Mechanochemical synthesis of activated Me-BN (Me=Al, Mg, Ti) nanocomposites

Mechanochemical synthesis in mixtures of light metals (Al, Mg, Ti) with hexagonal boron nitride under ball milling was studied. Well-pronounced stage behavior of the synthesis process was established and described in terms of dose of mechanical energy supplied to the material under milling (energy approach). At the initial stage the porous composite with nanometer-sized metal crystallites and high specific surface forms. The composite exhibits high reactivity with respect to external reactants, such as atmosphere and water. Mechanical activation also strongly facilitates the solid-state reaction between components, decreasing the temperature required for its initiation down to 450 deg. C. Solid-state reaction under milling takes place only after prolonged milling and results in formation of poorly crystallized metal borides and nitrides.