|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||High Entropy Alloys VI
||Loss of Crystallographic Anisotropy and Deformation Heterogeneity in FCC and BCC High-entropy Alloys
||Chi-Huan Tung, Wen-Ju Chen, Tai-Jan Huang, Yu-Chieh Lo, Shou-Yi Chang
|On-Site Speaker (Planned)
Crystallographic anisotropy and deformation heterogeneity are typical behaviors of crystalline materials but however diminish in high-entropy alloys (HEAs). Our recent structural analyses of FCC-series and BCC-series of low-to-high-entropy alloys using systematic high-energy diffractions and density functional theory calculations indicated that, compared to the low- and medium-entropy alloys, the FCC HEA exhibited an expanded unit volume (a decreased packing density of atoms), while the BCC HEA exhibited a shrunk unit volume (an increased packing density), causing the loss of crystallographic anisotropy. Nanoscopic mechanical behaviors in different crystal orientations (100, 110 and 111) were characterized by nanoindentations and the in-situ compression of micropillars in a scanning electron microscope. The nanomechanical characterizations revealed that the loss of structural anisotropy yielded a diminished heterogeneity of elastic deformation, and the activated partial dislocations and multiple cross slips on the roughened slip planes led to a diminished heterogeneity of plastic deformation.
||Planned: Supplemental Proceedings volume