Advanced Polymer Matrix Composite for Aircrafts

Compared with metals, the isotropic structure of composite materials can be controlled to obtain extremely high strength and tough mechanical properties at reduced costs. A distribution graph shows the developed PAN and Pitch family of composites' tensile elasticity vs. strength. Matrix resins used are Ep, BMI, PI. New potential applications have prompted Narmco, US Polymeric, and Hexcel companies to compete for Advanced Tactical Fighter (ATF) in this field. In addition to thermoplastics, PEEK, Torlon, Avimid K, and PEX are among thermo-resistant resins for aircraft and space. Regarding safety issues, their impact resistivity is important due to increased compressive strength after impact. Schematics of impact test device are shown. Composite materials molding techniques for aerospace applications are discussed with several photographs showing AV-8B main wing, and other airplane components hardened in autoclave. Time vs. hardening temperature is plotted describing regions of ungelled glass, char, vitrification, gelation, etc. of composites.