Nano-structured alloys and their composites have been found to be an appropriate material system for use as engineering materials with improved characteristics in terms of mechanical, physical, thermal and wear properties. Powder metallurgy (P/M) and chemical routes are generally adopted for synthesizing the nanostructured materials. The P/M technique involves steps like powder milling, compaction and sintering while the chemical route includes sol-gel process, pyrometallurgical process (a solid state reaction between the constituents at temperatures in the range of 1200-1500oC) etc. In the latter case, the reactivity of the reactants can be greatly enhanced by synthesizing novel ceramic precursors. The precursors possess a very high surface area and thus facilitate more uniform mixing of the constituent elements resulting into faster rate of reaction.
The P/M technique consisting of novel processing steps like milling at subzero temperatures and high energy ball milling in a controlled atmosphere has been employed on a preliminary scale for synthesizing nano-sized Cu-alumina composites for possible applications as contact materials, electrical switches, reactor chamber etc. Detailed studies in this area are in progress. The work on the development of P/M based MMCs has been carried out in collaboration with the University of Hertfordshire, U.K. However, required facilities for such studies are being created at AMPRI also.Next