Torsional creep of tin at high temperatures
Zama, Walter Allan
Brotzen, Franz R.
Master of Science
Steady-state creep data are presented for tin tested in torsion at temperatures from 1000C to 228°C. Results obtained below 210°C verify observations of other investigators. A creep activation energy of 22.5 Kcal/mol in this temperature range is determined. Above 210°C, an abnormal increase in the steady-state creep rate is observed. Results are discussed in terms of Weertman's dislocation climb mechanism. Tertiary-creep data are presented for three temperatures near the melting point. It is observed that the strain at which tertiary creep begins is independent of stress, though highly temperature dependent. These results are discussed in terms of current tertiary-creep and creepfracture theories.