In-situ fabrication of Al3Zr aluminide reinforced AA3003 alloy composite by friction stir processing

A rolled AA3003-H14 aluminum alloy sheet and Zirconium metal powder were used to fabricate Al-surface composites reinforced by in-situ formed Al3Zr aluminide nanoparticles while applying friction stir processing (FSP). Tensile strength and the hardness of the surface composites were determined after applying 2, 4, and 6 passes of FSP. Its phase analysis was done by using a X-ray diffraction and the microstructural examinations were performed using an optical microscope, scanning electron microscope (SEM) and the transmission electron microscope (TEM). The effective Gibbs free energy change of formation ΔGe model was used to thermodynamically predict the Al3Zr phase formation at the interface between the base and the reinforcing Zr particles. Results showed that, by increasing the number of FSP passes, more Al3Zr aluminide particles were formed and distributed more uniformly throughout the matrix. It was also found that tensile strength and the hardness of the base metal were increased by more than 70% after 6 passes. The prediction of Al3Zr aluminide phase formation at the interface was accomplished by the ΔGe model and confirmed by the experimental observations.