Strengthening and toughening of carbon fiber reinforced AA2024 by interface self-regulation reaction

Abstract

To better develop the potential properties of the short carbon fiber reinforced aluminum alloy 2024 composite in high-temperature environments, TiO2 coating was introduced. The composites were fabricated through powder metallurgy and extrusion. The effects on the tensile strength and elongation ratio of composites were investigated by the coating thickness and testing temperature. The yield strength of AA2024 was improved by the short carbon fiber addition at all testing temperatures, and the ultimate tensile strength was strengthened by short carbon fiber with proper coating thickness. Short carbon fiber with 100 nm thickness can improve both tensile strength and elongation ratio of the composites compared with that with uncoated short carbon fiber. The interphase component and fracture surfaces were investigated, and the self-regulating mechanism and fracture mechanism were discussed. The interfacial products are mainly composed of TiO2, MgO, and TiC, resulting in a self-regulation interface, that transforms the fracture mechanism from fiber shear failure to fiber pulled-out.