No abstract

The phenomenal increase during the past decade in research utilizing pulsed electric current to activate sintering is attributed generally to the intrinsic advantages of the method relative to conventional sintering methods and to the observations of the enhanced properties of materials consolidated by this method. This review focuses on the fundamental aspects of the process, discussing the reported observations and simulation studies in terms of the basic aspects of the process and identifying the intrinsic benefits of the use of the parameters of current (and pulsing), pressure, and heating rate. Feature D. J. Green-contributing editor

Nanostructured ␤-SiC, with crystallite size in the range of 5-20 nm in agglomerates of 50 -150 nm, was formed by reactive high-energy ball milling and consolidated to a relative density of 98% by sintering at 1700°C without the use of additives. X-ray line broadening analysis gave a crystallite size of 25 nm, while transmission electron microscopy observations showed the crystallite size to be in the range of 30 -50 nm. Evidence demonstrating the role of a disorder-order transformation in the densification process is provided by changes in the diffraction peak patterns and in the integral width with temperature. R. Riedel-contributing editorManuscript No. 10245.