INVESTIGADORES
BOLMARO Raul Eduardo
congresos y reuniones científicas
Título:
Cube texture due to dynamic recrystallization in Pb and PbSn alloys under Equal Chanel Angular Extrusion processing
Autor/es:
R.E. BOLMARO; V. L . SORDI; M. FERRANTE; WEIMIN GAN; H.-G. BROKMEIER
Lugar:
Pittsburg
Reunión:
Congreso; XVth International Conference on Texture and Microstructure; 2008
Institución organizadora:
Carnegie Melon University. Materials Science Department.
Resumen:
ECAE has been one of the most prolific techniques in the study of severe deformations of metallic alloys. The case of severe deformation on low melting temperature alloys has not been studied due to the high dynamic recrystallization effects they usually present. In the current presentation we show ECAE deformation experiments performed in a 120o tool at room temperature in pure Pb and near eutectic composition PbSn alloy. The samples were passed 5 times in a route A. After each pass they showed a completely recrystallized structure under metallographic observation. Due to the high absorption presented for X-rays by Pb the sample textures were measured by neutron diffraction. Because of their high penetration and superior statistical capabilities the textures showed well defined patterns even in the cases when the strengths were rather weak. The textures presented a well defined cube texture rotated between 20 and 25 degrees around an axis coincident with the transversal direction. Even on the two-phase PbSn samples the cube component was clearly the major and better defined one. Despite Pb is a low stacking fault energy FCC metal, that orientation shows a recrystallization behavior resembling the regular static recrystallization texture presented by high stacking fault FCC materials after rolling processing. The nature of the recrystallization process is discussed tacking in account the texture results. Because of the severe deformation it is possible that the subgrain size due to fragmentation might have reached a value close to the grain thickness and geometrical dynamic recystallization is the most probable mechanism. That hypothesis is difficultly testable because of the readily occurring recrystallization.
