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 .2. TENSILE PROPERTIES AT DIFFERENT TEMPERATURES/

In this paper, the second part of our trilogy, the mechanical properti es of as-cast and extruded composites and of the extruded monolithic 5 083 aluminum alloy are discussed. Tensile tests were carried out at 25 , 350 and 550 degrees C. The effects of extrusion on the properties of the composites were investigated. Three types of composites reinforce d 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; where as artificial oxidation of SIC particles (with 3.04 wt.% SiO2) has the opposite effect. These properties are interpreted in terms of the var ious possible strengthening and fracture mechanisms as a function of t emperature.