Development of fed friction-stir (FFS) process for dissimilar nanocomposite welding between AA2024 aluminum alloy and polycarbonate (PC)

Abstract

In this research, a new fed friction-stir (FFS) technology was implemented for dissimilar nanocomposite joining between AA2024 aluminum alloy and polycarbonate (PC) polymer with a T-joint design. Alumina (Al2O3) nanoparticles in the form of paste were injected through the stir zone (SZ) during dissimilar mixing of aluminum and polymer using the FFS system to strengthen the polymer side. The effects of processing parameters on the soundness and characteristics of dissimilar weldments were examined in terms of rotational tool speed (w = 1400−2100 r/min), traverse velocity (v = 25−55 mm/min), and reinforcement powder feeding. Stiff competition was found between w and v on controlling the weld nugget formation and its property. Increasing w and heat input ratio showed a beneficial influence on the materials flow and intermixing. Meanwhile, increasing v revealed detrimental impact by affecting the alumina powder feeding rate into the SZ. According to experiments, to attain a sound and defect-free dissimilar nanocomposite joint with superior mechanical property, the central processing parameters were optimized in the moderate range as w = 1750 r/min and v = 35 mm/min. A maximum tensile strength of ∼36 MPa and maximum flexural strength of ∼74 MPa were noted. Hence, the maximum joining efficiency was determined by ∼53 % and 93 % ratios of PC as the weakest part of dissimilar weldment during tensile and bending tests, respectively, with a failure behavior across the SZ.