THE EFFECTS OF PRE-FORGE PROCESSING ON FORGEABILITY AND MECHANICAL-PROPERTIES OF CO-SPRAYED ALUMINUM-BASED MMCS

Pre-forge processes, comprising either extrusion or uniaxial/triaxial upset forging or pseudo-isostatic forging, were undertaken to reorgani se the existing disposition of SiC particles known as TRS and/or elimi nate residual porosity in co-sprayed aluminium-based MMCs. The objecti ve of undertaking these processes is to improve forgeability and mecha nical properties. The materials investigated are co-sprayed 2014 and 2 618 aluminium alloys reinforced by 15% (volume fraction) of SiC partic les. Billets of these materials were pre-forge processed at elevated t emperatures and specimens were cut from them for forgeability and tens ile tests performed at 450 degrees C and room temperature, respectivel y. Forgeability and tensile properties depend on the orientation of th e TRS and inherent cluster-pores relative to the direction of induced tensile stresses/strains. The pre-forge processes that increased forge ability did not, therefore, necessarily have the same effect on tensil e properties. Forgeability increased as a result of triaxial/uniaxial upset forging and pseudo isostatic forging. Significant increases in t ensile properties were observed in extruded and triaxially upset forge d material only. (C) 1997 Elsevier Science S.A.