Twin-roll casting of aluminium alloys produces sheets with high solid-solution supersaturation. During high temperature processing the solid solution decomposes and cubic alpha-Al(Mn,Fe)Si precipitates form.
Processing by equal channel angular pressing introduces new grain boundaries into the material and shifts the precipitation to lower temperatures. In-situ annealing in a transmission electron microscope enables dynamic observation of recovery, precipitation, particle dissolution and grain growth.
However, most of the processes observed by in-situ transmission electron microscopy occur at temperatures that are lower than temperatures estimated from specimens annealed conventionally in a furnace.