SPRAY COATING FILM, ENGINE HAVING THE SPRAY COATING FILM AND FILM-FORMING METHOD OF THE SPRAY COATING FILM

A spray coating film has a first spray coating film formed on a surface of an aluminum substrate and a second spray coating film formed on a surface of the first spray coating film. In the first spray coating film, an inorganic material with a layered crystalline structure is dispersed in a Ni-based alloy material, and an area ratio of the inorganic material is in a range from 40% to 80% relative to the sectional area of the first spray coating film. The second spray coating film is a porous film composed of ZrO 2 -SiO 2 based ceramic containing 30% to 50% by mass of SiO 2 , and the second spray coating film has an area ratio of pores of 30% to 80% relative to the sectional area of the second spray coating film.