Microstructural and textural evolution of calcite deformed to high shear strain by high-pressure torsion

Calcite powder aggregates were deformed to shear strains up to 80 by high-pressure torsion at temperatures of 235 and 450 °C and confining pressures of 1–4 GPa. At 235 °C the deformation occurs by twinning and limited dislocation creep as well as by brittle processes. In contrast, subgrain rotation recrystallization is the predominant deformation mechanism at 450 °C. The high confining pressures affect the microstructural evolution by inhibiting...