Development of a compound for low temperature joining of SiC ceramics and CFCC composites

Conference · Sat Nov 01 04:00:00 EST 1997

OSTI ID:539130

Anderson, I E; Ijadi-Maghsoodi, S; Uenal, O ^[1]

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1. Ames Lab., IA (United States); and others

This investigation was driven by the need for a robust, practical method to join continuous fiber-reinforced ceramic composite (CFCC) materials composed of SiC fibers in a SiC matrix (SiC/SiC). A new filler compound composition resulted from this research which is composed primarily of a silicon-acetylene ceramic precursor polymer blended with fine alloy and elemental powders. Joint formation relies on reaction of the powders with the products of the polymer pyrolysis reaction and the CFCC on continuous heating from room temperature to the curing temperature. The joint can be heated and cured either in an inert or air atmosphere furnace or in air upon heating with a propane torch to a maximum curing temperature of about 1200{degrees}C. This curing temperature is effective for joint formation while preventing degradation of the SiC fibers in the CFCC material and permitting field joining of SiC CFCC parts with an open flame torch. The joining compound demonstrated good wetting and joint filling characteristics. Mechanical property testing revealed a room temperature bend strength of 50 to 100MPa (7 to 14ksi), depending on care in joint preparation. There was a tendency for partial SiC fiber pullout as the crack propagation path wandered in and out of the joint material during fracture, adding toughness. Preliminary mechanical tests of joined samples, after exposure to high temperature (1100{degrees}C) ambient air for 100 hours. indicated excellent retention of strength.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 539130
• Report Number(s): CONF-9604124--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BINDERS
FIBERS
JOINING
PERFORMANCE
REINFORCED MATERIALS
SILICON CARBIDES