An Iowa State professor and his PhD student are gaining global recognition for their work on multivariant martensitic phase transformations.
Valery Levitas, Schafer 2050 Challenge Professor and faculty member of aerospace engineering and mechanical engineering, along with PhD student Mahdi Javanbakht was published in Physical Review Letters (PRL, 2010, Vol.105, No.16, 165701), the world’s foremost physics journal.
The researchers advanced the Ginzburg-Landau theory for multivariant martensitic phase transformations in their paper “Surface tension and energy in multivariant martensitic transformations: Phase-field theory, simulations, and model of coherent interface.”
Through their paper, Levitas and Javanbakht introduce three new directions to the Ginzburg-Landau theory. First, they introduced interface tension that was developed using the large-strain theory. No one had done this before because Levitas only recently developed the large-strain theory in a previous PRL paper. He used the new theory to develop the physical phenomenon of interface tension using geometric nonlinearities.
Secondly, they developed the possibility to control martensite-martensite interface energy independent of martensite-austenite interface energy. The third direction they developed was the non-contradictory description of the surface-induced phenomena. Also, the obtained results represent an advanced model for coherent interface.
The new theory and computational tool developed by Levitas and Javanbakht has been applied to illustrate the nontrivial effects on microstructure evolution during multivariant martensitic phase transformations, surface-induced pre-transformations, and barrierless multivariant nucleation.
Similar developments can be applied for various phenomena involving interfaces, including liquid-liquid melting, amorphization, evaporation, electromagnetic and reconstructive phase transformations, twinning, dislocations, fracture, grain growth, and recrystallization.
While Levitas has published scholarly articles in the topic of phase transformations, Javanbakht had no preliminary knowledge in phase transformations or phase field approach prior to the start of his PhD study in November 2009. Since then, Javanbakht has received his second award in the graduate student competition at the Annual Meeting of Society of Engineering Sciences.