Direct observation of particle flow in semi‐solid alloys by synchrotron X‐ray micro‐radioscopy

Abstract

Abstract The flow of a semi‐solid aluminium–germanium alloy Al–Ge32 (wt.%) into a thin cavity was monitored by in situ micro‐radioscopy using polychromatic hard X‐ray synchrotron radiation. X‐ray images were recorded at an acquisition speed of 67 frames/s using an indirect X‐ray pixel detector in combination with a CMOS camera. Liquid drainage and de‐/re‐agglomeration of small aluminium‐rich solid particle clusters – associated with the slurry's thixotropic behaviour – could be visualized. The technique and first results obtained are discussed in terms of their future application and possible improvements. magnified image Radiographic image sequence showing fast injection of semi‐solid slurry into the mould. Solid Al‐rich particles appear brighter than the surrounding liquid Al–Ge melt.