Unraveling the Mechanical Behavior of AA 7075 - WC Nanocomposites Developed through FSP Route

Friction Stir Processing (FSP) is a solid-state processing approach that alters and enhances the properties of the matrix material. The prime objective of this research work was aluminium alloy 7075-T6 which has zinc as key alloying element next to aluminium and other alloying elements is reinforced by varying 0, 3, 6 and 9 wt.% tungsten carbide nanoparticles by FSP route. During experimentation, the FSP processing parameters like tool speed, traverse speed, axial load, and tool were being kept constant with four passes of processing. The test samples were prepared and tested as per standard procedures like hardness, ultimate tensile strength, impact strength and average values were recorded. Also, fracture surface morphology was studied. Among all the combinations of test samples at a 9 wt% addition of tungsten carbide nanoparticles of FSP-ed aluminium alloy 7075-T6 sample exhibited a higher value of 53 HV microhardness and 150 MPa increase in the ultimate tensile strength and 5.1 J/mm² increased impact strength were obtained. This was due to the presence of more wt% tungsten carbide nanoparticles plays a major role in the stirred zone. The microhardness and tensile strength increased due to the four passes resulting in a decrease of the grains in the stir zone as the dislocations become more difficult and tungsten carbide nano particles restrict the movement of grain boundaries. The tensile tested samples fracture surface morphology of the revealed deep dimples representing a good ductility. Thus, the processed metal matrix composites were suitable for higher-end applications like marine, automobile, and military.