2, Mechanical Engineering, Kennesaw State University, Kennesaw, Georgia, United States
Gradient grain size structure in metals become a new approach to yield a greater combination of high strength and good ductility. The gradient grain size structure has been reported to often consists of both a coarse-grained (CG) sizes layers and bounded by nanostructured (NS) layers .Due to the NS layer in a gradient grain size structure tolerate a large amount of tensile strain and because also are constrained by the CG layer. Nevertheless, producing a heterogeneous mixed structure consist of deformed grains (rolled grains) layer and undeformed (coarse-grained) layers, has not yet been reported. These mixed structures are expected to produce an essential synergetic strengthening, with its yield strength much higher than that calculated by the rule of mixture from separate gradient which is attributed to the macroscopic stress gradient and plastic incompatibility between layers.The objective of this work is to devise computational microstructural evolution tools to design partial heterogenous microstructures that can be verified computionally by using VPFFT method.