Direct beam x-ray imaging, with intense coherent monochromatic synchrotron radiation and a fast readout low noise detector has been used for in situ studies of cellular and dendritic solidification of Sn-Pb alloys. Temporal and spatial resolutions down to $\sim 0.7\mathrm{s}$ and $\sim 2.5\mu \mathrm{m}$, respectively, with a field of view up to $1{\mathrm{mm}}^2$ were obtained. The collected images display features from both phase and amplitude contrast which, combined with the attainable temporal resolution, provide a method with the potential to uncover dynamic processes in nonequilibrium solidification.

• Received 2 July 1999

DOI:https://doi.org/10.1103/PhysRevLett.83.5062