Civil Engineering Reference
In-Depth Information
Upper Grip
Electric Lead
Workpiece
Forging Die
FLIR Camera
Lower Grip
Fig. 5.9
Experimental test setup. The close-up view of the dies and specimen is shown in the
top left-hand corner
5.2.6.1 Force Reduction Due to EAF
Figures
5.10
and
5.11
display the stress-strain profiles of baseline and EAF tests run
at die speeds of 12.7 and 25.4 mm/min, respectively. In both figures, when a higher
current density is applied, the reduction in material flow stress becomes greater. Of
note is that, irrespective of the die speed, the 25 A/mm
2
EAF test reduced the over-
all flow stress compared to the baseline test by approximately 30 % in both cases.
This significant reduction in flow stress signifies that the electrical parameters that
were run were well within the “electroplastic region” with respect to this particular
material. Additionally, when comparing these results with results from Perkins et al.
Fig. 5.10
EAF flow stress
reduction (12.7 mm/min)
[
13
]. The reduction in flow
stress is proportional to the
magnitude of the applied
electricity
1400
CD15
CD10
1200
Baseline
1000
800
CD20
CD25
600
400
200
0
0
0.2
0.4
True Strain
0.6
0.8
1
