ABSTRACT
Surface texturing as a means for enhancing tribological properties of mechanical components is well known for many years. Perhaps the most familiar and the earliest commercial application of surface texturing is that of cylinder liner honing. For many years, the landing zone of thin-Ÿlm magnetic storage disks was laser textured, and surface texturing is also being considered as a means for overcoming adhesion and stiction in micro-electro mechanical systems (MEMS) devices. Fundamental research work on various forms and shapes of surface texturing for tribological applications is carried out worldwide and various texturing techniques are employed in these studies, including abrasive blasting, ultrasonic machining, electrical discharge machining, ion beam texturing, vibrorolling, various etching techniques, and laser texturing. Of all the practical microsurface patterning methods, it seems that laser surface texturing (LST) oµers the most promising concept. ˜is is because the laser is extremely fast and allows short processing times; it is clean to the environment and provides excellent control of the shape and size of the texture, which allows realization of optimum designs. By controlling energy density, the laser can safely process hardened steels, ceramics, and polymers as well as crystalline structures. Indeed, LST is gaining more and more attention in the tribology community as is evident from the growing number of publications on this subject. LST produces a very large number of microdimples on the surface (see Figure 53.1), and each of these microdimples can serve either as a microhydrodynamic bearing in cases of full or mixed lubrication, a microreservoir for lubricant in cases of starved lubrication conditions, or a microtrap for wear debris in either lubricated or dry sliding.
