|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Fracture Properties and Residual Stresses in Small Dimensions
||Enhancing Ductility of Metal-Metal (BCC-HCP) and Metal-Ceramic Multilayered Nanocomposites
||Nathan Mara, Siddhartha Pathak, William Mook, Youxing Chen, Nan Li, Jon Baldwin, Jian Wang, Irene Beyerlein
|On-Site Speaker (Planned)
In this work we explore the mechanical response of multilayered composites where one constituent phase has a low ductility, with a final goal of enhancing both the strength and ductility of the system. Using physical vapor deposition (PVD) techniques we synthesized two multilayered systems: a metal-ceramic (Cu-TiN and Al-TiN) nanocomposite (where the ceramic TiN is the brittle phase) and a hexagonal close-packed (HCP) – body-centered cubic (BCC) Mg-Nb system (where twinning in Mg leads to its lack of ductility), over a range of layer thicknesses ranging from 5 nm to 200 nm. We utilize a combination of nanoindentation, in-situ SEM compression testing of micro-pillars, in-situ SEM fracture toughness testing of 3-point bend micro-beams containing these multilayered nano-composites, and post-deformation TEM analysis to evaluate their deformation mechanisms. These results are analyzed as a function of decreasing layer thicknesses using the concepts of dislocation motion within the confined nanoscale layers.