Applications of Polystyrene Particles in Conjunction with Shadow Casting to the Study of Polished Metallic Surfaces

Abstract

This is a report of a study of polished metallic surfaces with the electron microscope. Negative collodion replicas were used in this experiment. The determination of width and depth of scratches by means of polystyrene particles and shadow casting is briefly discussed. Experimental results are summarized as follows: The effect of polishing pressure applied is that greater pressure gives wider and deeper scratches and also causes severer flow and distortion of metal near the scratch. In comparison with unidirectional polishing, multidirectional polishing gives better surface finish with fewer scratches: these scratches run in all directions and have a wide range of width and depth; mostly they are shallower and narrower than would be the case with unidirectional polishing. The average widths and depths of scratches on surfaces polished with various conditions are also given here. Harder abrasives give a higher depth/width ratio.