CompositesWorld
Issue link: https://cw.epubxp.com/i/632301
TRENDS FEBRUARY 2016 18 CompositesWorld Each year, Carbon Fiber confer- ence director Scott Stephenson puts together an engaging roster of speakers. During the 2015 event, held in Knoxville, TN, US at the Knoxville Convention Center from Dec. 7-9, in addition to the speakers spotlighted on pp. 16 and 17, the CW staf took special note of the following: John Russell of the Air Force Research Laboratory (AFRL, Wright-Patterson AFB, OH, US) contended during his presentation, titled, "Carbon Fiber Composites for Next Generation Military Aircraft," that military aerospace has become a "niche appli- cation." That was difcult to take in for those in the industry long enough to remember the F-22's development and the excitement of the F-35 program. But Russell pointed out that military programs today can no longer drive the advanced composites market, given total builds of fewer than 100 units for potential future aircraft and the fact that aircraft certifcation methods are stuck in the 1960s, so it will be difcult to ft next-generation composites into Carbon Fiber 2015: Knocking on future doors in Knoxville that still metals-centric certifca- tion framework. Nevertheless, he believes composites will play a role in both future airframes and turbojet engines, as OEMs seek to meet speed, range and payload requirements. Russell challenged listeners to come up with (among other things) a composite system for large parts that shows a 25% improvement in notched properties and better thermal performance. Speaker Ryan Williams, senior scientist at N12 Technologies (Cambridge, MA, US), asserted that his company's material is capable of meeting Russell's challenge. N12 produces vertically aligned carbon nanotubes (VACNTs) trademarked NanoStitch, which it combines with conventional prepregs to form a "hybrid" nanocomposite. The VACNTs are grown, at a thick- ness of 10 microns, in a continuous process that produces a "forest" of vertically aligned nanofbers on a tape, or they can be directly grown on a prepreg. In a laminate stack, the NanoStitch layer, in essence, "stitches" adjacent prepreg plies together. Williams says that when cured, the hybrid Source | CW / Photo | Jef Sloan