On The Lay Selection With Determined Surface Frictional Properties

Abstract

The paper deals with a geometrical model of the wear mechanism initiation according to the macroroughness tops radii R, the rnicroroughness peaks radii r, and their inclination angle h, in relation to the friction element movement direction. It was found that kinematic apparent self-sharpening some surface roughness tops occurs according to a physical phenomenon during the oblique cutting process. Experimentally carried out validation of the wear mechanism initiation was in good agreement with theoretical assumptions and analyses. The mechanism developed is explained in light of the geometrical structure of friction surfaces with the determined frictional properties, both in technology and nature. Analysis of the conditions affecting chip formation start-point initiation allow us to give guidelines to minimise initiation friction surfaces geometry as well as loss of the frictional properties of the friction surface considered. Two ranges were distinguished with h, angles: h, = 0-45' and h, -90°, which are advantageous according to the reduced frictional properties of friction surfaces. It was also formulated that the friction surface with higher frictional properties should have the lay with angle h, ca. 60-80.