Abstract
A method of predicting fatigue strengths using fracture mechanics on noched components of ferrous sintered materials is investigated. By applying Lukas's formula for evaluation of AK and a intrinsic crack model for small crack propagation on notched components, a simple formula for predicting fatigue limits was derived. This method requires three material properties: the fatigue limit of smooth specimen, the threshold stress intensity range for long crack, and the threshold value of the effective stress intensity. For experimental verification, a notched specimen for fatigue tests as sintered was designed, and fatigue tests were conducted with notched specimens of ferrous sintered materials with two different pore sizes. The predicted fatigue limits are comparatively in good agreement with the experimental results.