DEVELOPMENT OF PROCESSES FOR THE PRODUCTION OF HIGH-QUALITY, LONG-LENGTH SIC WHISKERS.
Abstract
Beta silicon carbide whiskers in the form of long staple wool (1 - 10 microns diameter by 1/2 in. 1 in. length) have been grown by flowing a H2, CO, CH4, and N2 gas mixture through a reactor containing a silica source, and five pounds of the output whisker product have been delivered. Growth studies have been made in the temperature range of 2300 to 2800F in growth times ranging from 4 to 24 hours. The reactor consisted of a 20 KW furnace containing a quartz muffle. Gas composition, collector geometry, and materials have been studied to enhance the type and quantity of silicon carbide wool produced. The whiskers appear to grow by a vapor-liquid-solid mechanism. The wool formed has a cotton-like texture and is amenable to forming into yarns. The wool varies in color from buff to dark green presumably because of trace impurities. The whiskers are triangular in cross section and X-ray analysis has identified the material as beta silicon carbide. Tensile tests on the product have measured average rupture strengths in excess of one million psi and elastic modulus in the range of 92-95 million psi. Engineering design and scale-up studies at the level of 100 pounds per year of whisker wool have been conducted in a furnace with a 15-foot growth zone designed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1968
- Accession Number
- AD0826346
Entities
People
- Andrew L. Cunningham
- James J. Shyne
- John V. Milewski
- Robert G. Shaver