Bc. Ko et al., The effects of SiC particle volume fraction on the microstructure and hot workability of SiCp/AA 2024 composites, J MATER PR, 95(1-3), 1999, pp. 210-215
The hot workability of AA 2024 composites reinforced with different volume
fractions (5, 10, 15, 20, and 30 vol%) of SiCp was investigated within the
temperature range 320-500 degrees C at a strain-rate of 1.0 s(-1). Dynamic
recrystallization (DRX) or dynamic recovery (DRV) of the composites was stu
died from the flow curves and deformed microstructures. The effect of the S
iCp volume fraction on the critical strain for the onset of DRX was analyze
d from the relationship between the work-hardening rate and effective strai
n during hot deformation. The addition of the SiCp to an AA 2024 matrix all
oy increased the dislocation density, resulting in a high flow stress and a
low critical strain for the DRX of the composites. Upon increasing the SiC
p volume fraction, the flow stress and the temperature showing the highest
failure strain increased. Also, the difference in flow stress amongst the c
omposites decreased with increasing deformation temperature. This result ha
s been discussed in relation to dislocation density and stacking fault in t
he matrix of the composites. (C) 1999 Elsevier Science S.A. All rights rese
rved.