Microstructures and Mechanical properties of Spray deposited and Heat-treated Al-25Mg2Si-2Cu alloy

The microstructural characteristics and mechanical properties of Al–25Mg 2 Si-2Cu alloy were investigated.
The alloy produced by spray atomization and deposition techniques followed by hot
compression(HC) and age hardening(AGH) at 180ºC for 2h and 2h intervals after the solution heat treatment. The microstructure features of as cast, spray deposited (SD),hot compressed and heat-treated alloys were studied. the results show the microstructure of spray-deposited alloy mainly comprised of a uniform distribution of intermettalics β-Mg 2 Si phase, θ- Al 2 Cu and Q phase in Al-matrix.
Eliminating the porosity of deposit and fragmentation of the θ And Q phases is the main features during hot
compression. After solution treating and age hardening, the microstructure found to be comprised of mainly
Mg 2 Si phase in a fine spherical form. Large quantity of θ- Al 2 Cu phase and Q Phase less than 50 nm in size
uniformly distributed in the Al- matrix during aging. These fine β particles combined with the θ can
significantly increase the tensile strength and hardness of the alloy. In the peak-aged condition is because of
high concentration of Mg 2 Si and Al 2 Cu metastable phases. The microstructural features of alloys been
investigated through Optical (OM) and Scanning electron microscopy (SEM) and analyses of phases were
carried out using Energy dispersive X-ray( EDS).The improvement in the tensile and hardness properties of
studied alloys was investigated by tensile test and micro- hardness.