| 摘要 |
PURPOSE: A high density plasma ion nitriding method and an apparatus thereof are provided to efficiency of ion nitriding by increasing formation of active ions inducing the reactivity with the surface of a metallic material in plasma using a composite plasma discharging source having a + pulsed negative voltage. CONSTITUTION: The method comprises the processes of increasing a temperature of a metallic material; forming plasma surrounding the metallic material by impressing a rf power source and a pulsed negative voltage to the metallic material, and removing an oxide film layer that exists on the surface of the metallic material; increasing a temperature of the metallic material to a plasma nitriding temperature by infusing a gas for nitriding into a reaction furnace and heating the gas for nitriding after discharging gases inside the reaction furnace in the state that the impressed voltage is cut off, thereby making the inside of the reaction furnace in the vacuum state; forming and diffusing a nitride layer by impressing the rf power source and the pulsed negative voltage to the reaction furnace after increasing the temperature of the reaction furnace; and cooling the metallic material after the formation and diffusion of the nitride layer. The apparatus comprises a reaction furnace (10), a metallic material supporting means, a vacuum pump (30), a means for increasing a temperature of the inside of the reaction furnace, a gas infusion part (50) infusing a gas for cooling the metallic material (1) into the reaction furnace, a pulsed negative voltage generator (60), and a rf plasma generating means.
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