|About this Abstract
||MS&T21: Materials Science & Technology
||Probing Defect Properties and Behavior under Mechanical Deformation and Extreme Conditions
||Lattice Distortion in NbTaTiV and NbTaTiVZr Refractory High-entropy Alloys
||Chanho Lee, Yi Chou, George Kim, Michael C Gao, Ke An, Jamieson Brechtl, Chuan Zhang, Wei Chen, Jonathan D Poplawsky, Gian Song, Yi-Chia Chou, Peter K. Liaw
|On-Site Speaker (Planned)
||Peter K. Liaw
The lattice distortion is the core effect of HEAs to enhance the strength at room as well as high temperatures. The number of constituent elements with various atomic sizes have the identical possibility to occupy at atom positions of a crystal lattice, which induces a severe distortion of the crystalline lattice. Several studies have attempted to quantitatively measure the lattice distortion with increasing the number of alloying elements, using x-ray diffraction (XRD) and neutron diffraction (ND). However, only limited alloy systems have succeeded to demonstrate the correlation between lattice distortion and mechanical properties. In this study, we have systematically investigated the evolution of lattice distortions for Nb-Ta-Ti-V-Zr systems as function of number of additional elements and its effect on mechanical properties, using experimental [atom-probe-tomography (APT at CNMS), transmission-electron microscopy (TEM)] and modeling methods [density-functional-theory (DFT)]. It is found that lattice distortions have a critical role in improving yield strength.