carbon+nitrogen) in the hard phase is at least 0.2 and less than 0.5. The alloy includes a soft layer containing a binder phase metal and WC at its outermost surface, and includes a layer that hardly contains any of the hard phase containing WC in a region immediately under the soft layer, with a thickness of at least 3 .mu.m and not more than 30 .mu.m.

Abstract: The ceramic insert made from a silicon nitride ceramic material and formed with a recess for fastening in the center of its rake face. The recess has a surface roughness Rmax not exceeding 4 .mu.m. The angle between a side face of the recess and a centerline perpendicular to the rake face of the insert is 50-70 degrees. The ratio of the diameter of the recess to the diameter of a circle inscribing the perimeter of the rake face is 30-85%. The recess has a flat or curved bottom. The connecting portion between the side face and the bottom of the recess forms a smoothly curved surface.

Abstract: A coated tool includes a base material and a wear-resistant coating film formed on the base material. The composition of the wear-resistant coating film is expressed as (Ti.sub.x,Al.sub.y,V.sub.z)(C.sub.u,N.sub.v,O.sub.w). Relations x+y+z=1, u+v+w=1, 0.2<x<1, 0.ltoreq.y<0.8, 0.02.ltoreq.z<0.6, 0.ltoreq.u<0.7, 0.3<v.ltoreq.1 and 0.ltoreq.w<0.5 hold between x, y, z, u, v and w. The thickness of the wear-resistant coating film is at least 0.5 .mu.m and not more than 15 .mu.m. A coated cutting tool in particular includes a base material consisting of cemented carbide and a wear-resistant coating film formed on the surface of the base material.

Abstract: An indexable insert with a chip breaker configured such that chips produced under various cutting conditions from rough cutting to finish cutting can be disposed of in an optimum way. Protrusions are provided in a chip breaker groove to extend from a central land toward the respective corners of the insert. Each protrusion has a breaker wall which is concave and curved such that chips produced always collide against the breaker wall at an angle of 10.degree.-40.degree. so that the chips are curled helically with a helix angle of 10.degree.-40.degree. and broken into small pieces reliably.

Abstract: A titanium carbonitride-based alloy which is excellent in chipping resistance and wear resistance is disclosed. A hard phase is a carbide (TiMC), a nitride (TiMN) or a carbonitride (TiMCN) of Ti and at least one metal (M), other than Ti, selected from those belonging to the groups IVa, Va and VIa of the periodic table. A binder phase contains Co and Ni as main components. When the structure of the titanium-based alloy is observed with a scanning electron microscope, particles forming the hard phase in the alloy have black core parts which are located on core portions to appear black and peripheral parts which are located around the black core parts to appear gray. Assuming that A and B represent particles having the black core parts occupying areas of at least 30% of the overall particles A and those having the black core parts occupying areas of not more than 30% of the overall particles B respectively, the area ratio of the particles A to the particles B satisfies a condition of 0.3.ltoreq.A/(A+B).ltoreq.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 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: Disclosed is a method of preparing a cemented carbide or a cermet alloy by mixing and kneading cemented carbide powder or cermet alloy powder with an organic binder, shaping this mixed powder into a prescribed configuration by an injection molding method and thereafter removing the organic binder from this compact and sintering the same, in order to obtain a dense alloy. Removal of the organic binder is performed in a first step in an inert gas atmosphere as a first removal step, and then continued in a second step in a vacuum of not more than 1 Torr. In the first removal step, the pressure is held in excess of the atmospheric pressure, to prevent the formation of imperfections in the compact. After continuous pores are formed in the interior of the compact, the atmosphere pressure is brought close to a vacuum, thereby facilitating the evaporation of gas from the surface and desorption of gas generated in the interior of the compact.

Abstract: A nitrogen-containing sintered hard alloy in which the content of the binder phase is at the highest level in an area to a depth of between 3 .mu.m and 500 .mu.m from its surface and its content in this area is between 1.1 and 4 times the average content of the binder phase in the entire alloy. Below this area, the content of the binder phase decreases gradually so that its content becomes equal to the average content of the binder phase at a depth of 800 .mu.m or less. The content of the binder phase in the surface layer is 90% or less of its maximum value. The depth of 800 .mu.m is a value at which the thermal conductivity is kept sufficiently high and at the same time a tool can keep high resistance to plastic deformation during cutting.

Abstract: A hard sintered component of a cemented carbide or a stellite alloy having a complex three-dimensional shape and a small hole or the like and the high strength originally provided by the used material for making the component without any secondary working, is formed by injection molding a compact molding die having an inner mold surface roughness R.sub.max of not more than 3 .mu.m. Where a core pin is used the outer surface of the pin has a surface roughness R.sub.max of not more than 3 .mu.m. The compact is then sintered. The hard sintered component is composed of a cemented carbide or a stellite alloy. In such a hard sintered component, the surface of a complex three-dimensional shape such as a disc portion or a thin portion, or the inner surface of a small hole, is defined by a sintered surface which has a surface roughness R.sub.max of not more than 4 .mu.m.

Abstract: A watch exterior part is formed of cemented carbide or stellite alloy, and has a three-dimensionally curved as-sintered surface or a small hole with an as-sintered interior peripheral surface, or has a three-dimensionally curved polished surface obtained by polishing an as-sintered surface. The watch exterior part is manufactured by a method in which organic binder is milled into a material powder, and a molded body obtained by injection molding is subjected to a binder removing process and then sintered. By the manufacturing method, a watch exterior part formed of cemented carbide or stellite alloy has a high strength and a complicated configuration such as a three-dimensional curved surface and a small hole, without applying secondary machining operations such as discharge operations.

Abstract: The invention provides a method for manufacturing sintered parts, which uses as a debinder solvent a substance harmless to the human body and which can enhance the strength of an injection-molded product.

Abstract: A throw-away tipped drill has an insert removably connected to a shank for cutting a workpiece. The insert (31) and the shank (32) have mutually engaging surfaces respectively, and a slit (34, 39) is formed either in the insert (31) or in the shank (32) for mounting the insert to the shank, whereby the insert (31) is fixed to the shank (32) by an elastic force which is caused by an elastic deformation upon mutual movement of opposite surfaces of this slit (34, 39) in engagement of the insert (31) and the shank (32). Therefore, the insert (31) and the shank (32) are coupled by simple press fitting without any requirement for a screw or other connection, whereby the assembly is improved.

Abstract: A drill is formed by a hard dispersed phase of WC and a B-1 type solid solution, and a bond metal phase of an iron family metal. The composition of the hard dispersed phase is expressed as (W.sub.a M.sub.b) (C.sub.x N.sub.y), where M represents Ti, or two or more metals, including Ti but excluding W, selected from the group IVa, Va and VIa of the periodic table, and a, b, x and y represents molar fractions which are defined by relational expressions of a+b=1, x+y=1, x>0, y.gtoreq.0 and b.gtoreq.0.4. The bond metal phase occupies at least 13 volume percent and not more than 30 volume percent of the cemented carbide.

Abstract: High hardness and high toughness nitrogen-containing sintered hard alloys or cermets useful for cutting tools, in particular, high speed cutting are provided which comprises a hard dispersed phase consisting essentially of a mixed carbonitride of titanium and at least one element selected from the group consisting of Group IVa, Va, and VIa elements of Periodic Table, except titanium, and a binder metal phase consisting essentially of at least one metal selected from the group consisting of nickel and cobalt, and unavoidable impurities, the hard dispersed phase having previously been subjected to a solid solution forming treatment at a temperature of at least the sintering temperature before sintering.