Alumina zirconia fibers Nextel 650 fiber

FIGURE 8. A comparison of the creep rate of the Nextel 650 and PRD-166 fibers, both of which are composed of a-alumina and zirconia, the Nextel 720 which is composed of a-alumina and mullite and the pure a-alumina Fiber FP. (Reprinted, from reference 12, "Mechanical and Microstructural Characterization of Nextel 650 Alumina-Zirconia Fibres , with kind permission of Elsevier). 

Oxide fibers include glass fibers, mullite fibers, zirconia fibers and alumina fibers. Of these, a-alumina-based fibers have been used intensively for ceramic matrix composites. Fiber FP, manufactured by Du Pont in 1979, was the first wholly a-alumina fiber produced [34]. At present, Almax (Mitsui Mining Material Co. Ltd., Japan) and Nextel 610 (3M Co., USA) are commercially available a-alumina fibers. Almax contains 99.5% alumina and has an elastic modulus of 330 GPa, and Nextel 610 has a tensile strength of 2.4 GPa and an elastic modulus of 380 GPa [35]. 

A prerequisite for an effective fiber coating is chemical stability with the fiber and matrix phases of a composite. If reactions occur, the fiber-coating-matrix interface would become strongly bonded, and the composite would exhibit brittle fracture behavior. Based on currently available phase diagrams, oxide compounds have been identified that do not show compound formation with commercially available oxide fibers. Particular attention has been paid to fibers that show the highest temperature capability (alumina fibers, such as Fiber FP, PRD-166, and Nextel 610). Oxide compounds identified as stable with alumina included tin oxide, zirconia, titania (at temperatures below 1,150°C [2,102°F]), zirconia titanate (ZrXi04, also at temperatures below 1,150°C [2,102°F]), and possibly zirconia tin titanate (Zr(Sn,Ti)04). 

The Nextel 650 fiber is continuous and circular in cross-section with a diameter of 11.2 p,m and is composed of a-alumina and 10% wt of cubic zirconia stabilized by 1 %wt of... 

F igure 8 shows the creep behavior from 1100 to 1300°C of several fibers FP and Nextel 610 represent pure alumina fibers, PRD-166 and Nextel 650 zirconia-alumina fibers and... 

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