Seminar: Deformation Mechanisms of Metastable Complex Concentrated Alloys

ABSTRACT

In contrast to conventional alloys, which consist of one or two dominant metals with a pinch of other alloying elements, complex concentrated alloys (CCAs) are a new family of alloys usually made up of five or more metallic elements in approximately equal proportions to maximize the configurational entropy, hence also termed as high entropy alloys or the multiprincipal-element alloys. CCAs are currently the focus of intense research in the fields of materials science and condensed matter physics due to the intrinsically heavy lattice distortion and the large local chemical/crystal ordering fluctuation, which are intuitively expected to induce the lattice/structural metastability. Although great progress on mechanical behavior has been made in this rapidly developing area, challenges remain in fundamental understanding of metastability-related phenomena and their underlying deformation mechanisms. In this talk, some important experimental findings on microscopic mechanisms on the confined-phase transformation and the associated anomalous deformation behaviors will be presented in several CCAs.

BIOGRAPHY

Prof. Yandong Wang is currently a Changjiang Chair Professor in the State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing (USTB). He leads a team of faculty members conducting research, using synchrotron X-ray and neutron scattering methods, on stress and texture measurements, deformation, and phase transformation in metallic materials.

He received his B. Eng. and M. Sc. Degrees from Northeastern University (NEU), China (1982-1989). He got his Ph.D. in 1993 at USTB, China. During 1994-1998, he joined NEU as a lecturer and then associate professor. During 1998-2000, he conducted research as a postdoctoral research fellow at the Studsvik Neutron Research Laboratory with Uppsala University, Sweden. During 2001-2003, he participated in the Spallation Neutron Source (SNS) project as a postdoctoral research associate in Oak Ridge National Laboratory, USA. In 2004, he returned to China as a full professor.