APPLICATION OF THE FRACTAL GEOMETRY IN WEAR VOLUME CALCULATIONS AT MICRO SCALE

Abstract

This paper presents five different approaches in wear volume calculations when the contact loads are low, in micro scale. Experimental ball-on-flat tribological tests were realised, with flat samples of AlMg4.5Mn0.7 aluminium alloy in linear reciprocating contact with the ball made of aluminium oxide (Al2O3). Five different low loads were applied: 0.1 N, 0.25 N, 0.5 N, 0.75 N, and 1 N. Two methods of wear volume calculations can be considered as a common practice since they used geometrical approximation of the worn track, including optical images measurements and penetration depth parameter, as obtained by the nanotribometer. Three methods of wear volume calculations studied the possibility to use fractal theory. Fractal model wear was compared with wear volume calculated based on the wear track geometry. Results showed that fractal models are promising method in determination of the wear volumes under low loads. However further research is needed to define influential factors and how to define variables in the fractal model for the wear volume calculations.