| 摘要 |
<p>PURPOSE:To form a thermally-sprayed film having high density and high strength on the surface of a base material by providing a bored baffle plate between a nozzle and the surface of the base material, and making both the central axis of this bore and the central axis of a plasma jet nearly coaxial. CONSTITUTION:A baffle plate 4 having a bore is provided between the nozzle 2 of a plasma gun 1 and a bass material 8 in a reduced pressure tank 10, and both the central axis of this bore are the central axis of a plasma jet 5 are made nearly coaxial. In this state, the inside of the reduced pressure tank 10 is sufficiently exhausted and thereafter gaseous Ar is introduced to hold the pressure at about 20-100mmHg and powder is sent to the plasma gun 1 from a powder feeder 3. The powder 6 introduced into the high-temp. region of the center of the plasma jet 5 is sufficiently heated, melted and laminated on the base material 8 to form a thermally-sprayed film 9 but the powder 7 which is deviated from the center and insufficiently heated is laminated on the baffle plate 4 and substantially excepted from the thermally-sprayed film 9. Thereby only the sufficiently melted powder 6 is laminated on the surface of the base material and the thermally-sprayed film 9 having high density and high strength is formed.</p> |
