The following is was part of Dr. Hane's Ph. D. thesis. Professor T. W. Shield was his thesis advisor.

Dr. Hane is currently a faculty member at the University of Akron.

**Research:**

** Microstructures in Thermoelastic
Martensitic Transformations**

My research is concerned with the construction of various
microstructures seen during thermoelastic martensitic transformations. Such
microstructures are of interest because it is their formation and evolution
which gives rise to the shape memory
effect and superelastic
behavior. Both of these phenomena occur by the nucleation and growth of
microstructure in the body due to the thermoelastic martensitic transformation.
In addition, this type of transformation is a reversible, diffusionless,
structural transformation usually between a high temperature, high symmetry
parent phase called * austenite * and a low temperature, low symmetry
product phase called * martensite.* The martensite phase has multiple
variants, because there is more than one path by which the transformation from
the parent phase to the product phase can take place. Microstructures are
geometric arrangements of the two phases, and they provide a means by which the
transformation between the phases can occur.

Specifically, I am interested in how the change in symmetry observed during the transformation and the lattice parameters of the parent and product phases both influence the kinds of microstructures which are possible in a material. I hope that these calculations may be useful in the design of new alloy systems which may exhibit interesting and potentially useful microstructures.

The theory used to construct microstructures is a geometrically nonlinear thermoelastic theory of martensite. Below are links to various pages discussing some aspects of this theory.

- Constitutive assumptions
- Variants of martensite
- Energy functional and energy wells
- Compatibility equation

I have considered several microstructures. Follow the links below to learn more about each of the microstructures.

- Twinned martensite
- Parallelogram martensite
- Austenite single variant of martensite
- Austenite twinned martensite
- Wedge
- Triangle and Diamond

I have constructed some microstructures in four transitions that are commonly observed in experiments. Follow the links below to learn more about each of the transformation.

- Cubic-to-Trigonal Transition
- Cubic-to-Tetragonal Transition
- Cubic-to-Orthorhombic Transition
- Cubic-to-Monoclinic Transition