TY - JOUR

T1 - Hot working mechanisms and texture development in Mg-3Sn-2Ca-0.4Al alloy

AU - Dharmendra, C.

AU - Rao, K. P.

AU - Prasad, Y. V.R.K.

AU - Hort, N.

AU - Kainer, K. U.

PY - 2012/10/15

Y1 - 2012/10/15

N2 - Hot deformation mechanisms in Mg-3Sn-2Ca (TX32) alloy containing 0.4% Al are evaluated in the temperature and strain rate ranges of 300-500 °C and 0.0003-10 s-1 using processing map and kinetic analysis. The evolution of microstructure and texture during high temperature compression of the alloy has been studied using an electron back scatter diffraction (EBSD) technique. The processing map for hot working revealed two domains of dynamic recrystallization (DRX) occurring in the temperature and strain rate ranges of: (1) 300-360 °C and 0.0003-0.001 s-1 and (2) 400-500 °C and 0.005-0.7 s-1, which are the two safe hot workability windows for this alloy. A regime of flow instability occurs at higher strain rates and lower temperatures where adiabatic shear banding and flow localization are the microstructural manifestations. The onset of DRX during compression at lower temperatures and strain rates (Domain 1) resulted in a fine, partially recrystallized and necklaced grain microstructure along with a texture where the basal poles are spread along 30° from the compression direction. Specimens deformed at temperatures higher than 450 °C (Domain 2) resulted in a fully recrystallized microstructure and an almost random crystallographic texture, which was attributed to the significant occurrence of pyramidal slip and associated cross-slip.

AB - Hot deformation mechanisms in Mg-3Sn-2Ca (TX32) alloy containing 0.4% Al are evaluated in the temperature and strain rate ranges of 300-500 °C and 0.0003-10 s-1 using processing map and kinetic analysis. The evolution of microstructure and texture during high temperature compression of the alloy has been studied using an electron back scatter diffraction (EBSD) technique. The processing map for hot working revealed two domains of dynamic recrystallization (DRX) occurring in the temperature and strain rate ranges of: (1) 300-360 °C and 0.0003-0.001 s-1 and (2) 400-500 °C and 0.005-0.7 s-1, which are the two safe hot workability windows for this alloy. A regime of flow instability occurs at higher strain rates and lower temperatures where adiabatic shear banding and flow localization are the microstructural manifestations. The onset of DRX during compression at lower temperatures and strain rates (Domain 1) resulted in a fine, partially recrystallized and necklaced grain microstructure along with a texture where the basal poles are spread along 30° from the compression direction. Specimens deformed at temperatures higher than 450 °C (Domain 2) resulted in a fully recrystallized microstructure and an almost random crystallographic texture, which was attributed to the significant occurrence of pyramidal slip and associated cross-slip.

KW - Electron diffraction

KW - Hot working

KW - Metals

KW - Microstructure

KW - Recrystallization

KW - Thermomechanical effects

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=84867398963&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/541db9be-6846-3cd3-a0e0-b7f746dfe58b/

U2 - 10.1016/j.matchemphys.2012.08.054

DO - 10.1016/j.matchemphys.2012.08.054

M3 - Journal articles

AN - SCOPUS:84867398963

VL - 136

SP - 1081

EP - 1091

JO - Materials Chemistry and Physics

JF - Materials Chemistry and Physics

SN - 0254-0584

IS - 2-3

ER -