Investigation on AA5083/AA7075+Al2O3 Joint Fabricated by Friction Stir Welding: Characterizing Microstructure, Corrosion and Toughness Behavior

Abstract

The effects of Al2O3 reinforcements on microstructure, corrosion and toughness properties of dissimilar aluminum alloys joint fabricated by friction stir welding (FSW) technique were explored in this research. AA5083-H116 and AA7075-T6 were selected as the primary base materials. FSW was conducted with and without reinforcing particles through the joint line. Optical microscopy (OM) confirmed uniform distribution of reinforcement particles within the stir zone (SZ) of Al2O3-included specimen. It is demonstrated that the grain size of Al2O3-included specimen in SZ was smaller than that of fabricated without Al2O3. Besides, a comparative corrosion test was performed to assess the effectiveness of Al2O3 particles on corrosion resistance of the joint. The resultant polarization curves gave evidence to a perceptible enhancement in corrosion resistance of the Al2O3-included specimen. Fracture toughness, on the other hand, was examined through impact testing. Surprisingly, Al2O3-included specimen showed inferior impact toughness due to unsatisfactory bonding between matrix and reinforcements.

Keywords

• friction stir welding
• aluminum alloy
• al2o3
• corrosion resistance
• composite