Article ID Journal Published Year Pages File Type
1447791 Acta Materialia 2010 10 Pages PDF
Abstract

A martensitic transformation from the α to the γ phase of aluminum oxide was observed by transmission electron microscopy (TEM) upon rapid heating induced by pulsed laser irradiation. Two variants possessing a twin relationship were found in the product. High-resolution TEM reveals that the transformation is achieved via the glide of quarter partial dislocations on every other basal plane of α-Al2O3. The high thermal stress caused by pulsed laser irradiation is believed to be the main driving force of the phase transformation. This martensitic transformation is associated with a positive volume change and substantial shear strain. The overall shear strain could be minimized by the self-accommodating variants. These characteristics suggest potential application of the martensitic transformation for transformation toughening in ceramic materials.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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