The IDEAs Laboratory
Interface Dynamics and Energetics of Alloys

Our primary research interest deals with the role of interfaces and their evolution during processing and performance of materials. We study a variety of interfaces: solid-liquid (solidification, colloids), solid-solid (defects, grain boundaries, phase boundaries) and solid-gas (gas-metal reactions, interactions with plasma). Accurate mathematical descriptions of interfaces and their dynamical evolution as a fundtion of environmental parameters remain a significant challenge in this area. As the length scale changes, the relative interfacial area to bulk volume also changes, which is a major contributor to the length scale effects in materials. In a sense, understanding the role of interfaces is critical for understanding the multiscale phenomena and pattern formation in materials. We approach the science of interfaces using a number of techniques, ranging from in-situ diffraction, electron microscopy, time-resolved measurements, physical property measurements on one hand to computational approaches such as Molecular Dynamics, Cellular Automata and semi-empirical thermodynamics. In addition to experimental and computational methods, the group is also interested in developing an informatics platform for correlating interface evolution with underlying mechanistic changes. Currently, we are studying interface dynamics and energetics for two broad problems - (i) non-equilibrium processing and (ii) high temperature materials and degradation processes.


On-going Research

  • Institute Start up research grant - "Phase selection in Multi-principal element alloys (MPEAs)"
    (under review) The underlying challenge is to develop phase selection criteria beyond the current state of art methods that rely largely on semi-empirical relations similar to Hume-Rothery rules. In this project, we will be investigating the role of solid-liquid and solid-solid interfaces in phase evolution in multicomponent systems.
  • Collaborative Research with Ames Laboratory - "Designing novel Ni based alloys"
    The objective of this collaborative effort is to investigate Ni-based superalloys such as Haynes 282 and HR-120, with the goal of identifying critical issues in phase stability and oxidation behavior. This effort will follow up with an integrated computational and experimental effort for ascertaining alloying additions that enhance phase stability at elevated temperatures in oxidative conditions. The focus is on understanding, predicting and controlling the solid-gas and solid-solid interfaces in Ni-based alloys.
  • Collaborative Research with Lehigh University - "Mechanical behavior and oxidation of equiatomic solid solutions"
    The goal of this effort is to understand the role of different factors such as lattice strain, energetics, etc. on the strength of equiatomic solid solutions.



Recent Research

  • SMARTER (Science of Multicomponent Alloys: A Roadmap for Theoretical and Experimental Research)
    The objective of this work was to explore the unique properties and ordering behavior in Near- Equiatomic Systems (NEAs). We established the role of Al:Cr ratio in the oxidation of high temperature NEAs. Furthermore, we demonstrated that the phase selection occirs through a delicate balance of enthalpy, entropy, size effects, defect population and kinetics.
    Singh et.al. NPJ Cmput. Mater. 4(2018) 16.
  • Materials for Hypersonic applications
    The objective of this work was to assess the potential of two alloy systems - Mo-Si-B and ZrB2-SiC ultra-high temperature composites (UHTCs) for hypersonic applications. We established the oxidation mechanism and ultra-high temperatures for W substituted Mo-Si-B alloys. We also demonstrated the effect of viscosity on the oxidation behavior of UHTCs.
    Ouyang et.al., J. Am. Ceram. Soc. 99(2016) 808.
    Karahan et.al., Intermetallics 87(2017) 38.