Abstract: A friction stir welding method for bonding a to-be bonded material, includes: a step of supplying nitrogen and introducing nitrogen into the to-be bonded material while melting the to-be bonded material; and a step of friction stir welding a portion of the non-bonded material in which the nitrogen is introduced. A friction stirring device for bonding a to-be bonded material, includes: a heating source for melting the to-be bonded material; a nitrogen supply source for supplying nitrogen to a melted portion of the to-be bonded material and introducing nitrogen into the to-be bonded material; and a friction stir tool for friction stir welding a portion of the non-bonded material in which the nitrogen is introduced.

Abstract: A friction stir welding method for bonding a to-be bonded material, includes: a step of supplying nitrogen and introducing nitrogen into the to-be bonded material while melting the to-be bonded material; and a step of friction stir welding a portion of the non-bonded material in which the nitrogen is introduced. A friction stirring device for bonding a to-be bonded material, includes: a heating source for melting the to-be bonded material; a nitrogen supply source for supplying nitrogen to a melted portion of the to-be bonded material and introducing nitrogen into the to-be bonded material; and a friction stir tool for friction stir welding a portion of the non-bonded material in which the nitrogen is introduced.

Abstract: It is an objective of the invention to provide a slide part in which a seal member formed of an elastic body is in sliding contact with a hard member. There is provided a slide part comprising: a hard member having an amorphous carbon coating containing nitrogen formed on an outermost surface of a substrate; and a seal member formed of an elastic body, the seal member being in sliding contact with the hard member, wherein: content of the nitrogen in the coating is 3 at. % or more and 25 at. % or less, taking a total content of the carbon and the nitrogen in the coating as 100 at. %; the seal member contains fluorine at least in a sliding contact surface region thereof; and content of the fluorine in the surface region of the seal member is equal to or more than the nitrogen content in the coating.

Abstract: There is provided a slide part used in an environment where there is a lubricant containing a molybdenum compound including a hard protective layer formed on an outermost surface of a substrate of the slide part; in which: the hard protective layer includes mainly carbon, nitrogen, and a metal element; the hard protective layer is composed of a complex of an amorphous carbon body containing nitrogen and a compound crystal of the metal element; the compound crystal is composed of at least one of a metal carbide, a metal nitride, and a metal carbonitride; and a surface hardness of the hard protective layer is 1800 or larger in Vickers hardness.

Abstract: Disclosed herein is a hard film containing boron and carbon, wherein the hard film includes a plurality of concave portions and a plurality of convex portions formed on a surface of the hard film, and wherein carbon concentration in the concave portion is higher than that in the convex portion and boron concentration in the convex portion is higher than that in the concave portion. Further, disclosed herein is a method of manufacturing a sliding part having a hard film containing boron and carbon disposed over a substrate; wherein the hard film is manufactured by using at least one of an unbalanced magnetron sputtering method or a high power pulsed magnetron sputtering method, both sputtering methods using a target containing at least one of elements of silicon, chromium, titanium, and tungsten and a boron carbide target.

Abstract: Disclosed herein is a hard film containing boron and carbon, wherein the hard film includes a plurality of concave portions and a plurality of convex portions formed on a surface of the hard film, and wherein carbon concentration in the concave portion is higher than that in the convex portion and boron concentration in the convex portion is higher than that in the concave portion. Further, disclosed herein is a method of manufacturing a sliding part having a hard film containing boron and carbon disposed over a substrate; wherein the hard film is manufactured by using at least one of an unbalanced magnetron sputtering method or a high power pulsed magnetron sputtering method, both sputtering methods using a target containing at least one of elements of silicon, chromium, titanium, and tungsten and a boron carbide target.

Abstract: The object of the present invention is to provide a slide member excellent in wear resistance and highly reliable over a long period by improving the adhesion property (anti-flaking property) of a diamond-like-carbon coating in the slide member including the diamond-like-carbon coating. The sliding member includes a substrate; and a diamond-like-carbon film including layers serially stacked in order of a first layer, a second layer and a hard carbon layer, in which the substrate is formed of an alloy steel containing at least one element selected from the group consisting of V, Cr, Nb, Mo, Ta and W, in which the first layer contains at least one element selected from the group consisting of V, Cr, Nb, Mo, Ta and W, and in which the first layer adheres to the substrate.

Abstract: It is an objective of the invention to provide a slide part in which a seal member formed of an elastic body is in sliding contact with a hard member. There is provided a slide part comprising: a hard member having an amorphous carbon coating containing nitrogen formed on an outermost surface of a substrate; and a seal member formed of an elastic body, the seal member being in sliding contact with the hard member, wherein: content of the nitrogen in the coating is 3 at. % or more and 25 at. % or less, taking a total content of the carbon and the nitrogen in the coating as 100 at. %; the seal member contains fluorine at least in a sliding contact surface region thereof; and content of the fluorine in the surface region of the seal member is equal to or more than the nitrogen content in the coating.

Abstract: There is provided a slide part used in an environment where there is a lubricant containing a molybdenum compound including a hard protective layer formed on an outermost surface of a substrate of the slide part; in which: the hard protective layer includes mainly carbon, nitrogen, and a metal element; the hard protective layer is composed of a complex of an amorphous carbon body containing nitrogen and a compound crystal of the metal element; the compound crystal is composed of at least one of a metal carbide, a metal nitride, and a metal carbonitride; and a surface hardness of the hard protective layer is 1800 or larger in Vickers hardness.