Publication details
Plasma chemical studies of nitrocarburizing with an active screen made of carbon in laboratory and industrial scale reactors
| Authors | |
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| Year of publication | 2019 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Active screen plasma nitrocarburizing (ASPNC) is an advanced technology for the surface treatment of steel components. Compared with conventional methods it reduces sooth formation and the risk of cementite precipitation in the compound layer of the treated materials. A new approach for this method is the usage of an active screen made of solid carbon as a substitute for carbon-containing gas supplements. In the laboratory-scaled plasma nitriding monitoring reactor (PLANIMOR), see Fig.1, low-pressure pulsed DC N2-H2 plasmas have been studied by infrared absorption spectroscopy (IRLAS) techniques. Similar studies have been conducted at an industrial-scaled plasma nitrocarburizing reactor in Freiberg, see Fig.2. Tunable diode lasers (TDL) and external-cavity quantum cascade lasers (ECQCL) were used as radiation sources to monitor the concentrations of ten stable species, CH4, NH3, H2O, C2H2, HCN, C2H4, CO, C2H6, CO2, C2N2, and of the CH3 radical. In dependence on plasma power at the active screen, the gas pressure and flow, and the feed gas composition, the concentrations ranged between 1012 and 1016 cm-3 . The gas and rotational temperature of select species have been determined using Boltzmann plot and line profile analysis. A detailed analysis of the surface microstructure of samples treated in the industrial-scaled reactor in plasma chemical monitored atmosphere has been performed. This included glow discharge optical emission spectroscopy (GDOES), optical microscopy, micro hardness measurements, as well as X-ray diffraction analysis. |