48 Prakt. Met. Sonderband 38 (2006) 
DRX. MDRX differs from SRX in a number of significant ways [15]. First, the rate of MDRX If Vv. 
is sensitive to the prior strain rate but is relatively insensitive to the strain and temperature. nuc 
Conversely, the rate of SRX strongly depends on the pre-strain and temperature, but only Fig. 
slightly on the strain rate. Additionally, MDRX only completes the DRX cycles, whereas ider 
SRX forms new nuclei, which of course needs incubation time, and can only take place if ang 
there is no moving MDRX front. Therefore, specimens with different pre-strains and soak pre 
times were used in order to elucidate the microstructures caused by MDRX and SRX. The the 
influence of the previous mentioned parameters are clearly demonstrated in Fig. 6. For a Bes 
soak time of 1s, which can be related to DRX and MDRX predominately, the fraction of wer 
recrystallized grains is small and there is only slight increase of this fraction due to the pre- indi 
strain. In the opposite after a soak time of 10s the number of recrystallized grains is grai 
significantly increased and in addition there is an obvious increase of the recrystallized DR 
fraction with increasing pre-strain. This behaviour can be assigned to SRX. take 
with 
whe 
rece 
« | £20.07, t=1s £=0.07, t=10s diffe 
* ! ) ’ aris 
incr 
indi 
=0.12, t=1s £=0.12, t=10¢ the 
pre- 
£=0.17, t=1s ¢=0.17, t=10s 
£=0.27, t=1s §=0.27, t=10s 
Fig. 6: Grain maps of partly recrystallized microstructures for different pre-strains and two 
soak times. The black areas represent the deformed fraction (all twins removed). 
4. 
The 
bacl 
the 
frac 
strai 
(a) (b) sign 
Fig. 7: Metadynamic and static recrystallization: unrecrystallised grains and small angle Grai 
misorientations 1°-5°, >2° at £=0.27 and t=1s; large white area: advanced growing MDRX did | 
grains, single arrows: growing MDRX or SRX nuclei, double arrow: possible SRX stror 
nucleation sites; image (b) is a magnification of image (a); Image size: 1729x732um (a) obs 
and 532x347um (b).