Optimisation of Downskin Parameters to produce Metallic Parts Via Laser Powder Bed Fusion process: an overview

Additive manufacturing technologies are considered as advanced processes in which it is possible to produce complex shape components in a layer-by-layer manner. In these technologies, it is reported that in the production of parts with angles higher than 45 degrees, no support is required. Whereas, below this angle, depending on the material it is necessary to use the support structures to dissipate the heat and counterbalance the force of the recoding blade. There is a risk of part detachment at these angles during the building process and, consequently, failure. On the other hand, if no failure happens, a heavy dross formation on the downskin surface will occur, resulting in a surface with high roughness. Hence, many studies have been undertaken to face this topic and study the effect of various parameters, such as layer thickness, laser power, and scan speed, on the quality of the downskin surface of the minimum printable angle without the support requirement. This paper offers an overview of the last progress on the effect of process parameters on the surface quality of the downward surfaces in the production of complex parts via the laser powder bed fusion process. This review highlights the best practices that may be considered for future works to find the effective parameters for producing complex shape components with low angles without support structures