MODIFICATION OF SILICON-NITRIDE CERAMICS WITH HIGH-INTENSITY PULSED ION-BEAMS

Sintered Si3N4 ceramics were irradiated with intense plasma pulses con taining metal (Ti, Ni) and nitrogen ions in various proportion. The en ergy density of the pulse was 6.5 J cm(-2) with a duration in the mu s range. The samples were characterised by Rutherford backscattering, A uger electron spectroscopy, scanning electron microscopy and by tribol ogical tests. For Ti deposition the top layer is relatively uniform an d consists of TiNx, titanium silicide and possibly metallic Ti. For Ni nodules composed mainly from nickel silicide were observed with an ad ditional thin surface layer containing nickel silicide and metallic Ni . Both for Ti and Ni, the plasma irradiation results in a considerable improvement of the wear resistance. (C) 1998 Elsevier Science S.A. Al l rights reserved.