In situ and real-time analysis of TGZM phenomena by synchrotron X-ray radiography

Metal Foaming Investigated by X-ray Radioscopy

“…Synchrotron radioscopy featuring good spatial (in the µm-range) and time resolution (<1 s) is suitable for in-situ analyses of various phenomena in materials science and was successfully applied in recent years [4][5][6][7][8][9][10][11] as will be reviewed for a few examples closely related to the foaming process including solidification, diffusion and flow in metals.…”

“…It can be either columnar, equiaxed or mixed, and the factors influencing its formation and evolution need to be studied. In-situ synchrotron X-ray radioscopy of the solidification process was performed in the past years, for example by groups in Norway and France, which studied the solidification behavior of different alloys [4][5][6][7][8]. They were able to observe directly dendrite fragmentation, porosity formation, directional and equiaxed dendritical solidification, phase separation and even fluctuations in elemental concentration at the solidification front in Al-based alloys.…”

Mushy Zone Coarsening in an AlCu30 Alloy Accelerated by a Rotating Magnetic Field

“…It was pointed out by Nguyen Thi et al [19] that fluid flow modifies the rate of mush change during a temperature gradient anneal. They compared experiments with AlNi and AlLi alloys performed on earth (natural convection) and in space (microgravity).…”

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

“…thermal conductivity, heat capacity, chemical potentials, etc.). 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.…”

“…While our experiments did not provide sufficient statistical data regarding the frequency of such events, they are a longidentified problem. [1,10,11] In addition to strengthening our understanding of fundamental mechanisms at the origin of solidification defects, [6][7][8][9][10][19][20][21][22][23][37][38][39][40][41][42][43][44][45][46][47][48][49] in situ x-ray imaging with real-time monitoring and feedback control could be used to adapt processing routes to mitigate defects as they form and are detected. For instance, one could "erase" a microstructure by remelting it, and then control the subsequent microstructural development by refinement and live management of the processing parameters during solidification.…”