Review on electron beam based additive manufacturing

Negi, Seema; Nambolan, Athul Arun; Kapil, Sajan; Joshi, Prathamesh; Manivannan, Ramalingam; Karunakaran, K. P.; Bhargava, Parag

doi:10.1108/rpj-07-2019-0182

Cited by 69 publications

(52 citation statements)

References 47 publications

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“…Extrusion‐based printing (EBP) of polymer melts (including fused filament fabrication) is the most inexpensive and readily accessed method for additive manufacturing (AM). [ 1 ] Other well‐known AM technologies such as electron beam melting [ 2 ] and selective laser sintering [ 3 ] involve melt processing to form their final products; however, they are less accessible due to printer costs. In AM, melt processing is a sustainable approach to avoid the use of solvents for product fabrication in a diverse range of end uses.…”

Section: Introductionmentioning

confidence: 99%

Hydrophilic (AB)_n Segmented Copolymers for Melt Extrusion‐Based Additive Manufacturing

Mechau

Frank

Bakırcı

et al. 2020

Macro Chemistry & Physics

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Several manufacturing technologies beneficially involve processing from the melt, including extrusion‐based printing, electrospinning, and electrohydrodynamic jetting. In this study, (AB)n segmented copolymers are tailored for melt‐processing to form physically crosslinked hydrogels after swelling. The copolymers are composed of hydrophilic poly(ethylene glycol)‐based segments and hydrophobic bisurea segments, which form physical crosslinks via hydrogen bonds. The degree of polymerization was adjusted to match the melt viscosity to the different melt‐processing techniques. Using extrusion‐based printing, a width of approximately 260 µm is printed into 3D constructs, with excellent interlayer bonding at fiber junctions, due to hydrogen bonding between the layers. For melt electrospinning, much thinner fibers in the range of about 1–15 µm are obtained and produced in a typical nonwoven morphology. With melt electrowriting, fibers are deposited in a controlled way to well‐defined 3D constructs. In this case, multiple fiber layers fuse together enabling constructs with line width in the range of 70 to 160 µm. If exposed to water the printed constructs swell and form physically crosslinked hydrogels that slowly disintegrate, which is a feature for soluble inks within biofabrication strategies. In this context, cytotoxicity tests confirm the viability of cells and thus demonstrating biocompatibility of this class of copolymers.

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Section: Introductionmentioning

confidence: 99%

Hydrophilic (AB)_n Segmented Copolymers for Melt Extrusion‐Based Additive Manufacturing

Mechau

Frank

Bakırcı

et al. 2020

Macro Chemistry & Physics

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“…The Protocol presented here focuses on the 3D printing technique known as selective laser sintering (SLS), which affords high-quality results at relatively low costs. The current Protocol does not report on other types of printing (Negi et al, 2020), which, on the basis of years of experience are considered less satisfactory.…”

Section: Troubleshootingmentioning

confidence: 96%

A Comprehensive 3D-Molded Bone Flap Protocol for Patient-Specific Cranioplasty

Bertani

Novo

Freitas

et al. 2021

Preprint

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We present a detailed step-by-step approach for the low-cost production and surgical implantation of cranial prostheses, aimed at restoring aesthetics, cerebral protection, and facilitating neurological rehabilitation. This protocol uses combined scan computed tomography (CT) cross-sectional images, in DICOM format, along with a 3D printing (additive manufacturing) setup. The in-house developed software InVesalius®️ is an open-source tool for medical imaging manipulation. The protocol describes image acquisition (CT scanning) procedures, and image post-processing procedures such as image segmentation, surface/volume rendering, mesh generation of a 3D digital model of the cranial defect and the desired prostheses, and their preparation for use in 3D printers. Furthermore, the protocol describes a detailed powder bed fusion additive manufacturing process, known as Selective Laser Sintering (SLS), using Polyamide (PA12) as feedstock to produce a 3-piece customized printed set per patient. Each set consists of a “cranial defect printout” and a “testing prosthesis” to assemble parts for precision testing, and a cranial “prostheses mold” in 2 parts to allow for the intraoperative modeling of the final implant cast using the medical grade Poly(methyl methacrylate) (PMMA) in a time span of a few min. The entire 3D processing time, including modelling, design, production, post-processing and qualification, takes approximately 42 h. Modeling the PMMA flap with a critical thickness of 4 mm by means of Finite Element Method (FEM) assures mechanical and impact properties to be slightly weaker than the bone tissue around it, a safety design to prevent fracturing the skull after a possible subsequent episode of head injury. On a parallel track, the Protocol seeks to provide guidance in the context of equipment, manufacturing cost and troubleshooting. Customized 3D PMMA prostheses offers a reduced operating time, good biocompatibility, and great functional and aesthetic outcomes. Additionally, it offers greater than 15-fold cost advantage over the usage of other materials, including metallic parts produced by additive manufacturing.

