Modification of silicon nitride ceramics with high intensity pulsed ion beams

Sintered Si3N4 ceramics were irradiated with intense plasma pulses containing metal (Ti, Ni) and nitrogen ions in various proportion. The energy density of the pulse was 6.5 J cm−2 with a duration in the μs range. The samples were characterised by Rutherford backscattering, Auger electron spectroscopy, scanning electron microscopy and by tribological tests. For Ti deposition the top layer is relatively uniform and consists of TiNx, titanium silicide and possibly metallic Ti. For Ni nodules composed mainly from nickel silicide were observed with an additional 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.