Current research and industrial application of laser powder directed energy deposition

Abstract

Additive Manufacturing (AM) technologies are recognized as the future of the manufacturing industry thanks to their possibilities in terms of shape design, part functionality, and material efficiency. The use of AM technologies in many industrial sectors is growing, also due to the increasing knowledge regarding the AM processes and the characteristics of the final part. One of the most promising AM techniques is the Directed Energy Deposition (DED) that uses a thermal source to generate a melt pool on a substrate into which metal powder is injected. The potentialities of DED technology are the ability to process large build volumes (> 1000 mm in size), the ability to deliver the material directly into the melt pool, the possibility to repair existing parts, and the opportunity to change the material during the building process, thus creating functionally graded material. In this paper, a review of the industrial applications of Laser Powder Directed Energy Deposition (LP-DED) is presented. Three main applications are identified in repairing, designed material, and production. Despite the enormous advantages of LP-DED, from the literature, it emerges that the most relevant application refers to the repairing process of high-value components.

3D-Printing for Critical Sized Bone Defects: Current Concepts and Future Directions

“…Another interesting additive manufacturing techniques is directed energy deposition (DED), which consists of the delivery of a heated substrate, typically a metallic alloy, to the nozzle head, where a high-energy laser is simultaneously focused, to generate a layered construct in a melt pool [ 150 ]. DED is unique in that multi-material constructs can be rapidly fabricated, though its use in a biomedical context has been limited due to difficulty in controlling the resolution of the generated construct, especially surface topography [ 151 , 152 ]. However, DED may have some clinical utility when used to coat metallic implants intended for load-bearing applications, as it has been shown to improve in vitro cell viability, cell-scaffold interactions, and bony ingrowth while retaining mechanical strength when compared to non-coated implants [ 153 , 154 , 155 ].…”

An Overview of Physical Phenomena Involved in the Laser Powder Directed Energy Deposition Process

“…Therefore, a sequential approach is used to study the process, in which the output obtained as a result of each mechanism is used as an input variable for the following mechanism. Several reviews are available in the literature however most of them are focused on the application of the LP-DED process [6,14], on the modelling techniques [12], on the powder feed equipment [15,16], on the monitoring techniques [17] and on the feasibility of different alloys [18][19][20][21][22].…”

“…The main PBF and DED systems are listed in Table 1, indicating the building volume. It is possible to observe that, despite PBF processes dominates the market [6], they can be used only to produce components with a maximum dimension of 400 mm. On the other hand, DED processes do not use a closed chamber and consequently the deposited dimension can reach up to 3000 mm in size.…”

TiNi-Based Bi-Metallic Shape-Memory Alloy by Laser-Directed Energy Deposition

“…Joining different metal alloys into a single bi-metallic component can realize a wide variety of combinations with excellent material properties [ 1 , 2 , 3 ], and the joining of bi-metals is necessary in many industrial environments where different properties are needed at different locations [ 3 ]. The directed energy deposition (DED) additive manufacturing (AM) process has become an important approach to realize various types of metal joining and metal repair since strong metallurgical bonding can be achieved [ 4 , 5 , 6 ]. So far, DED has been used in various applications including metal joining and part repairing [ 2 , 6 , 7 , 8 ].…”