Dynamic Response of Metals Subject to Rapid DC Current Pulses

Published

June 3, 2013

Author(s)

Steven P. Mates, Graham Cullen, Eran Vax, Eli Marcus, Brad Kinsey

Abstract

Recent investigations indicate that metals will deform plastically at much lower stress levels when subject to high density DC currents due to an influence of electrical current on dislocation motion that is athermal in nature. Practical applications in metal manufacturing have inspired the new research area known as Electrically-Assisted Manufacturing (EAM). While the effect has been investigated at low strain rates, it remains unexplored at high strain rate. We use a unique, electrically-pulse heat tension Kolsky Bar to observe the dynamic plastic response of metals subject to controlled, rapid DC current pulses. Experiments are conducted on 1 mm thick sheet specimens of 304 SS and Ti-6AI-4V. Specimen temperatures are monitored with a thermocouple, and efforts are made to limit the temperature rise in the sample by keeping current pulses to less than 100 ms. Flow stress data are measured with and without DC current flowing, but in both cases current pulses are used to achieve equal specimen heating so as to isolate the effect of current on flow stress from thermal softening. Results indicate that, for current densities up to 180 A/mm2 where strong effects are reported at low strain rates, no noticeable effect is observed at high strain rates.

Proceedings Title

Society for Experimental Mechanics (SEM) Annual Meeting

Conference Dates

June 3-5, 2013

Conference Location

Lombard, IL

Pub Type

Conferences

Keywords

Kolsky Bar, Electroplasticity, High Strain Rate, Titanium, Stainless Steel

Citation

Mates, S. , Cullen, G. , Vax, E. , Marcus, E. and Kinsey, B. (2013), Dynamic Response of Metals Subject to Rapid DC Current Pulses, Society for Experimental Mechanics (SEM) Annual Meeting, Lombard, IL (Accessed May 18, 2024)