Premium
Prismatic Slip in Beryllium and the Relative Ease of Glide in H.C.P. Metals
Author(s) -
Regnier P.,
Dupouy J. M.
Publication year - 1970
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.19700390110
Subject(s) - beryllium , slip (aerodynamics) , materials science , crystallography , ribbon , stacking , basal plane , dislocation , stacking fault energy , stacking fault , condensed matter physics , geometry , composite material , chemistry , physics , thermodynamics , mathematics , nuclear magnetic resonance , organic chemistry
The macroscopic C.R.S.S. for prismatic slip in Beryllium is found to increase with increasing temperature in the range −100 to +50 °C while the microyield limit decreases regularly. Slip is initiated on the prism planes from the edge dislocations present in the annealed material. Evidences of a thermally activated locking of screw dislocations are presented. This locking is thought to occur by the usual splitting in the basal plane. The assumption that the a dislocations can also dissociate in the prismatic plane seems necessary to account for the activation of this locking. Possible dissociations in the prismatic plane are proposed; the most probable of them is a → a / 3 + 2 a / 3 . It gives a ribbon of stacking fault corresponding to the transformation of two {10 1 0} h.c.p. “flat planes” into two {112} b.c.c. planes. It is suggested that there is a relationship between the energy of the stacking fault on the prismatic plane and the temperature of the phase transformation h.c.p. → b.c.c. This relationship permits to account for the relative ease of slip in h.c.p. metals.