Revealing the transient states of rapid solidification in aluminum thin films using ultrafast<i>in situ</i>transmission electron microscopy

Abstract

Using high time resolution transmission electron microscopy, we have observed rapid solidification dynamics in 80 nm thick Al thin films after pulsed laser melting. The nanometer spatial and 15 nanosecond temporal resolution of the dynamic transmission electron microscope (DTEM) at Lawrence Livermore National Laboratory allowed us to study the morphology and dynamics of the transformation front moving at speed of 0.1–10 m/s during rapid solidification. Additionally, we used an automated orientation imaging system in the TEM for the post-mortem analysis of grain orientations of the solidified microstructure near the position of the solid liquid interface at the start of solidification.