There is provided a method for manufacturing a nitride semiconductor template, including the steps of: growing and forming a buffer layer to be thicker than a peak width of a projection and in a thickness of not less than 11 nm and not more than 400 nm on a sapphire substrate formed by arranging conical or pyramidal projections on its surface in a lattice pattern; and growing and forming a nitride semiconductor layer on the buffer layer.

A piston ring for a piston of a reciprocating internal combustion engine. The piston ring comprises a body having an outer contact surface. A tribological coating is formed on the outer contact surface of the body. The tribological coating comprises a quaternary Cr—V—Ti—N system. In one form, the tribological coating is deposited on the outer contact surface of the body as a stack of multiple layers.

A coated cutting tool has a hard coating on a surface of a base material. The hard coating is a nitride of Al, Cr, and Si in which Al is 50 atom % or more, Cr is 30 atom % or more, and Si is 1 atom % or more and 5 atom % or less. The hard coating contains 0.02 atom % or less of Ar, and the atomic ratio A and the atomic ratio B of nitrogen satisfy the relationship of 1.02≤B/A≤1.10, and a diffraction peak originating from the (111) plane of a face-centered cubic lattice structure shows the maximum intensity. In the cross-sectional observation of the hard coating, the number of droplets having an equivalent circle diameter of 3 μm or more is less than 1 per 100 μm.sup.2. The surface of the hard coating has an arithmetical mean curvature Spc value of 5000 or less.

A cutting tool for machining titanium alloy or superalloy includes a Me-B-N coating. The Me-B-N coating is Me1-B-N; Me1 is one or more selected from transition metal elements Hf, V, Nb, Ta and Mo, and the atomic percentage of each element is: Me1: 8-40%, B: 15-60%, and N: 10-65%; and the Me-B-N coating includes Me1Nx phase and BN phase; or, the Me-B-N coating is Me1-Me2-B-N, Me1 is one or more selected from transition metal elements Hf, V, Nb, Ta and Mo; Me2 is one or more selected from transition metal elements Ti, Zr, Cr, and W; and the atomic percentage of each element is: Me1: 4-36%, Me2: 4-36%, B: 15-60%, and N: 10-65%; and the Me-B-N coating includes Me1Nx phase, Me2Nx phase and BN phase.

A hard coating for cutting tools according to the present invention is a hard coating for cutting tools which is formed on and adjacent to a hard base material by a PVD method, and is characterized in that the thickness of the entire hard coating is 0.5 to 10 μm, and the hard coating includes one or more nitride layers and one or more oxide layers. Each of the one or more nitride layers has a thickness of 0.1 to 5.0 μm and is composed of Al.sub.aTi.sub.bMe.sub.cN (wherein Me is at least one selected from Si, W, Nb, Mo, Ta, Hf, Zr, and Y, and 0.55≤a≤0.7, 0.2<b≤0.45, and 0≤c<0.1) or Al.sub.aCr.sub.bMe.sub.cN (wherein Me is at least one selected from Si, W, Nb, Mo, Ta, Hf, Zr, and Y, and 0.55≤a≤0.7, 0.2<b≤0.45, and 0≤c<0.1) in a cubic phase, and each of the one or more oxide layers has a thickness of 0.1 to 3.0 μm and is composed of γ-Al.sub.2O.sub.3 in a cubic phase. When the number of compositionally discontinuous interfaces throughout the hard coating including the hard base material is n, the n satisfies 4≤n≤9, and the ratio of the microhardness (H1) of the nitride layer to the microhardness (H2) of the oxide layer satisfies 1.03<H1/H2<1.3, and the ratio of the elastic modulus of the nitride layer (E1) to the elastic modulus of the oxide layer (E2) satisfies 1.1<E1/E2<1.3. Each of the nitride layers and each of the oxide layers have an elastic deformation resistance index (H/E) of 0.07 to 0.09 and a plastic deformation resistance index (H.sup.3/E.sup.2) of 0.13 to 0.29, and the elastic deformation resistance index (H/E) of the entire hard coating is 0.09 to 0.12, and the plastic deformation resistance index (H.sup.3/E.sup.2) of the entire hard coating is 0.29 to 0.32.

A cutting tool comprises a rake face and a flank face, the cutting tool being composed of a substrate made of a cubic boron nitride sintered material and a coating provided on the substrate, the coating including a MAlN layer, when a cross section of the MAlN layer is subjected to an electron backscattering diffraction image analysis to determine a crystal orientation of each of the crystal grains of the M.sub.xAl.sub.1−xN and a color map is created based thereon, then on the color map, the flank face having the MAlN layer occupied in area by 45% to 75% by crystal grains of the M.sub.xAl.sub.1−xN having a (111) plane with a normal thereto extending in a direction within 25 degrees with respect to a direction in which a normal to the flank face extends, the MAlN layer having a residual stress of −2 GPa to −0.1 GPa.

The process for producing an orthopedic implant having an integrated ceramic surface layer includes steps for positioning the orthopedic implant inside a vacuum chamber, emitting a relatively high energy beam into the at least two different vaporized metalloid or transition metal atoms in the vacuum chamber to cause a collision therein to form ceramic molecules, and driving the ceramic molecules with the ion beam into an outer surface of the orthopedic implant at a relatively high energy such that the ceramic molecules implant therein and form at least a part of the molecular structure of the outer surface of the orthopedic implant, thereby forming the integrated ceramic surface layer.

A coated cutting tool comprises a substrate and a coating layer formed on a surface of the substrate, and has a rake face and a flank. The coating layer comprises an alternating laminate structure in which first compound layers containing AlN and second compound layers containing a compound are laminated in an alternating manner, the compound having a composition represented by formula (1) below:

(Ti.sub.1-xAl.sub.x)N  (1)

(wherein x satisfies 0.40≤x≤0.70). An average thickness T.sub.1 per first compound layer is 5 nm or more to 160 nm or less, and an average thickness T.sub.2 per second compound layer is 8 nm or more to 200 nm or less. A ratio of T.sub.1 to T.sub.2 is 0.10 or more to 0.80 or less. An average thickness T.sub.3 of the alternating laminate structure is 2.5 μm or more to 7.0 μm or less. A ratio (H/E) of hardness H to elastic modulus E is 0.065 or more to 0.085 or less at the rake face or the flank.

A process in which both an optical coating, for example, an AR coating, and an ETC coating are deposited on a glass substrate article, in sequential steps, with the optical coating being deposited first and the ETC coating being deposited second, using the same apparatus and without exposing the article to the atmosphere at any time during the application of the optical coating and ETC coating.

To provide a hot forging die made of a Ni-based superalloy, which is free from any deteriorations in working environment and die shape during hot forging in the air, and also provide a manufacturing process for a forged product using the same and a manufacturing process for a hot forging die. The hot forging die includes: a base body made of a Ni-based superalloy consisting of, by mass, 10.3 to 11.0% of W, 9.0 to 11.0% of Mo, and 5.8 to 6.8% of Al and balance of Ni with inevitable impurities; and a coating layer of inorganic material that is formed on at least one of a forming surface and a side surface of the die and contains 30 mass % or more in total of one or more of Si, Cr, and Al out of Si and metal elements.