12:15 PM - 12:30 PM
△ [22a-W611-13] Atmospheric Pressure Plasma Nitriding using Dielectric Barrier Discharge
Keywords:nitriding,DBD
Nitriding treatment has been widely used in industry in order to improve the mechanical properties of the metallic molds/dies and the automobile components made of steels. As an unique technology, we have researched atmospheric pressure plasma nitriding without vacuum system. We already succeeded in local nitriding of steel and titanium by pulsed-arc (PA) atmospheric-pressure plasma jet. On the other hand, plasma nitriding using dielectric barrier discharge (DBD) with NH3 gas is reported by Yan et al. DBD has a potential to treat large area than PA plasma. However, environmental load of NH3 is high. Therefore, we conducted principle demonstration on nitriding treatment using DBD with N2/H2/Ar gas mixture instead of NH3 gas.
As a sample, we used hot work tool steel JIS SKD61. The discharge gap and barrier (alumina) thickness are 1 and 2.5 mm, respectively. The operating gas is N2/H2/Ar gas mixture. AC high voltage (6 kV, 11 kHz) is applied to the sample and the other electrode is grounded. The treatment time is 2 h. The treatment temperature is raised up to ca. 500ºC by an external heater.
As a result, we succeeded in forming nitrided layer on the sample surface using DBD with N2/H2/Ar gas mixture. The surface hardness was increased from 550 to more than 1000 Hv.
As a sample, we used hot work tool steel JIS SKD61. The discharge gap and barrier (alumina) thickness are 1 and 2.5 mm, respectively. The operating gas is N2/H2/Ar gas mixture. AC high voltage (6 kV, 11 kHz) is applied to the sample and the other electrode is grounded. The treatment time is 2 h. The treatment temperature is raised up to ca. 500ºC by an external heater.
As a result, we succeeded in forming nitrided layer on the sample surface using DBD with N2/H2/Ar gas mixture. The surface hardness was increased from 550 to more than 1000 Hv.