Tracking mechanical Dauphine twin evolution with applied stress in axial compression experiments on a low-grade metamorphic quartzite

摘要

The stress-dependent evolution of mechanical Dauphine twinning has been investigated in axial compression experiments on a low-grade metamorphic quartzite, applying both time-of-flight neutron diffraction and electron backscatter diffraction. The data of the experimentally stressed quartzite samples were compared with those of the naturally deformed starting material to monitor Dauphine twinning in relation to different experimental stress states. This comparison shows that in the experimental conditions of 500 degrees C temperature and 300 MPa confining pressure, Dauphine twinning initiates below 145 MPa differential stress and saturates between 250 MPa and 460 MPa differential stress.