Effect of equal channel angular pressing on the distribution of reinforcements in the discontinuous metal matrix composites

The 6061 Al-10 vol% SiCw composites were prepared by powder metallurgy with the powders having the different sizes, i.e. < 30mum and 30mum <. The composites were subjected to equal channel angular pressing (ECAP) under various conditions and the microstuctural changes during ECAP were examined, A special focus was made on the effect of ECAP conditions on the distribution of SiC whiskers. The present investigation was aimed at exploring the feasibility of ECAP as a post working process for manufacturing the discontinuous metal matrix composites. The microstructural examination and the microhardness measurement of the ECAPed samples suggested that the optimum combination of the uniform microstructure and enhanced mechanical properties would be obtained by (a) using the powders having the smaller size, (b) decreasing ECAP temperature, and (c) repeating ECAP.