Artificial lift pump components such as couplings are disclosed, all having a body formed from a selected material, the body having an inner diameter and an outer diameter, a first surface treatment introducing carbon, nitrogen, boron into the material to form a first and hard layer, and a second layer defined as an deposited coating to the first layer that is also made of a carbon, nitrogen, or boron and is further characterized as being ceramic like (hard) and having a low-friction.

A multilayer structure includes: a base material made of an iron-based metal material; a nitride layer that is provided on a surface of the base material through a nitriding treatment performed to the base material; an intermediate layer provided on a surface of the nitride layer; and a DLC layer provided on a surface of the intermediate layer. The intermediate layer is made of Si.sub.3N.sub.4, and the DLC layer has a thickness of 2 m to 10 m.

The present invention discloses a two-dimensional AlN material and its preparation method and application, wherein the preparation method comprises the following steps: (1) selecting a substrate and its crystal orientation; (2) cleaning the surface of the substrate; (3) transferring a graphene layer to the substrate layer; (4) annealing the substrate; (5) using the MOCVD process to introduce H.sub.2 to open the graphene layer and passivate the surface of the substrate; and (6) using the MOCVD process to grow a two-dimensional AlN layer. The preparation method of the present invention has the advantages that the process is simple, time saving and efficient. Besides, the two-dimensional AlN material prepared by the present invention can be widely used in HEMT devices, deep ultraviolet detectors or deep ultraviolet LEDs, and other fields.

A sliding member includes a base material, and an amorphous hard carbon film formed on a surface of the base material, in which a sp.sup.2 ratio of the amorphous hard carbon film increases from an inner surface side corresponding to the base material side toward an outer surface side thereof to become a maximum value and further decreases toward the outer surface side.

A rotary cutting tool includes a main body and a shank. The main body has a tip end. The shank is continuous with the main body on the side opposite to the tip end. The main body is provided with a first cutting edge having a positive twist angle, and a second cutting edge having a negative twist angle and separated from the first cutting edge. Each of the first cutting edge and the second cutting edge extends continuously from the tip end to the shank.

The present disclosure relates to a coated substrate having a hard material coating, which comprises a hard carbon layer of the hydrogen-free amorphous carbon layer type, wherein the coating comprises a layer consisting of zirconium between the substrate and the hydrogen-free amorphous carbon layer; wherein between the layer consisting of zirconium and the hydrogen-free amorphous carbon layer, a layer consisting of ZrC.sub.x can be formed in which a zirconium monocarbide is formed; and the layer consisting of ZrC.sub.x and comprising zirconium monocarbide is applied directly to the adhesive layer consisting of zirconium.

A grain-oriented electrical steel sheet according to the present invention includes a base steel sheet having plural grooves on a surface and a glass film formed on the surface of the base steel sheet. In case of viewing region including grooves in cross section orthogonal to groove longitudinal direction, a straight line passing through peak point present on profile line of glass film and parallel to groove width direction orthogonal to sheet thickness direction in cross section is defined as reference line, a point present on boundary line between glass film and base steel sheet and present at lowest location in sheet thickness direction is defined as deepest point, and a point present on boundary line and present at the highest location in the sheet thickness direction in region having the deepest point in a center and having length of 2 m in groove width direction is defined as shallowest point, a relationship between shortest distance A between reference line and deepest point and shortest distance B between reference line and shallowest point satisfies Expression (1).

0.1 mAB5.0 m(1)

Provided are: an oriented electrical steel sheet having a high tension applied to a steel sheet and excellent adhesion to a film; and a method for producing the same. This oriented electrical steel sheet includes: a steel sheet; a film A containing a crystalline material disposed on the steel sheet; and a film B containing a vitreous material disposed on the film A, wherein an element profile, which is obtained by using a high-frequency glow discharge light-emission surface analysis method, in the direction from the film B to the steel sheet satisfies formulae (1) and (2). 0.35(t.sub.A/t.sub.Fe/2)0.75 . . . (1), 0.25(t.sub.A/2/t.sub.Fe/2)1.00 . . . (2), where t.sub.A represents the peak time of an alkali metal element profile, t.sub.A/2 represents the half time of an alkali metal.

A black member includes a base and a black layer laminated on the base. The black layer contains titanium aluminum nitride, titanium silicon nitride, or titanium aluminum silicon nitride. The black layer may also contain at least one type of elements selected from the group consisting of oxygen, fluorine, and carbon. When the black layer contains carbon, and assuming that a total amount of elements contained in the black layer is 100 at %, the black layer contains carbon of 10 at % or less. In a color evaluation according to an L*, a*, b* color system (CIE color system), the black layer satisfies L*48.0, 2.0a*3.0, and 3.5b*3.0.

A sliding member includes a base material and an amorphous hard carbon film formed on a surface of the base material, and the amorphous hard carbon film has a graded structure in which a sp.sup.2 ratio increases from an inner surface side corresponding to the base material side toward an outer surface side. A piston ring includes the sliding member.