Alumina densification

Figure 7.35 Densification behavior of compacts of two alumina powders (0.8- and 1.3 — /rm average particle size), with the sintering stages indicated for the coarser powder. A hot-pressed powder is shown for comparison. From J. S. Reed, Principles of Ceramics Processing, 2nd ed. Copyright 1995 by John Wiley Sons, Inc. This material is used by permission of John Wiley Sons, Inc.

Roeder et al. [14] used dilute mixtures (8 vol-% solids) for the preparation of dense alumina composites with CeC>2-Zr02 and AhCb-platelets. As main alumina powder (the matrix), AKP-30 was used with an average particle diameter of 0.4 pm and a surface area of 6.5 m /g. The resulting specimens were sintered at 1600°C. No further densification behaviour was mentioned. 

FIGURE 162 Densification of two log-nonnal alumina powders (dg = 1.3 and 0.8 fan) showing the initial, intermediate, and final stages of sintering. Sintering is under constant heating rate conditions tf 7.3°C/min. Data from Reed [1]. 

Vendange, V, and Colomban, P, Densification mechanisms of alumina, aluminosilicates and aluminoborosilicates gels, glasses and ceramics, J. Sol-Gel Set Tech-nol, 2, 407, 1994. 

Figure 2. (a) The surface of an alumina ceramic from which all porosity has been removed during sintering the microstructure consists of grains and the boundaries between them, (b) The sintering of silicon results in the formation of a continuous network of solid material (white) and porosity (black). The microstructural change is not accompanied by any densification. (Reprinted from R. J. Brook, ed., Concise Encyclopedia of Advanced Ceramic Materials, eopyright ( 1991, p. 4, with kind permission from Elsevier Science Ltd.)... 

Preparation of Solid State Electrolytes 17.3.7.1. -Alumina Ceramic Electrolytes 17.3.7.1.3. Sintering (Densification) and Annealing. 

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