Powder Technology, Vol.256, 540-544, 2014
Colloidal processing of highly concentrated aqueous copper suspensions
This work deals with the preparation of copper dense compacts using an aqueous colloidal route. Concentrated suspensions of Cu powders were prepared in water with a polyelectrolyte and tetramethylammonium hydroxide at alkaline pH as dispersing agents. Suspensions were optimized by measuring the theological behavior as a function of pH and volume fraction of solids. The slurries showed a pseudoplastic behavior with thixotropy due to the additives added. The suspensions were slip cast in plaster molds leading to high green densities (similar to 61% TD), as a consequence of the particles' shape and size distribution packing characteristics. Sintering studies were performed at 900 degrees C in flowing Ar/5% H-2 atmosphere. The green and dense compacts shaped by this route were characterized by SEM and Archimedes' density. (C) 2014 Elsevier B.V. All rights reserved.