Compact x-ray microradiograph for in situ imaging of solidification processes: Bringing in situ x-ray micro-imaging from the synchrotron to the laboratory

Abstract

A laboratory based high resolution x-ray radiograph was developed for the investigation of solidification dynamics in alloys. It is based on a low-power microfocus x-ray tube and is potentially appropriate for x-ray diagnostics in space. The x-ray microscope offers a high spatial resolution down to approximately 5 μm. Dynamic processes can be resolved with a frequency of up to 6 Hz. In reference experiments, the setup was optimized to yield a high contrast for AlCu-alloys. With samples of about 150 μm thickness, high quality image sequences of the solidification process were obtained with high resolution in time and space.

The Use of In Situ X-ray Imaging Methods in the Research and Development of Magnesium-Based Grain-Refined and Nanocomposite Materials

“…This confirms that a higher zirconium addition level indeed enhances grain size reaches a minimumrefinement, as well as that a higher cooling rate leads to finer grains. The last-mentioned grain-size value of ~170 µm, beingin this set appears to be in reasonablefair agreement with earlier grain-refinement efficiency tests using a Mg-Nd-Zn alloy [4]. Also, an increased sensitivity to the 5].…”

“…Associated with the differences in the used imaging principles and instruments, there are also differences in the capabilities of the two methods [4]. Where micro-focus X-ray radiography can be implemented as a stand-alone facility and be based for most on commercially available X-ray sources and other components, synchrotron X-ray tomography requires access to one of the few dedicated large-scale facilities.…”

Equiaxed dendritic solidification and grain refiner potency characterised through in situ X-radiography

“…1(a) schematically illustrates the experimental configuration employed in this work, comprising a microfocus X-ray source (Viscom XT9100-T), solidification furnace (XRMON-GF), and a specialised digital camera (Vosskuhler 11000) equipped with a Scint-X scintillator. A spatial field-of-view (FOV) of 4327 Â 2882 lm was obtained, giving a virtual pixel size of $2.16 lm at the CCD, with a maximum spatial resolution of $7 lm, which is a function of the source size, the chosen geometric magnification, and the scintillator pitch [19]. Optimal operating parameters for the X-ray source, providing the best compromise between sample transmission and absorption contrast for the chosen alloy system, was calibrated to 50 keV and 60 lA.…”

“…horizontal beam and vertical sample [16,17]. Recent advances in compact microfocus X-ray source and detector technology have allowed solidification experiments, with spatiotemporal resolutions comparable to those reported in synchrotron-based studies, to be performed in home-laboratories [18,19] as well as under microgravity conditions on-board parabolic flights [20] and sounding rockets [21]. This article describes the results of extensive terrestrial-based near-isothermal in situ solidification experiments of Al-Ti-B inoculated and non-inoculated Al-Cu alloy samples using the XRMON-Gradient Furnace (GF) and associated X-ray diagnostics [21].…”

X‐ray Imaging and Controlled Solidification of Al‐Cu Alloys Toward Microstructures by Design

“…Since early developments of synchrotron x-ray radiography for observing metal and alloy solidification, [10,[21][22][23] Al-based alloys have been extensively used to study numerous solidification aspects, from dendritic fragmentation, [6][7][8][9] columnar-to-equiaxed transition, [8,37,38] temperature gradient zone melting, [39] melt convection, [40] gravity, [41] polycrystalline solutal interactions, [42] and dendritic coarsening, [43] to semi-solid deformation [44][45][46][47][48] and permeability, [49] just to name a few. More recently, "microfocus" x-ray sources [50] have provided additional tools for real-time metal and alloy observations, enabling in situ imaging with laboratory-sized equipment previously only possible at large synchrotron facilities. [51] In situ imaging has deepened our understanding of fundamental mechanisms associated with solidification processing.…”