Powder-based laser hybrid additive manufacturing of metals: a review

Abstract

Recent advances in additive manufacturing (AM) have attracted significant industrial interest. Initially, AM was mainly associated with the fabrication of prototypes, but the AM advances together with the broadening range of available materials, especially for producing metallic parts, have broaden the application areas and now the technology can be used for manufacturing functional parts, too. Especially, the AM technologies enable the creation of complex and topologically optimised geometries with internal cavities that were impossible to produce with traditional manufacturing processes. However, the tight geometrical tolerances along with the strict surface integrity requirements in aerospace, biomedical and automotive industries are not achievable in most cases with standalone AM technologies. Therefore, AM parts need extensive post-processing to ensure that their surface and dimensional requirements together with their respective mechanical properties are met. In this context, it is not surprising that the integration of AM with post-processing technologies into single and multi set-up processing solutions, commonly referred to as hybrid AM, has emerged as a very attractive proposition for industry while attracting a significant R&D interest. This paper reviews the current research and technology advances associated with the hybrid AM solutions. The special focus is on hybrid AM solutions that combine the capabilities of laser-based AM for processing powders with the necessary post-process technologies for producing metal parts with required accuracy, surface integrity and material properties. Commercially available hybrid AM systems that integrate laser-based AM with post-processing technologies are also reviewed together with their key application areas. Finally, the main challenges and open issues in broadening the industrial use of hybrid AM solutions are discussed.

Tool Wear and Milling Characteristics for Hybrid Additive Manufacturing Combining Laser Powder Bed Fusion and In Situ High-Speed Milling

“…A promising variant of these hybrid approaches combines laser powder bed fusion (LPBF) with in situ milling [ 12 ], allowing for the freedom of design offered by additive manufacturing (AM) [ 13 , 14 ] combined with the accuracy and surface quality of precision milling within a single, automated process [ 15 , 16 ]. In particular, precision milling allows for the manufacturing high-value-added parts with high form accuracy and superior surface quality that is generally not attainable by pure LPBF, thus allowing mechanical or biomedical applications [ 17 , 18 ]. The advancement of such hybrid approaches requires a thorough understanding of the fundamental properties of these new technologies, their restrictions and requirements.…”

Porosity, cracks, and mechanical properties of additively manufactured tooling alloys: a review

“…After the consolidation of one layer, the powder bed is lowered, and a new powder layer is spread on the surface of the formerly created layer, that is, successive layers of powder are formed, and the process continues until completion of the fully dense 3D component according to the digital design [20][21][22]. Figure 2 shows a schematic of L-PBF technology [23].…”

Precise machining based on Ritz non-uniform allowances for titanium blade fabricated by selective laser melting

“…Selective laser melting (SLM) is a typical common AM technology. It is a powder layer fusion technology that can produce complex structures with relatively good surface quality [1]. Ti-6Al-4V titanium alloy is a common SLM forming material.…”