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Botero Vega, Carlos Alberto
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Publications (10 of 32) Show all publications
Sjöström, W., Koptyug, A., Rännar, L.-E. & Botero, C. (2024). Near-infrared radiation: A promising heating method for powder bed fusion. Materials and Manufacturing Processes, 39(3), 320-328
Open this publication in new window or tab >>Near-infrared radiation: A promising heating method for powder bed fusion
2024 (English)In: Materials and Manufacturing Processes, ISSN 1042-6914, E-ISSN 1532-2475, Vol. 39, no 3, p. 320-328Article in journal (Refereed) Published
Abstract [en]

Metal additive manufacturing technologies, such as electron beam powder bed fusion (PBF-EB), rely on layer heating to overcome the so-called “smoke” phenomenon. When scaled up for industrial manufacturing, PBF-EB becomes less productive due to the lengthy preheating process. Currently, only the electron beam (EB) is used for preheating in PBF-EB, resulting in increased manufacturing times, energy consumption, and in some cases limiting the applicability of the technology. In this study, a new preheating approach is suggested that incorporates a near-infrared radiation (NIR) emitter inside an PBF-EB system. The NIR unit eliminates the need for EB heating, reducing build time and powder charging. Successful builds using 316 L and Ti6Al4V precursor powders validate the feasibility of the proposed approach. The produced samples exhibit similar properties to those obtained by the standard PBF-EB process. The introduction of NIR technology also reduced build cost and increased the service intervals of the electron gun. 

Place, publisher, year, edition, pages
Informa UK Limited, 2024
Keywords
316L, additive, beam, Electron, infrared, manufacturing, Ti6Al4V
National Category
Materials Engineering
Identifiers
urn:nbn:se:miun:diva-48165 (URN)10.1080/10426914.2023.2195910 (DOI)000961192700001 ()2-s2.0-85152071465 (Scopus ID)
Available from: 2023-04-19 Created: 2023-04-19 Last updated: 2024-02-27Bibliographically approved
Roos, S., Barbera Flichi, F., Ortiz-Membrado, L., Botero Vega, C. A., Jiménez-Piqué, E. & Rännar, L.-E. (2023). Assessing the viability of high-frequency spot melting for super duplex stainless steel 2507 via electron beam powder bed fusion. Journal of Materials Research and Technology, 27, 5720-5728
Open this publication in new window or tab >>Assessing the viability of high-frequency spot melting for super duplex stainless steel 2507 via electron beam powder bed fusion
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2023 (English)In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 27, p. 5720-5728Article in journal (Refereed) Published
Abstract [en]

This study investigates the use of Electron Beam Powder Bed Fusion (PBF-EB) spot melting on SDSS 2507, a material known for its high tensile strength, corrosion resistance, and welding properties. Spot melting, a localized melting technique, utilize a stationary beam to create melt pools before rapidly repositioning to form new ones, offering precise control over material properties in additive manufacturing. We conducted a design of experiments with 32 samples and analysed them using SEM, XRD, EBSD, optical microscopy, nanoindentation and statistical modelling. Elevated PBF-EB processing temperatures significantly influence microstructure and phase composition. XRD analysis identified the presence of the detrimental sigma phase. EBSD analysis revealed a composition primarily consisting of austenite (63 %) and sigma phase (33.5 %), with residual ferrite (3.5 %). Statistical modelling demonstrated that a combination of spot-time, spot distance, focus offset, and layer thickness was the most reliable predictor for density while area energy proved to be the most accurate predictor for hardness, with R2adj values of 0.766 and 0.802, respectively. Our study confirms that PBF-EB is capable of processing SDSS 2507 through spot melting, resulting in high-density samples at high productivity rates. The presence of sigma phase shows a need for post build heat treatment to achieve the desired phase distribution. This research enhances the understanding of the process and also holds promise for industrial applications. 

