New creep region in pure face-centered cubic metals at low temperatures

Creep behavior was investigated carefully for typical face-centered cubic (fcc) metals, i.e., high purity Al, Cu, and Pb, below 0.3Tm, where Tm is the melting temperature. All samples showed marked creep behavior at such low temperatures, with an apparent activation energy of 15–30 kJ mol−1, a stress exponent of 2–5 and a grain size exponent of 0. These results show a new creep region that has not appeared in deformation mechanism maps of pure fcc metals.