On the Coefficient of Friction under High Pressures (2nd Report)

Abstract

In the preceding paper the author obtained experimentally the values of coefficient of dry friction for five metallic materials under high pressures and they decrease generally with the increase of contact-pressure. In this paper the author obtains the same tendency for copper. Furthermore, the values under low pressures are measured to compare with them under high pressures. Then factors to have an effect on the values under low pressures are researched and recognized that roughness of contact surface and hardness are essentialy effective to them. On the relation between the values and roughness, taking the values as ordinate and roughness as abscissa, the graph for each combination of six materials becomes a smooth curve respectively and the values suddenly increase with increase of roughness where be about 10^-3mm. And the values decrease with increase of hardness number for every combination of materials and roughness.