THE INFLUENCE OF PROCESS PARAMETERS ON THE PROPERTIES OF CHROMIUM-NITROGEN COATING BY DC REACTIVE SPUTTERING AT ROOM-TEMPERATURE

A chromium-nitrogen coating (10 mu m thick) was successfully applied to the contact surfaces of line matrix printer heads by d.c. reactive sputtering for the prevention of mechanical degradation caused by impact wear. The coating was deposited at room temperature where the substrate was maintained below 93 degrees C (200 degrees F) during the sputtering. A microgrit blasting process was used for the surface preparation. The effect of chamber pressure, bias voltage and reactive gas flow rate on the resulting coating properties was studied. The hardness, morphology and adhesion of the coatings were examined. With the optimal settings of the process parameters, the chromium-nitrogen coating can withstand more than 5000 h of continuous printing without any evidence of degradation.