Ultrafine microstructures by powder metallurgical methods.

Metallic and ceramic dense nanocrystalline (nc-)materials with grain sizes ranging form 5 to 100 nm may be produced by using nano-dispersed, i.e. highly sinter-active starting powders. It is the extremly high grain-/phase-boundary area that determines the unusual properties of the resultant PM-components. The various suitable PM-methods for the production of pure as well as composite nc-materias are shortly reviewed including the sol-gel process, mechanical alloying and the inert gas evaporation method. Some of the faszinating potentials of PM-fabricated nc-materials in due to their peculiar magnetic, elctronic and mechanical behaviour are elucidated.