Modification of metal surface by direct ion implantation from a nitrogen plasma

Nitrogen ions were implanted into an aluminum alloy (Al-7Si) for casting mold materials by plasma-based ion implantation. The AES analysis of ion-implanted Al-7Si indicated that the depth profile of implanted nitrogen ions was approximated by a Gaussian, and that the AlN layer was formed by nitrogen-ion-implantation. The tribological test showed the reduction of friction coefficient from 0.60 to 0.12 and the improvement of wear resistance by nitrogen-ion implantation. The oxide resistance of the nitrogen-implanted sample was also enhanced.