In situ synthesized nano-Al4C3 reinforced aluminum matrix composites via friction stir processing

Abstract

The strength-ductility trade-off problem of carbon nanotube (CNT) reinforced aluminum matrix nanocomposites (AMNCs) restricts its further application. Hence, we report the fabrication of nano-Al4C3 reinforced AMNCs through friction stir processing (FSP) on CNT/Al composites which can simultaneously elevate the ductility of the composite and maintain the original strength. The microstructure evolution and the dispersion of reinforcement are investigated. Tensile tests show that the elongation of the Al4C3/Al composites fabricated via FSP at a rotation rate of 800 rpm increased by 1.6 times than that of CNT/Al composite and the yield strength retained 95%. The improvement of the mechanical properties is due to the strong Al4C3–Al interface, homogeneous dispersion, nano size, and dynamic recrystallization during FSP. Grain refinement and Orowan strengthening are the main strengthening mechanisms of Al4C3/Al composites. This research shares an approach to preparing a nano-Al4C3 reinforced aluminum matrix composite with well strength and outstanding ductility.

Keywords

• Aluminum matrix nanocomposite (AMNCs)
• Al4C3
• Carbon nanotube (CNT)
• Friction stir processing (FSP)
• Mechanical properties