AFRL Commercializes Advanced Silicon Carbide Fibers

  • Published
  • By Materials & Manufacturing Directorate
  • AFRL/ML
WRIGHT-PATTERSON AIR FORCE BASE, Ohio --  Working under contract with ATK-COI Ceramics, Inc. (ATKCOIC), San Diego, California, and in collaboration with the National Aeronautics and Space Administration (NASA), AFRL engineers commercially established an advanced silicon carbide (SiC) fiber technology for use in gas turbine engine components and other high-temperature applications. 

AFRL and NASA have identified Sylramic™ SiC fiber and its derivative Sylramic-iBN [in situ boron nitride] SiC fiber as having superior performance capabilities over other commercially available SiC fibers. The use of these fibers, which are not only capable of withstanding temperatures >2600 degrees F but exhibit high thermal conductivity, will extend to a range of engine components that must endure extremely harsh service environments. 

Phase I contract activity included initial processing runs of the Sylramic fiber in ATK-COIC's new facility, mechanical testing of the fiber, and subsequent transfer of the Sylramic-iBN process from NASA to ATK-COIC. Efforts conducted at the conclusion of Phase I determined that the ATK-COIC- manufactured Sylramic fiber was equivalent to the original Dow Corning fiber, thus validating the manufacturing process at the company's new facility. The successful transfer of the Sylramic-iBN process from NASA to ATK-COIC also entailed the demonstration of equivalent properties for fibers produced at NASA and ATK-COIC facilities. 

Phase II objectives targeted both the collection of additional data on ATK-COIC's Sylramic fiber and the performance evaluation of Sylramic and Sylramic-iBN fibers in several ceramic matrix composite (CMC) materials. Overall, Phase II efforts demonstrated the viable reestablishment of Sylramic fiber processing capability, which was the primary goal. Ceramic composites reinforced with ATK-COIC-produced
Sylramic and Sylramic-iBN fibers were also shown to have properties equivalent to legacy composites reinforced with the fibers produced by Dow Corning. 

As a result of this collaborative AFRL/NASA/industry effort, Sylramic fiber is again available for purchase, and Sylramic-iBN fiber is commercially available for the first time. ATK-COIC is currently supplying these fibers for use in Air Force and NASA programs that seek to improve the temperature capability and durability of CMCs for application in advanced aircraft turbine engines.