Optimisation of downskin parameters to produce metallic parts via laser powder bed fusion process: an overview

Abstract

Additive manufacturing technologies are considered advanced processes in which it is possible to produce complex shape components layer-by-layer. In these technologies, it is reported that in producing parts with angles higher than 45°, no support is required. Depending on the material below this angle, it is necessary to use the support structures to dissipate the heat and counterbalance the force of the recoding blade. During the building process, it is well documented that there is a risk of part detachment at low angles that can result in failure. On the other hand, a heavy dross formation on the downskin surface will occur if no failure happens, resulting in a surface with scarce quality. Hence, many efforts have been undertaken to face this challenge 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 review 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 effective parameters for producing complex shape components with low angles without support structures.