Low-thermal-conductivity high-strength oxide thermal bridge blocking material and preparation method thereof

The invention relates to a low-thermal-conductivity high-strength oxide thermal bridge blocking material and a preparation method thereof. The low-thermal-conductivity and high-strength oxide thermal bridge blocking material comprises alumina fibers, an oxide matrix and an alumina interface layer, the alumina fibers are polycrystalline fibers taking gamma-alumina and amorphous silicon dioxide as main components; the oxide matrix is aluminum oxide modified silicon oxide with high porosity; the aluminum oxide interface layer is prepared by a sol-gel process. The preparation method comprises the following steps: preparing a normal enhanced three-dimensional alumina fabric with low fiber volume content; preparing aluminum oxide modified silica sol; the preparation method comprises the following steps: dipping a three-dimensional aluminum oxide fabric in aluminum oxide sol, drying and carrying out heat treatment to obtain a three-dimensional aluminum oxide fabric containing an aluminum oxide interface layer, dippi