Novel Equipment for the Study of the Compaction of Fine Powders

Abstract

This paper describes a highly specialized system for studies of time‐dependent compaction of nano‐size and other fine‐size powders under a variety of atmospheres and at temperatures ranging from 77 to 1000 K. The system incorporates a 10 000 kg screw‐driven press with a piston–cylinder 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 sample volume with an uncertainty of 0.07 mm 3 and, after appropriate calibration, can determine the rate and degree of densification of the compacting powder as pressure is applied. To illustrate its capabilities, the system was used to study the densification of several powders, including nano‐size γ‐Al 2 O 3 , submicrometer 95%α‐Si 3 N 4 , RbBr, and KC1. The results obtained on RbBr and KC1, used for calibration and testing of the equipment, are in good agreement with previously published data for these materials.