The Relationship between the Friction Coefficient and the Asperities Original Inclination Angle

Abstract

Because of the contact deformation, the inclination of the contact face is decreased gradually when contact and deformation. Base on the change of inclination of the contact surface, the concept repose angle set out. The tangent of the initial inclination of two asperities is three time of the tangent of the repose angle. The relationship set up a bridge between the initial surface geometric configuration (can be detect) and the configuration which after the deformation (can not be detect). Static Friction Coefficient is the max value of Kinetic Friction Coefficient before the deformation process of instantaneous contact surface. The Ratio of Kinetic and Static Friction Coefficient distribute from 0.771 to 0.9117 and were inversely proportional to the inclination of the contact face .Kinetic Friction Coefficient is the average friction coefficient of the deformation process of instantaneous contact surface. In the sandstone, the value of Kinetic Friction Coefficient which more than 0.5546 is because of the coupling of different classes zigzag-shape surface asperities mostly. The study puts forward the new ideas dynamic deformation tribology which will promote the development of the Tribology.