Effect of SiO2 and B4C Nanoparticles Hybrid Addition on Mechanical Properties of AA6061-T6 Surface Composite via Friction Stir Processing

This paper studies the effect of SiO2 and B4C nanoparticles on the mechanical properties (microhardness, wear resistance, and tensile strength) of an aluminum alloy 6061-T6 composite. The friction stir process was used to generate a composite surface layer by incorporating Nano-sized SiO2 and B4C nanoparticles as a hybrid addition into the AA6061-T6 alloy at the best rotational speed of (1200) rpm, (30 ) mm/min travel speed, 3 mm hole depth, and an equal amount of SiO2 and B4C (7.5) wt.% for each nanoparticle. Samples were examined microstructurally using optical and Field Emission Scanning Electron Microscopy. Adding SiO2 and B4C nanoparticles as a hybrid addition to AA6061-T6 gives a superior improvement in the hardness (155) HV as compared to the parent material (65) HV. The wear test showed that the wear type was oxidative or mild at (5 N) low load and became metallic or severe wear when loading was increased to (15 N) for a sliding time of 20 minutes.