METHOD FOR FORMING THERMAL SPLAY COATING

PROBLEM TO BE SOLVED: To provide a method for forming a thermal splay coating by which, when raw material powder is thermally sprayed on an objective face for film formation, the film formation is performed in such a manner that, in a liquid phase part contributing to the sticking of the raw material powder to the objective face for film formation, the ratio is reduced and is left, and the ratio of a solid phase part is increased, thus high thermal conductivity is secured.SOLUTION: When raw material powder P is classified, and is thermally sprayed on the objective face for film formation, by alternately thermal-spraying large-sized powder Pb as a solid phase and perfectly melted small-sized powder Ps upon its arrival at the objective face for film formation, thermal spraying timing is controlled in such a manner that the large-sized powder Pb arrives at the objective face for film formation before the small-sized grain powder Ps is solidified. The ceramic film 10 to be deposited is solidified as a solid phase part 10Sp (about 50 to 90%, desirably 70 to 80%) and a liquid phase part 10Lp (about 10 to 50%, desirably 20 to 30%) with the small-sized powder Ps in a liquid phase state (melted state) as a binder.