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

Al-4%Cu alloy with 3% TiB2 in situ composite, fabricated by stir casting route, was cryorolled at -80 degrees 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 degrees C) for 3 min. followed by a standard ageing treatment. Tensile tests were performed at room temperature, 150, 250 and 350 degrees 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 degrees C showed better strength than the other two treated conditions. Irrespective of the composite condition, the strength obtained was similar at 350 degrees C, due to complete recrystallization and dissolution of precipitates.