Wear Resistance and Mechanical Properties of 7085 Alloy via Adding CNTs Based on Ultrasonic Casting

Abstract

High-energy ultrasound has been proposed to ameliorate the uniform dispersion the reinforcement and used widely fabricating in high strength metal matrix composites. In this work, 7085 aluminum (Al) metal matrix composites with varying contents of reinforcement carbon nanotubes (CNTs) (0–1.2 wt.%) were fabricated by surface modification treatment and ultrasound-assisted casting technique. The wear resistance and mechanical properties of the composites were investigated. The addition of reinforcement CNTs particles led to an improvement in the mechanical properties of the composite from 126.4 to 187.2 MPa and the hardness from 128 to 169.4 HV. The wear resistance results showed that with the addition of the 1.0 wt.% CNTs, the wear rate of the reinforcement composite was 1.42×10⁻³mm³/Nm, and the depth and width of the abrasion marks reached the optimal value. At the same time, the formation of Al₄C₃ will be beneficial to further enhance the mechanical properties of the alloy. However, excess CNTs tends to agglomerate, which will deteriorate the properties of the composites. This also indicates that the synergistic fabrication of multiple processes could offer CNTs/7085 composite a great promising candidate for engineering applications.