E. Tzimas et A. Zavaliangos, Mechanical behavior of alloys with equiaxed microstructure in the semisolid state at high solid content, ACT MATER, 47(2), 1999, pp. 517-528
The mechanical response in compression of A2014 and Al-4 wt% Cu alloys with
equiaxed microstructure in the semisolid state at high volume fraction of
solid (>0.6) is studied. When the amount of liquid is low, deformation in c
ompression is highly non-uniform due to strain localization. In the range o
f conditions examined no phase segregation was detected. The stress-strain
curve exhibits a peak at low strain, around 5-10%, and then decreases to a
plateau value. Secondary phase particles in A2014 that remain solid in the
semisolid range of the alloy are responsible for the lower peak and higher
plateau stress compared to Al-4 wt% Cu alloy. The effect of the grain size
for the alloys tested was small. Strain rate jump experiments show that the
instantaneous strain rate sensitivity in the semisolid state is similar to
that of the solid phase. As the volume fraction of solid decreases, the pl
ateau stress becomes rate insensitive to the strain rate jump. The results
allow the relative importance to be assessed of various mechanisms responsi
ble for resistance to flow of semisolid alloys with equiaxed microstructure
in compression. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Scie
nce Ltd All rights reserved.