Ceramic Microstructure Development.
Abstract
This research sought to gain some fundamental understanding about the preparation, consolidation, and sintering of ceramic powder compacts. It covered preparation of powders by vapor phase hydrolysis, molten salt oxidation and decomposition, and controlled precipitation from urea solutions. Consolidation by centrifugal casting was investigated. Nickel oxide powders were prepared by vapor phase hydrolysis of nickel chloride. The process is controlled by nucleation and growth of the powder particles in the gas phase and results in small, about one micrometer, nonagglomerated powders with narrow size distributions. The major part of the research focused on the effect of vapor transport on microstructure development in porous powder compacts. Sintering Fe203 in HCL, and ZnO, CdO, and SnO2 in hydrogen was studied. These systems were chosen because of the high vapor pressures of the product gases which could be achieved. In all cases, sintering was retarded even to the point of zero densification as predicted from sintering models. However, the main microstructural feature produced by enhanced vapor transport is coarsening of the microstructure in general. It was concluded that in most cases, grain boundary motion controlled particle coarsening.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1984
- Accession Number
- ADA145753
Entities
People
- D. W. Readey
Organizations
- Ohio State University