Laser cladding of Inconel 718 powder on a non-weldable substrate: Clad bead geometry-solidification cracking relationship

The present paper addresses the solidification cracking during laser cladding of Inconel 718 powder on A-286 iron based superalloy which is known as hot crack susceptible alloy. Linear regression analysis was performed to propose empirical-statistical correlations between the key processing parameters and the geometrical attributes of single laser clad tracks. These correlations were used in the development of a processing map to study the effects of geometrical characteristics on the solidification cracking and the required conditions to obtain crack-free clads. The solidification cracking of the single clad tracks was inspected by macrostructural examinations using scanning electron microscopy in backscattered electron mode. The processing map revealed that the dilution ratio is the governing macrostructural attribute to avoid solidification cracking. The role of this macrostructural feature in reducing the susceptibility of fusion zone to solidification cracking is discussed.