Improvement of surface properties of polymers by ion implantation

The surface properties of PC, PE-HD, and PMMA after ion implantation were investigated. It resulted in an increase of microhardness, which strongly depends on the implanted ion dose. The microhardness grows with the implanted dose. A dose of 1 x 10 high16 cm high-2 yielded the highest increase of microhardness without any saturation. The wear behavior for the three materials tested was quite different. PC showed a high wear reduction with increasing dose. The wear behavior between unimplanted and impanted PC with doses of 1 x 10 high15 and 1 x 10 high16 cm high-2 was totally changed. For PE-HD, we found a drastically reduced wear, nearly "zero wear", for doses of 1 x 10 high14 cm high-2 and above (energy: 200 keV). For PMMA, the wear was increased after ion implantation owing to abrasive wear caused by hard particles of the destroyed surface layer in the wear track. In all cases, there was no dependence of the changed properties on the ion species. The wear reduction was correlated wit h a reduction of the friction coefficient. RBS measurements indicated a higher carbonization at the surface and higher carbonization for increasing energies probably owing to the increased electronic collision. Wear investigations for PE-HD confirm these results.