Tribological Study of Textured Surfaces created using Modulation Assisted Machining for Steel-Aluminum Contact

One of the major problems the world faces currently is the loss of energy and mechanical efficiency in machine components due to friction. Also, surface damage due to friction and resulting part repairs and replacement has cost US industries a reportedly US $280 billion/year. Recent work in the field of surface modification and texturing has shown, that, artificially created micro textures significantly reduce friction and wear of lubricated surfaces. Micro-scale artificial textures in friction paring contacts acts as lubricant reservoirs and wear particle receptacles to boost hydrodynamic pressure, which influences the lubrication regimes. In this study, the Stribeck curve of untextured and textured surfaces created using vibration/modulation-assisted-machining are determined experimentally and numerically. Aluminum 6061-T6 disk mated with a high speed steel pin are studied in a pin-on-disk tribometer configuration for varying speeds and texture depths. Results show that at low speeds, textured surfaces accelerate the appearance of elasto-hydrodynamic lubrication regime. A 56% reduction in coefficient of friction was observed for 7 µm at 60 Hz, with a 90% wear reduction for similar conditions as compared to untextured surfaces. A numerical model based on the average Reynolds flow equation yielded similar results