Civil Engineering Reference
In-Depth Information
Table 5.1
Test combinations
Deformed/Stationary
Current density (A/mm
2
)
Conv./EAF
Die speed (mm/min)
Deformed
Conv.
-
12.7
EAF
10
12.7
Deformed
EAF
15
12.7
Deformed
Deformed
EAF
20
12.7
EAF
25
12.7
Deformed
Conv.
-
25.4
Deformed
Deformed
EAF
15
25.4
EAF
25
25.4
Deformed
EAF
10
-
Stationary
Stationary
EAF
15
-
EAF
20
-
Stationary
EAF
25
-
Stationary
stress per strain as the response. All specimens in this research were made from the
same 4.61 mm-diameter rod of 304 Stainless Steel. An EDM process was used to cut
the specimens to a height of 7.154 mm and to maintain surface finish consistency.
Deformation and stationary electrical tests were run as part of this work. The
deformation tests were run at speeds of 12.7 and 25.4 mm/min, coupled with start-
ing current densities of 10, 15, 20, and 25 A/mm
2
. Further, stationary electrical
tests, where a small static load is applied to the specimen while an electrical cur-
rent is applied, were also run at the same starting current densities as deforma-
tion tests. Three repetitions were run on all test configurations. Of note is that, all
of these tests were consistent with each other; therefore, only a single test will
be plotted which is representative of the three tests for each test combination. All
experimental test combinations can be seen in Table
5.1
.
Figure
5.9
displays the experimental setup for both the deformation and stationary
electrical testing (specimen area is magnified in the upper-left corner of figure). An
Instron Model 1332 hydraulic testing machine was used to compress the specimens
at the desired die speeds. Machined, hardened, and insulated dies, made from A2 tool
steel, were fitted to the Instron machine (insulation was used to isolate the electricity
from the test machine). For thermal measurements, a FLIR A40 M thermal camera,
with a temperature capacity of 550 °C and a resolution of 0.1 °C, was utilized. All
force and position data was gathered using an Instron on-board data acquisition system.
5.2.6 Experimental and Modeling Results
This section contains two subsections. First, several stress-strain profiles will be
shown (conventional and EAF) to illustrate that the various test parameters are
indeed in the electroplastic region, where formability improvements are apparent.
Second, the EEC profiles, obtained using both methodologies, will be compared to
each other.
