Aluminium-rich Stray Crystal
2,590 views · Published 26 April 2015 · 0:36 · Indexed 25 October 2026
Channel: bhadeshia123 · 2015 · Education
Stray Crystal Growth in an Aluminium-Copper Alloy A.J. Clarke, S.D. Imhoff, P.J. Gibbs, J.W. Gibbs, D. Tourret, K. Fezzaa Los Alamos National Laboratory Advanced Photon Source, Argonne National Laboratory X-ray imaging permits the microscopic visualization of metal alloy solidification dynamics. Here we witness early stage growth of an aluminium-rich crystal in an aluminium-16at.%copper (aluminium- 31 wt%copper) alloy, just after nucleation in the melt ahead of the advancing eutectic solid interface. The aluminium-rich dendrite is less dense than the liquid, so it floats and later becomes trapped within the lamellar, two-phase eutectic solid. The section thickness is about 200 micrometres, the thermal gradient (G) is about 137 K/cm, the eutectic interfacial velocity (V) is ≈ 4.0 micrometres per second, and the cooling rate is about 3.3 K/min. X-ray imaging was performed at Argonne National Laboratory’s Advanced Photon Source (Argonne, IL, USA) at 18 keV. This work was supported by A.J.C.’s Early Career award from the U.S. DOE, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering. Additional details are available in the open access article by A.J. Clarke et al. entitled “X-ray imaging and controlled solidification of Al-Cu alloys toward microstructures by design”, Advanced Engineering Materials 2015, 17(4):454-459, or please feel free to contact Amy Clarke at [email protected]. Video courtesy of Amy Clarke
