Fatigue Characterization of Fluorogold and Fluorogreen Polymers
- PDF / 577,209 Bytes
- 7 Pages / 593.972 x 792 pts Page_size
- 62 Downloads / 185 Views
AMONG various fluorocarbon polymers, polytetra fluoroethylene (PTFE), commercially known as Teflon, is the most widely used. Due to the strong carbon– carbon bond, it has been reported[1] that PTFE is serviceable over a wide temperature range from 5 K to 533 K (–268 C to 260 C) without any appreciable change in the physical or mechanical properties. However, limited research can be found in the literature characterizing the mechanical properties of the fluorocarbon polymers. PTFE is a self-lubricating fluorocarbon with an extremely low friction coefficient below 0.1 that is used with or without fillers for diversified application purposes.[2,3] Applications include lubricating high-pressure sealing, protective coatings for materials that are used in the building industry, airplane gaskets, bearings, and O-rings for flexible films.[3] Furthermore, it has been reported to be used in electrical insulating,[1] microelectronics, microwave, and electrooptical industries due to its unique dielectric and optical properties.[4] To improve the strength, stiffness, and oil resistivity of PTFEs, reinforcements such as chopped fiberglass and carbon fibers are added to PTFE materials. Fiberglass is widely used as a reinforcement for PTFE to enhance the mechanical properties of PTFE with different weight fractions.[5] With the enhancement of the chemical composition of PTFE, newly emerged fluoropolymers have been developed to possess desirable MEDHAT AWAD EL-HADEK, Associate Professor, is with the Department of Mechanical Design & Production, Port-Said University, Port-Fouad, Port-Said 42523, Egypt. Contact e-mail: melhadek@ gmail.com Manuscript submitted May 4, 2013. Article published online September 17, 2013 METALLURGICAL AND MATERIALS TRANSACTIONS A
characteristics. Fluorogold and fluorogreen polymers[6,7] are reinforced Teflon PTFE with a strong glass aggregate, glass grains, and other reinforcing agents. This provides a structural material that offers significant compressive strength without cold creep and chemical inertness of virgin Teflon.[8] Fluorogold accommodates minimal friction movement under loading conditions and absorbs dirt and grit without increasing the coefficient of friction. Moreover, it is easy to install a bolt in it or a weld, making it a candidate material for bearing.[9] Fluorogold is reported to offer an approximately 2000 times improvement of wear resistance, about 250 pct higher creep resistance, and around 45 pct better immunity to deformation compared to unfilled PTFE.[9] Fluorogold can withstand compressive loads of 75 psi to 2000 psi, as well as providing release or sliding surfaces of force system to prevent stresses from accumulating in certain parts of structures.[9] Fluorogreen is a high-quality glass-filled PTFE that was the first gasketing material approved by NASA for use in their piping equipment.[6] Fluorogreen has excellent electrical and chemical resistance properties, which makes it a key material in NASA cryogenic systems and is the material of choice in the aerospace industry. Fluorogreen[6] has been use
Data Loading...
