Introduction of Coal Reinforcing Particles on the Dissimilar FSW AA608/AA5083 Joint via Friction Stir Processing

Abstract

This study investigates the mechanical characteristics of friction stir processed dissimilar joints between AA5083 and AA6082 alloys reinforced with coal particles. Employing friction stir welding (FSW), the mean grain size measured 19.7 μm, but using the FSP technique with coal reinforcement (FSP + Coal) significantly refined the grain size to 8.75 μm. In flexural testing, FSW face samples exhibited failure at 12.7% strain and 535 MPa stress, while FSP + Coal face specimens showed diminished performance at 3% strain and 222 MPa stress. Similar trends were observed in root specimens. For FSW joints, the ultimate tensile strength (UTS) peaked at 145.90 MPa, with the lowest recorded UTS at 93.43 MPa. FSP + Coal joints reached a maximum UTS at 142 MPa and minimum UTS at 104.06 MPa. Fractures in both FSWed and FSPed samples occurred on the AA5083 side. In terms of hardness, FSW joints exhibited 80.33 HV, while FSP + Coal joints displayed a higher hardness of 83.66 HV at the nugget zone. Fracture surface morphology analysis revealed a prominent ductile failure mechanism for both FSWed and FSP + Coal joints. This study provides insight into the enhanced mechanical properties achieved through FSP + Coal processing, offering valuable implications for dissimilar alloy joints in various applications.