A framework was developed for extracting reliable twin statistics from a deformed microstructure using crystallographic twin identification techniques with spatially correlated electron back-scatter diffraction data. The key features of this analysis were the use of the mathematical definition of twin relationships, the inclination of the common K1 plane at a twin boundary, and the correct identification of the parent orientation in a parent/twin pair. Methods for identifying the parent in a parent/twin pair will be briefly discussed and compared. Twin area fractions were then categorized by operative twin systems, number of active twin variants in each system, and corrected twin widths. These statistics were reported here for alpha;-zirconium samples deformed in quasi-static 4-point bend beams and in a 100m/s Taylor cylinder impact test. Analysis of the statistics also begins to reveal the roles that deformation rate and relative orientation of the boundary conditions to the material's symmetry axes play in determining the twinning activity that accommodates the imposed boundary conditions. These improved twin statistics could help quantify the deformation processes in materials that deform by twinning as well as serve to provide better validation of proposed models of the deformation processes.

A Semiautomated Electron Backscatter Diffraction Technique for Extracting Reliable Twin Statistics. B.L.Henrie, T.A.Mason, B.L.Hansen: Metallurgical and Materials Transactions A, 2004, 35[12], 3745-51