Effect of individual and hybrid additions of Al2O3 NP and CNTs on the mechanical strengthening of aluminum-bronze alloy

Abstract

Aluminum bronze metallic composite (ABMCs) alloys were fabricated via the powder metallurgy technique. The present work has been incorporated an individual as well as hybrid additions of Al2O3 nanoparticles and multiwall carbon nanotubes (CNTs) into ABMCs. Microstructural characteristics and mechanical properties and sliding wear behavior plus some of the physical properties such as density, electrical conductivity, and thermal conductivity of the composite alloys have been studied. Microstructure features were discovered by utilizing FE-SEM and XRD measurements. The addition of 2 wt% of CNTs was caused more uniform distributed refined grains, but the adding of 2 wt% Al2O3 was formed an agglomeration upon the active grain boundaries. Moreover, the yield stress and ultimate tensile strength of AB/Al2O3/CNTs hybrid composite alloy were improved up to ≈ 84% and ≈ 52%, respectively with respect to the plain monolithic alloy. Also, the hybrid addition enhanced both hardness and wear resistance by ≈ 12% and ≈ 189%, respectively. This enhancement may be attributed to the physical synergistic reinforcement of the hybrid addition and improvement of the internal microstructure as well as the Zener pinning effect which restricted the growth of the grains. Additionally, the addition of 2 wt% CNTs enhanced the electrical and thermal conductivity up to ≈ 5.3% and ≈ 22.8, respectively. Because the CNTs creating new conductive paths in the Aluminum bronze alloy.