Self-supporting overhang structures produced by additive manufacturing through electron beam melting

Ameen, Wadea; Al-Ahmari, Abdulrahman; Mohammed, Muneer Khan

doi:10.1007/s00170-019-04007-3

Cited by 44 publications

(25 citation statements)

References 18 publications

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“…Yield strength of 930 MPa and an elasticity modulus of 120,000 MPa were exhibited by the EBM-fabricated Ti6Al4V parts. ARCAM leading to good microstructures and mechanical properties [43,44]. Yield strength of 930 MPa and an elasticity modulus of 120,000 MPa were exhibited by the EBM-fabricated Ti6Al4V parts.…”

Section: Experimental Workmentioning

confidence: 98%

“…Table 2 shows the main EBM process parameters used to fabricate the Ti6Al4V parts. The EBM parameters in Table 2 were selected on the basis of previous studies, indicating that those parameters were suggested as default from ARCAM leading to good microstructures and mechanical properties [43,44]. Yield strength of 930 MPa and an elasticity modulus of 120,000 MPa were exhibited by the EBM-fabricated Ti6Al4V parts.…”

Section: Experimental Workmentioning

confidence: 99%

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On the Effect of Electron Beam Melted Ti6Al4V Part Orientations during Milling

Dabwan

Anwar

Al-Samhan

et al. 2020

Metals

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The machining of the electron beam melting (EBM) produced parts is a challenging task because, upon machining, different part orientations (EBM layers’ orientations) produce different surface quality even when the same machining parameters are employed. In this paper, the EBM fabricated parts are machined in three possible orientations with regard to the tool feed direction, where the three orientations are “tool movement in a layer plane” (TILP), “tool movement perpendicular to layer planes” (TLP), and “tool movement parallel to layers planes” (TPLP). The influence of the feed rate, radial depth of cut, and cutting speed is studied on surface roughness, cutting force, micro-hardness, microstructure, chip morphology, and surface morphology of Ti6Al4V, while considering the EBM part orientations. It was found that different orientations have different effects on the machined surface during milling. The results show that the EBM parts can achieve good surface quality and surface integrity when milled along the TLP orientation. For instance, surface roughness (Sa) can be improved up to 29% when the milling tool is fed along the TLP orientation compared to the other orientations (TILP and TPLP). Furthermore, surface morphology significantly improves with lower micro-pits, redeposited chips, and feed marks in case of the TLP orientation.

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Section: Experimental Workmentioning

confidence: 98%

Section: Experimental Workmentioning

confidence: 99%

On the Effect of Electron Beam Melted Ti6Al4V Part Orientations during Milling

Dabwan

Anwar

Al-Samhan

et al. 2020

Metals

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“…The profile of the EBM parts can be seen on the screen, as shown in Figure 20. The projector magnifies the profile of the specimen and displays this on the built-in projection [1] screen on this screen. There is typically a grid that can be rotated 360 degrees so that the X-Y axis of the screen can be aligned with a straight edge of the part to be examined or measured.…”

Section: Experimental Validationmentioning

confidence: 99%

“…Manufacturing methods and designs have been improved to make life easier and more straightforward, especially concerning technologies that allow for accurate and fast manufacturing. Electron beam melting (EBM) is a relatively new additive manufacturing technology based on the powder bed fusion process [1]. The components can be produced on a layer-by-layer basis by melting the powder metal using an electron beam.…”

Section: Introductionmentioning

confidence: 99%

“…The key findings of this study are as follows. (1) Temperature predictions during each accumulated layer could be useful in determining the phase transform from powder to the liquid and from liquid to solid. (2) The residual stress patterns of the deposited layers with supports were found to be completely different from the unsupported model.…”

Section: Introductionmentioning

confidence: 99%

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Thermomechanical Simulations of Residual Stresses and Distortion in Electron Beam Melting with Experimental Validation for Ti-6Al-4V

Abdullah

Anwar

Al-Ahmari

2020

Metals

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Electron beam melting (EBM) is a relatively new process in three-dimensional (3D) printing to enable rapid manufacturing. EBM can manufacture metallic parts with thin walls, multi-layers, and complex internal structures that could not otherwise be produced for applications in aerospace, medicine, and other fields. A 3D transient coupled thermomechanical finite element (FE) model was built to simulate the temperature distribution, distortion, and residual stresses in electron beam additive manufactured Ti-6Al-4V parts. This research enhances the understanding of the EBM-based 3D printing process to achieve parts with lower levels of residual stress and distortion and hence improved quality. The model used a fine mesh in the layer deposition zone, and the mesh size was gradually increased with distance away from the deposits. Then, elements are activated layer by layer during deposition according to the desired material properties. On the top surface, a Gaussian distributed heat flux is used to model the heat source, and the temperature-dependent properties of the powder and solid are also included to improve accuracy. The current simulation has been validated by comparing the FE distortion and temperature results with the experimental results and other reported simulation studies. The residual stress results calculated by the FE analysis were also compared with the previously reported simulation studies on the EBM process. The results showed that the finite element approach can efficiently and accurately predict the temperature field of a part during the EBM process and can easily be extended to other powder bed fusion processes.

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