NOVEL EQUIPMENT FOR THE STUDY OF THE COMPACTION OF FINE POWDERS

This paper describes a highly specialized system for studies of time-d ependent compaction of nano-size and other fine-size powders under a v ariety of atmospheres and at temperatures ranging from 77 to 1000 K. T he system incorporates a 10000 kg screw-driven press with a piston-cyl inder type of die and can produce cylindrical powder compacts, 3mm in diameter and of various thicknesses, utilizing pressures up to 3 GPa. The system is computer-controlled and permits measurements of the samp le volume with an uncertainty of 0.07mm3 and, after appropriate calibr ation, can determine the rate and degree of densification of the compa cting powder as pressure is applied. To illustrate its capabilities, t he system was used to study the densification of several powders, incl uding nano-size gamma-Al2O3, submicrometer 95% alpha-Si3N4, RbBr, and KCl. The results obtained on RbBr and KCl, used for calibration and te sting of the equipment, are in good agreement with previously publishe d data for these materials.