Humping defects in laser based direct metal deposition

Abstract

Laser based direct metal deposition is one of the prominent technologies of metal additive manufacturing. This process follows a layer-wise fabrication strategy and, each layer consists of multiple tracks. Since, each tack acts as a building block, the morphology of each track firmly affects the shape and size of the final component. To achieve close dimensional tolerances on the final component, it is important to have prior knowledge on process parameters and their correlation with the output/deposited track’s morphology. The present work deposited Inconel 718 alloy single tracks, and studied their external morphology. Humping, and discontinuous track deposition is observed at particular parameter set. In-depth investigations are carried, to understand the role of input parameters on the defect formation. The results show that the scanning speed and powder feed rate are majorly affecting the deposition. High powder feed rates and scan speed are resulting discontinuous tacks uneven surfaces.