Creep Behavior
Abstract:
Transient creep tests are performed under constant stress conditions at temperatures ranging from 533 to 653˚ K for Cu-38wt%Zn, and Cu-38wt%Zn-2wt% Pb samples. The transient creep is described by _tr= βt^n, where _tr and t are the transient creep strain and time. However, the parameters n, β are calculated, and the activation energy of the transient creep shows for both alloy two regions at low and high temperatures. Also, the activation energy were determined to clarify the controlling mechanism. At low temperature rang (240-360˚C), the strain rate sensitivity parameter m has values (0.247-0.174) while its values at high temperatures ranging from (0.192 up to 0.263) at 653˚K. These values give an indication that dislocation glide is probably an operating mechanism is grain boundary diffusion. Also, the change of microstructure was studied, grain size, microhardness, and stress-strain behavior has been studied too.

Keywords: Transient creep, Cu-Zn-Pb, lattice-diffusion, dislocations.