skip to main content

SciTech ConnectSciTech Connect

Title: Electric current induced flow of liquid metals: Mechanism and substrate-surface effects

Long range, continuous flow of liquid metals occurs upon application of an electric current. Here, we report experimental results elucidating the mechanism of current-induced liquid metal flow, and its dependence on substrate surface condition. It is shown that the observed flow is diffusion-controlled, with the flow-rate depending linearly on applied current density, indicating that it is driven by electromigration. The effective charge number for liquid electromigration, Z*, of several pure metals, such as Al, Bi, Ga, Sn, and Pb, were deduced from the experimental results and were found to be close to the elemental valency. With the exception of liquid Pb, Z* for all liquid metals tested in this study were positive, indicating that: (i) electron wind contributes much less to Z* in liquid metals than in solids, and (ii) with a few exceptions, liquid metals generally flow in the direction of the electric current. On smooth substrates which are wetted well by the liquid metal, flow occurs in a thin, continuous stream. On rough surfaces which are poorly wetted, on the other hand, discrete beads of liquid form, with mass transport between adjacent beads occurring by surface diffusion on the substrate. A rationale for the role of substrate roughnessmore » in fostering this observed transition in flow mechanism is presented.« less
Authors:
 [1] ; ;  [2]
  1. Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India)
  2. School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164 (United States)
Publication Date:
OSTI Identifier:
22275606
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM; CURRENT DENSITY; DIFFUSION; EFFECTIVE CHARGE; ELECTRIC CURRENTS; ELECTRONS; ELECTROPHORESIS; FLOW RATE; GALLIUM; LEAD; LIQUID METALS; ROUGHNESS; SOLIDS; SUBSTRATES; SURFACES; TIN; VALENCE