Abstract
Creep data of eutectic tin-silver alloy at temperatures between 298K and 398K has been analyzed using the modified theta projection concept instead of the steady state creep constitutive equation in following formula : ε_<cr>=A{1-exp(-*)}+B{exp(*)-1}, where A, B and α are constants to be experimentally determined. The equation well describes the creep curves of the eutectic tin-silver alloy up to tertiary stage. All constants exhibited power law type relation to the applied stress. The rate constant α has high stress exponent which is attributed to the dispersion strengthening. The rate constant α and the strain factor B only showed temperature dependence, while the strain factor A was independent of temperature. The activation energy for α was 65kJ/mol at low stress and 90kJ/mol at low stress. The energies suggest that the dislocation pipe diffusion and the lattice diffusion are predominant at high stress and low stress, respectively.
