High temperature tensile properties of cryorolled Al-4wt%Cu-3wt%TiB₂ in-situ composites

Abstract

Al-4%Cu alloy with 3% TiB₂ in situ composite, fabricated by stir casting route, was cryorolled at −80°C from 7 mm to 0.25 mm with a total true strain of around 3.33. The as-rolled composite was subjected to short annealing treatment at three different temperatures (150, 175, 200°C) for 3 min. followed by a standard ageing treatment. Tensile tests were performed at room temperature, 150, 250 and 350°C as per the standard on all samples with different treatments (as-cryorolled, short annealed after cryorolling and cryorolled-short annealed-aged conditions). It was observed that with increasing test temperature, the strength of the samples in all conditions reduced with significant increase in ductility. Samples treated at 175°C showed better strength than the other two treated conditions. Irrespective of the composite condition, the strength obtained was similar at 350°C, due to complete recrystallization and dissolution of precipitates.