|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Fracture Properties and Residual Stresses in Small Dimensions
||Micro-Compression Testing of Mg-Nb Multilayered Nano-Composites for Ultra-High Strength, Formability and Ductility
||Manish Jain, Marko Knezevic, Nathan Mara, Irene J. Beyerlein, Siddhartha Pathak
|On-Site Speaker (Planned)
In this work we explore the mechanical response of Mg-Nb multilayered nanocomposites as a function of decreasing layer thickness. Layers of Mg and Nb, with individual layer thicknesses varying from 5 to 50 nm, were synthesized using physical vapor deposition. Transmission electron microscopy (TEM) and X-Ray diffraction (XRD) studies reveal that at lower thicknesses of ~5 nm Mg undergoes an interface strain induced phase transition from hexagonal close-packed (HCP) to a metastable body centered cubic (BCC) structure. Using a combination of indentation testing and micro-pillar compression experiments – where the multilayers were tested in 3 different orientations: with interfaces oriented normal, parallel and inclined 450 to the loading axis – we analyze the elastic and plastic anisotropy of this hitherto unstudied BCC Mg structure. These studies reveal BCC Mg to be super-strong and more ductile than its HCP counterpart, suggesting significant implications for potential lightweight aerospace and automotive applications.