Size Effects On Deformation And Fatigue Behavior Of A Micron-Sized Stainless Steel
微米尺寸不锈钢的形变与疲劳行为的尺寸效应

Micron-sized cantilever beams of a 304 stainless steel were fabricated by focused-ion beam (FIB). The static bending and dynamic bending tests of the microbeams were carried out. The results show that with decreasing the beam thickness, the yield strength of the microbeam increases and .the ductility decreases. The relation between the yield strength of the microbeam and beam thickness is similar to the Hall-Petch relation of the grain size strengthening. The increase in the yield strength of the thinner microbeam is attributed to the increase in the strain gradient contribution due to inhomogeneous deformation of the small dimensional material. The decrease in the ductility of the microbeam is attributed to fewer mobile dislocations in the grain. The threshold of the fatigue crack initiation from the notch of the microbeam is close to that of the bulk material.