Friction-Assisted Additive Manufacturing (FAAM) for Multistack Aluminum AA6061-T6/ AA7075-T6 Armor Plates: Numerical Investigation, Fabrication, and Characterization

Abstract

Composite armoring materials are generally fabricated using multiple layers of metallic and non-metallic materials such as titanium, steel, aluminum, ceramics, epoxy, resins, etc. Building these armor materials in the first place aims to withstand high-velocity bullets. Aluminum alloys are the best choice to offer increased mobility and excellent properties like a high strength-to-weight ratio, fracture toughness, and corrosion resistance. In this research, Forrestal and Warren scaling law techniques were employed to determine the optimal aluminum armor plate thickness to withstand 500 m/s velocity 7.62 mm projectile releasing from the pistol . FEA package Ansys was utilized for numerical simulations of bullet penetration, validating the results obtained from the scaling laws. After that, friction-assisted additive manufacturing (FAAM) was explored to build an AA6061/AA7075 laminated aluminum metal matrix composite (AMMC) for armor. Considering the plate thickness, the FAAM tool was designed with an optimum shoulder length, shoulder diameter, pin length, and pin diameter. Then the optimized process parameters were utilized to build the multi-stack armor plate using dissimilar aluminum alloys. Microstructural, and mechanical characterizations were conducted to assess the feasibility of the FAAM-built multi-stack armor plate. The findings of the work revealed better-refined grain’s microstructural profile in comparison with base materials and resulted in higher tensile and micro-hardness results. FAAM build improved the mechanical strength and yield strength of the base alloy AA6061 by roughly 25% and 31%, respectively.

Keywords

• friction-assisted additive manufacturing
• aluminium alloys
• microstructural characterization
• multistack armor plate
• impact analysis