Application of generalized non-Schmid yield law to low-temperature plasticity in bcc transition metals

Abstract

In this work, a generalized yield criterion that captures non-Schmid effects is proposed and implemented into a finite element crystal plasticity model to simulate plastic deformation of single and polycrystals. The parameters required for the constitutive formulation were calibrated to deformation experiments on single crystals. This model is used to investigate the effects of non-Schmid effects on the predictions of the stress–strain response and texture evolution in body-centered-cubic (bcc) metals. The non-Schmid contributions are required to accurately predict the stress–strain response of single crystals, and the concomitant non-associativity of the flow also increases the tendency of localization in polycrystal deformations.

Anomalous plasticity of body-centered-cubic crystals with non-Schmid effect

“…Non-Schmid effects have also been experimentally evidenced in many BCC transition metals (Byron, 1968;Carroll et al, 2013;Ferriss et al, 1962;Irwin et al, 1974;Kim et al, 2010;Sherwood et al, 1967), in which orientation-dependent tension-compression asymmetries and anomalous yield loci were reported across length-scales. Moreover, such unusual plastic deformations have been reported in some FCC and HCP metals (Dao and Asaro, 1993;Lim et al, 2013).…”

Crystal plasticity finite element analysis of ferritic stainless steel for sheet formability prediction

“…More sophisticated equations for latent hardening and interactions between slip systems, dislocation densitybased formulation, and non-Schmid effect may help better represent the microstructure evolution for large deformation (Cereceda et al, 2016;Lee et al, 1999;Beyerlein and Tom e, 2007;Alankar et al, 2014;Lim et al, 2013). In addition, finite element models of the RVE may be refined.…”

A multi-scale model for texture development in Zr/Nb nanolayered composites processed by accumulative roll bonding

“…The need for employing these two families of slip for capturing the plastic anisotropy of this metal was elucidated by a combined atomic-discrete dislocation simulation [62]. Several dislocation-based models for BCC metals, like Nb, have been developed to account for strain hardening, substructure development, [63][64][65] and non-Schmid effects [62,66,67]. From these works, it is clear that ሼ110ሽ〈111〉 and ሼ112ሽ〈111〉 slip dislocations have different slip resistances and dependencies on stress, temperature, and strain rate.…”