Abstract
Precipitation in deformed and undeformed Al-300 ppm Fe alloy has been investigated by means of resistivity measurements and transmission electron microscopy. The undeformed specimens were solution-heat-treated at 913 K for 3.6 ks, quenched in iced water and then aged at the temperatures between 393 and 848 K, while the deformed specimens were cold-drawn for resistivity measurement or cold-rolled for TEM observations after the same solution heat treatment, and then aged. Resistivity in the undeformed specimens decreased in two stages, while in the deformed specimens, resistivity decreased in two or three stages depending on aging temperatures. Time-Temperature-Precipitation (TTP) diagram for the undeformed specimens consisted of one C-curve which corresponded to precipitation of stable Al3Fe. The TTP diagram for the 65% cold-drawn specimens was separated into two C-curves: the curves in high and low temperature ranges corresponded to precipitation of Al3Fe and Al6Fe, respectively. The precipitation of metastable Al6Fe was observed only in the cold-rolled specimens. Acceleration effects of cold drawing on Al3Fe precipitation were hardly recognized.
