Effect of Inter-Cavity Spacing and Heat Treatment in Friction Stir Processing/Welding (FSP/FSW) Al۷۰۷۵ Composites Containing Al۲O۳ and Graphene Nanomaterials using Charpy Impact Test

In this research, the friction stir process by adding Al۲O۳ and graphene nanoparticles at two different distances have been investigated. Nanoparticles are inserted in cavities with a diameter of ۲ mm and a depth of ۳ mm. Nanoparticles of Al۲O۳, graphene, and equal compositions of Al۲O۳ and graphene, each with two cavity spacings of ۸ and ۱۰ mm, have been performed in six different groups of friction stir process. From each group, Six Charpy specimens were separated. Charpy impact test was performed on six samples, three of which were heat-treated after the friction stir process. Charpy impact test has shown that the specimens have higher fracture energy after heat treatment. Also, in all cases, the fracture energy at the distance between the two cavities are۱۰ mm more than the distance of ۸ mm, this is since nanoparticles do not accumulate at a more distance. Also, to observe the resulting microstructures using optical microscopy and scanning electron microscopy on the friction welding process and the fracture surface of Charpy impact specimens were performed. The results show that the nanoparticles are accumulated in some samples and well dispersed in the materials in others.

Keywords:

Aluminum matrix composites , Al۲O۳ , Charpy Impact Test , Friction Stir Processing , grapheme , Nanoparticle