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
2507, Additive manufacturing, EBSD, Electron beam powder bed fusion, Nanoindentation, Stainless steel
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:miun:diva-49961 (URN)10.1016/j.jmrt.2023.11.028 (DOI)001148284900001 ()2-s2.0-85176960460 (Scopus ID)
Available from: 2023-11-30 Created: 2023-11-30 Last updated: 2024-02-09Bibliographically approved
Sjöström, W., Botero, C. & Jimenez-Pique, E. (2023). Coating as a methodology to increase processability of Al2O3 in electron beam powder bed fusion. In: : . Paper presented at EBAM 2023, Erlangen, Germany, 22-24 March, 2023. Frösön
Open this publication in new window or tab >>Coating as a methodology to increase processability of Al2O3 in electron beam powder bed fusion
2023 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

Additive manufacturing (AM) by electron beam powder bed fusion (E-PBF) is available for a growing number of metal alloys. So far, processing ceramic powders by E-PBF is problematic due to limited flowability, powder charging and beam instability. However, metal coating has recently been found to increase the processability of such powders. This work investigates the feasibility to create Al2O3 parts by electroless Ni coating and E-PBF. Resulting powder properties and morphology as well as melted powder was studied by microscopy, nanoindentation and energy dispersive X-ray analysis. By the suggested approach angular Al2O3 powder particles could be fully melted under the electron beam, although there is still development needed to attain a stable layer environment. The results disclose that coating can be a feasible method for increasing the processability of Al2O3 and how process settings affect residual metal elements after melting.

Place, publisher, year, edition, pages
Frösön: , 2023
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:miun:diva-48006 (URN)
Conference
EBAM 2023, Erlangen, Germany, 22-24 March, 2023
Available from: 2023-03-28 Created: 2023-03-28 Last updated: 2023-05-23Bibliographically approved
Ramírez, A., Zapata, C., Vargas, C., Tamayo, A., Baena, L., Castaño, J. G., . . . Gómez, M. (2023). Comportamiento biotribológico de prototipos de implantes de la aleación Ti6Al4V fabricados por EBM y posteriormente anodizados. TecnoLógicas, 26(57), Article ID e2642.
Open this publication in new window or tab >>Comportamiento biotribológico de prototipos de implantes de la aleación Ti6Al4V fabricados por EBM y posteriormente anodizados
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2023 (Spanish)In: TecnoLógicas, ISSN 0123-7799, Vol. 26, no 57, article id e2642Article in journal (Refereed) Published
Abstract [es]

Las articulaciones de la cadera pueden resultar dañadas por causas metabólicas (enfermedad degenerativa) o mecánicas (fractura), limitando su funcionalidad. Para restablecer el movimiento de la articulación, esta debe ser sustituida por una prótesis de cadera. En las articulaciones se producen fenómenos de lubricación, fricción y desgaste que, a su vez, suelen ser responsables del fallo de la prótesis, provocando su aflojamiento. Por tal motivo, el objetivo del presente estudio consistió en evaluar el comportamiento biotribológico de un prototipo de prótesis de cadera de Ti6Al4V manufacturado mediante fabricación aditiva por haz de electrones (EBM) y posteriormente modificado superficialmente mediante anodizado. Una vez obtenido el prototipo, se pulieron algunas muestras para realizar ensayos biotribológicos y otras para anodizarlas. Las pruebas biotribológicas se realizaron en un tribómetro de esfera sobre disco utilizando contracuerpos de alúmina de 6 mm de diámetro, empleando una carga de 5 N y velocidades de 30, 50 y 70 rpm. Se obtuvieron huellas de desgaste de 2 mm de diámetro, utilizando como medio un fluido corporal simulado (SBF) a una temperatura de 37 °C. El proceso EBM incrementó la dureza de la aleación Ti6Al4V respecto al proceso de forja convencional. Las muestras fabricadas por EBM, y posteriormente anodizadas, revelaron los valores más altos de coeficientes de fricción, mientras que las muestras fabricadas por forja y EBM indicaron coeficientes de fricción similares para todas las velocidades estudiadas. Adicionalmente, las muestras fabricadas por EBM, y después anodizadas, señalaron la menor tasa de desgaste, seguidas por las muestras fabricadas por EBM, mientras que las muestras fabricadas por forja evidenciaron la mayor tasa de desgaste. Igualmente, se encontró abrasión como principal mecanismo de desgaste en todas las condiciones evaluadas en las pruebas biotribológicas. Con la velocidad de 30 rpm se obtuvieron las menores tasas de desgaste para la aleación de Ti6Al4V con los diferentes procesos de fabricación; con esta misma velocidad se obtuvieron las mayores tasas de desgaste de los contracuerpos de todos los pares biotribológicos.

