Tribological effect of micro surface irregularities (surface porosity and texture) on lubricated sliding/rolling tests

Abstract

This research project aims to evaluate the tribological influence of micro surface irregularities (pores and laser texture) in carbon steel during lubricated sliding/rolling tests. These materials have a potential application for manufacturing sintered gears. The sintered material will be produced by the conventional technique due to samples dimensions. Specimens' characterization will be carried out by relative density (Archimedes method), microstructural analysis (Optical Microscopy LOM, Scanning Electron Microscopy - SEM, semi-quantitative chemical analysis - EDS-SEM), X-ray diffraction and hardness measurements. Surface topography and roughness parameters will be measured using 3D optical profiling system. Sliding/rolling lubricated tests will be performed in non-compliant point contact - ball on disk. A Mini Traction Machine MTM will be used to vary the Slide-to-Roll Ratio SRR. The ball and the disk are driven by two different motors, so it allows the possibility of a great variation of SRR values. The effect of micro surface irregularities (texture and porosity) morphology, features, orientation and size will be studied in different lubrication regimes and SRR values. The counter body material is made of the chromium steel AISI 52100. A textured material will be used as a reference for benchmark tests to be compared with sintered steel in order to understand if the performance of sintered material can match those obtained with ad-hoc and more expensive solutions. This texture is applied using laser texturing and will be conducted at the IPEN or in a private company. These results will be used to validate theoretical models being produced as part of this project, whose main outcome is the development of an analytical or phenomenological model that contributes to understanding how micro-irregularities (texture and porosity) could change lubricant conditions and increase the efficiency of mechanical systems. (AU)