2002 article

Thermally activated plastic flow of metals and ceramics with an electric field or current

Conrad, H. (2002, January 15). MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, Vol. 322, pp. 100–107.

By: H. Conrad n

co-author countries: United States of America πŸ‡ΊπŸ‡Έ
author keywords: electric current pulses; electric field; electron wind; electron push coefficient; electrochemical potential; space-charge
Source: Web Of Science
Added: August 6, 2018

The effects of high density electric current pulses (103–106 A cmβˆ’2) on the flow stress of metals at low homologous temperatures and of a modest external electric field on the flow stress of fine-grained oxides at high temperatures is presented. The results in both cases are evaluated in terms of thermally-activated plastic deformation processes. In the case of the metals, the influence of an electron wind on each of the parameters in the equation for the thermally-activated motion of dislocations was determined, the largest effect being on the pre-exponential. The derived electron wind push coefficient was one or more orders of magnitude larger than the value normally accepted for the electron drag coefficient. In the case of the oxides, the substantial effect of an applied electric field on the flow stress was evaluated in terms of its influence on the electrochemical potential of vacancies in the space-charge cloud adjacent to the grain boundaries. Both the derived space-charge cloud width and the electric potential/stress parameter Ξ”βˆ…/Δσ are in reasonable accord with theoretical predictions.