Papers by Author: Chong Yu Wang

Abstract: Crack propagation in bcc iron at different strains under low temperature (30K) has been studied using the atomistic simulation. We show that cracks display a brittle character of extension at low strains, and at relative higher strains cracks extend with a periodic series of twins(or SF) bursts. These bursts decrease the crack speed and produce velocity oscillations with an increase in energy dissipation that increases the toughness. Here we also develop a new form of dynamic fracture energy. Using our form of dynamic fracture energy, the results therefore are in quantitative agreement with the theoretical single-crack equation of motion.

Abstract: The dislocation 1/2[111](1-10) in iron is constructed. The motion behaviors of dislocation 1/2[111](1-10) in iron, as well as the dislocation with the Carbon located in dislocation core, are simulated by the molecular dynamics method with a modified analytic embedded atomic method (MAEAM). The carbon atoms are easy captured by the dislocation core and they can block the dislocation moving. After the carbon atoms are separated from the dislocation, the moving velocities of the dislocation are similar as the case of single dislocation.