Influence of UAFSP on Microstructure and Mechanical Properties of AA7075 Surface Composites

Abstract

Friction stir processing (FSP) is a novel solid-state technique and lower energy consumption route that produces the surface composites by reinforcing nano B4C particles in the AA7075 matrix. FSP enhances their local surface modification with the homogenization of distributed particles and improved the material characteristics such as high hardness, improve strength, and high resistance to wear. Moreover, the conventional AA7075 alloys have a high demand in aerospace applications. FSP overcomes the difficulties faced by the conventional techniques such as reinforcing the carbides (SiC, B4C, TiC), Borides (ZrB2, TiB2) nitrides (AlN, Si3N4), and oxides (TiO2, SiO2, Al2O3 ), etc, where alloy fabrications are very challenging tasks as they lead to workpiece damage and tool wear. After experimentation reinforcement of particles in the FSP resulted in little change in hardness and enhancement in the other mechanical characteristics for instance tensile strength, impact strength, and yield strength. Refinement of particles was seen in microstructural and fractographic studies. It is visible that the particles were refined on the advancing side and some particles got agglomerated or not refined on the retreating side. Apart from the wide advantages, FSP also faces some issues like clustering of particles due to inhomogeneous distribution of particles which leads to a decrease in the properties and uninterrupted conducting investigations causes the tool to wear and lessen its existence. To overcome those difficulties Ultrasonic assisted vibrations were assisted to FSP to enhance the material properties.Ultrasonic vibrator-assisted Friction stir processing (UAFSP) also works in the solid state which produces high-quality processed surfaces. This technique has various benefits like mechanical and thermal properties such as yield strength, ultimate tensile strength, impact strength, hardness, percentage of elongation, and corrosion behavior. UAFSP eliminates the drawbacks of friction stir processing and generates processed