Publication

Abstract : The significant advantage of laser-based powder bed fusion (L-PBF) process is to produce extremely complex-shaped lightweight engineering parts through layer-by-layer fabrication. The control of excessive residual stress (RS) formation is one of the primary challenges in the L-PBF process. The restraining action caused by thermal gradient (TG) between the layers and between the adjacent laser scan tracks within layer is the main factor responsible for RS formation in L-PBF process. The dimensional changes, localized distortion of parts, delamination of layers during fabrication, and crack nucleation upon cooling are the significant drawbacks of excessive accumulation of RS. It is essential to control the RS accumulation to avoid build failure and to improve the load carrying capacity of parts in as-built condition. The present review delivers the influence of major L-PBF parameters such as laser power (LP), scan speed (SS), scan strategy, scan vector length, layer thickness, hatch spacing and build orientation on the control of RS formation. The present review also focusing the selection strategy of major L-PBF parameters with respect to their contribution on RS control. The role of process parameters in controlling the volumetric energy density (VED) and their effect on melt pool size have been discussed. As an outcome, the current review addresses the existing challenges and research opportunities on control of RS in the L-PBF parts.