Fracture Behavior of Micro-Sized Fe-3%Si Alloy Single Crystals

Abstract

Fracture tests have been performed for both millimeter-sized and micro-sized specimens prepared from a Fe-3 mass%Si alloy single crystal, and the size effects on fracture behavior have been considered. Notch plane was set to be (100), which is a cleavage plane of this material, and notch direction was set to be [010] for both type of specimens. For millimeter-sized specimens, cleavage fracture occurred during introducing a fatigue pre-crack. In contrast, the micro-sized specimens were fractured by ductile manner. This phenomenon is discussed based on the plastic zone at crack tip and the ligament size. The results obtained in this investigation provide important information for designing actual MEMS devices.