Tribological characterization of different geometries generated with laser surface texturing for tooling applications

Many techniques have been used to improve the tribo-characteristics of surfaces in contact and relative movement under applied load: coatings, heat treatments, lubricants, additives, and laser surface texturing (LST). Regarding LST, researchers have worked with different applications, geometries, pressure, and lubricants having positive results in enhancing the tribological properties of coefficient of friction (COF) and wear. Circles, triangles and lines are the micro cavities geometries with the most documented studies and positive results. In this work, a comparative study of these three geometries, as well as the square, crosshatch and “S” shape was performed. A T-05 conformal contact block-on-ring tribotester with reciprocating movement was used to measure COF and wear values according to ASTM G77 standard applying three different pressures and a PAO4 lubricant fluid. The results indicate that geometries behave differently according to the applied pressure. For low pressures, textured circles showed the best performance with a reduction of COF and wear of 38% and 57% respectively. For high pressures the “S” shape geometry had a reduction of COF and wear of 78% and 54%, respectively. Finally, a comparative study of the tribo-characteristics for possible applications for tools for common manufacturing processes is presented.