Mesoscale Modeling and Validation of Texture Evolution during Asymmetric Rolling and Static Recrystallization of Magnesi
- PDF / 809,581 Bytes
- 8 Pages / 593.972 x 792 pts Page_size
- 100 Downloads / 254 Views
.
INTRODUCTION
WROUGHT magnesium alloys have limited roomtemperature (RT) ductility that is closely related to the crystallographic texture that develops during plastic deformation.[1] For example, during rolling or extrusion, a strong basal texture develops that severely reduces the available deformation modes by slip or twinning. Considerable effort has been made to increase the RT ductility of wrought magnesium alloys by inducing the formation of nonbasal texture components during thermomechanical processing. One set of approaches is based on alloying that induces deformation banding[2] or particle-stimulated nucleation,[3] resulting in significant weakening of the basal texture component. Another approach involves designing deformation paths and annealing sequences that weaken the basal texture[4–6]
B. RADHAKRISHNAN and S.B. GORTI, Senior Research Staffs, are with the Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830. Contact e-mail: radha krishnb@ornl.gov G.M. STOICA, Postdoctoral Researcher, A.D. STOICA, Research Staff, and X.-L. WANG, Distinguished Research and Development Staff, are with the Neutron Scattering Sciences Division, Oak Ridge National Laboratory. G. MURALIDHARAN, Research and Development Staff, E.D. SPECHT, Senior Research Staff, and T. MUTH, Research Scientist, are with the Materials Science and Technology, Oak Ridge National Laboratory. E. KENIK, now retired, was formerly Senior Research Staff with the Materials Science and Technology, Oak Ridge National Laboratory. Manuscript submitted February 25, 2011. Article published online October 1, 2011 METALLURGICAL AND MATERIALS TRANSACTIONS A
such as asymmetric rolling, cyclic extrusion, and compression and electropulsing. The texture that develops during asymmetric rolling of wrought magnesium alloys is influenced by several variables, including rolling temperature, speed, compression to shear ratio, and the plastic strain. Texture can also be influenced significantly by the components that nucleate and grow during static/dynamic recrystallization that occurs under a given deformation path. Even though micromechanical models that can predict the texture evolution through dislocation slip and twinning during large plastic deformation in magnesium alloys have been under development for a while,[7–9] microstructural length scale models that can predict the texture evolution under the combined influence of deformation and recrystallization in these alloys are not well developed. The focus of this effort is to develop a coupled deformation and recrystallization model for a wrought magnesium alloy and to validate the model using experimental data. Specifically, the effort involved the investigation of static recrystallization of the magnesium alloy AZ31 using in situ neutron diffraction. The computational approach is based on an extension of previous work by the authors in predicting the texture evolution during thermomechanical processing of aluminum alloys and steels using a coupled deformation and annealing simulation a
