EFFECT OF THERMOMECHANICAL PROCESSING ON THE MICROSTRUCTURE AND MECHANICAL-PROPERTIES OF AL-MG (5083) SICP AND AL-MG (5083)/AL(2)O(3)P COMPOSITES .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 me thod and extruded at 480 degrees C with an extrusion ratio of 16:1. Ex trusion of these composites causes large scale dynamic recrystallizati on resulting in a fine matrix microstructure. The extrusion increases not only the ultimate tensile strength, but also the elongation to fra cture of the composites. In the first part of our series of three arti cles, the microstructure of as-cast composites, extruded composites an d extruded monolithic 5083 aluminum alloy is studied. The effects of r einforcing particles and other parameters on the dynamic recrystalliza tion behaviour of the composites are discussed.