Grain boundaries in ultrafine grained materials processed by severe plastic deformation and related phenomena

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:540

Review

Sauvage, X.¹  Wilde, G.²  Divinski, S. V.²  Horita, Z.³  Valiev, R. Z.⁴ 

[1] Univ Rouen, CNRS UMR 6634, Grp Phys Mat, Fac Sci, F-76801 St Etienne, France

[2] Univ Munster, Inst Mat Phys, Munster, Germany

[3] Kyushu Univ, Dept Mat Sci & Engn, Fac Engn, Fukuoka 8190395, Japan

[4] Ufa State Aviat Tech Univ, Inst Phys Adv Mat, Ufa 450000, Russia

关键词: SPD;    UFG;    Grain boundary;    Grain boundary segregation;    Grain boundary diffusion;   

DOI  :  10.1016/j.msea.2012.01.080

来源: Elsevier

【 摘 要 】

Grain boundaries in ultrafine grained (UFG) materials processed by severe plastic deformation (SPD) are often called non-equilibrium grain boundaries. Such boundaries are characterized by excess grain boundary energy, presence of long range elastic stresses and enhanced free volumes. These features and related phenomena (diffusion, segregation, etc.) have been the object of intense studies and the obtained results provide convincing evidence of the importance of a non-equilibrium state of high angle grain boundaries for UFG materials with unusual properties. The aims of the present paper are first to give a short overview of this research field and then to consider tangled, yet unclear issues and outline the ways of oncoming studies. A special emphasis is given on the specific structure of grain boundaries in ultrafine grained materials processed by SPD, on grain boundary segregation, on interfacial mixing linked to heterophase boundaries and on grain boundary diffusion. The connection between these unique features and the mechanical properties or the thermal stability of the ultrafine grained alloys is also discussed. (C) 2012 Elsevier B.V. All rights reserved.

【 授权许可】

Free