Effective Nanoparticles Feeding Treatment in Casting of A356/ZrO 2 Nano-reinforced Composite

Recent studies have shown that the properties of cast aluminum alloys are modified by the insertion of reinforcement nanoparticles. In this study, A356.0 aluminum alloy was reinforced with (30 nm) ZrO2 ceramic particles, using stir casting technique in semisolid state. Different nanoparticles feeding routes like direct, capsulate and regular treatments were studied at different particles addition rates of 1, 2 and 3%. The effect of nano ZrO2 reinforcement on the cast microstructure produced by different treatments was examined using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM). The mechanical properties were found to be enhanced compared to monolithic alloy at same casting conditions. However, the capsulate feeding mechanism, of 3% ZrO2 nanoparticles, was the most effective in particles dispersion and silicon refinement, with an increase in ultimate strength and hardness of the as-cast cast sample from (119 MPa and 22.5 HRC) to (165.5 MPa and 60.4 HRC), after treatment, respectively.