The Influence of Deformation History on Creep of Pure Copper

Summary

A series of combined stress tests in tension-torsion space was performed on thin-walled tubes of M1E commercially pure copper. Interaction between plastic and creep deformations was studied experimentally with respect to creep behaviour subsequent to plastic pres train ing. In combined plasticity-creep tests, specimens were first prestrained plastically at the room temperature in axial tensile or pure torsional directions, and were subsequently subjected to constant stress creep under various biaxial states with the two identical effective stress σ_i=31 and 41 [MPa] at 573K. Results for virgin material were utilized to verify of the basic assumptions of the quasi-linear creep theory. The stationary creep rates either for virgin copper or the same material plastically prestrained have been described using a modified Norton’s law.