Plasma immersion ion implantation into inner and outer races of industrial bearings

Plasma immersion ion implantation (PIII) is a proven surface treatment technique and can be used to prolong the working lifetime of industrial components. However, the lateral implantation dose uniformity may not be very good, particularly for samples with an irregular shape. In this work, we focus on the PIII treatment of the inner and outer races of industrial bearings. The sheath expansion around the inner and outer races is simulated using a time-dependent, two-dimensional fluid model. The angular and spatial distributions of the incident ions along both the exterior and interior groove surfaces are derived. It is found that the ion dose is the highest on the bottom or center of the groove for both the inner and outer races. The minimum ion dose is near the corner of the groove as the ions impinge at a more glancing incident angle as a result of the ion-matrix sheath evolution. Compared with the exterior groove, the interior groove receives a smaller ion dose in the same implantation time. Our results also indicate that the spatial ion dose uniformity can be improved by reducing the implantation pulse width.