PURPOSE: To prevent adhering of a thermal spraying material to the inner wall of a thermal spraying torch nozzle, and generation of dripping during thermal spraying work.
CONSTITUTION: An arc 3 is generated between a positive electrode 1 comprising copper, for example, and a negative electrode 2 of whose front end comprises tungsten, for example, and actuation gas 4 supplied from the back is heated by this to be jetted as high temperature plasma jet 5 from a nozzle part 1a of the positive electrode 1. A part of the nozzle part 1a from a flame coating material carrying hole 8 to a nozzle opening is formed of ceramic material 1b, so an inner wall surface of the nozzle part 1a can be kept at a relatively high temperature. Even when run of flame coating material 7 down along a wall surface of the nozzle part 1a of the positive electrode 1 is generated, it is not cooled below the melting point due to contact with the wall surface of the nozzle part 1a, so it is hardly solidified inside the nozzle. A thermal spray film itself is harder to adhere to ceramic than to metal, so its stay inside the nozzle is extremely reduced.
SUZUKI SHIGEO
ASABE MITSUO
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