Mechanically alloyed nanocomposites

Mechanical alloying (MA) is a solid-state powder processing technique that was developed in the 1960s to synthesize nickel-based oxide-dispersion strengthened (ODS) superalloys that combine the twin effects of precipitation hardening (for intermediate temperature strength) and dispersion hardening (for elevated temperature strength). These ODS alloys contain very fine, nanometer-sized, oxide (and other ceramic) phase particles to impart the high-temperature strength and can be considered the first nanocomposites synthesized by MA. In comparison to other techniques such as solidification processing or internal oxidation, MA is a simple technique with unique advantages. For example, it is very easy to obtain nanostructures in most cases, a high volume fraction of the reinforcement phase can be introduced into the composite, and consolidation of the milled powder to full density is relatively easy. Recent advances in the synthesis and properties of nanocomposites obtained by MA have been reviewed here. Both metal-based and ceramic-based nanocomposites have been discussed. Extensive list of references, majority of them published after the year 2000, have been provided. The review also contains complete listing of all the data that is available for each category of the composites.