Microbeam X‐Ray Grain Averaged Residual Stress in Dental Ceramics

X-ray diffraction mapping on a curved surface

“…(a) Typical optical image from the video system and a top view of the grid (25 Â 28). (b) Point heights obtained from the laser-video auto z measurement superimposed on a three-dimensional rendering of the sample surface from tomography [tomography method described elsewhere (Bale et al, 2009)].…”

“…A wide range of industrially important materials, from aircraft engine parts to welds and even dental crown ceramics, can have complex shapes and potentially detrimental residual stress or phase distributions. Micro-X-ray diffraction is a nondestructive technique that provides information on mapped regions of interest (Allahkarami & Hanan, 2011a,b;Bale et al, 2009). In general, X-ray diffraction mapping involves analysis and comparison of several diffraction patterns, at multiple sites, that change as a function of two independent variables.…”

“…In two dimensions, modern motion control software allows mapping on selected positions of a rectangular grid or with arbitrary distances in both x and y directions. In recent years, with advances in focusing micro-X-ray lenses, which provide high-intensity very small beams down to a few micrometres in diameter (Bale et al, 2009;Li et al, 2010), and two-dimensional detectors, short-time diffraction measurements (down to a few seconds) have become possible (He, 2009). Accurate motorized XYZ axis stages in a variety of configurations along with an auto z alignment system, such as a laser-video system, are available to fulfill the requirement of automated sample positioning at the diffraction center and height adjustment with high precision and repeatability.…”