Search

The laser-based powder bed fusion (LPBF) process is able to produce complex part geometries. The fast development of the LPBF process offers new opportunities for the industries. Most research done to date has focused on the modeling of the process, which shows that both part geometries and process parameters play an essential role in the result of end-product quality. The definition of the manufacturability of the LPBF is vague. In this review, the focus is set on the manufacturability of the metal-LPBF process. What manufacturability is in the LPBF process and how it is investigated so far are discussed. All process parameters and design constraints for LPBF processes are introduced. The relationship between process parameters and design constraints and how they affect the manufacturability are discussed as well. A detailed discussion on how other researchers evaluate manufacturability analysis of LPBF is conducted. Finally, the manufacturability of LPBF is defined, and future prospects on filling the research gaps on the manufacturability analysis of the LPBF are presented. [ABSTRACT FROM AUTHOR]

Laser powder–based directed energy deposition (DED) is a specific additive manufacturing process that offers an effective way to fabricate parts via simultaneous delivery of powders and laser beam. It has been developing greatly in the recent decades and being widely used for manufacturing, prototyping, and repairing. Complex physical events take place during the manufacturing process and have great impacts on its overall performance. To build high-quality parts through the laser powder–based DED process, its physical insights and process parameters need to be understood and optimized, for which modeling provides an efficient way. This article gives a review of the modeling work for the laser powder–based DED process, in which the models developed for powder stream and its interaction with laser beam, melt-pool, and bulk heating are discussed in detail. Different modeling approaches and methods towards overall and specific physical processes of the laser powder–based DED are analyzed and compared. Suggestions towards the modeling are also given at the end. [ABSTRACT FROM AUTHOR]

Additive manufacturing has become very popular nowadays to create complex geometries that cannot be achieved by any other manufacturing processes. The purpose of this study is to investigate and characterize the electrochemical polishing and chemical etching methods as a post-process treatment to improve the surface finish of lattice structures made from Ti-6Al-4V manufactured by direct metal laser sintering (DMLS). A lattice sample is designed with external and internal struts to compare the influence of the post-processing on different features. The post-processing parameters are studied via the Taguchi method. This work will provide critical information on the surface and geometrical characterization as well as the post-process treatment of a Ti-6Al-4V lattice. The metrological data will be analyzed to determine how the post-process treatment affects the surface finish, considering the final roughness and geometrical integrity of lattice samples. It is found that the material removal rate was more important at the edges, specifically on the external features. It was also confirmed that the average roughness is linked to the material removal for both processes. The more material is removed from the parts, the better the surface finish. It is also found that the etching process helps the electrochemical polishing go deeper inside the geometry. [ABSTRACT FROM AUTHOR]