We have investigated the work softening （WS） phenomena during a cold-roll process of an Al-Fe alloy, based on hardness measurements,
electron microscopy observations, and thermodynamic calculations. The WS behavior was conrmed in the Al-Fe alloy when the rolling
rate was larger than 80％, which contained ne grains with severe deformation. In contrast, the behavior and microstructural features were
hardly observed in the A1050 alloy. Composition analyses showed that almost all Fe in the present Al-Fe alloy form the θ-Al13Fe4 phase, in
which a trace impurity element, Si, is found to be signicantly segregated. This Si partitioning behavior is conrmed by the thermodynamic
calculations and consequently leads to a higher purication of the relevant Al matrix as being almost close to the 4N （99.99 mol％） level,
known as a“ scavenging effect” of the impurities. It can be concluded that the highly puried aluminum matrix provides an intrinsic origin of
the WS of the present Al-Fe alloy. Signicant reductions of the impurities may lead to an extended mean-free path of dislocation motions and
related grain boundary effects, which promote the occurrence of dynamic recovery and/or recrystallizations at severe deformation ranges even
during the cold-roll process.