Estimation of electrical heating load-shares for sintering of powder mixtures

Abstract

Rapid, energy-efficient sintering of materials comprised heterogeneous powders is of critical importance in emerging technologies where traditional manufacturing processes may be difficult to apply. In particular, electrically aided sintering, which uses the material's inherent resistance to flowing current—resulting in Joule heating to bond the powder components—has great promise because it produces desired materials without much post-processing. Furthermore, it has advantages over other methods, such as high purity of processed materials, in particular, because there are few steps during the approach. In order to electrically process the material properly, one must ascertain the externally applied field to properly Joule heat the various material components in the powder mixture. The Joule-heating field is mathematically expressed by the inner product ( J ⋅ E ) of the current ( J ) and electric ( E ) fields throughout the system. This study develops estimates for the Joule-heating fields carried by each phase in a powder mixture, using knowledge of only the externally applied current, and the material properties of the components comprising the mixture. These estimates are useful in guiding and reducing time-consuming material synthesis involving laboratory experiments and/or large-scale numerical simulation.