Patent ID: 8637121

Claim:
A coating method through HVOF (high-velocity oxy fuel) spraying that comprises generating a combustion jet in a combustion chamber connected to one end of a barrel while controlling the temperature of the combustion jet by supply of an inert gas to the jet, feeding resin coating particles into the temperature-controlled combustion jet and leading the resin coating particles and the combustion jet to pass through the barrel, and spouting the resin coating particles through a spout port along with the combustion jet therethrough to thereby coat the substrate surface; wherein the length of the barrel, the temperature of the combustion jet and the physical properties of the resin coating particles are defined so as to satisfy both the following formulae (1) and (2): Numerical ⁢ ⁢ Formula ⁢ ⁢ 1 α × t r > 0.5 ( 1 ) α: thermal diffusion coefficient of the resin coating particles (m 2 /s), t: heating time of the resin coating particles in the barrel (s), r: radius of the resin coating particles (m), Numerical ⁢ ⁢ Formula ⁢ ⁢ 2 2.5 < Tav Tcp < 4.5 ( 2 ) Tav: average temperature of combustion jet in the barrel (° C.), Tcp: cohesion critical temperature of the resin coating particles (° C.),