Nano-structure and tribological properties of B+ and Ti+ co-implanted silicon nitride

Silicon nitride ceramics have been co-implanted with boron and titanium ions at a fluence of 2 × 1017 ions/cm2 and an energy of 200 keV. TEM results indicated that the boron and titanium-implanted layers were amorphized separately and titanium nitride nano-crystallites were formed in the titanium-implanted layer. XPS results indicated that the implantation profile varied a little depending on the ion implantation sequence of boron and titanium ions, with the boron implantation peak shifting to a shallower position when implanted after Ti+-implantation. Wear tests of these ion-implanted materials were carried out using a block-on-ring wear tester under non-lubricated conditions against commercially available silicon nitride materials. The specific wear rate was reduced by ion implantation and showed that the specific wear rate of Ti+-implanted sample was the lowest, followed by B+, Ti+ co-implanted and B+-implanted samples.