Uwe Preckwinkel

Texture Analysis with Area Detectors

Starting from simple geometric considerations concerning directions and orientations, intelligent strategies for pole figure measurements were developed for the area detector. The amount and quality of texture information contained in measured or available data sets can be directly controlled. The texture approximation is done by the component method. The method does not have any restrictions concerning the grids of sample directions in the pole figures. An almost constant information depth can be obtained at a low angle of incidence of the primary beam for the study of thin surface layers.

D009 Retractable Knife-Edge for XRD Combinatorial Screening

A motorized retractable knife-edge (patent pending) for two-dimensional X-ray diffraction is introduced for combinatorial screening at low Bragg angles. The knife-edge can control the size of the viewed diffracting sample surface, so as to improve diffraction resolution and eliminate cross contamination between adjacent cells in the materials library. It also reduces the background by blocking off the primary beam air scatter. The retractable knife-edge can be driven into two positions, retracted position for automatic sample alignment and sample viewing, and extended position for data collection.

Stress and Texture Analysis with Two-Dimensional X-Ray Diffraction

Two-dimensional x-ray diffraction (XRD 2 ) refers to x-ray diffraction applications with two-dimensional (2D) detector and corresponding data reduction and analysis. The two-dimensional diffraction pattern contains far more information than a one-dimensional profile collected with the conventional diffractometer. In order to take the advantages of the 2D detector, new approaches are necessary to configure the two-dimensional x-ray diffraction system and to analyze the 2D diffraction data. The present paper is an introduction to some fundamentals about stress and texture analysis with two-dimensional x-ray diffraction using the Bruker GADDS system as an example.

Gage R&R Study on Residual Stress Measurement System with Area Detector

Gage repeatability and reproducibility (Gage R&R) test is a statistic quality control method for evaluating the precision of a measurement system. By evaluating large amount of measurements performed by several operators on certain number of parts for several times, the method estimates a measurement system on its repeatability, reproducibility, part to part variation, and variation of the total system. The residual stress measurement system evaluated in this study is a Bruker General Area Detector Diffraction Systems (GADDS). Gage R&R test shows that the overall measurement error is 6% or less. The repeatability error of the system is 5.5% or less, and the reproducibility error is 2.3% or less.