Process Development for Silicon Carbide Based Structural Ceramics.
Abstract
The objective of this program is to develop a process for making shaped silicon carbide based ceramic materials with reduced microstructural flaw size by in situ reaction of silicon with fine, ultra-uniform pored carbon skeletons that are produced from liquid polymer solutions without particulate additions. Subsidiary objectives are: (1) delineation of the maximum section size producible while maintaining microstructural uniformity; (2) production of microstructures with characteristic features reduced from the current level of approximately 5-10 microns to the level of 1 micron or less; (3) characterization of microstructure, corresponding strength levels, and statistical uniformity; and (4) delineation of dimensional tolerances and surface finish that can be held during processing without finished machining. Very uniform and reproducible carbon skeletons have been produced and modified to provide for easy siliconization without extensive grain coarsening or formation of silicon veins and/or lakes have been achieved from 1 cm thick samples of carbon skeleton with particle size of 3.2 microns and pore size of 1.9 micrometers. The siliconized material has a maximum grain size of <10 micrometers and a Weibull characteristic four point bend strength of 660 mPa, which significantly exceeds other reaction bonded silicon carbide materials and compares favorably with hot pressed SiC (NC203) tested under similar circumstances.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1982
- Accession Number
- ADA114834
Entities
People
- Edward E. Hucke
Organizations
- University of Michigan