Resistance of Phenolic Composites to Various Powertrain Fluids

摘要

The Ford Motor Company accomplished an excellent testimonial to the use of phenolic composites in 1969. Working together with Chicago Molded Products Corporation, the forerunner of MacLean Products Corporation, Ford designed and developed the first composite torque converter reactor. The reactor, molded of an asbestos-reinforced phenolic compound, replaced several metal parts in the torque converter of an automatic transmission utilized in some of Ford's popular vehicle models like the Crown Victoria and the F-150 pickup truck. The stator remained in production until 1976 when the use of asbestos was restricted. This innovative use of phenolics met all of the original performance objectives and demonstrated their durability in powertrain applications involving high mechanical and thermal stresses plus continuous exposure to transmission fluid. In 1983, Ford introduced a new composite reactor, this time molded of a Rogers glass-fiber reinforced phenolic composite. From these beginnings, glass-fiber reinforced phenolic has been used in numerous reactor applications. More than 15 million pounds of composite materials have been consumed in reactor applications by four original equipment manufacturers (OEMs). The use of phenolic composites has also spread to several other powertrain components, which will be briefly described in this paper. The inherent phenolic resistance to automotive fluids, high temperatures and pressures makes these composites ideal in powertrain applications. As always, the driving force behind the substitution of phenolic composites for metal is cost reduction, but their potential for performance enhancements is an added factor for their popularity. Significant cost savings have been achieved due to the well-known advantages of plastics molding. They include the ability to integrate several metal parts into a single molded component, and the possibility of molding to net shape and uniform density, which eliminates the need for balancing dynamic components. The effective use of phenolic composites requires the integration of material selection, part design, and processing. Chemical resistance is often an important material selection criterion because powertrain components are commonly exposed to different fluids. This paper presents a review of several studies documenting the resistance of phenolic composites to automotive fluids. A number of phenolic materials were immersed in brake fluid, motor oil, antifreeze solutions, transr lission fluid, and various fuel mixtures at elevated temper; tures. Changes in dimensions, weight and selected properties were monitored as a function of immersion time. Details of the test protocols are also outlined. As new fluids and applications are developed, testing is conducted to ensure that the pi tenolic composites can perform and maintain integrity throughout the life of the application.