Hybrid Anisotropic Materials for Structural Aviation Parts.

Abstract

Ceramic technology was enhanced through NASA’s space programs and used in heat-protective tiles on rockets and most recently the turbine engine components for space vehicles. The Joint Strike Fighter F-35 and other military platforms are targeting ceramic matrix composites (CMCs) for exhaust and engine applications with an ultimate goal of weight reduction. However, concerns exist over acquisition cost, reliability, durability, and life expectancy. CMCs are typically fabricated with two-dimensional (2-D) woven ceramic grade (CG) Nicalon fabric reinforcement, which is coated with a boron nitride (BN) interface coating. 2-D CMC components have been found to be life-limited in high thermal gradient environments due to inherently low matrix dominated interlaminar shear strength, but cost less than 3-D fiber architectures. 3-D fiber architectures offer the promise of increased durability by enhancing the interlaminar and through-thickness mechanical properties specially developed for 3TEX Inc.’s 3-D orthogonal weaving machines. The purpose of this research is to develop effective low-cost BN interface coatings for 2-D reinforced CMC components and to investigate the fractographic model prediction deformations and fatigue strength.