Effect of Process Parameters on the Geometry of Single-Track Deposits of Inconel 718 onto AISI4140 Using Laser Cladding

Abstract

AISI 4140 alloy steel finds extensive applications in industrial settings such as gears and blades owing to its exceptional combination of high strength and ductility. However, prolonged exposure to harsh operating conditions can result in significant mechanical failures, necessitating essential repair techniques to restore functionality and preserve the substantial value of these components. Among the various repair methods, directed energy deposition, an additive manufacturing technique, is gaining prominence for its efficacy in producing and restoring mechanically stressed components. Compared to traditional welding methods and metal spraying, laser cladding offers advantages such as reduced heat input and minimal dilution, resulting in superior metallurgical bonds. This research focuses on depositing Inconel 718 on AISI 4140 substrate using the laser cladding technique to evaluate the feasibility of this alloy for repairing AISI 4140 components. The investigation explores the influence of key laser cladding parameters, including laser power, scanning speed, and mass flow rate, on critical attributes of deposited beads such as width, height, clad angle, and dilution ratio. The results elucidate the effects of varying parameters: increasing scanning speed reduces bead dimensions and clad angle while increasing dilution. Elevating the powder-feeding rate increases bead height and wetting angle, with minimal impact on width and decreased dilution. Augmenting laser power increases bead width and reduces wetting angle, with dilution showing minimal change. Based on the findings, the optimal process parameters for future investigations are identified as a laser power of 950W, a laser scan speed of 300mm/min, and a mass flow rate of 4.31 g/min. Furthermore, the research demonstrates commendable metallurgical bonding at the interface between the two dissimilar materials, affirming the feasibility of integrating them through laser cladding.