Tribological Performance of Textured Surfaces Created by Modulation-Assisted Machining

Methods for scalable surface texturing continue to receive significant attention due to the importance of microtextured surfaces toward improving friction, wear, and lubrication ability of mechanical devices. Controlled textures on surfaces act as fluid reservoirs and receptacles for debris and wear particles, reducing friction and wear of mating components. There are numerous fabrication techniques that can be used to create microsized depressions on surfaces, but each has limitations in terms of control and scalability. In the present study, modulation-assisted machining (MAM) is demonstrated as a viable approach to produce such textures, offering a potentially cost-effective approach for scalable production of these features on component surfaces. In this work, the wear behavior of several textured surfaces created by MAM was studied using a ball-on-flat reciprocating tribometer. Textured and untextured alloy 360 brass disks were mated with stainless steel AISI 440C balls under lubricated conditions and variable sliding distance. The textured surfaces exhibited noticeably reduced wear under the longer sliding distances and the tribological performance of the surfaces depended on the size of the microdimples. Wear mechanisms are elucidated from the optical microscopy, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) observations and the implications for using such surfaces in practice are briefly discussed.