Abstract:
A novel stir casting technique have been used for the development of
AA2218-based metal matrix composite with the reinforcement of Al2O3 (TiO2)
particles. Coarser Al2O3 and finer TiO2 particles are ball milled together after
mixing in different proportion to achieve coating of the coarser particles by the
finer one to promote wettability. The composite have been prepared by the
addition of ball milled powder by 2% and 5% weight fraction in an aluminium
melt. The developed as cast composites have been artificially aged using T61
heat treatment at 510°C for 4 hours and peak aging at 170°C for 10 h followed
by squeeze cast between 100–220 MPa pressure. Tensile studies have been
conducted on the specimens. Hardness and tensile strength is increased by
adding alumina and TiO2. The improvement in ductility has been observed after
aging at higher squeeze pressure. The fractured surfaces of tensile test
specimens have been analysed and mechanism of fracture along with the effect
of squeeze pressure and effect of particle wt% has been discussed.
