Based on energy approach for the fatigue life evaluation of micrometric-sized single-crystal silicon notched specimens

Abstract

Fatigue behavior of single-crystal silicon notched specimens have been analyzed employing a strain energy density parameter. The micrometric specimens obtained from {1 0 0} and {1 1 0} wafers and characterized by five different crystal orientations have been experimentally tested by performing repetitive bending fatigue tests. Fatigue life has been originally synthesized considering the peak stress at the notch tip. Strain energy density averaged on a control volume around the notch tip has been successively obtained through a 3D finite element model. The radius of the control volume has been calculated analytically for each crystal orientation, considering the static and fatigue mechanical properties of each configuration. The energetic parameter has been finally correlated with fatigue life data of the notched specimens, returning satisfying results and improving the previous data.