CompositesWorld
Issue link: https://cw.epubxp.com/i/830100
NEWS 37 CompositesWorld.com Hynes further explains that in "Looking for a lower cost alternative to the industry- standard ceramic fabric forms, CHI began working with Nextel fiber supplier 3M Advanced Materials and prepreg supplier Axiom Materials to test several oxide fabrics using the AXC oxide matrix." Most Ox-Ox CMC work has been done using very fine (and expensive) 1,500 denier yarns, but 3M can supply higher denier yarns (3000, 4,500 and 10,000 denier), increasing the number of filaments in the tow bundle while keeping the same individual filament diameters. is results in a significant cost advantage in fiber production that can be passed along to the supply chain and part manufacturers. "It's the same fiber," Roberts clarifies, "but the tow bundles are larger, reducing the fabrication costs." It is highly recommended, however, that part contours and layup characteristics be carefully considered when selecting the lowest cost CMC fabric suitable for a specific application. For example, tight contours have been achieved using prepregs made with up to 3,000 denier, but are not recommended for 4,500 denier yarns. But gentler geometries are possible with the higher deniers. e results of these investigations were reported in two papers. e first, presented by 3M, Axiom and CHI to the American Ceramic Society Meeting June 2015 in Toronto, ON, Canada, was titled "Oxide- oxide ceramic matrix composites — enabling widespread industry adoption." e other, presented at the United States Advanced Ceramics Assn. (USACA) meeting January 2017 in Coca Beach, FL, US, dealt with "Designing with oxide-oxide CMCs: Under- standing the price-performance relationship in new fabric designs." Using lower-cost fabric forms, the program successfully demonstrated mechanical properties equivalent to those achieved with more expensive industry standard ceramic fabric forms, up to temper- atures of 2150°F, Hynes says. In addition to woven fabric, Ox-Ox CMC tows, tapes or chopped fiber also can be made. e markets for such lower cost, higher denier Ox-Ox CMC materials include high-performance aerospace applications, as well as industrial, energy and, possibly, high-end automotive applications. Less yields more Ceramic-matrix composites are making a strong contribution to what some consider a disruptive advancement in aircraft engines, a game-changing transition to an integrated propulsion system that incorporates advanced materials and technology (including GE's innovative carbon fiber composite fan case). e result has been an 8% reduction in specific fuel consumption, lower vibration and noise, significantly fewer emissions and long-range performance. Donna Dawson is CW's (previously) retired senior writer emeritus, now residing and writing in Lindsay, CA, US, in the foothills of the Sierras. donna@compositesworld.com CMCs for the Hot Zone W T F yoming est ixtures INC. • Over 40 types of fixtures in stock, ready to be shipped. • Expert consultation with Dr. Adams • Email or call today to discuss your fixture and custom design needs. Three and Four Point Short Beam Fixture ASTM D 790, D 6272, D 7264, D 2344 2960 E. Millcreek Canyon Road Salt Lake City, UT 84109 Phone (801) 484.5055 Fax (801) 484.6008 email: wtf@wyomingtestfixtures.com www.wyomingtestfixtures.com Dr. Donald F. Adams President 50 years of Composite Testing Experience FLEXURE FIXTURES FOR EVERY SPECIMEN SIZE We provide quotes for a variety of grips, fixtures, and jigs. We carry over 40 types of fixtures in stock, available for immediate delivery. Email or call us today. We look forward to hearing from you. Three and Four Point Flexure ASTM D 790, D 6272, D 7264 Long Beam Flexure Fixture w/Alignment Rods and Bearings ASTM C 393, D 7249 Reversed Cycle Flexural Fatigue Miniature Flexure Fixture