Yr. Kolobov et al., Effect of the grain-boundary state and grain size on the mechanisms of creep of submicrocrystalline nickel, PHYS MET R, 91(5), 2001, pp. 532-537
The effect of preliminary annealings at temperatures below the recrystalliz
ation temperature (T < 573 K) on the microstructure and activation energy o
f creep (Q(c)) at T = 423 and 473 K of submicrocrystalline nickel obtained
by severe plastic deformation (equal-channel angular pressing) was studied.
The substantial change in the magnitude of Q(c) in the samples after such
"hyporecrystallization" annealings, in which only the specific grain-bounda
ry state changes without changes in grain size, is explained as a consequen
ce of various contributions of grain-boundary sliding to the total deformat
ion upon creep.