Thermal monitoring of Direct Laser Metal Deposition of a Nickel-based superalloy

Additive Manufacturing has been increasingly successful in the industrial and aeronautical sector. The Direct Laser Metal Deposition (DLMD) technology is taking a leading role in the field of coating and repair of components with complex geometries. The process is characterised by high cooling rates that produces extremely fine microstructures with high mechanical properties. The monitoring of process parameters and thermal cycles assumes a key role and determines the quality of the deposition. In this work, an Ytterbium fiber laser source was used to build several single clad depositions of a Nickel-based superalloy powder on a substrate of the same material. Field temperature monitoring was performed using a high frequency (100Hz) IR thermal camera which allowed an accurate monitoring of maximum temperature and thermal cycles. Thermal data and process parameters were compared with metallographic analysis in order to understand the relation between geometrical characteristics and defects of clads.