INFLUENCE OF THERMO-MECHANICAL TREATMENT ON THE TENSILE BEHAVIOUR AND CNT EVALUATED FRACTURE TOUGHNESS OF BORAX PREMIXED SiCp REINFORCED AA 6063 COMPOSITES

The influence of thermo-mechanical treatment on the percent porosity and mechanical behaviour of SiC reinforced aluminium alloy (6063) composites was investigated. AA 6063 – SiCp composites having 6 and 9 vol. % of SiC were produced by the use of Borax additive and double stir casting process. The composites were cold rolled to 20, 25 and 35% deformation before solution heat-treating at 550 ˚C for 1hour cooling rapidly in water. Density measurements and percent porosity of the composites were evaluated; also their tensile properties and fracture toughness were assessed. The results indicate that the cold rolling and solution heat-treating processes resulted in remarkable reduction in porosity levels in the composites (≤ 1.9 % porosity). A good uniform distribution of the SiC particulates in the AA 6063 was also produced. The tensile properties and fracture toughness of the composites improved significantly with the adoption of the cold rolling and solution heat-treatment process