Mukesh Bachhav

Atomic Scale Investigation of Orthopyroxene and Olivine Grain Boundaries by Atom Probe Tomography

Olivine (Mg1.8Fe0.2)SiO4 and orthopyroxene (Mg 0.9Fe0.1)SiO3 are the most abundant minerals in Earth’s upper mantle and represent important geochemical reservoirs in Earth. In addition, the rheological properties of these two minerals exert first order control on mantle convection and the dynamics of Earth’s tectonic plates [1, 2]. Both olivine and orthopyroxene have nominal compositions that include Mg, Fe, Si, and O. However due to extensive solubility of non-stoichiometric elements, both minerals may contain a number of impurities, including Ca, Al, Mn, Cr. During deformation, dynamic recrystallization generates new grain-boundaries, which then migrate due to differences in dislocation strain energy between adjacent grains. It has been shown that this grain boundary migration will cause impurities to become segregated along new grain boundaries. Thus, grain boundaries may represent important additional geochemical reservoirs in Earth.

On Growth and Chemistry of Electrodeposited Mg Layers with Electrolytes Having Varying Cl Content for Battery Application

There is increasing interest in finding alternative solutions to Li based batteries due to its high cost, safety issues, and sensitivity to high temperatures. Among alternative materials, Mg-based batteries are promising candidates due to magnesium metal’s low cost, environmentally benignity, high theoretical specific charge capacity (2.205 Ah/g), and high theoretical energy density (3.8 Ah/cm) [1]. A major challenge in the application of rechargeable Mg batteries is the development of a suitable electrolyte that is compatible with a Mg anode and a high voltage/capacity cathode. In this study, atom probe tomography (APT) and transmission electron microscopy (TEM) have been successfully applied to elucidate the differences in Mg growth from a series of Mg-based electrolytes.

Microscopic Characterization of Electrodeposited Mg Layers for Battery Application

Magnesium has been considered as a strong candidate for metal air battery applications due its low cost, environmentally benignity, high theoretical specific charge capacity (2.205 Ah/g), and high theoretical energy density (3.8 Ah/cm ) [1, 2]. However, one of the current technical limitations is the understanding of the interactions taking place at the electrolyte/Mg interface. In this study, atom probe tomography (APT) and transmission electron microscopy (TEM) have been successfully applied to the characterization of electrodeposited Mg layers to understand the functionality of electrolytes in Mg deposition.

Clustering and Radiation Induced Segregation in Neutron Irradiated Fe-(3-18)Cr Alloys

High chromium ferritic-martensitic (F-M) steels are one of the promising structural material classes for future nuclear power plants. These steels are designed to combine corrosion resistance, conferred by chromium, with low swelling, high resistance to irradiation damage as well as to retain adequate toughness and elevated-temperature strength during service [1]. However, the long-term use of these steels in intense neutron irradiation environments requires reliable predictions of the evolution of their microstructures and mechanical properties. Binary Fe-Cr alloys constitute a model system for high Cr ferritic/martensitic steels and have therefore generated lot of interest by allowing the systematic study on irradiation induced microstructural changes.