National Category
Materials Engineering
Identifiers
urn:nbn:se:miun:diva-50140 (URN)10.22430/22565337.2642 (DOI)
Available from: 2023-12-20 Created: 2023-12-20 Last updated: 2023-12-20Bibliographically approved
Roos, S., Botero, C. & Rännar, L.-E. (2023). Electron beam powder bed fusion processing of 2507 super duplex stainless steel. as-built phase composition and microstructural properties. Journal of Materials Research and Technology, 24, 6473-6483
Open this publication in new window or tab >>Electron beam powder bed fusion processing of 2507 super duplex stainless steel. as-built phase composition and microstructural properties
2023 (English)In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 24, p. 6473-6483Article in journal (Refereed) Published
Abstract [en]

This study focuses on adapting the Electron Beam Powder Bed Fusion (E-PBF) process for the manufacturing of parts from 2507 super duplex stainless steel, combining high strength and corrosion resistance, therefore presenting an interesting choice for E-PBF implementation. Samples manufactured using four sets of process parameters were characterized by scanning electron microscopy, tensile testing, X-ray diffraction analysis, energy dispersive X-ray spectroscopy and nanoindentation. The different E-PBF process temperatures investigated had the strongest influence on the phase characteristics and the resulting microstructure. The processability of the material was good, and high productivity rates were achieved, indicating good suitability for industrial transfer.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
1.4410, 2507, Additive manufacturing, Electron beam powder bed fusion, Nanoindentation, Stainless steel
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:miun:diva-48320 (URN)10.1016/j.jmrt.2023.04.230 (DOI)001026745000001 ()2-s2.0-85156260914 (Scopus ID)
Available from: 2023-05-16 Created: 2023-05-16 Last updated: 2023-09-19Bibliographically approved
Sjöström, W. & Botero Vega, C. A. (2023). Feasibility of electron beam melting metal coated ceramic powders. In: : . Paper presented at The Swedish Arena for Additive Manufacturing of Metals 2023. Stockholm
Open this publication in new window or tab >>Feasibility of electron beam melting metal coated ceramic powders
2023 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Electron beam powder bed fusion (E-PBF) is a known metal additive manufacturing (AM) technology. Processing non-conducting powders such as ceramics has so far been considered as non-feasible because of the inherent issues related to powder charging. This study investigates the feasibility to process and melt ceramic powders by innovative beam strategies as well as powder modification by metal coating. The proposed approach allowed melting and fusing of ceramic particles by the action of the electron beam. New challenges with powder bed balling and thermal incompatibility towards the 304 stainless start plate were identified. The results suggest that processing ceramics using metal coated powders can be feasible. Further research should address process parameters development and the use of a more compatible surface such as a ceramic start plate

Place, publisher, year, edition, pages
Stockholm: , 2023
Keywords
Additive manufacturing, Al2O3, high temperature materials
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:miun:diva-46817 (URN)
Conference
The Swedish Arena for Additive Manufacturing of Metals 2023
Available from: 2023-01-13 Created: 2023-01-13 Last updated: 2023-02-20Bibliographically approved
Ocampo, R. A., Bedoya Ochoa, N., Tamayo, J. A., Botero, C., Vargas, C. A., Gómez, M., . . . Zuleta Gil, A. A. (2023). Formation of highly ordered TiO2 nanotubes on Ti6Al4V alloys manufactured by electron beam powder bed fusion (E-PBF). The International Journal of Advanced Manufacturing Technology, 128(1-2), 257-266
Open this publication in new window or tab >>Formation of highly ordered TiO2 nanotubes on Ti6Al4V alloys manufactured by electron beam powder bed fusion (E-PBF)
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2023 (English)In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 128, no 1-2, p. 257-266Article in journal (Refereed) Published
Abstract [en]

