A method for intragranular orientation and lattice strain distribution determination

作者：Barton Nathan R^*; Bernier Joel V

来源：Journal of Applied Crystallography, 2012, 45: 1145-1155.

DOI：10.1107/S0021889812040782

• orientation distribution function
• X-ray diffraction
• lattice strain
• iron
• phase transformations

A novel approach to quantifying intragranular distributions is developed and applied to the a?? phase transition in iron. The approach captures both the distribution of lattice orientation within a grain and the orientation dependence of the lattice strain. Use of a finite element discretization over a ball in Rodrigues space allows for the efficient use of degrees of freedom in the numerical approach and provides a convenient framework for gradient-based regularization of the inverse problem. Application to the a?? phase transition in iron demonstrates the utility of the method in that intragranular orientation and lattice strain distributions in the a phase are related to the observed ? orientations. Measurement of the lattice strain distribution enables quantitative analysis of the driving forces for ? variant selection. The measurement and analysis together indicate quantitatively that the Burgers mechanism is operative under the experimental conditions examined here.

• 出版日期2012-12