Mechanics of Materials

Research by Kevin F. Hane

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.


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.

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

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.