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from the MSEL Annual Report 1997:  

ADVANCED PROCESSING PROGRAMS:  Ceramic Processing

Contact:  George Y. Ononda (301) 975-4489

Ceramic products are primarily produced by powder processing, where raw material powders are mixed with forming additives and shaped by various means into green bodies, which are then fired to the final, hardened state. The processing costs can vary greatly depending on the reproducibility and reliability of the process operation. One key to reliable and rapid development of new products is having good test methods to analyze the material at its different stages of processing. Unfortunately, no satisfactory measurements infrastructure yet exists within the ceramics industry, and as a result, much processing relies largely on art and experience.

The program on ceramic processing focuses on measurement methods of generic value to all ceramic companies. Clearer definitions are needed as to what needs to be measured, how is it to be measured, and how reliable is the measurement. Also, the value of the measurement to optimizing the processing operations is needed.

All subsequent operations depend on the raw materials characteristics, and therefore the measurement of the physical and chemical properties of powders is an important component of the program. The reliability of various measurement techniques is being assessed in a cooperative international program under the direction of the International Energy Agency and its subtask on ceramic powder characterization which is being coordinated at NIST in the ceramic processing program. In addition, SRMs needed to calibrate the measurement instruments in use are being developed. An intramural ATP project on the mechanism of drying, using NMR imaging, is in progress and is providing direct insight on the moisture gradients formed during drying.

A new consortium called the Ceramic Processing Characterization Consortium (CPCC) was formed in June, 1997. Its mission is to assist the U.S. ceramics industry in establishing a generic, powder processing measurements infrastructure. The goal is to assess the measurement needs in ceramics processing and to take all necessary and feasible actions to find viable solutions. Measurement procedures are generally non proprietary, so ceramic companies can work together to improve the measurement methods of common interest and benefit. The members of the CPCC are volunteers, from companies, instrument makers, universities, and national laboratories. Their contributions to the projects of the CPCC should result in rapid advances in the near future. The current projects are: (1) powder characterization; (2) green body characterization; (3) moisture measurements; (4) dispersion and rheology; and (5) microstructure development. Teams for each of these projects have been formed. The reliability and reproducibility of commonly used instruments will be assessed, new methods will be developed, and a better understanding of how the measured properties affect the behavior of the material at different stages of processing will be developed through basic research studies. All studies will be generic and nonproprietary. All members of the CPCC share in the carrying out the work in the CPCC project teams. The present number of members is 80 persons and represent 64 organizations (50 companies, 5 government laboratories, 10 universities).