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“…Sheet-based structures have been manufactured by selective laser sintering (SLS) [6,15], L-PBF [5,19] but so far not by EBM. It is well-known that EBM structures have lower resulting porosity [18] and lower residual stress as compared to similar L-PBF-and SLS-manufactured structures because of the preheating during manufacturing that acts as a stress relief heat treatment [20,21]. Internal defects of the EBM-manufactured objects affect their fatigue life [22].…”

Section: Introductionmentioning

confidence: 99%

Different Approaches for Manufacturing Ti-6Al-4V Alloy with Triply Periodic Minimal Surface Sheet-Based Structures by Electron Beam Melting

et al. 2021

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Targeting biomedical applications, Triply Periodic Minimal Surface (TPMS) gyroid sheet-based structures were successfully manufactured for the first time by Electron Beam Melting in two different production Themes, i.e., inputting a zero (Wafer Theme) and a 200 µm (Melt Theme) wall thickness. Initial assumption was that in both cases, EBM manufacturing should yield the structures with similar mechanical properties as in a Wafer-mode, as wall thickness is determined by the minimal beam spot size of ca 200 µm. Their surface morphology, geometry, and mechanical properties were investigated by means of electron microscopy (SEM), X-ray Computed Tomography (XCT), and uniaxial tests (both compression and tension). Application of different manufacturing Themes resulted in specimens with different wall thicknesses while quasi-elastic gradients for different Themes was found to be of 1.5 GPa, similar to the elastic modulus of human cortical bone tissue. The specific energy absorption at 50% strain was also similar for the two types of structures. Finite element simulations were also conducted to qualitatively analyze the deformation process and the stress distribution under mechanical load. Simulations demonstrated that in the elastic regime wall, regions oriented parallel to the load are primarily affected by deformation. We could conclude that gyroids manufactured in Wafer and Melt Themes are equally effective in mimicking mechanical properties of the bones.

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Review on electron beam based additive manufacturing

Cited by 69 publications

References 47 publications

Hydrophilic (AB)_n Segmented Copolymers for Melt Extrusion‐Based Additive Manufacturing

Hydrophilic (AB)_n Segmented Copolymers for Melt Extrusion‐Based Additive Manufacturing

A Comprehensive 3D-Molded Bone Flap Protocol for Patient-Specific Cranioplasty

Different Approaches for Manufacturing Ti-6Al-4V Alloy with Triply Periodic Minimal Surface Sheet-Based Structures by Electron Beam Melting

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Review on electron beam based additive manufacturing

Cited by 69 publications

References 47 publications

Hydrophilic (AB)n Segmented Copolymers for Melt Extrusion‐Based Additive Manufacturing

Hydrophilic (AB)n Segmented Copolymers for Melt Extrusion‐Based Additive Manufacturing

A Comprehensive 3D-Molded Bone Flap Protocol for Patient-Specific Cranioplasty

Different Approaches for Manufacturing Ti-6Al-4V Alloy with Triply Periodic Minimal Surface Sheet-Based Structures by Electron Beam Melting

Contact Info

Product

Resources

About

Hydrophilic (AB)_n Segmented Copolymers for Melt Extrusion‐Based Additive Manufacturing

Hydrophilic (AB)_n Segmented Copolymers for Melt Extrusion‐Based Additive Manufacturing