High-energy x-ray diffractometer for nondestructive strain depth profile measurement.

We describe a lab-based high-energy x-ray diffraction system and a new approach to nondestructively measuring strain profiles in polycrystalline samples. This technique utilizes the tungsten K(α1) characteristic radiation from a standard industrial x-ray tube. We introduce a simulation model that is used to determine strain values from data collected with this system. Examples of depth profiling are shown for shot peened aluminum and titanium samples. Profiles to 1 mm depth in aluminum and 300 µm depth in titanium with a depth resolution of 20 µm are presented.