Papers by Keyword: Orientation Measurements

Abstract: In the present work, we summarize three calculation methods to determine some specific crystallographic elements based on electron diffraction orientation measurements by SEM and TEM. The first one is to determine the plane indices of the faceted interfaces where the orientation relation¬ships (ORs) between the adjacent crystals are reproducible. To acquire the orientation data, we need to prepare only one sample surface but not two perpendicular sample surfaces as usually required in the standard double trace method. The second is to characterize the surface crystalline planes and directions of a faceted nano-particle under TEM imaging and diffraction mode. With the determination of the edge trace vectors and then the plane normal vectors in the screen coordinate system of TEM, their Miller indices in the crystal coordinate system can be calculated through coordinate trans¬formation. The third method is to determine the twin type and the twinning elements based on the orientation information acquired by SEM EBSD measurements from the two twinned crystals through misorientation calculations. These methods will facilitate related studies.

Abstract: Long range scanning stages with very small positioning errors are the key elements in the nano-CMM that is used to determine the sizes and coordinates of micromachines and parts in three dimensions to realize MEMS/nano technology. A transmission stage needs six degree-of-freedom precision motion controls. A compact critical angle sensor (CAS) can be mounted on the base or frame to be used to monitor the orientation parameters of the scanning/transmission stage along the 3 axes and feedback the error signal of the sensor output to maintain the stage moving performance. By calibration with an autocollimator, the resolution is better than 0.1 arcsec with a measurement range above 600 arcsec.

Abstract: A new method for in-situ studies of nucleation in bulk metals based on high energy synchrotron radiation is presented. Copper samples cold rolled 20% are investigated. The crystallographic orientations near triple junctions are characterized using non-destructive 3DXRD microscopy before, during, and after annealing for 1 hour at 290°C. This method allows in-situ identification of new nuclei and the deformed material, which spawns the nuclei. Also, since data is acquired during annealing nucleation kinetics can be studied.