The invention discloses a micro-nano intragranular multiphase granule and a
thermal explosion reaction synthetic method thereof. According to the multiphase granule, micron-level alpha-Al2O3 and nanometer-level TiB2 are taken as the multiphase, and alpha-Al2O3 is grown and formed by taking nanometer-level TiB2 as a
nucleus. The multiphase granule is prepared according to the following steps: mixing
Al powder, TiO2
powder and B2O3
powder, and performing ball milling, wherein the
molar ratio of Al, TiO2 and B2O3 is (10-17):1:1; extruding the
powder subjected to ball milling into a blank sample; placing the sample in a
vacuum furnace and vacuumizing; controlling the temperature raising speed at 15-20 K / min, heating to the moment that the sample is subjected to the
thermal explosion reaction; after the reaction is finished, keeping the temperature for 30-60 min, shutting down the furnace to obtain intragranular multiphase granule blocks; and dissolving residual
aluminium with an alkali
aqueous solution, washing and filtering to obtain a wet powder, and
drying to obtain the intragranular granule powder. Micro-nano granules forming the intragranular multiphase granules are all generated through the
thermal explosion reaction, and the surface are clean and free of
pollution; and under the exothermic effect of the reaction, the micro-nano intragranular multiphase granules are grown and formed through intracrystallization, the interfaces of the micro-nano granules are clean, the
bonding strength is high, and the
toughness of the intragranular multiphase granules is substantially improved.