Dr. Srinivasan G. Srivilliputhur
Department of Materials Science & Engineering, University of North Texas
Friday, January 24, 2014
Refreshments will be offered at 1:30 p.m. before the seminar.
Science and Engineering Research Facility (SERF)
"Cementite: Ancient Material,
Based on electronic density of states and charge density distribution, the chemical bonding in Fe3C is shown to exhibit a complex mixture of metallic, covalent, and ionic characters. In a recent paper in Nature , Srivilliputhur's team used density functional theory calculations to predict unexpected strain-stiffening in inorganic crystals.
Strain-stiffening—an increase in material stiffness at large strains—is a vital mechanism by which many soft biological materials thwart excessive deformation to protect tissue integrity. Using cementite and aluminum borocarbide as prototypes, the team's research shows that this phenomenon also unexpectedly occurs in simple inorganic crystalline solids. It confers exceptionally high strengths to these two solids which otherwise have anomalously low resistance to deformation to begin with.
Understanding the fundamental science of strain-stiffening and incorporating this concept into the design of metals and ceramics for advanced applications is an exciting prospect for developing ultrastrong materials. This work identifies two new mechanisms that cause this fascinating strain-stiffening response and challenge the conventional wisdom that large shear modulus is a reliable predictor of hardness and strength of materials, and may provide new lessons for materials selection and design.
 "Unexpected strain-stiffening in crystalline solids," Chao Jiang and Srivilliputhur G. Srinivasan, Nature, Vol. 496, p. 339 (2013).
Dr. Srinivasan G. Srivilliputhur received his PhD in Materials Science and Engineering from the University of Washington in 1998. He was a postdoc in the Theoretical Division at Los Alamos National Laboratory (LANL) from 1999-2002, and later served as a Technical Staff Member in the Materials Science and Technology Division until 2008.
He left Los Alamos for an assistant professor position in the Department of Materials Science and Engineering at the University of North Texas, and became an associate professor in 2011.
His research includes atomistic modeling of deformation behavior and defect physics, radiation effects in materials, phase transformations, and structure property relations in metals and alloys. He is a recipient of NSF CAREER award and has over fifty publications in several high-impact journals.