Abstract:

A simplifted potential model of contact surfaces,which is based on the strong volume-dependent charac-teristic of metal.is established to caleulate the static friction force and the coefficient of two flat surfaces made of the same metal and to exDlain the origin of static friction force.The static friction force and the coefficient are then calculated according to the principle of energy,and the potential change of the contact surfaces is obtained by a universal adhesive energy function. Moreover,the relationships between the static friction force and the parameters of a tribo-system.such as the surface energy,the micro-stru ctural parameters of material,etc.,are revealed.The resuIts of the calculation using some known experimental data demonstrate apparent regularity and are proved to be consistent with the experimental results of copper specimen carried out by an ultra high-vacuunl atomic-force micro-scope,thus illustrating the feasibility of the proposed method.It is concluded that,as the surface energy can reflect the status 0f contact surfaces sensitively,the proposed method may improve the accuracy of friction calculation.

Key words: static friction force, potential, contact surface, surface energy, micro-stru ctural parameter, adhes Ve energy function