MAE Distinguished Speaker Series 2026 Seminar on Designing Metastable Alloys to Enable Properties Beyond Conventional Limits

06 Oct 2026 02.00 PM - 03.00 PM LT4 (North Spine, NS4-02-34) Current Students, Public

Professor En (Evan) Ma

Xi’an Jiaotong University, China

This seminar will be chaired by Asst Prof Liang Xuan.

Seminar Abstract

This talk uses two examples, one each for crystalline alloys and amorphous materials, as case studies for designing the nanoscale/atomic-level structure to achieve unprecedented properties. In the first example, we discuss how to fill the blank in the strength-ductility space, pushing towards 2 GPa yield strength in combination with 30% uniform tensile elongation [Nature 643 (2025)119]. In particular, we leverage additional strengthening and strain hardening mechanisms enabled by the expanded compositional scope in complex multi-principal-element (“high-entropy”) alloys, on top of previously known plasticity mechanisms. Furthermore, desirable property combinations have been achieved as well for refractory alloys, as shown by renovating an ODS Ta-alloy to reach 200 MPa strength at ultrahigh temperatures (>2000oC) [Nature 655 (2026) 109], while retaining high tensile ductility for easy processing near ambient temperature. In the second example, we show that "structure determines properties” also works for the crystallization speed of amorphous solids, as demonstrated with chalcogenide glasses used for non-volatile memory. There, the key idea is to design a single type of robust coordination motif, thus limiting the flexibility in the amorphous structure. This reduces the inevitable structural relaxation (especially rampant after rapid quench) and therefore the electrical resistance drift that hampers reliable multi-value recognition. The amorphous Cr-Te alloy designed as such offers the first no-drift phase-change memory material for information storage [Nature Materials 25 (2026) 456].

Speaker's Biography 

Professor En (Evan) Ma is currently at the Center for Alloy Innovation and Design (CAID), Xi’an Jiaotong University in China. Dr. Ma received his degrees from Tsinghua University, and worked at Caltech, MIT/IBM, University of Michigan, UIUC, and LSU. He was a tenured professor at Johns Hopkins University for 22 years. Prof. Ma’s research interest focuses on metastable alloys, including metallic glasses, nanostructured metals, chalcogenide phase-change materials for memory applications, multi-principal element complex concentrated alloys, mechanical properties and plasticity mechanisms, and thermodynamics/kinetics of phase transformations. Dr. Ma has published ~450 papers, including 34 in Science, Nature, and Nature Materials (or Nature Physics/Electronics), plus 24 in Nature Communications. His publications have received 76,500 citations (Google Scholar) with an H index of 139. Prof. Ma is an elected Fellow of TMS, MRS, ASM International, APS and the European Academy of Sciences.

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