Friction in Scratching without Metal Transfer

Abstract

Scratch friction has been investigated in which the metallic transfer could be neglected. The scratch tests on some metal surfaces were carried out using conical and spherical sliders of hard materials. the geometric shapes of the scratched groove were examined in detail and a comparison of the friction force with these was made. Experiments showed obviously that there is a good correlation between the friction force and the groove shape. The coefficient of friction on the slider face was found to decrease with a decreasing groove depth under an influence of the surface films on the softer metal. An analysis to determine the friction force quantitatively has been developed. This theory specially includes an effect of the height of front ridge formed in front of the slider during scratching on the friction force. The results of the scratch tests show that the theory is very useful for the derivation of the friction force.