Flexible and robust YAG-Al2O3 composite nanofibrous membranes enabled by a hybrid nanocrystalline-amorphous structure

A flexible and robust YAG-Al2O3 composite nanofibrous membrane was fabricated by a combination of sol-gel and electrospinning methods, then a sintering at 900 degrees C. The effects of Al2O3 on the microstructure and mechanical performance of YAG nanofibrous membranes were investigated. The YAG nanofibrous membrane is brittle but the composite membranes exhibit a brittle-to-flexible transformation as the Al2O3 content reaches 30 wt.%, which can be attributed to an optimized dense hybrid microstructure consisting of finer YAG grain size surrounded by amorphous Al2O3. The YAG-30 wt.% Al2O3 nanofibrous membrane sintered at 900 degrees C shows a tensile strength of 3.52 +/- 0.31 MPa, three times of that of pure Al2O3 sintered at the same temperature. The membrane still presents a decent flexibility with a tensile strength of 0.75 +/- 0.25 MPa after sintering at 1000 degrees C, which is at least 100 degrees C higher than the sintering temperature of most reported ceramic nanofibrous membranes.