Generalized Slip Operation Factor Considering Contribution of Secondary Slip Systems

Slip operation factor (SOF), which considers the effect of mechanical interactions between plastically “soft” and “hard” regions, is a function of the Schmid factor (SF) and critical resolved shear stress (CRSS). It is used as an indicator to efficiently predict the ease of slip operation of metal materials at the grain level. While SOF could predict strain distributions, it was not compliant to the prediction of those for individual slip systems. Additionally, the contribution of secondary slip systems was disregarded in the SOF. In this study, the SOF was first extended to adapt to individual slip systems. This extended and generalized form of the SOF was called SOFS. Next, the contribution of secondary slip systems was considered in SOF, where the modified version of the SOF was called MSOF. Polycrystalline α-Ti models were built from crystal orientation maps obtained by electron back-scattered diffraction (EBSD), and the strain distributions under uniaxial tensile loading were predicted using the SOF, SOFS, and MSOF. The results obtained were compared with those obtained via crystal plasticity finite element (CPFE) analysis. The distributions obtained by the SOFS were similar to slip strain distributions for individual slip systems when single slips were dominant and the deformation was slight. The MSOF also successfully predicted the strain distributions with higher accuracy than that offered by the SOF.