Deformation experiments were conducted with the intention of identifying how the mechanical behavior and deformation microstructures of a basalt are influenced by the presence of glass that can crystallize to metamorphic minerals or flow. A glassy plagioclase-rich basalt was tested for periods of up to 649 hours at temperatures of 675-875°C, a confining pressure of 1.0 GPa, and strain rates of ...

Twinning is a major mechanism of plastic deformation in hexagonal close-packed (hcp) structures. However, mechanistic understanding twin nucleation and growth has yet to be established. This paper reviews the recent progress twinning hcp materials—particularly newly discovered phase transformation-mediated mechanisms—in terms crystallographical analysis, theoretical mechanics calculations, nume...

In recent years, great attention has been paid to the development of high manganese austenitic TWIP steels exhibiting high tensile strength and exceptional total elongation. Due to low stacking fault energy (SFE), cross slip becomes more difficult in these steels and mechanical twinning is then the favored deformation mode besides dislocation gliding. Chemical composition along with processing ...

The deformation microstructure of face-centered cubic cobalt subjected to surface mechanical attrition treatment was studied as a function of strain levels. Strain-induced c ! e transformation and twinning deformation were evidenced by transmission electron microscopy and were found to progress continuously in ultrafine and nanocrystalline grains as the strain increased. 2004 Acta Materialia In...