A test method for manufacturing effect assessment in HCF

Surface conditions produced by manufacturing processes are known to significantly affect the fatigue strength of metallic materials. However, tests on planar specimens usually present onset crack in a specimen edge, where superposition different machining techniques and subsequent operations can hide effects studied process. This study deals with design test able reliably assess high cycle any process used produce surfaces. It was devised configuration geometry loading aimed locate nucleation middle surface machined investigated condition is achieved employing notched three-point bending configuration, position notches designed relieve specimen's edges. Nevertheless, critical region, stress state quite uniaxial uniform longitudinal direction. The manufactured using same parameters adopted for full-scale components, thus producing properties as real component. validated compare broaching wire electrical discharge Wöhler curve (S-N curve). tailored so that it has sufficient stiffness both directions parallel perpendicular Fatigue were carried out resonant machine, allowed detect monitoring frequency.