Effect of Structural Transformation on the Mechanical and Electrical Properties of Quenched (Pb - 1.5 wt % Sb) Alloy

Creep tests of the quenched (Pb-1.5 wt% Sb) alloy have been carried out under three different constant stresses of 12 MPa, 13 MPa and 15 MPa. Transient and steady state creep of this alloy showed a transition point at 443K. The transient creep parameters (β and n) were found to change with the applied stress and ageing temperature. The activation energy of the transient creep (Qtr ) was found to be 52kJ/mole, and 92kJ/mole, above and below 443 K, respectively. Grain boundary sliding was suggested to be the rate controlling mechanism. Steady state creep of the tested alloy has been investigated around the transformation temperature region. The strain rate sensitivity parameter (m) was found to be in the range (0.11 to 0.33), characterizing a cross - slipping and climb dislocation mechanisms. The microstructure analysis showed that the residual internal strain was relatively recovered and segregated in the phase transformation temperature region. Moreover, the temperature dependence of the relative resistivity ( ) ρ t ρ o change was studied. The energy activating the precipitation process ranged from (0.11 to 0.12eV) suggesting the migration of vacancy and antimony solute atom.