Fabrication of Al/Al2Cu in situ nanocomposite via friction stir processing

The aim of present work is fabrication of Al/Al2Cu in situ nanocomposite by friction stir processing (FSP) as well as investigation of FPS parameters such as rotational speed, travel speed, number of FSP passes, and pin profile on the microstructure, chemical reaction, and microhardness of Al based nanocomposite. The Al2Cu particles were formed rapidly due to mechanically activated effect of FSP as well as high heat generation due to Al-Cu exothermic reaction. The microstructure of the nanocomposites consisted of a finer grained aluminium matrix (∼15 µm), unreacted Cu nanoparticles (∼40 nm), and reinforcement nanoparticles of Al2Cu. Irregular morphology of Al2Cu is attributed to the local melting during FSP. Pin diameter has a higher effect on the microstructure and hardness values. The hardness measurements exhibited enhancement by 57% compared with the base metal.