Nanoceramic Toys

Abstract

This paper reviews several potential applications of nanocrystalline ceramics, both frivolous and functional, and discusses the processing challenges in making 3D and 2D shapes from nanoscale powders. Structural applications, usually 3D in nature, can benefit from nanocrystalline ceramics’ superplasticity, diffusion bonding ability, and/or high fracture toughness. A major limitation in making such structures is the small scale of the parts which can be produced, which in turn is a function of the difficulty in compacting the original nanopowders to the high densities needed for subsequent pressureless sintering. Nanopowders are also used in 2D coatings or films, either for purposes of lowering the sintering temperatures or achieving finer scale structures than are possible with coarser powders. However, the tendency of nanopowders to react extensively with water or other liquid media, and the large drying stresses engendered by small pore sizes in the wet body, have meant that many of the wet-processed coatings are made from powders that actually have a submicrometer particle size, though the grain (primary crystallite) size may be nanometer scale.