Investigation of dose uniformity on the inner races of bearings treated byplasma immersion ion implantation

Plasma immersion ion implantation (PIII) is an effective technique for the surface modification of industrial components possessing an irregular shape . We have recently used PIII to treat a real industrial ball bearing to enh ance the surface properties of the race surface on which the balls roll. Th e implantation dose uniformity along the groove is assessed using theoretic al simulation and experiments. The two sets of results agree very well, sho wing larger doses near the center. However, the highest dose is not observe d at the bottom or center of the groove, but rather offset toward the side close to the sample platen when the bearing is placed horizontally. The min imum dose is observed near the edge or corner of the groove and our model i ndicates that it is due to the more glancing ion incidence as a result of t he evolution of the ion sheath near the corner. The dose nonuniformity alon g the groove surface is about 40% based on our experimental data. (C) 1999 American Institute of Physics. [S0021-8979(99)06013-2].