Influence of the magnetic field on DLC coatings grown by plasma immersion ion implantation and deposition in crossed fields

• The magnetic mirror geometry allows the better confinement of the plasma.
• Good tribological properties were measured in DLC films deposited in crossed fields.
• The deposition rate was significantly increased when using the magnetic field.
• PIII&D in crossed fields was an effective system to synthesize DLC films.

Because of the problem of film peeling, it is generally difficult to obtain thick and well adherent diamond-like carbon (DLC) coatings on metallic substrates with good tribological properties. In this work, we propose to apply a plasma immersion ion implantation and deposition (PIII&D) process in magnetic bottle configuration using high voltage glow discharge in order to deposit DLC films directly over 304 stainless steel (SS) alloy. In such configuration, two couples of coils wound outside the vacuum chamber are used to produce region of low magnetic field for plasma confinement (~ 60 G at the center axis). DLC coatings are characterized by Raman spectroscopy, scanning electron microscopy (SEM) and also morphologically by means of atomic force microscopy (AFM). Tribological behavior is investigated using a pin-on-disk tribometer, and after that, the scars are evaluated by means of SEM and Wyko NT1100 optical profiler. PIII&D experiments in crossed fields have been demonstrated to be an effective system to synthesize DLC films with good adhesion, excellent resistance against wear as well as good dry lubricant surfaces.