A crystal plasticity model for body-centered cubic single crystals, taking into account the plastic anisotropy due to non-planar spreading of screw dislocation cores was presented. In view of the longstanding contradictory statements on the deformation of body-centered cubic single crystals and their macroscopic slip planes, recent insights and developments were reported and included in this model. The flow stress of body-centered cubic single crystals exhibited a pronounced dependence upon the crystal orientation and the temperature, mostly due to non-planar spreading of a/2<111> type screw dislocation cores. The main consequence here was the well-known violation of Schmid's law in these materials, resulting in an intrinsic anisotropic effect which was not observed in, for example, face-centered cubic materials. Experimental confrontations at the level of a single crystal were generally missing in the literature. To remedy this, uniaxial tension simulations were done at material point level for α-Fe, Mo and Nb single crystals and compared with reported experiments. Material parameters, including non-Schmid parameters, were calibrated from experimental results using a proper identification method. The model was validated for different crystal orientations and temperatures.

BCC Single Crystal Plasticity Modeling and its Experimental Identification. T.Yalcinkaya, W.A.M.Brekelmans, M.G.D.Geers: Modelling and Simulation in Materials Science and Engineering, 2008, 16[8], 085007 (16pp)