Chapter 44. Nextel™ 650 Ceramic Oxide Fiber: New Alumina-Based Fiber for High Temperature Composite Reinforcement

Summary

A new alumina-based ceramic fiber, Nextel™ 650 Ceramic Oxide Fiber, has been developed for high temperature composite reinforcement applications. Nextel 650 fibers, which have the composition Al₂O₃ + 10 wt % ZrO₂ + 1 wt % Y₂O₃, were measured to have 10–100 times lower creep rate than Nextel™ 610 Ceramic Oxide Fibers. This represents an improvement in high temperature creep capability of 80°C relative to Nextel 610 fibers. Nextel 650 single filaments retained 70% of their room temperature strength at 1200C, 200°C higher than Nextel 610 fibers. The improvement in high temperature properties was attributed to a reduction in grain boundary diffusivity by the Y₂O₃ dopant. The single filament strength of Nextel 650 fibers was 2.5 — 2.7 GPa, 20% less than Nextel 610 fibers. Analysis after thermal aging at 1200°C for 100 hours indicated good microstructural stability and strength retention.