Fabrication and Mechanical Properties of In Situ Monazite-Coated Alumina Fiber-Reinforced Alumina/YAG Composites
Monazite(LaPO4)-coated alumina-fiber/alumina-YAG (Y3Al5O12) matrix composites were fabricated by in-situ coating of monazite followed by hot-pressing, and the effects of coating and sintering condition on mechanical properties of the composite were examined. Alumina powder and YAG powder (weight ratio, 95:5) were used as raw materials for green sheets, which was fabricated by tape casting technique. Monazite was synthesized by the in-situ reaction of La(NO3) solution with H3PO4 on the surface of fibers. After slurry infiltration into the coated fiber bundles, the fiber cloths were laminated with the green sheets alternately, then they were heat-treated, finally sintered by hot-pressing at various temperatures. The mechanical properties of the composites were changed by the fabrication conditions. Non-brittleness of the composites reduced with the increase of sintering temperature. The composites sintered at 1200oC showed the highest Weibull modulus and pseudo-ductility.
Katsutoshi Komeya, Yohtaro Matsuo and Takashi Goto
K. Matsukawa et al., "Fabrication and Mechanical Properties of In Situ Monazite-Coated Alumina Fiber-Reinforced Alumina/YAG Composites", Key Engineering Materials, Vol. 352, pp. 213-218, 2007