Effect of Cold Rolling on AA6061/SiCp Nanocomposites

F. AUDEBERT; M. GALANO; X. JIANG

Brotas

Conferencia; VII Latin American Conference on Metastable and Nanostructured Materials; 2017

AA6061 alloy composites reinforced with 10wt% and 15wt% of SiC nanoparticles with an average diameter of around 500nm have been produced by powder metallurgy routes followed by extrusion and cold rolling. The effect of cold rolling and the additions of SiC particles to the microstructural evolution and mechanical properties have been investigated. During cold rolling a significant redistribution of SiC nanoparticles was obtained, resulting in a homogeneous distribution of SiC particles within AA6061 alloy matrix. A typical cold rolling β fibre texture has developed for AA6061 alloy while for AA6061/SiCp composites, Al grain orientations have been randomized due to the presence of non-deformable SiC particles. It was found that for cold rolled AA6061 alloy, the initially elongated Al matrix grains have been subdivided into smaller sub-grains with higher fractions of low angle grain boundaries while the cold rolled AA6061/SiCp composites show finer grains with higher fractions of high angle grain boundaries. All cold rolled samples exhibit improved strength in both Vickers hardness and three-point bending tests mainly due to grain boundary and dislocation strengthening mechanisms.