부산대학교 도서관

This work focuses on designing a pin-on-disk tribometer used to perform dry or lubricated wear tests according to the ASTM G99 standard method. The pin-on-disk device was developed using the engineering design process (EDP) based on steps related to problem understanding and solution construction stages. The tribometer is composed of an aluminum structure, a cylindrical test chamber, a disk rotation control system, load cells for measuring normal and tangential forces, a disk position sensor, and temperature sensors. A 7” touch screen was selected for the user interface (HMI). Wear tests to verify the reliability and usefulness of the tribometer were carried out on disk samples extracted from a hot-rolled AISI 1025 carbon-steel commercial bar, and performed with 2 and 10 N normal loads, linear sliding speeds of 0.27, 0.54, 0.82, 1.10, and 1.63 m/s, 500 m total sliding distance, using alumina ball as counterbody material. Dry and lubricated conditions were considered. Parameters as sliding distance, normal and frictional forces, and coefficient of friction (COF) were monitored during real-time tests. The procedure proved to be simple and safe. HMI enables the user to configure easily and quickly the test condition. A good agreement between the duplicate results was observed. During calibration, it was observed that the load cells and the servomotor presented standard deviations lower than 1.1 g and 0.2 r/min, respectively, and a percentage of uncertainty lower than 0.3. The LVDT showed a correlation regression coefficient of 0.999 between measured and output signals. During wear validation tests, all variations in results were less than 2% under the investigated conditions.