Influence of Al2O3 nanocomposites on mechanical properties and fatigue corrosion interaction of AA7049 alloy using stir casting route

Abstract

In the current study, stir casting process was used to fabricate AA7049-Al2O3 nano particulate composite containing 6 wt% Al2O3. The characterization work was conducted by scanning electron microscope (SEM). The hardness mechanical properties and fatigue behavior of AA7049-6 wt% Al2O3 composite were investigated by Brinell hardness test, tensile test and rotating bending fatigue test respectively at room temperature (RT). The (SEM) revealed uniform distribution of Al2O3 into matrix. It was observed that the Brinell hardness number (BHN), tensile properties and fatigue behavior of 6 wt% Al2O3 nanocomposite improved in compare to the base metal. The maximum improvement percentage for nanocomposite were enhanced by 5.3%, 4.81% and 8.92% for BHN, ultimate tensile strength (UTS) and yield stress (YS) respectively compared to the unreinforced matrix. Ductility decreased with reduction percentage of 16.6%. The fatigue strength of nanocomposite showed 3.31% improvement compared to the unreinforced matrix. Corrosion of the composite at 3.5% NaCl solution for 60 days is also reported and it was observed that the corroded reinforced matrix still better in fatigue strength and life compared with the base metal.