Rolling Friction of Metals

Theoretical equations of rolling friction coefficient of metal by the rigid pendulum method were obtained as a function of dynamic mechanical properties of metal for the case of cylinder and sphere as follows, λ c =3 k /2π(3/2) 1/3 tan δ( W / E 1 (ω)) 1/3 r -2/3 and λ s =128 k /15π 2 (4/π) 1/4 tan δ( W / E 1 (ω)) 1/4 r -3/4 , respectively, where tan δ is the mechanical loss, E 1 (ω) the Young's modulus, W the load, r the radius of roller and k the adjusting parameter. In the case of no micro plastic deformation due to adhesion these equations have good agreement with experiments over a wide temperature range by putting k =1/2 (this is the case of a continuous one dimensional generalized Voigt model). In the case of some micro plastic deformation, however, the experimental value of friction coefficient increases to the case of k =2.