Severe plastic deformation to obtain ultra fine grain Silver with high mechanical proprieties

The present contribution is aimed at investigating the microstructure evolution of commercially pure silver under severe plastic deformation conditions. ECAP billets have been produced by using a die with channels intersecting at 90° and straining the samples at room temperature. The evolution of the microstructure as a function of imparted strain was evaluated by scanning electron microscopy as well as X-ray diffractometry. Furthermore, tensile properties were measured from ECAP billets in order to evaluate the strengthening and work hardening behavior of silver as a function of structure evolution.  Comparison in terms of grain structure and corresponding properties are also drawn by considering published data about Al-Mg-Si alloy samples ECAP-processed by identical routes and parameters.

Representative SEM micrographs of Ag samples:
(a) annealed conditions; (b) ultra fine grain structure after 8 passes ECAP.

This work has been produced in the project PRIN2008: Microstructural characterisation through transmission electron microscopy (TEM) of silver and Ag alloys refined by severe plastic deformations (SPD) in which the U.O.S. of IENI - Milano is involved, in collaboration with Politecnico di Milano, University of Torino and University of Padova

Reference
Microstructural and mechanical properties of UFG Silver subjected to severe plastic deformation by ECAP
G. Angella, P. Bassani, S. Farè, N. Lecis, D. Ripamonti, F. Spagnoli, A. Tuissi, M. Vedani. 
The talk was presented in International Conference THERMEC’11, 1-5 August 2011, Quebec City, Canada, and has been published in Mat. Science Forum Vols. 706-709 (2012) pp 1847-1852.

giuliano.angella@ieni.cnr.it