Assessing the Enhancement of the Mechanical Properties of Aluminium 7075 using Gula Clay at Constant 2wt% Soot for Military Application

Abstract

This study investigates the enhancement of mechanical properties of Aluminium 7075 alloy by incorporating Gula clay and soot as reinforcements for ballistic application. Aluminium 7075, widely used in aerospace, defense, and automotive industries, is known for its excellent strength-to-weight ratio but requires improved impact resistance and tensile properties for advanced ballistic applications. The research involves systematically varying the composition of Gula clay (1 - 5wt.%) at constant amount of 2wt.% soot to produce six distinct samples through liquid metallurgy and heat treatment processes. Microstructural analysis, Mechanical tests, including Vickers micro-hardness, tensile strength, impact resistance, total elongation, and wear resistance, were conducted to evaluate the composite properties. Based on the obtained optical micrographs, dendritic structure, and Zn – Al rich matrix of unreinforced Al7075 was vividly seen, the reinforced Al7075 consist of both primary matrix of Zn – rich phase, Al – rich secondary phase with uniform distribution reinforcements in the Al7076 alloy. It was observed that as the volume of Gula clay was increased, the dendritic structure of Al7075 was covered with the reinforcement. The mechanical tests results revealed that the addition of Gula clay in the range of 1 – 5 wt.% and at 2wt.% soot enhances tensile strength from 186 MPa (aluminium 7075) to 269 MPa (44.6% increment), while impact resistance improves from 17.6J to 34J (48% improvement), the wear resistance of Al7075 was enhanced by 81%. But there was a gradual marginal decrease in the ductility of Al7075 from 3.4 – 10.9%. The improved properties demonstrate the potential of this composite material to meet international standards for ballistic applications. These findings fill a significant gap in lightweight, cost-effective ballistic materials, providing an alternative to conventional alloys. This research contributes to the development of advanced materials for military applications while promoting the use of sustainable reinforcements