화학공학소재연구정보센터
Applied Surface Science, Vol.303, 187-195, 2014
DLC coating on stainless steel by pulsed methane discharge in repetitive plasma focus
Amorphous hydrogenated carbon (a-C:H)/diamond-like carbon (DLC) coatings have been achieved on AISI 304 stainless steel (SS) substrates by employing energetic ions emitted from a repetitive plasma focus operated in CH4 discharge. The Raman spectroscopy of the coatings exhibits the evolution of a-C: H/DLC coatings with clearly observed D and G peaks centered about 1320-1360 and 1560-1620 cm(-1) respectively. The diamond character of the coatings is influenced by the ion flux and repetition rate of the focus device. The repetitive discharge mode of plasma focus has led to the formation of a-C: H/DLC coatings in short duration of time. The coatings transform from a-C to a-C: H depending upon substrate angular position. X-ray diffraction (XRD) analysis confirms the formation of DLC coating owing to stress-induced restructuring in SS. The estimated crystallite size is found to be similar to 40-50 nm. Field emission scanning electron micrographs exhibit a layered granular surface morphology of the coatings. The Vickers surface hardness of the DLC coated SS samples has been significantly improved. (C) 2014 Elsevier B.V. All rights reserved.