Processing Studies on Pure Oxide Bodies

Abstract

The results of some studies on the effect of (1) ball-milling time, (2) granulating by “slugging,” and (3) dry pressing of pure oxide ceramic bodies are presented. When the compressive strength of specimens of single-component bodies was plotted against ball-milling time (in revolutions), minima in the curves were found between 30,000 and 50,000 revolutions. For a multicomponent body of the porcelain type and one of the oxide porcelain type, when the same data were plotted, maxima in the curves were found between 30,000 and 40,000 revolutions. Granulating by slugging provided 30% greater compressive strength, 1.5% less shrinkage, and 1% less absorption in the specimens as compared with specimens formed from ungranulated material. High-pressure forming, preferably by hydrostatic pressure, was desirable; however, there appeared to be an optimum pressure for the physical properties of each material.