Texture evolution in oriented magnesium single crystals processed by equal channel angular pressing

Magnesium single crystals with different initial orientations were processed by single-pass equal channel angular pressing (ECAP) at 503 K. The texture in the crystals after ECAP was investigated by electron backscatter diffraction and compared to texture simulations based on a visco-plastic self-consistent model. The results show that orientation of [0001] and ⟨10 0⟩ axes in single crystals with respect to ECAP die geometry significantly influences activation of various deformation modes and resulting texture evolution. Depending on initial orientation, {10 2} twinning represents an important deformation mechanism at the early stages of forming because it causes reorientation of the matrix to orientations suitable for slip activity. Simulations indicate that, in addition to ⟨a⟩ basal slip, there is an activity of ⟨c + a⟩ pyramidal slip in all crystals. The ⟨a⟩ non-basal slip systems (⟨a⟩ prismatic and ⟨a⟩ pyramidal) were active in crystals containing structure components with [0001] axis parallel to the transverse direction of the ECAP die. Occurrence of this component in resulting texture caused better deformation behavior without crack formation.

[1]  I. Beyerlein,et al.  Microstructure, crystallographic texture, and plastic anisotropy evolution in an Mg alloy during equal channel angular extrusion processing , 2011 .

[2]  P. Lejček,et al.  { }-{ } Double twinning in magnesium , 2011 .

[3]  I. Beyerlein,et al.  Effect of microstructure on the nucleation of deformation twins in polycrystalline high-purity magnesium: A multi-scale modeling study , 2011 .

[4]  P. Lejček,et al.  Characteristics of coincident site lattice grain boundaries developed during equal channel angular pressing of magnesium single crystals , 2011 .

[5]  T. Langdon,et al.  The contributions of grain size, dislocation density and twinning to the strength of a magnesium alloy processed by ECAP , 2010 .

[6]  C. Tomé,et al.  Evaluation of self-consistent polycrystal plasticity models for magnesium alloy AZ31B sheet , 2010 .

[7]  M. Barnett,et al.  Effective values of critical resolved shear stress for slip in polycrystalline magnesium and other hcp metals , 2010 .

[8]  D. Ando,et al.  Relationship between deformation twinning and surface step formation in AZ31 magnesium alloys , 2010 .

[9]  S. Suwas,et al.  Room-temperature equal channel angular extrusion of pure magnesium , 2010 .

[10]  I. Beyerlein,et al.  Evolution of texture in a magnesium alloy processed by ECAP through dies with different angles , 2010 .

[11]  J. Wang,et al.  The effect of hydrostatic pressure on the activation of non-basal slip in a magnesium alloy , 2009 .

[12]  I. Beyerlein,et al.  Plastic flow anisotropy of pure zirconium after severe plastic deformation at room temperature , 2009 .

[13]  B. Klöden,et al.  Texture after ECAP of a cube-oriented Ni single crystal , 2008 .

[14]  Saiyi Li.  Orientation stability in equal channel angular extrusion. Part II: Hexagonal close-packed materials , 2008 .

[15]  S. Suwas,et al.  Evolution of crystallographic texture during equal channel angular extrusion (ECAE) and its effects on secondary processing of magnesium , 2007 .

[16]  Saiyi Li,et al.  Influences of crystallographic orientations on deformation mechanism and grain refinement of Al single crystals subjected to one-pass equal-channel angular pressing , 2007 .

[17]  T. Langdon,et al.  The processing of difficult-to-work alloys by ECAP with an emphasis on magnesium alloys. , 2007 .

[18]  M. O. Lai,et al.  A model for the grain refinement mechanism in equal channel angular pressing of Mg alloy from microstructural studies , 2006 .

[19]  R. Valiev,et al.  Principles of equal-channel angular pressing as a processing tool for grain refinement , 2006 .

[20]  T. Langdon,et al.  Influence of crystal orientation on ECAP of aluminum single crystals , 2006 .

[21]  T. Langdon,et al.  Exceptional superplasticity in an AZ61 magnesium alloy processed by extrusion and ECAP , 2006 .

[22]  P. Liaw,et al.  Texture evolution of five wrought magnesium alloys during route A equal channel angular extrusion: Experiments and simulations , 2005 .

[23]  S. Li,et al.  Non-uniform microstructure and texture evolution during equal channel angular extrusion , 2005 .

[24]  M. Barnett,et al.  Microstructures and textures of pure magnesium deformed in plane-strain compression , 2004 .

[25]  A. Vinogradov,et al.  Microstructure and texture development of copper single crystals deformed by equal-channel angular pressing , 2004 .

[26]  T. Langdon,et al.  Principle of equal-channel angular pressing for the processing of ultra-fine grained materials , 1996 .

[27]  Ricardo A. Lebensohn,et al.  A self-consistent anisotropic approach for the simulation of plastic deformation and texture development of polycrystals : application to zirconium alloys , 1993 .

[28]  Ricardo A. Lebensohn,et al.  A model for texture development dominated by deformation twinning: Application to zirconium alloys , 1991 .

[29]  U. F. Kocks,et al.  The relation between macroscopic and microscopic strain hardening in F.C.C. polycrystals , 1984 .

[30]  Kenneth W. Neale,et al.  Analysis of texture evolution in magnesium during equal channel angular extrusion , 2008 .

[31]  M. Barnett,et al.  Non-Schmid behaviour during secondary twinning in a polycrystalline magnesium alloy , 2008 .