Internal combustion engine

Abstract

The present embodiment relates to an internal combustion engine having an anodic oxide coating formed on at least a portion of an aluminum-based wall surface facing a combustion chamber. The anodic oxide coating has a plurality of nanopores extending substantially in the thickness direction of the anodic oxide coating, a first micropore extending from the surface toward the inside of the anodic oxide coating, and a second micropore present in the inside of the anodic oxide coating; the surface opening diameter of the nanopores is 0 nm or larger and smaller than 30 nm; the inside diameter of the nanopores is larger than the surface opening diameter; the film thickness of the anodic oxide coating is 15 μm or larger and 130 μm or smaller; and the porosity of the anodic oxide coating is 23% or more.

Dependencies are inferred from the claim text.