Wednesday, June 29 2016
15:30 - 16:30

Alladi Ramakrishnan Hall

Phase-ordering kinetics in martensites

N Shankaraiah

School of Physical Sciences, JNU, Delhi

Martensites (steels, shape memory alloys and high-Tc superconduc-
tors) undergo solid-solid unit-cell shape changes from high-temperature
austenite to low-temperature martensite on cooling. We study phase-
ordering underdamped dynamics of 1-D Bales-Gooding triple-well model
free energy in 2- and 3- spatial dimensions, and with added power-
law interactions for square-rectangle martensitic transition. After
quenching a dilutely seeded austenite below a first-order transition, we
find dynamical scaling in strain-strain correlation functions with a coars-
ening length L(t) ∼ t^alpha and Porodís tail in structure factor for sharp interfaces. The exponent α behavior is understood by inserting the dynamical scaling ansatz into correlation function dynamics whose solutions g(t) ∼ 1/t^alpha have exponent values matching with simulations.



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