Refurbishing damaged surfaces of nickel-aluminum bronze propellers: A robotic approach using gas metal arc welding and friction stir processing

Abstract

Gas Metal Arc Welding (GMAW) are well known due to its cost effective and easy accessibility. The technique is commonly used in shipping maintenance to repair corrosion and erosion affected propeller blades. Recently, studies of the Friction Stir Process (FSP) have shown its capability to generate a very fine microstructure and enhancement of the metal surface properties. This paper proposes an integrated approach for repairing larger sized nickel-aluminum bronze (NAB) components using a single robotic system. The process includes surface cleaning, weld deposition (WD), welding deposition Friction Stir Process (WD-FSP), surface and contour finishing. The mechanical properties, including hardness, cavitation erosion and corrosion performance, are tested on as-cast NAB, WD and WD-FSP surfaces. The weld deposition and WD-FSP surfaces showed an enhancement in hardness compared to as-cast NAB. As for cavitations erosion and corrosion, the weld deposition and WD-FSP sample exhibited an improvement in the cumulative mass loss and shifting of the electrode potential to the more noble section signifying that using the proposed approach is feasible for NAB repair.