Effects of Fe₂O₃ nanoparticle on quality of medium-density polyethylene friction stir weld joint

This study presents a comprehensive investigation into the effects of incorporating Fe₂O₃ nanoparticles in medium-density polyethylene (MDPE) during friction stir welding (FSW). It systematically explores the metallurgical and mechanical characteristics through quantitative analyses. FSW with Fe₂O₃ nanoparticles (n-FSW) mitigates thermo-mechanical changes in the upper joint area, enhancing the overall structural and mechanical properties of the welded joint. Examination of the stir zone indicates a slightly larger area in n-FSW, highlighting the influence of nanoparticle reinforcement. The ultimate tensile strength (UTS) of the n-FSW sample improved to 27 MPa, which is 34% higher than the 21 MPa of the FSW sample. Additionally, the formation of microscale voids in the stir zone of n-FSW was reduced by 60% compared to the FSW sample. The impact energy of the n-FSW sample was 4 J/cm² more than that of the FSW sample. Fracture surface analysis reveals nanoparticle contributions to fracture mechanics, while impact properties suggest potential air bubble entrapment.