A laboratory transmission diffraction Laue setup to evaluate single-crystal quality

Abstract

<jats:p>A scanning laboratory Laue transmission setup is developed to probe extended quasi-monocrystalline samples. Orientation mapping is achieved by controlling the collimation of the incident beam and scanning the position of the specimen. An automated indexing algorithm for transmission Laue patterns is presented, together with a forward simulation model adapted for a laboratory setup. The effect of the main parameters of the system is studied with the aim of achieving exposure times of the order of one second. Applications are presented to probe the orientation of an extended part and detect disoriented regions within the bulk. Finally, the analysis of diffraction spot shapes shows that the misorientation within the illuminated volume can be measured, and a new method is proposed to evaluate its complete mean lattice rotation tensor.</jats:p>

Mechanical Fatigue Testing Under Thermal Gradient and Manufacturing Variabilities in Nickel-Based Superalloy Parts with Air-Cooling Holes

“…Although grain selector restrict crystal primary orientation, a misorientation can still occur during casting and have a major impact on mechanical behaviour. NDT are used to measure that disorientation in industry such as, Auleytner X-ray topography [28] or reflection Laue's Diffraction [29]. That technology is based on X-Ray Diffraction of materials coupled to the Bragg's law : a single crystal will have a specific diffraction pattern.…”