A cutting tool comprises a substrate and a coating layer provided on the substrate, the coating layer including a multilayer structure layer composed of a first unit layer and a second unit layer, and a lone layer, the lone layer including cubic Ti.sub.zAl.sub.1-zN crystal grains, an atomic ratio z of Ti in the Ti.sub.zAl.sub.1-zN being 0.4 or more and less than 0.55, the lone layer having a thickness with an average value of 2.5 nm or more and 10 nm or less, the multilayer structure layer having a thickness with an average value of 10 nm or more and 45 nm or less, one multilayer structure layer and one lone layer forming a repetitive unit having a thickness with an average value of 20 nm to 50 nm, a maximum value of 40 nm to 60 nm, and a minimum value of 10 nm to 30 nm.

Provided is a titanium cast product made of commercially pure titanium, the titanium cast product being produced by electron-beam remelting or plasma arc melting, comprising: a melted and resolidified layer in a range of 1 mm or more in depth at a surface serving as a surface to be rolled, the melted and resolidified layer being obtained by adding one or more kinds of β stabilizer elements to the surface and melting and resolidifying the surface. An average value of β stabilizer element(s) concentration in a range of within 1 mm in depth is higher than β stabilizer element(s) concentration in a base material by, in mass %, equal to or more than 0.08 mass % and equal to or less than 1.50 mass %. As the material containing the β stabilizer element, powder, a chip, wire, or foil is used. As means for melting a surface layer, electron-beam heating and plasma arc heating are used.

The present invention provides a titanium copper foil having improved adhesion to solder and higher resistance to discoloration due to a high temperature and high humidity environment, an acid solution or an alkaline solution, and as well as having improved etching processability. The present invention provides a titanium copper foil comprising a base metal, the base metal having a composition containing Ti of from 1.5 to 5.0% by mass, the balance being copper and inevitable impurities, and having a thickness of from 0.018 to 0.1 mm, wherein the titanium copper foil has an Sn plated layer on a surface of the base metal, and has an adhesive strength of 0.5 N or more as measured by a solder adhesive strength test according to the definition in the specification.

A cubic boron nitride (cBN)-based composite including about 30-65 vol. % cBN, about 15-45 vol. % titanium (Ti)-containing binders, about 2-20 vol. % zirconium dioxide (ZrO.sub.2), about 3-15 vol. % cobalt-tungsten-borides (Co.sub.xW.sub.yB.sub.z), and about 2-15 vol. % aluminum oxide (Al.sub.2O.sub.3).

There is provided a coated tool in which an aluminum oxide layer has improved wear resistance. The coated tool is, for example, a cutting tool (1) which is provided with a base material (5) and a coating layer (6) located on a surface of the base material (5), wherein a cutting edge (4) and a flank surface (3) are located on the coating layer (6), the coating layer (6) has a portion in which at least a titanium carbonitride layer (8) and an aluminum oxide layer (10) having an α-type crystal structure are laminated in this order, and, with regard to a texture coefficient (Tc) (hkl) which is calculated on a basis of a peak of the aluminum oxide layer (10) analyzed by an X-ray diffraction analysis, a texture coefficient (Tc1) (4_0_10) as measured from a surface side of the aluminum oxide layer (10) in the flank surface (3) is 0.6 or more.

A high-strength galvanized steel sheet comprising a cold-rolled steel sheet, an intermetallic compound formed on the cold-rolled steel sheet, and a galvanizing layer formed on the intermetallic compound, the cold-rolled steel sheet having a specific composition and a microstructure having a martensite area ratio of 7% or more and less than 25% and a ferrite area ratio of 50% or more and which includes a base metal surface portion in which the amount of internal oxides per single side is 0.05 g/m.sup.2 or less.

A high-strength galvanized steel sheet comprising a cold-rolled steel sheet, an intermetallic compound formed on the cold-rolled steel sheet, and a galvanizing layer formed on the intermetallic compound, the cold-rolled steel sheet having a specific composition and a microstructure having a martensite area ratio of 7% or more and less than 25% and a ferrite area ratio of 50% or more and which includes a base metal surface portion in which the amount of internal oxides per single side is 0.05 g/m.sup.2 or less.

The present invention addresses the problem of providing a piston ring covered with a DLC coating that has excellent wear resistance and shows a low attacking property on a cylinder bore sliding surface. The problem is solved by a piston ring which is used in the presence of an engine lubricating oil and includes a DLC coating on an outer peripheral sliding surface. The DLC coating has an sp.sup.2 component ratio of 0.5 to 0.85 as determined from a TEM-EELS spectrum obtained by a combination of a transmission electron microscope (TEM) and electron energy loss spectroscopy (EELS), as well as a coating hardness of 12 GPa to 26 GPa and a Young's modulus of 250 GPa or less as measured by a nanoindentation method.

A cutting tool comprises a substrate and a coating layer provided on the substrate, the coating layer including a multilayer structure layer composed of a first unit layer and a second unit layer, and a lone layer, the lone layer including cubic Ti.sub.zAl.sub.1-zN crystal grains, an atomic ratio z of Ti in the Ti.sub.zAl.sub.1-zN being 0.4 or more and less than 0.55, the lone layer having a thickness with an average value of 2.5 nm or more and 10 nm or less, the multilayer structure layer having a thickness with an average value of 40 nm or more and 95 nm or less, one multilayer structure layer and one lone layer forming a repetitive unit having a thickness with an average value of 50 nm to 100 nm, a maximum value of 90 nm to 110 nm, and a minimum value of 40 nm to 60 nm.

A cutting tool comprises a substrate and a coating layer provided on the substrate, the coating layer including a multilayer structure layer composed of a first unit layer and a second unit layer, and a lone layer, the lone layer including cubic Ti.sub.zAl.sub.1-zN crystal grains, an atomic ratio z of Ti in the Ti.sub.zAl.sub.1-zN being 0.55 or more and 0.7 or less, the lone layer having a thickness with an average value of 2.5 nm or more and 10 nm or less, the multilayer structure layer having a thickness with an average value of 10 nm or more and 45 nm or less, one multilayer structure layer and one lone layer forming a repetitive unit having a thickness with an average value of 20 nm to 50 nm, a maximum value of 40 nm to 60 nm, and a minimum value of 10 nm to 30 nm.