Tailoring of surface topography for tribological purposes by controlled solid particle impacts

Abstract

This study proposes a novel, cost-efficient and productive technique, Tribo-blast, to tailor surface topography for tribological purposes. Tribo-blast is based on mask-less micro-blasting with spherical or angular particles and precisely controlled process parameters. This approach enables rapid fabrication of μ-pockets (5–50 μm) on free-form surfaces comprised of any material. A particle with a new 3D geometry—a spinning top—is proposed to match the shape and dimensions of the irregular craters formed in a metallic target by an angular particle at the normal impact angle. The results were experimentally validated on stainless steel 316L, Co–Cr–Mo and Ti–6Al–4V alloys. A simple analytical routine allowed for control over the size, area, concentration and homogeneity of randomly distributed angular and spherical μ-pockets with <20% error. The Abbott-Firestone curve and texture ratio can be tailored according to one's intended design. The bearing index of the tailored surface was more than two times that of the lapped surface, and fluid retention was increased one hundred times. Thus, this approach is considered to be more productive, cost-effective and simple than current micro-texturing techniques.