Mechanical and thermal conductive properties of fiber‐reinforced silica‐alumina aerogels

Abstract We report the formation of Al 2 O 3 ‐SiO 2 fiber‐reinforced Al 2 O 3 ‐SiO 2 aerogels with the content of fibers in the range from 40 wt % to 55 wt % by sol‐gel reaction, followed by supercritical drying. The structure and physical properties of fiber‐reinforced Al 2 O 3 ‐SiO 2 aerogels are studied. We find that the fiber‐reinforced Al 2 O 3 ‐SiO 2 aerogels can be resistant to the temperature of 1200°C. The integration of fibers significantly improves the mechanical properties of Al 2 O 3 ‐SiO 2 aerogels. We find that the bending strength of fiber‐reinforced Al 2 O 3 ‐SiO 2 aerogels increases 0.431 MP a to 0.755 MP a and the elastic modulus increases from 0.679 MP a to 1.153 MP a, when the content of fibers increases from 40 wt % to 50 wt %. The thermal conductivity of the fiber‐reinforced Al 2 O 3 ‐SiO 2 aerogels is in the range from 0.0403 W/ mK to 0.0545 W/ mK , depending on the content of fibers.