Study on synergistic friction between surface micro-texture and hot-pressing filling coal-to-oil soot solid lubricant

Abstract

To study the combination of triangle micro-texture (TM) and coal-to-oil soot (CS) solid lubricants to improve the tribological properties of steel balls and disc surface, three filling processes (hot pressing, mechanical pressing, and alcohol coating) were used to prepare CS composite lubricating film on TM surface (TM-CS). The tribological behavior of CS was examined across various experimental parameters using the WTM-2E controlled atmosphere micro-friction and wear tester. The structure and morphology of CS were scrutinized with high-resolution transmission electron microscopy. The tribological mechanisms were involved by X-ray photoelectron spectroscopy and scanning electron microscopy. The results reveal that the hot press filling is the most effective method, which can achieve a 97 % filling rate. The optimal tribological performance is observed at a speed of 900 rpm and a load of 2.5 N. Under this condition, the TM-CS surface reduces by 75 % in the average friction coefficient (AFC) and 88 % in the average wear scar diameter (AWSD) compared to the TM surface. The analysis of the friction mechanisms indicates a substantial synergistic effect between the TM surface and the CS solid lubricant. This synergy is significantly potentiated by the electrostatic adsorption phenomenon and the impact of airflow at high rotational speeds, which play a pivotal supportive role in enhancing tribological performance.