Classification of the critical resolved shear stress in the hexagonal-close-packed materials by atomic simulation: Application to α-zirconium and α-titanium

We have studied the hierarchy of the activation of dislocation glide in zirconium and titanium alloys and presented experimental results in zirconium alloys. We have compared the experimental results with simulations obtained by two different approaches. The first is by using the stacking fault energy maps (gamma surfaces) obtained by molecular dynamics (MD) and by ab initio approaches. A good agreement was observed between the two approaches and with recent published work. The second is to compare the experimental critical resolved shear stresses (CRSS) with those determined by MD simulations based on embedded atom method (EAM) potentials. The CRSS for slip in the -direction for the basal, prismatic (type 1) and pyramidal (type 2) planes for edge dislocations are obtained. Finally, we discuss the hierarchy of the glide systems with the energy criterion of the c surfaces and with the CRSS values and we compare with both experimental and modeling data. (C) 2011 American Institute of Physics. [doi:10.1063/1.3599870]