Full-field energy-dispersive powder diffraction imaging using laboratory X-rays

Abstract

A laboratory instrument with the ability to spatially resolve energy-dispersed X-ray powder diffraction patterns taken in a single snapshot has been developed. The experimental arrangement is based on a pinhole camera coupled with a pixelated spectral X-ray detector. Collimation of the diffracted beam is defined by the area of the footprint of a detector pixel and the diameter of the pinhole aperture. Each pixel in the image, therefore, contains an energydispersed powder diffraction pattern. This new X-ray imaging technique enables spatial mapping of crystallinity, crystalline texture or crystalline phases from within a sample. Validation of the method has been carried out with a back-toback comparison with crystalline texture mapping local to a friction stir weld in an aluminium alloy taken using synchrotron radiation.

Rapid prototyping of cost efficient X-ray collimators

“…There have been several examples of collimators used for EDXRD systems including simple geometry such as slits [1,[7][8][9], pin-holes [10,11], conical collimators [12,13], and more complex arrangements [14][15][16][17] The layer height, print speed and build plate temperature were set to be 0.06 mm, 40 mm/s and 73 °C respectively, with other settings at default. A 10 mm height raft was added into the model as a sacrificial material during 3D printing to prevent deformation of the collimator channels due to a combination of the weight of the printed part and the softening effect of being in close contact to the heated bed.…”