Table of Contents
ISRN Materials Science
Volume 2012 (2012), Article ID 698158, 9 pages
http://dx.doi.org/10.5402/2012/698158
Research Article

Numerical Simulation of the Temperature and Stress Field Evolution Applied to the Field Assisted Sintering Technique

1Computational Science and Engineering Division, U.S. Army Engineer Research and Development Center, Vicksburg, MS 39180-6199, USA
2Department of Materials, Imperial College London, London SW7 2AZ, UK

Received 17 January 2012; Accepted 16 February 2012

Academic Editors: U. Gomes and N. Uekawa

Copyright © 2012 J. B. Allen and C. Walter. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The field assisted sintering technique (FAST) is a high-amperage, low-voltage, powder consolidation technique that employs pulsed direct current and uniaxial pressure. Over the past several years, FAST has been successfully used to produce a variety of different materials including metals, composites, and ceramics. In this paper we present a transient finite element model of aluminum oxide sintering that incorporates a coupled electrical, thermal, and mechanical analysis that closely resembles the procedures used in physical experiments. Within this context, we outline the governing equations that pertain to a balanced energy equation and include the effects of thermal and electrical contact forces, radiation, and Joule heating. We couple this with the relevant equations pertaining to mechanical displacements and prescribe the necessary initial and boundary conditions for a complete solution. As part of our transient analysis, we also present our implementation of a proportional integral derivative controller, which (similar to actual experimental conditions) affords the use of a predetermined heating rate conditioned upon a variable voltage. Finally, we discuss implications relating to the temperature and stress fields and suggest possible avenues for improvement.