Informace o publikaci
Spectroscopic study of plasma nitrocarburizing processes with an industrial-scale carbon active screen
| Autoři | |
|---|---|
| Rok publikování | 2020 |
| Druh | Článek v odborném periodiku |
| Časopis / Zdroj | Plasma Sources Science and Technology |
| Fakulta / Pracoviště MU | |
| Citace | |
| www | https://doi.org/10.1088/1361-6595/ab6e58 |
| Doi | http://dx.doi.org/10.1088/1361-6595/ab6e58 |
| Klíčová slova | plasma diagnostics; infrared absorption spectroscopy; pulsed dc discharge; plasma chemistry |
| Popis | The active screen plasma nitrocarburizing technology is an improvement of conventional plasma nitrocarburizing by providing a homogeneous temperature distribution within the workload and reducing soot formation. In this study, an industrial-scale active screen (AS) made of carbon-fibre-reinforced carbon serves as the cathode as well as the carbon source for the plasma-chemical processes taking place. The pulsed dc discharge was maintained at a few mbar of pressure while simultaneously being fed with a mixed gas flow of hydrogen and nitrogen ranging from 10 to 100 slh. Using in situ infrared laser absorption spectroscopy with lead salt tuneable diode lasers and external-cavity quantum cascade lasers, the temperatures and concentrations of HCN, NH3, CH4, C2H2, and CO have been monitored as a function of pressure and total gas flow. To simulate industrial treatment conditions the temperature of the sample workload in the centre of the reactor volume was kept at 773 K by varying the plasma power at the AS between 6 and 8.5 kW. The resulting spectroscopically measured temperatures in the plasma agreed well with this value. Concentrations of the various species ranged from 6 x 10(13) to 1 x 10(16) cm(-3) with HCN being the most abundant species. |