Influence of subsurface plastic deformation on the running-in behavior of a hypoeutectic AlSi alloy

The present publication elaborates on the influence of the initial microstructure preset by machining on the friction and wear behavior of a hypoeutectic AlSi9Cu3 alloy. During running-in the subsurface microstructure of tribological contacts is subjected to shear followed by plastic deformation. Aluminum disks were tested with a steel pin on a pin-on-disk tribometer with focus on running-in and sensitivity phenomena. The systems were operated in the ultra-low wear regime. Wear was measured continuously using Radionuclide Technique. The microstructure of the samples was characterized by nanoindentation, x-ray photoelectron spectroscopy and focused ion beam microscopy. The visualization of subsurface shear by markers in the disks showed a significant correlation of subsurface deformation and wear. With the experiments the relationship between machining and tribological behavior was analyzed and ways to optimize tribological systems were shown. (C) 2016 Elsevier Ltd. All rights reserved.