Back pressure equal channel angular consolidation—Application in producing aluminium matrix composites with fine flyash particles

Back pressure equal channel angular consolidation (BP-ECAC) is an innovative process to synthesise bulk materials from particles. It enables particles from nano to micro scales to be consolidated into fully dense materials at much lower temperatures and under much simpler conditions. It is particularly useful in consolidating particles with non-equilibrium microstructures and in producing metal matrix composites (MMCs). As an example, BP-ECAC was used in this investigation to produce aluminium matrix composites with flyash particles. Compared to the conventional powder metallurgy (PM) and ingot metallurgy, BP-ECAC is more efficient and capable of incorporating very fine particles at higher volume fractions with more uniform particle distribution. In particular, it can be used to produce master composite billets for subsequent melting and casting.