abstract For a long time, scientists have been exploring ways to control friction and abrasion. Changing surface texture through creating grooves and dimples is one of those ways. In this research, the effect of creating micro-dimples using metal forming on friction and abrasion was studied for St-37 steel. The effect of surface texture parameters including shape and size of dimples, surface pattern, dimple density and ratio of depth to diameter was first introduced. Then, different techniques for creating dimples on the surface such as mechanical, laser, chemical and abrasive jet machining was explained. The advantages of mechanical methods use often include relatively low cost and short time for generation of dimples. In this word, a new forming tool based on mechanical indentation and a proper mechanism for tool holding was designed. The tool and workpiece were mounted on a CNC-milling machine and square-shaped dimples with 6% density were created on the workpiece surface. A pneumatic cylinder was used to press the tool into the workpiece. The dimensions and profiles of dimples were measured using an optical microscope and a surface roughnes measuring machine, respectively. The results showed that the proposed mechanism was able to create dimples of approximately 200 µm. In order to eva‎luate the effect of generated dimples on friction and abrasion, pin-on-disk test were carried out on both the textured and untextured surfaces. Given that the available pin-on-disk tribometer at Isfahan University of Technology uses spherical end pins, a self-adjusting mechanism was designed to replace the spherical end pin by a flat end pin. The tests were conducted at sliding speed of 0.1 and 0.2 m/s and applied normal forces of 25 and 50 N. The tests were stopped at a sliding distance of 250 m and weight loss was eva‎luated as a measure of abrasion. The results showed 5-19% reduction in friction and 22-32% decrease in abrasion for textured surfaces in the absence of lubricant. Moreover, in the presence of lubricating oil, the textured surfaces showed 4.5-24% reduction in friction and 30-50% decrease in abrasion. An investigation of dimple profiles was also showed that the peaks formed around the surface of dimples had a negative impact on the tribological behavior of the surfaces. Therefore, polishing the workpiece surface after forming dimple is required to improve the tribological effects of surface texturing using the proposed method. Keywords: Surface texture, Micro-dimple, Metal forming, Abrasion, Friction

صالح اكبرزاده

صالح اكبرزاده

صالح اكبرزاده , محمدرضا فروزان