Record number :
2165909
Title of article :
Deformation behavior of magnesium in the grain size spectrum from nano- to micrometer
Author/Authors :
Choi، نويسنده , , H.J. and Kim، نويسنده , , Y. and Shin، نويسنده , , J.H and Bae، نويسنده , , D.H.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2010
Pages :
6
From page :
1565
To page :
1570
Abstract :
This study investigates the deformation behavior of magnesium produced by hot extrusion of ball-milled powders in grains ranging from 120 μm down to 60 nm in size. For microcrystalline magnesium, lattice dislocation interactions with grain boundaries and/or twin boundaries provide a Hall–Petch relationship between the flow stress and the grain size. The Hall–Petch slope is negatively deviated as the grain size is reduced below 1 μm since twinning offers an additional deformation mode. As the grain size is further reduced below 100 nm, twinning is significantly suppressed and a portion of grain boundary sliding for plastic deformation increases, providing an inverse Hall–Petch relationship. Microstructure observation, a negligible strain hardening rate, a relatively high index of strain rate sensitivity, and a low activation volume in compression tests also demonstrate the particular deformation behavior of nanocrystalline magnesium.
Keywords :
Deformation behavior , Nanocrystalline metals , Magnesium , Twin , grain boundary sliding
Journal title :
MATERIALS SCIENCE & ENGINEERING: A
Journal title :
MATERIALS SCIENCE & ENGINEERING: A
Serial Year :
2010
Link To Document :
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