Production of Dispersed Ceramic Nano-Particles in Al Alloy Using Friction Stir Processing

In this research, surface composite layers containing nano sized TiB2, Al2O3-TiB2, ZrO2 and CNT particles have been fabricated on Aluminum alloy substrates by friction stir processing. The effects of different processing variables such as number of passes and strengthening particle distribution, hardness, and wear properties of surface nanocomposite layers have been evaluated by electron microscopy, hardness, and wear test. Results showed that surface properties of aluminum alloy will be enhanced and the optimum conditions of properties which can be determined by comparing the effects of different parameters will be obtained. An increasein the number of passes up to four modifies microstructure and accordingly mechanical and wear properties were enhanced.Surface composite produced by FSP significantly improved the dry sliding wear resistance of the Al 6061 alloy by changing the wear mechanism. The FSPed sample with Al2O3-TiB2 particles had higher wear resistance in comparison with those with TiB2, ZrO2 and CNT. This enhancement is a consequent of better bonding between particles and aluminum matrix and higher microhardness.