Quasi-elastic strain fields in a lattice of SnSbCu alloy during creep

Apparent steady state creep of Sn0.65Sb0.25Cu0.10Sn0.65Sb0.25Cu0.10 alloy is studied under different constant stresses ranging from 19.27 to 21.67 MPa near the transformation temperature ≅443K. Analysis creep data in the quasi-steady state regime at 443 K reveals an anomalous creep behavior with a strain rate sensitivity parameter m   changing from 0.15±0.01 to 0.33±0.01 which points to cross-slipping dislocation mechanism. The activation energy for creep deformation, QstQst, was determined to be 45.47±5.96 kJ/mole in the temperature region investigated. The experimental results obtained of QstQst are compared with those predicted by Friedel–Jaffe–Dorn and Escaig cross-slip models. The results indicated that the rate controlling dominant mechanism for creep regime is cross-slip of screw dislocations. X-ray and microstructural analysis supports that the relaxation of the internal lattice strain fields takes place during apparent steady state creep.