Effect of thermomechanical processing on the microstructure and mechanical properties of AlMg (5083)/SiCp and AlMg (5083)/Al2O3p composites. Part 1: Dynamic recrystallization of the composites

Three types of composites, reinforced by as-received SiC, artificially oxidized SiC or Al2O3 particles, were fabricated by a compocasting method and extruded at 480 °C with an extrusion ratio of 16:1. Extrusion of these composites causes large scale dynamic recrystallization resulting in a fine matrix microstructure. The extrusion increases not only the ultimate tensile strength, but also the elongation to fracture of the composites. In the first part of our series of three articles, the microstructure of as-cast composites, extruded composites and extruded monolithic 5083 aluminum alloy is studied. The effects of reinforcing particles and other parameters on the dynamic recrystallization behaviour of the composites are discussed.