Dry sliding wear behavior of AM60B magnesium alloy

Wear resistance of as-cast AM60B magnesium alloy was tested using pin-on-disc configuration with carbon steel discs as counterpart on dry-sliding wear conditions. Wear rates and friction coefficient were measured in a sliding velocity range of 0.1-1 m s(-1) using different normal force range 10-250 N. Analyses of the worn surfaces were carried out using scanning electron microscope (SEM) and energy dispersive X-Ray spectrometer (EDS) to define the wear mechanism for each tested condition. The main wear mechanisms observed were adhesion, delamination, oxidation, and plastic and severe plastic deformation. Specific testing parameters led to the formation of a mechanically mixing layer (MML) characterized by SEM, EDS and microhardness tests. Oxidation mechanism dominated at the lowest sliding velocities and applied loads. Increasing load and speed led to combination of oxidation, delamination and adhesion. At 40 N of load an abrupt change in wear mechanism from delamination to plastic deformation was observed, clearly associated with a mild to severe wear transition. At the highest applied load and sliding velocity tested severe plastic deformation was the main wear mechanism. A wear mechanism map that allows identifying the main wear mechanism for each wear conditions has been developed. (C) 2012 Elsevier B.V. All rights reserved.