[1] Univ Minho, Ctr Fis, P-4710057 Braga, Portugal
[2] Inst Pedro Nunes, Lab Ensaios Desgaste & Mat, P-3030199 Coimbra, Portugal
[3] Univ Coimbra, Dept Mech Engn, SEG CEMUC, P-3030788 Coimbra, Portugal
[4] Univ Porto, Fac Engn, Dept Engn Met & Mat, P-4200465 Oporto, Portugal
[5] Univ Franche Comte, CNRS, Inst FEMTO ST, UMR 6174,ENSMM,UTBM, F-25030 Besancon, France
[6] Univ Lisbon, Inst Super Tecn, Ctr Ciencias & Tecnol Nucl, P-2695066 Bobadela, Lrs, Portugal
[7] Univ Lisbon, Inst Super Tecn, Inst Plasmas & Fusao Nucl, P-2695066 Bobadela, Lrs, Portugal