In one aspect, articles are described herein comprising refractory coatings employing alumina-based hybrid nanocomposite architectures. A coated article described herein comprises a substrate and a coating deposited by CVD adhered to the substrate, the coating including a composite refractory layer having a matrix phase comprising alumina and at least one particulate phase within the matrix phase, the particulate phase comprising nanoscale to submicron particles formed of at least one of an oxycarbide and oxycarbonitride of one or more metals selected from the group consisting of aluminum and Group IVB metals.

A process for producing a component includes providing a composition comprising hard material particles and a binder metal, and sintering the composition at a sintering temperature of from 1250 C. to 1400 C. for a period of from 3 to 15 minutes. The hard material particles comprise an inner core comprising fused tungsten carbide and an outer shell comprising tungsten carbide. The binder metal is selected from the group consisting of Co, Ni, Fe and alloys comprising at least one metal selected from Co, Ni and Fe.

A cutting tool rotates about a rotation axis, and includes a tip end portion. The tip end portion includes a partially spherical surface that is brought into contact with a workpiece. The surface is provided with a plurality of recesses disposed apart from each other. An opening edge of each of the plurality of recesses constitutes a cutting edge.

There is provided a cutting tool having high wear resistance and fracture resistance by reducing the occurrence of thermal cracking on a cutting edge even during a cutting process of a heat-resistant alloy in which the cutting edge reaches high temperatures. The cutting tool is made from a cemented carbide that is composed mainly of a WC phase and contains 11.5-12.5% by mass of Co and 0.2-0.6% by mass of Cr in terms of Cr.sub.3C.sub.2. The WC phase has a mean particle size of 0.85-1.05 m, an antimagnetic force (Hc) of 13.0-16.0 kA/m, and a Rockwell hardness (HRA) of 89.5-90.5.

A single-lip drill including at least one cutting edge on a drill head has a face which is concave along at least 75 percent of the width thereof and substantially along the entire length thereof, all the way to, and inclusive of, the cutting edge.

A coated cutting tool includes a body and a hard and wear resistant PVD coating on the body, wherein the body is made from a cemented carbide, cermet, ceramics, polycrystalline diamond or polycrystalline cubic boron nitride based materials. Th coating includes a first (Ti,Al)-based nitride sub-coating and a second (Ti,Al)-based nitride sub-coating. The first (Ti,Al)-based nitride sub-coating can be a single layer, and the second (Ti,Al)-based nitride sub-coating can be a laminated structure, wherein the first (Ti,Al)-based nitride sub-coating includes a (Ti.sub.1-xAl.sub.x)N.sub.z-layer where 0.1<x<0.4, 0.6<z<1.2, and wherein the second (Ti,Al)-based nitride sub-coating includes a (Ti.sub.1-x1-y1Al.sub.x1Cr.sub.y1)N.sub.z1 layer where 0.5<x1<0.75, 0.05<y1<0.2, 0.6<z1<1.2.

A method for drilling through an assembly forming a stack of at least two different materials uses a drill bit having at least a first cutting edge and a second cutting edge inclined in an axial plane of the drill bit so that the end of the drill bit has a projecting conical shape. The first cutting edge is configured to drill a first material. The second cutting edge is made differently from the first cutting edge, to drill a second material. A first rotational drive axis of the drill bit is laterally offset during the drilling by an offset distance D relative to the axis of the drill bit in a direction opposite the first cutting edge when the drill bit is drilling through the first material, and alternately, in a direction opposite the second cutting edge when the drill bit is drilling through the second material.

A composite part includes: a cutting edge part made of cubic boron nitride sintered material or WC-based cemented carbide; a cutting tool body made of cemented carbide; and a bonding part between the cutting edge part and the cutting tool body. A primarily TiC layer containing 50 area % or more of TiC is formed in an interface between the cemented carbide and the bonding part, and has a thickness of 0.5-3 m. TiNi enriched layer containing each of Ti and Ni at 30 atomic % or more is formed adjacent to the primarily TiC layer and has a thickness of 0.3-3 m. An intermittent net structure containing each of Ti, Ni and C at 10 atomic % or more is formed adjacent to the primarily TiC layer. A straight line overlapping with a major axis of each of crystal grains intersects 3 or more other crystal grains.

In one aspect, articles are described herein comprising refractory coatings employing alumina-based hybrid nanocomposite architectures. A coated article described herein comprises a substrate and a coating deposited by CVD adhered to the substrate, the coating including a composite refractory layer having a matrix phase comprising alumina and at least one particulate phase within the matrix phase, the particulate phase comprising nanoscale to submicron particles formed of at least one of an oxycarbide and oxycarbonitride of one or more metals selected from the group consisting of aluminum and Group IVB metals.

A surface-coated cutting tool of the invention is a surface-coated cutting tool in which a surface of a tool body is coated with a lower layer and an upper layer, in which at least one layer of the lower layer is made of a TiCN layer, the upper layer has an average layer thickness of 2 to 15 m and is made of an Al.sub.2O.sub.3 layer having an -type crystal structure in a chemically deposited state, and in a coincidence grain boundary distribution graph, a highest peak is present in 3 in the range of 3 to 29, a distribution ratio of 3 occupies 35 to 70% of the whole coincidence grain boundary length of 3 or more, and a coincidence grain boundary of 31 or more occupies 25 to 60% of the whole coincidence grain boundary length of 3 or more.