Impression creep behaviour of in-situ Al3Ti reinforced Al alloy composite fabricated by salt-melt reaction technique

Abstract

In the present study, Al3Ti reinforced Al6061 aluminium alloy matrix composites were fabricated by adding 5 wt.%, 10 wt.% and 15 wt.% K2TiF6 inorganic salt into the melt at 750 °C, respectively. For phase identification, scanning electron microscopy and X-ray diffraction techniques were used. Impression creep tests were performed on the composites at two different temperatures of 543 K and 573 K and three different stresses of 113, 142 and 170 MPa. Creep resistance of the composites increased as the amount of reinforced particles increased. The average value of stress exponent of the composites was in the range from 3 to 6 which suggested that the dislocation creep was the dominant creep mechanism. The creep activation energy of the composites was close to the lattice diffusion (142 kJ/mol.) which suggested that the lattice diffusion controlled dislocation creep is probably the dominant creep mechanism.