Highly ordered TiO2 nanotubes were obtained by anodization on Ti6Al4V substrates manufactured by electron beam powder bed fusion (E-PBF). Effects of anodization parameters such as anodizing time, stirring, fluoride concentration, and water content were analyzed in an organic electrolyte (ethylene glycol) that contains ammonium fluoride. The ordering of the nanotubes was measured by regularity ratio calculations based on fast Fourier transform (FFT) from SEM images. It was found that for the processed specimens, the highest ordering of the TiO2 nanotubes was reached at 30 V for 5000 s with a concentration of 9 vol% H2O and 0.4 wt.% NH4F, exhibiting nanotubes free of delamination, cracks, and coral-like structures with a regularity ratio (RR) of 1.91. This work offers a simple method for creating homogeneous and organized TiO2 nanotubes on Ti6Al4V substrates manufactured by E-PBF which potentially improves its functionality in diverse industrial applications such as nanosensors, controlled-release substances, solar cells, water splitting, electrochromic devices, and Li-ion battery anodes. Graphical Abstract: [Figure not available: see fulltext.]. 

Place, publisher, year, edition, pages
Springer Science+Business Media B.V., 2023
Keywords
Additive manufacturing, Anodizing, Electron beam melting, Self-organized nanotubes, TiO<sub>2</sub> nanotubes
National Category
Materials Engineering
Identifiers
urn:nbn:se:miun:diva-49024 (URN)10.1007/s00170-023-11701-w (DOI)001024926800013 ()2-s2.0-85164155854 (Scopus ID)
Available from: 2023-08-15 Created: 2023-08-15 Last updated: 2023-08-16Bibliographically approved
Botero, C., Koptyug, A., Sjöström, W., Jiménez-Piqué, E., Şelte, A. & Rännar, L.-E. (2023). Functionally Graded Steels Obtained via Electron Beam Powder Bed Fusion. Key Engineering Materials, 964, 79-84
Open this publication in new window or tab >>Functionally Graded Steels Obtained via Electron Beam Powder Bed Fusion
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2023 (English)In: Key Engineering Materials, ISSN 1013-9826, E-ISSN 1662-9795, Vol. 964, p. 79-84Article in journal (Refereed) Published
Abstract [en]

Electron-Beam Powder Bed Fusion (EB-PBF) is one of the most important metal additive manufacturing (AM) technologies. In EB-PBF, a focused electron beam is used to melt metal powders in a layer by layer approach. In this investigation two pre-alloyed steel-based powders, stainless steel 316L and V4E, a tool steel developed by Uddeholm, were used to manufacture functionally graded materials. In the proposed approach two powders are loaded into the feeding container, V4E powder on top of 316L one, preventing their mixing. Such type of feeding yields components with two distinct materials separated by a zone with gradual transition from 316L to V4E. Microstructure and local mechanical properties were evaluated in the manufactured samples. Optical Microscopy, Scanning Electron Microscopy and EDX on the polished cross-sections show a gradual microstructural and compositional transition from characteristic 316L at the bottom of the specimens to the tool steel towards the top. Nanoindentation experiments confirmed a consequent gradient in hardness and elastic modulus, which gradually increase towards the top surface of the samples. The achieved results provide great possibilities to tailor the composition, microstructure, mechanical properties, and wear resistance by combining different powders in the powder bed AM technology. Potential applications include the tooling industry, where hard and wear-resistant materials are demanded on the surface with tougher and more ductile materials in the core of the tool.

