Transient and steady state creep of Al-4.5 wt.% Mg during phase transformation
Abstract
Transient and steady state creep of Al-4.5 wt. % Mg alloy was studied under various constant stresses ranging from 91 MPa to 117 MPa in the temperature range from 473 K to 553 K. The results of creep characteristics have shown two main deformation temperature regions (below 493 K and above 513 K as well as a transient region between these temperatures). Peak values of transient creep parameters B and n were obtained at 493 K. The transient creep parameter B was related to the steady state creep rate ɛst through the exponent γ which was found to range from 0.85 to 0.5. The stress exponent m' of the steady state creep has been found to be minimum at the steady state strain peaks, which is characteristic of dislocation climb along the grain boundaries. Microstructural analysis confirmed that the above mentioned mechanism took place in the dissolution region of β-phase.
- Publication:
-
Czechoslovak Journal of Physics
- Pub Date:
- October 1991
- DOI:
- 10.1007/BF01598970
- Bibcode:
- 1991CzJPh..41..967K