Fabrication and Mechanical Characterization of Aluminium 7075 Reinforced with Nano Graphene / B4C / Inconel alloy 625 using Ultrasonic Stir Casting Method

Aluminium 7075 widely used in aerospace and defence applications. At the present time, hybrid composite material utility is refining in all engineering areas as a result of high strength /weight ratio, good corrosive and wear resistance. In this research work deals with the fabricating of hybrid metal matrix composite of aluminium 7075 as base metal reinforced by varying weight percentage of Nano graphene (0.5,1,1.5,2) , B4C (2,4,6,8,) and Inconel alloy 625 (2,4,6,8). This boron carbide, Inconel alloy 625 particles having particle size of 50μm. The hybrid aluminium composite material fabricated utilizing liquid metallurgy ultrasonic stir casting method. Tension test, compression test, hardness test and flexural test were conducted to determine mechanical properties of the hybrid composite material. Morphology of the hybrid metal matrix composite were analysed by using SEM.

Tribocorrosion Behavior of Inconel 718 Fabricated by Laser Powder Bed Fusion-Based Additive Manufacturing

Additive manufacturing (AM) by laser powder bed fusion (LPBF) has gained significant research attention to fabricate complex 3D Inconel alloy components for jet engines. The strategic advantages of LPBF-based AM to fabricate jet components for aerospace applications are well reported. The jet components are exposed to a high degree of vibration during the jet operation in a variable aqueous environment. The combined vibration and the aqueous environment create a tribological condition that can accelerate the failure mechanism. Therefore, it is critical to understand the tribocorrosion behavior of the Inconel alloy. In the present work, tribocorrosion behavior of the LPBF fabricated standalone coating of Inconel 718 in the 3.5% NaCl aqueous solution is presented. The LPBF fabricated samples are analyzed to determine the impact of porosity, generated as a result of LPBF, on the triobocorrosion behavior of AM Inconel 718. The study includes potentiodynamic tests, cathodic polarization, along with OCP measurements. The corrosive environment is found to increase the wear by 29.24% and 49.5% without the initiation of corrosion in the case of AM and wrought Inconel 718, respectively. A corrosion accelerated wear form of tribocorrosion is observed for Inconel 718. Additionally, the corrosive environment has a significant effect on wear even when the Inconel 718 surface is in equilibrium potential with the corrosive environment and no corrosion potential scan is applied. This study provides an insight into a critical aspect of the AM Inconel components.