Abstract:In order to develop high strength, high damping and low density Al matrix composites, the Al/Zn composite bar samples with Zn mass fraction of 10%-40% were prepared by powder extrusion. The tensile strength and damping properties of the samples are improved by controlling both the Zn/Al diffusion degree and the precipitation of the interfacial phases. The results show that the tensile strength of the samples with Zn mass fraction of 10%-30% increases with the increases of both the Zn content and annealing temperature. When the Zn mass fraction increases to 40%, the tensile strength of the sample remains basically unchanged or decreases slightly, and the plasticity decreases gradually. Alloying of Al matrix and the formation of Zn/Al interface layer are mainly responsible for improving the strength of the annealed samples. The damping properties increase with the increases of both the Zn content and annealing temperature. The Zn/Al eutectoid lamella eliminates the detrimental effects on damping properties due to both alloying of the Al matrix and reduction of pure Zn in the Al matrix. The Al-30%Zn sample annealed at 350 °C for 0.5 h has good comprehensive properties, including the tensile strength of 330 MPa, the elongation to failure of 10% and the room-temperature damping properties (tan θ) of 0.025.

Key words: aluminum matrix composites; fiber reinforcement; mechanical properties; damping properties