Applications of Numerical Parameters and Filtration

This chapter discusses the applications of 3-D characterization techniques, which is the area of biotechnical surfaces. Several case studies are discussed; first case study focuses on the development of surface topography during wear of matt finish femoral stems. From this study of matt finish femoral stems it is apparent that the wear could be classified as fretting in terms of the magnitude of micro-movements between the stem and the bone cement, due to the stress reversals of the limbs. Another case study discusses the wear of ultra high molecular weight polyethylene pins on TiN coated plates for use in total knee implants. It demonstrates that the origin of the high wear of the surface that consisted of shallow pits is due to the presence of the large peaks in the surface topography. The chapter concludes that 3-D surface metrology has a significant advantage to engineers and tribologists in gaining a deeper understanding of surface functionality.