Microstructure and mechanical properties of Al7075 and Al7075-based hybrid metal matrix composites by additive manufacturing

Aluminium-based hybrid composites have been successfully employed in many industrial sectors including marine, aerospace, military and transports for producing a wide range of devices and components. In this research, Al7075, titanium di boride (TiB₂) and molybdenum di sulphide (MoS₂) are selected as matrix material, hard reinforcement and soft reinforcement respectively. The Al7075/12 wt.% TiB₂/x wt.% MoS₂ (x = 0, 1.5, 3, 4.5, and 6) hybrid composites are fabricated with the help of Direct Energy Deposition Method (DEDM). To validate the presence of components and analyse the microstructure of the produced composites, energy-dispersive X-ray analysis (EDAX) and scanning electron microscopy (SEM) were utilized. Archimedes’ concept is used to calculate the density of DEDM composites. Vickers microhardness metre is used to determine the microhardness of DEDM composites. A micro UTM was used to assess the tensile and compressive strengths of DEDM composites. Density, microhardness, compressive and tensile strength of DEDM composites significantly overheads to 4.5 wt.% MoS₂ and decreased with the addition of 6 wt.% MoS₂.