抄録
Ceramics are traditionally synthesized by solid-state reactions of starting constituents at elevated temperatures. It is however difficult to realize a nanocrystalline feature, as a high-temperature calcination always leads to coarsening and aggregation of fine particles. In a fundamentally different approach, phase-formations in mechanical activation (MA) can be realized at room temperature, via one or more of the mechanically triggered chemical reactions, nucleation and growth from an amorphous state, decompositions and phase transformations. Over the past several years, there has been a surge in the efforts of employing MA for a wide range of nanocrystalline ceramics. MA promises a significant technological implication, whereby the currently employed multiple steps of phase-forming calcination/annealing at high temperatures can be skipped. In this paper, recent progress in MA for synthesis of nanocrystalline ceramics is presented, together with a number of new and unique phenomena, such as order-disorder transitions and cation inversions, brought about by MA.
