| Abstract Scope |
The martensitic transformation in zirconia and its alloys has been shown to lead to viable shape memory and superelastic properties. However, unlike most metallic shape memory alloys, the symmetry of the parent (tetragonal) phase in zirconia is noncubic, and thus introduces anisotropies in the transformation kinematics. Specifically, the transformation “correspondences” come in three flavors that correspond to three different alignments of the tetragonal c-axis with the resulting martensite orientation. While these correspondences have been somewhat mysterious in prior work, this talk will review new lines of progress on this topic, made possible with advanced methods based on electron backscatter diffraction. These methods allow us to survey many transformation domains and evaluate the statistics by which the correspondences appear in different alloys. While in general all three correspondences can be, and are, observed in many materials, our results suggest that only one of them is the primary transformation pathway.
|