Effect of cross slips on deformation microstructure and recrystallization in < 111 > and < 001 > Al single crystals

Citation
M. Tagami et al., Effect of cross slips on deformation microstructure and recrystallization in < 111 > and < 001 > Al single crystals, MATER TRANS, 42(9), 2001, pp. 2013-2020
Citations number
21
Language
INGLESE
art.tipo
Reprint
Categorie Soggetti
Material Science & Engineering
Journal title
MATERIALS TRANSACTIONS
ISSN journal
1345-9678 → ACNP
Volume
42
Issue
9
Year of publication
2001
Pages
2013 - 2020
Database
ISI
SICI code
1345-9678(200109)42:9<2013:EOCSOD>2.0.ZU;2-5
Abstract
(111) and (001) aluminum single crystal specimens with 99.99 mass% purity w ere deformed in tension to strains of about 20%. In all specimens, multiple slip structures without deformation bands were observed, In (111) specimen deformed at room temperature of 293 K (RT), fine wavy slip traces are reco gnized because of the difficulty of cross slips. The difficulty is due to t he tensile-orientation dependence of cross slips. The dislocation structure shows layered cell structures composed of cell walls with high dislocation density. In (001) specimen deformed at liquid nitrogen temperature of 77 K (LNT), complex fine slip traces similar to those in the case of (111) RT s pecimens are also observed because of the difficulty of cross slips. This d ifficulty is due to the temperature dependence of cross slips, The dislocat ion structure is composed of small isotropic cells with high dislocation de nsity around their cell walls. In the above two kinds of deformed aluminum single crystals, the formation of recrystallized grains (RGs) is very easy. On the other hand, in the (001) specimen deformed at RT, many cross slips with large steps are seen because all the eight primary slip systems have a n appropriate cross (i.e. another primary) slip system geometrically. The d islocation structure gives polygonal cells with low dislocation density. Af ter annealing no recrystallized grain is formed in the specimen. The stress values of the stress-strain curves in the (001) (RT), (111) (RT) and (001) (LNT) specimens are 22 MPa at 25% strain, 71 MPa at 22% and 106 MPa at 20% , respectively.