Study on the Influence and Mechanism of Different Micro-Texture Parameters on the Tribological Properties of Brass Under Multi-Working Conditions

Aiming at the problems of high friction coefficient, severe wear, and unsatisfactory service life and operational reliability of brass under complex working conditions such as dry friction, wet friction, and oil-lubricated friction, H62 brass was taken as the research object to improve its friction and wear properties via surface micro-texture technology. This study systematically compares the tribological performance of three typical geometric micro-textures under three coupled working conditions for the first time. Circular, rectangular, and hexagonal micro-dimple textures were fabricated on the brass surface using ultraviolet laser micromachining. The control variable method was adopted to systematically investigate the effects of micro-texture parameters including shape, size, and area density on the friction and wear properties of brass under the three typical working conditions, combined with reciprocating friction and wear tests and ultra-depth-of-field microscope characterization. The results show that the hexagonal micro-dimple texture (200 μm in size, 10% in area density) exhibits the optimal friction-reducing and anti-wear performance. Compared with the smooth surface, the friction coefficient decreases from 0.51 to 0.43, and the wear rate of the GCr15 steel ball is reduced by 2.8% under dry friction; the friction coefficient decreases from 0.43 to 0.12 with an 11.8% reduction in wear rate under wet friction; and the friction coefficient decreases from 0.29 to 0.24 with an 8.3% reduction in wear rate under oil lubrication. Relative to dry friction, the wear rates are further reduced by 16.7% and 8.3% under wet friction and oil lubrication, respectively. Different from most existing studies that only focus on a single texture type or a single friction condition, this paper systematically reveals the coupling regulation mechanism between texture parameters and working conditions, clarifies the optimal micro-texture design strategy for multi-working conditions, verifies that hexagonal micro-textures can significantly improve the wear resistance of brass, and provides technical support for the surface optimization design of brass workpieces under complex working conditions.