Reactive synthesis: A promising route for the in-situ formation of nanosized reinforcements in metal matrix composites

The present paper describes a new synthesis route for particulate reinforcement metal matrix composites. The process consists in the chemical reaction at high temperature between precursor materials to form in-situ both the matrix and the particles of the reinforcing phase. The main criteria that have to considered to determine if a given matrix/reinforcement couple can be obtained by this route are illustrated on specific examples. The main advantages are the quality of the matrix/reinforcement interface that is formed in-situ by a nucleation/growth mechanism (free of oxide layers) the homogeneity of the microstructure without any clustering effect, even for high volume fraction of reinforcement. Moreover, nano-sized particles of reinforcement with a mean that is about 30 nm can be obtained without any handling of nano-sized powders. The interest of this route is also illustrate by mechanical properties characterize by high strength values associated with a failure elongation of 6%.