Further study in friction, metallic transfer and wear debris of sliding surfaces

The variation in friction-coefficient with sliding distance for different sliding arrangements for both similar and dissimilar metals in a tri-pin-on-disk geometry is presented. It is shown that for similar metals sliding on each other there is a significant contribution to friction owing to severe ploughing. For dissimilar metals the friction coefficient is determined primarily by the way metal transfer occurs between sliding surfaces. While the pin-on-disk friction coefficient-sliding distance results agree in general with those of the crossed-cylinder tests (in which a static cylinder is loaded against a rotating cylinder), there are some distinct differences in the absolute magnitudes of the friction coefficients owing to variations in the ploughing intensity, metal transfer and embedding as affected by the two test geometries.