Most ceramic articles are produced by first dispersing powders in a suitable liquid, forming the dispersion (by casting, molding, extrusion, etc.), drying and then firing the body to its final sintered state. It has been recognized that dispersion characteristics strongly affect the green body which in turn determines properties of fired ceramic, and recently, dispersion science has become quite important in the development of ceramics processes. In this thesis research, colloidal size alumina powder was dispersed in secondary butyl alcohol with a phosphate ester dispersant. Dispersions were produced in an attrition mill and evaluated by viscometry and sedimentation. These dispersions were "optimized" by adjusting surfactant concentration and milling time. Zeta potential measurements indicated stabilization was not purely electrostatic. It was noted that a small amount of water added to the dispersions dramatically affected dispersion rheology. With slight water addition high solids content slurries (40 vol. percent) could be produced with rheological characteristics desirable for casting. Solution conductivity measurements were made to provide insight into the possible mechanism by which water affects dispersion stability.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/277307 |
| Date | January 1990 |
| Creators | Tarico, Daniel Joseph, 1965- |
| Contributors | Raghavan, Srini |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Thesis-Reproduction (electronic) |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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