Large-area surface treatment by ion beam technique

A large-area ion beam deposition system has been used extensively for depos iting diamond-like carbon films by a direct ion-beam process. An ultra high vacuum ion beam system, consisting of a 20-cm diameter RF excited (13.56 M Hz) ion gun and a four-axis substrate scanner, has been used to modify larg e surfaces (up to 1000 cm(2)) of various materials, including 304 and 316 s tainless steel, 440C and M50 steels, aluminum, aluminum alloys, Ti-6Al-4V, silicon carbide, silicon nitride, polycarbonates, infrared windows and poly crystalline diamond, by depositing varying chemical compositions of diamond -like carbon films. The influence of ion energy, RF power, and gas composit ion (H-2/CH4, Ar/CH4, O-2/H-2/CH4 and N-2/H-2/CH4), on the diamond-like car bon characteristics has been investigated. Particular attention was focused on the adhesion, environmental effects, coefficient of friction and wear f actors of the diamond-like carbon films on the various substrates under spa ce-like environments. A quadrupole mass spectrometer and a total ion-curren t measuring device have been utilized to monitor the ion compositions of th e gas mixtures of CH4/H-2, CH4/Ar, CH4/H-2/O-2 and CH4/H-2/N-2 during the d eposition process for quality control and process optimization. (C) 2001 El sevier Science B.V. All rights reserved.