Structural member
A structural member 10 has a base material 100 and a protective film 200 covering the surface S 1 of the base material 100 . When a section obtained by cutting the base material 100 perpendicularly to the surface S 1 thereof is defined as a cross-section, a shape of a line corresponding to the surface S 1 of the base material 100 in the cross-section is defined as a surface shape, and Fourier transformation is performed on a function representing the surface shape, and the transformed function is drawn as a graph with wavelength (μm) on a horizontal axis, an average slope of the graph in a range where the wavelength is 30 μm or less is 0.0050 or less.
1 . A structural member comprising:
a base material, and
a protective film covering a surface of the base material,
wherein,
when a section obtained by cutting the base material perpendicularly to the surface thereof is defined as a cross-section,
a shape of a line corresponding to the surface of the base material in the cross-section is defined as a surface shape, and
Fourier transformation is performed on a function representing the surface shape, and the transformed function is drawn as a graph with wavelength (μm) on a horizontal axis,
an average slope of the graph in a range where the wavelength is 30 μm or less is 0.0050 or less.
2 . The structural member according to claim 1 , wherein a surface roughness of the base material is a roughness with an arithmetic average roughness Ra of more than 0.15 μm.
3 . The structural member according to claim 1 , wherein the base material is formed of a material containing aluminum oxide.
4 . The structural member according to claim 1 , wherein the protective film is formed of a material containing yttrium oxide.
5 . The structural member according to claim 1 , wherein the protective film is formed by an aerosol deposition method.