Fabrication of AA6061/316 composites via a double pin FSP tool

In this study, a new double pin tool was utilized for the development of AA6061/316 stainless steel reinforced composite by employing the friction stir processing technique for the first time. The microstructure, hardness, tensile, tribological, and corrosion behaviors of the fabricated composites were investigated and comparative assessments were made with the results obtained from the single-pin tool. The results showed that particle-matrix reaction did not occur in the composites irrespective of the nature of the tool profile. The double-pin tool outstandingly boosted the grain refinement (7.01-5.78 μm), particle fragmentation, and distribution within the Al matrix due to the additional pin-assisted plastic deformation, high straining, dynamic recrystallization, and Zener pinning effects. The double-pin tool improved the microhardness (127-141 HV), tensile strength (162-233 MPa), and corrosion resistance of the composite with respect to the single-pin tool counterparts. The replacement of the single pin tool with a double pin tool diminished the specific wear rate (0.38-0.22 mm3/Nm) of the composite. The double-pin tool has a favorable impact on the structure, mechanical, and corrosion behaviors of the AA6061/316 stainless steel reinforced composite. It is thus recommended for composite development.