Dr. Sravya Tekumalla
National University of Singapore
Sravya Tekumalla is a Research Fellow at National University of Singapore, where she works on developing novel and advanced materials for several structural applications suiting different requirements including that of aerospace, automobile, biomedical and electronic applications.
As a curious mind, identifying the root cause for a problem and being able to solve it gives her immense satisfaction and she considers being a scientist is an opportunity to do something significant in this world. It is the incentive of making millions of lives more comfortable and at the same time protecting this planet with environment-friendly solutions, that spurs her on every day. In a world where global warming & climate change are major concerns, she considers it her duty and principle to make sure that the solutions she provides, ensure the safety & health of the planet while making the world a better & a more comfortable place for humans.
In an expansive field of metals, magnesium has been trending of late in automobile, aerospace, defense, sports, electronic and biomedical sectors as it offers an advantage in light-weighting. Magnesium nanocomposites, with excellent specific strength, thermal and damping properties, are not industrially viable due to poor control of dispersion of reinforcement in matrix and inability to tailor matrix-reinforcement interface which dictates their properties. This thesis describes a controlled approach combining the benefits of conventional processing with those of thermodynamic principles to synthesize magnesium nanocomposites and overcoming the abovementioned limitations. A reactive and ductile Mg-1.8Y alloy is chosen as the matrix and a mechanism of in-situ synthesis is established through addition of thermodynamically favorable nanoparticles (ZnO). Further, this in-situ synthesis is contrasted with ex-situ synthesis (through Y2O3 added Mg-1.8Y alloy) and a variation in the mechanisms of mechanical behavior including strength and ductility, microstructure and texture are identified and are correlated with the synthesis methodology. With this acquired understanding, the advantages of the in-situ synthesis technique are applied through tailoring the composition to synthesize an in-situ Mg-1.8Y/1CaO nanocomposite with unparalleled properties (tensile strength ~343 MPa, a weak texture mediated tensile ductility ~30%, compressive failure strain ~44%, ignition temperature ~1045 oC i.e. near the boiling point of Mg), outperforming other traditional Mg based materials. This approach, resultant of a vigilant choice of alloying element and reinforcement, is a solution to develop high performance magnesium nanocomposites, thereby enabling magnesium-based nanocomposites industrially realizable.