Method of formation or thermal spray coating

A method of formation of a thermal spray coating which forms a thermal spray coating on a coating-forming surface, characterized by comprising

• a step of coating big particle size powder classified from feedstock powder on the coating-forming surface as one layer and
• a thermal spraying step of thermally spraying small particle size powder classified from said feedstock powder on the coating-forming surface to fill in spaces between particles of the coated big particle size powder,
• the coating step and the thermal spraying step being repeatedly executed to obtain a coating of a desired thickness, and a ratio of presence of crystallite in the feedstock powder being raised to secure a high heat conductivity.

A method of formation of a thermal spray coating which forms a thermal spray coating on a coating-forming surface, characterized by comprising

• a thermal spraying step of thermally spraying feedstock powder on said coating-forming surface and a deposition and coating forming step of having the thermally sprayed feedstock powder deposit on said coating-forming surface and solidify to form a coating,
• in said deposition and coating forming step, when depositing the feedstock powder on said coating-forming surface by thermal spraying, it is deposited with 42% or more in a solid phase state so as to raise the ratio of the crystallite remaining in the feedstock powder to secure a high heat conductivity in forming the coating.