METHOD FOR FORMING HEAT-SHIELDING FILM AND HEAT-SHIELDING FILM STRUCTURE

摘要

A second heat-shielding film 20 produced by anodizing treatment of both surfaces of pure Al foil with an Al purity equal to or larger than 99.0% is disposed on a surface of a first heat-shielding film 12 that is formed by anodizing treatment of a surface of a combustion chamber configuring component 10 formed from an Al alloy (Al purity of less than 99.0%) as a based material. A heat resistant adhesive is poured from between these heat-shielding films, and the heat resistant adhesive is heated and cured (an intermediate layer 22). Since the second heat-shielding film has low surface roughness Ra of an average of approximately 1.0 μm even in an unpolished state, polishing or the like for the film with an objective of smoothing after bonding of the second heat-shielding film can be omitted. Further, the heat-shielding film structure with a smoothed surface can be provided.

主权项

1. A method for forming a heat-shielding film, comprising:
a step of forming, on a surface of a component that is formed from an Al alloy with an Al purity of less than 99.0% as a base material and configures a combustion chamber of an internal combustion engine, a first heat-shielding film that has a lower heat conductivity and a lower heat capacity per unit volume than the base material, and has a porous structure; a step of producing a second heat-shielding film in which a porous alumina having a lower heat conductivity and a lower heat capacity per unit volume than the base material is formed on a surface, by anodizing treatment of Al foil with an Al purity equal to or higher than 99.0%; and a step of bonding the second heat-shielding film onto a surface of the first heat-shielding film.