| 摘要 |
PURPOSE:To oscillate a thermal spraying body and to form a dense thermally sprayed layer by winding an excitation coil around the tungsten electrode of a plasma spraying burner and forming a strong alternating magnetic field in the plasma flow thereby so as to act on the thermally sprayed coating layer. CONSTITUTION:A negative voltage is impressed to the negative electrode of the tungsten electrode 1 and a positive voltage is impressed to the positive electrode 2a of a nozzle 2 and a work piece 10 to generate an arc discharge between the tip end of the electrode 1 and the nozzle 2. A working gas is forcibly fed through an inlet 3c and is electrolytically dissociated by the arc discharge heat to form the plasma flow 20 which is ejected from the nozzle 3 so as to be directed toward the work piece 10. Thermally spraying powder is supplied through a supply port 5 to the high-temp. Gas of the plasma flow 20 and is intruded therein, by which the powder is melted and is bombarded against the work piece 10. When alternating current is passed to the excitation coil 6, a strong magnetic field 30 is generated along the flow 20 and the thermal spraying body is oscillated by electromagnetic force. The cavity is thus crushed and the intrusion of the hazordous oxide is prevented. The defectless and dense thermally sprayed layer having high quality is thus formed. |
