Research @ IDEAs Lab
Interfaces in materials affect the stability and properties significantly. Our research aims to understand the role of interfaces in material behavior. We do this by investigating interfaces and phase stability in different classes of materials. Currently, we are studying various high-entropy alloys, high temperature Ni-based alloys, ultra-high temperature ceramics and nanomaterials - yes, you could say we are mostly high ;-)
High-Entropy and Disordered Solids
Recent efforts in our groups have focused on predicting phase stability in disordered alloys - both in crystalline high-entropy alloys and metallic glasses. In addition to phase stability, we also investigate properties depending/influencing phase stability such as hardness, strength and short-range ordering. As we move forward, our goal is to model and study solid-solid interfaces in these materials focusing on the alloy microstructures and grain boundaries in high-entropy alloys, glass/crystal interfaces during crystallization of metallic glasses and the solid/liquid interface during solidification of these materials.
Researchers: Dishant, Tirtharaj, Pratik
High Temperature Ni-based alloys
We are currently focusing on two-fronts - on one hand, we are investigating the role of reactive elements (such as Hf, Zr and Y) in bond coat materials where these elements segregate to the grain boundaries, while on the other hand we are investigating the creep and oxidation behavior of the base alloy itself (Haynes 282 and compositions modeled on the Haynes 282 architecture). Reactive elements segregate to the oxide/metal interface or to the oxide grain boundaries, while grain boundary precipitates in the base alloy affects its performance. In either case, the migration to grain boundary (a solid/solid interface) is critical.
Researchers: Santosh, Yatin, Pratik
Ultra-High Temperature Ceramics (UHTCs)
UHTCs are used in hypersonic applications for leading edges and thermal protection systems. These materials form a Zirconia top layer and a Silica scale underneath it above the active oxidation temperature of SiC. Our efforts focus on understanding the ionic diffusion behavior through these oxide scales (bulk and zirconia grain boundaries) through a combination of atomistic and mesoscale simulations in combination with targeted experiments. The thermal conductivity of these ceramics is also critical and can be influenced by the grain size with the grain boundaries acting as scattering centers. Overall, in addition to understanding grain boundary diffusion, our focus is largely on the gas/oxide, oxide/oxide and oxide/ceramic interfaces.
Researchers: Jhalak, Vaibhavi, Pratik
Processing of Nanomaterials
We are exploring the synthesis and processing of targeted nano-structures through a combination of self-assembly and ice-templating (or freeze casting, which is essentially solidification processing in disguise). Key to this problem is carefully investigating the factors affecting the stability of the solid/liquid interface, especially on the role played by surfactants, thermal gradient and externally applied fields. In addition to solidification of templated nano-structures, solvent removal is also a significant challenge. The capillary stresses during solvent removal can easily disrupt the solidified structures. This research is in its infancy as we are still developing the experimental facilities for this work.
Researchers: Sagarika, Nithin, Pratik