An Electron Backscattered Diffraction Specimen Preparation Technique for High Resolution Serial Sectioning

Extract

A high-resolution serial sectioning specimen preparation technique is described for acquisition of electron backscattered diffraction orientation imaging microscopy (OIM) data. The primary objective is to develop a method to reproducibly remove a controlled thickness of material (a serial section) from a polycrystalline Ta sample while producing quality surfaces for OIM imaging. This is integrated with the ability to accurately measure the amount of material removed with each iteration and experimentally register the ensuing OIM scans.

A Si metrology device is fabricated by lithographic techniques to facilitate the measurement of the amount of material removed with each lapping iteration and the alignment of each serial section image. This metrology device contains a herringbone pattern with two orthogonal etched lines oriented at 45 degrees and one vertical line normal to the OIM surface. The metrology device is epoxied to a polished side surface of the Ta sample. Due to the orthogonality of the lines, the thickness of material removed equals one-half the total linear motion of the etched lines as seen in cross-section. To accurately measure the distance between the grooves after each lapping iteration, a high-resolution (0.1 μm) linear measuring system is attached to the table of a light metallograph.