Quantitative analysis of deformation twinning in zirconium

We have used electron backscatter diffraction (EBSD) to quantify the contributions of first generation and second generation twinning to the total plastic strain of zirconium compressed at 76 K. For compression parallel to a primary c-axis texture, prismatic slip and first generation image compression twinning are the dominant deformation mechanisms with twinning accommodating roughly one third of the plastic strain. Second generation image and image tensile twins increase with the third power of the first generation image twin fraction. For compression perpendicular to the primary c-axis texture, prismatic slip and first generation image tensile twinning are the dominant deformation mechanisms with a small contribution from first generation image tensile twinning. Above approximately 17% strain, second generation image compression twins begin to make a contribution to the overall strain. These observations are used to explain the measured mechanical responses and texture evolution during deformation of zirconium.