Model of Structural Fragmentation Induced by High Pressure Torsion

0347197 - ÚTIA 2011 RIV RU eng J - Journal Article
Kratochvíl, J. - Kružík, Martin - Sedláček, R.
Model of Structural Fragmentation Induced by High Pressure Torsion.
Reviews on Advanced Materials Science. Roč. 25, č. 1 (2010), s. 88-98. ISSN 1606-5131. E-ISSN 1605-8127
Institutional research plan: CEZ:AV0Z10750506
Keywords : High-pressure torsion * intergranular glide * homogeneous deformation mode
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 0.649, year: 2010
http://library.utia.cas.cz/separaty/2010/MTR/kruzik-model of structural fragmentation induced by high pressure torsion.pdf

The paper analyzes mechanisms of ultra-fine grain substructure formation as observed in high pressure torsion (HPT) experiments. Accepting that HPT shearing is achieved by intergranular glide (M. Hafok and R. Pippan, Scripta Materialia, 56:757-760, 2007) the fragmentation process is interpreted within the framework of crystal plasticity. The deformation is treated as a plastic flow though the adjustable crystal lattice fragmented into misoriented regions. The basic feature of the substructure formation is an effective rotation of the slip systems approaching asymptotically the observed steady state. The fragmentation is interpreted as an instability of the homogeneous deformation mode. It is proposed that the rotation causes a continuous reconstruction of the substructure pattern. The hindered destruction of the previous pattern leads to enhanced hardening.
Permanent Link: http://hdl.handle.net/11104/0188029