Characterization of the surface topography of arc-treated aluminum alloys by fractal geometry

An atmospheric pressure plasma arc discharge creates a complex structure on an aluminum (Al) surface that is a challenging task to characterize by conventional techniques. The solution could be in applying the principles of fractal geometry to characterize the arc-treated aluminum surface while studying profiles obtained by an optical profilometer and SEM (scanning electron microscope) images. The fractal dimension (FD) is determined along with the other conventional surface characteristic parameters (Ra, Rq, Sa, and Sq). The influence of the arc process parameters such as the arc current (I) and plasma torch velocity (v) on the fractal dimension is explored.