Non-Equilibrium Statistical Model About the Fatigue Life of Polycrystalline Metals

In order to explore the effect of grain size on its fatigue life, formulas about the fatigue life of polycrystalline metals are derived. The fatigue life is seen to depend on the grain size and stress amplitude, based on the non equilibrium statistical theory of fatigue fracture and the model of interface energy. The fatigue life of pure copper and 70 30 brass having different grain sizes are calculated according to the formula. The results are in good agreement with the experimental results in general.