Abstract: A film formation portion is formed on an annular edge portion along an opening portion (16a) of an intake port (16) or an opening portion (17a) of an exhaust port (17). The cross section, along the radial direction of the intake port (16) or the exhaust port (17), of the film formation portion, on which a metal film (5) is formed by spraying a raw material powder using a cold spray method, is formed in a groove shape that includes a flat bottom surface (G1) and a pair of side surfaces (G2) adjacent to the bottom surface.

Abstract: A film forming method forms a coating film on a workpiece (e.g., a cylinder head) having a film-deposited portion (e.g., an annular valve seat part) by moving a nozzle of a cold spray device relative to the workpiece along a film formation trajectory having a film formation starting point and a film formation finishing point in which the film-deposited portion overlaps to form an overlapping portion. The coating film is formed by causing a raw material powder to collide in a solid-phase state with the workpiece and plastically deform. Also, the coating film on the film-deposited portion is further formed such that an inclination angle of an end part of the coating film relative to a surface of the film-deposited portion is 45° or less at the film formation starting point of the overlapping portion.

Abstract: A sliding mechanism of the present invention includes a cylinder bore having a thermally sprayed iron-based coating and includes a piston with a piston ring covered with a hard coating composed mainly of carbon. The thermally sprayed coating has diamond abrasive grains. An area ratio of the diamond abrasive grains to a surface of the thermally sprayed coating is 0.3 to 1.8%, which enables suppressing wear of the piston ring having the hard coating composed mainly of carbon.

Abstract: Provided is a thermal spray wire as a thermal spray material for use in continuous arc wire thermal spraying machines, the thermal spray wire being for performing continuous and stable arc thermal spraying with sufficient electrical conductivity and at a stable voltage. The thermal spray wire includes a copper-plated coating having a thickness of from 0.3 to 1.2 ?m on a surface of a rod made of stainless steel. Using the thermal spray wire allows for stable arc thermal spraying by a continuous arc thermal spraying machine including a wire feeding mechanism.

Abstract: A sliding mechanism of the present invention includes a cylinder bore having a thermally sprayed iron-based coating and includes a piston with a piston ring covered with a hard coating composed mainly of carbon. The thermally sprayed coating has diamond abrasive grains. An area ratio of the diamond abrasive grains to a surface of the thermally sprayed coating is 0.3 to 1.8%, which enables suppressing wear of the piston ring having the hard coating composed mainly of carbon.

Abstract: A film forming method forms a coating film on a workpiece (e.g., a cylinder head) having a film-deposited portion (e.g., an annular valve seat part) by moving a nozzle of a cold spray device relative to the workpiece along a film formation trajectory having a film formation starting point and a film formation finishing point in which the film-deposited portion overlaps to form an overlapping portion. The coating film is formed by causing a raw material powder to collide in a solid-phase state with the workpiece and plastically deform. Also, the coating film on the film-deposited portion is further formed such that an inclination angle of an end part of the coating film relative to a surface of the film-deposited portion is 45° or less at the film formation starting point of the overlapping portion.

Abstract: A film forming method forms a coating film on a workpiece having at least two film-deposited portions which are not continuous with each other by moving a nozzle of a cold spray device relative to each other along a continuous movement trajectory. The movement trajectory includes at least two trajectories corresponding to the film-deposited portions and a connecting trajectory linking the trajectories of the film-deposited portions. The film-deposited portions are formed by continuously spraying a raw material powder from the nozzle by cold spraying to form a coating film on each of the plurality of film-deposited portions. A turnback point of the spraying is set on the connecting trajectory where a relative speed between the workpiece and the nozzle decreases in the movement trajectory.