Comparison of Hardness and Tribological properties of Aluminum Alloy 5083 Nanocomposites using TiB2 Powder and Carbon Nanotube with Friction-Stir Process

Friction stir process (FSP) was used to improve hardness and tribological properties of Al-5083 aluminum alloy through formation of metal matrix composite (MMC) material. The process involved the use of titanium diboride powder (TiB2) and carbon nanotubes reinforcing materials. The number of passes during the process was varied. Observations of the microstructure of the composite materials were made using scanning electron microscopy (SEM), while the composited surface layers were examined using microhardness testing. After conducting four passes using FSP, the surface nanocomposite obtained from carbon nanotubes and TiB2 yielded a maximum increase in hardness of 32.3%, and 21.6% compared to the base alloy respectively. Moreover, the samples produced with four passes, containing carbon nanotubes, showed a hardness 8% greater than the samples produced with the same number of passes, but with TiB2. Additionally, the highest wear resistance was also obtained using four passes. The wear resistance exhibited by the carbon nanotube-reinforced composite was approximately 45% greater than the TiB2 powder-reinforced composite. Hence, the use of FSP can potentially increase the working life of the part in wear conditions by up to 3.5 times.