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Published 1997 | public
Book Section - Chapter

Tensile Tests of Miniature Fiber Reinforced Ceramic Composites for Screening Process-Property Relations

Abstract

Mechanical testing of 2-D and 3-D composites in bar geometries is material, time, and cost intensive. As an alternative low-cost, rapid-fabrication geometry, multifilament Nicalon™ (with pyrolytic carbon-coating) tows were densified with the preceramic polymer (Blackglas™) technology to form single tow ceramic "mini-composites". Using modified ASTM tow testing methods, the Blackglas-Nicalon(C) mini-composites were tested in tension at ambient temperatures. The ceramic mini-composites had fibrous failure with linear load-deflection curves and mean breaking loads of 70 N. Gage length (1, 2.5 & 5 cm) effects on breaking loads were minimal. The coefficient of variation (CoV) for the ceramic mini-composites was 19% as compared to a 10% CoV for earlier tensile tests on Blackglas-Nicalon 2-D fabric composite bars. Results were compared to tensile tests of epoxy-Nicalon tows. Breaking strengths of the ceramic mini-composites were roughly 30% of the breaking strengths of the epoxy-Nicalon composites. Oxidation at 600° and 1000°C for 1 hour embrittled the Blackglas-Nicalon (C) composites and reduced the breaking load to values of 42 N and 17 N, respectively.

Additional Information

Copyright © 1997 The American Ceramic Society. The authors would like to thank Mr. Rick Jones of Dow Corning and Dr. Jack Sikonia of AlliedSignal for the contribution of Nicalon tow and Blackglas resin. Dr. Gregory Morscher of NASA-Lewis, Mr. Daniel Boss of BIRL, and Dr. Edgar Lara-Curzio of ORNL provided valuable information and insights on the experimental details of the mini-tow test methods. Support for R. C. Sprandel was provided by the National Science Foundation through the Research Experiences for Science Teachers Program at Northwestern University.

Additional details

Created:
August 22, 2023
Modified:
January 13, 2024