Effect of thermomechanical processing on the microstructure and mechanical properties of AlMg (5083)/SiCp and AlMg (5083)/Al2O3p composites. Part 2: Tensile properties at different temperatures

In this paper, the second part of our trilogy, the mechanical properties of as-cast and extruded composites and of the extruded monolithic 5083 aluminum alloy are discussed. Tensile tests were carried out at 25, 350 and 550 °C. The effects of extrusion on the properties of the composites were investigated. Three types of composites reinforced by as-received SiC particles, artificially oxidized SiC particles or Al2O3 particles and deformed at different temperatures are examined. Extrusion increases both the UTS and the elongation to fracture; whereas artificial oxidation of SiC particles (with 3.04 wt.% SiO2) has the opposite effect. These properties are interpreted in terms of the various possible strengthening and fracture mechanisms as a function of temperature.