Place, publisher, year, edition, pages
Trans Tech Publications, Ltd., 2023
Keywords
Electron Beam Melting, Functional Graded Materials (FGMs), Nanoindentation, Steel
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:miun:diva-50147 (URN)10.4028/p-xaC6qO (DOI)
Available from: 2023-12-20 Created: 2023-12-20 Last updated: 2023-12-20Bibliographically approved
Sjöström, W., Botero Vega, C. A. & Johansson, F. (2023). In-situ compositional tuning of functionally graded lamellas by electron beam powder bed fusion. In: : . Paper presented at The Swedish Arena for Additive Manufacturing of Metals 2023. Stockholm
Open this publication in new window or tab >>In-situ compositional tuning of functionally graded lamellas by electron beam powder bed fusion
2023 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Although multi-material additive manufacturing (AM) recently has gained a lot of attention, it is still not commercially available for electron beam powder bed fusion (E-PBF). The controlled vacuum environment and fast beam deflection rates in E-PBF allows for steering the melting in each manufactured point. However, very few attempts have been made to create multi-materials by E-PBF. This study investigates the feasibility of using a small sized gravity-fed hopper setup to create multi-material components. The proposed approach includes loading two hoppers with dissimilar metal feedstock and controlling the fetching of specific powders layer-by-layer. The aim of this work is to investigate if this approach can be used to generate direct or gradient shifts that allows to create lamellas of different chemical compositions within one continuous build process. In doing so, samples with 316L to Ti6Al4V and 316L to V4E gradients were manufactured in different lamellar fashions. Microscopy, micro hardness and energy dispersive X-ray were implemented to evaluate the results. The analysis showed a high degree of blending of the two precursor powders during the build process which affected the final material properties. Further refinement of the method is needed, especially when it comes to powder dispensing and control during the build process.

Place, publisher, year, edition, pages
Stockholm: , 2023
Keywords
Steel based gradient materials, Stainless steel, 316L, V4E, Tool steel
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:miun:diva-46818 (URN)
Conference
The Swedish Arena for Additive Manufacturing of Metals 2023
Projects
Fun-Lam
Available from: 2023-01-13 Created: 2023-01-13 Last updated: 2023-02-20Bibliographically approved
Vargas, C. A., Zuleta, A. A., Botero, C. A., Baena, L. M., Castaño, J. G., Gómez, M. A. & Tamayo, J. A. (2023). Morphological analysis of plasma electrolytic oxidation coatings formed on Ti6Al4V alloys manufactured by electron beam powder bed fusion. Heliyon, 9(9), Article ID e19289.
Open this publication in new window or tab >>Morphological analysis of plasma electrolytic oxidation coatings formed on Ti6Al4V alloys manufactured by electron beam powder bed fusion
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2023 (English)In: Heliyon, E-ISSN 2405-8440, Vol. 9, no 9, article id e19289Article in journal (Refereed) Published
Abstract [en]

This study investigates and compares plasma electrolytic oxidation (PEO) coatings produced on wrought Ti6Al4V alloy substrates with those resulting from electron beam powder bed fusion (PBF-EB). For a duration of 1000 s, a phosphate/silicate electrolyte with a current density of 50 A/cm2 was employed to fabricate the coatings. Surface and polished cross-sections of the coated specimens underwent SEM and X-ray diffraction (XRD) analyses. The obtained coatings exhibit differences of up to approximately 18% in thickness and formation, as well as in their anatase phase. The anatase phase is present at a level of 54.09% in the substrates processed by PBF-EB and 38.54% in wrought substrates. After 1000 s of PEO, the coatings formed on the wrought substrates exhibited higher porosity and larger pores (>1 μm) compared to those produced on the PBF-EB specimens. The PBF-EB coatings had lower porosity because they contained fewer pores larger than 1 μm. The findings imply that the unique microstructural arrangement of PBF-EB-produced additively made Ti6Al4V materials plays a significant impact in the development and morphological properties of PEO oxide coatings. 

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Additive manufacturing, Coating morphology, Electron beam powder bed fusion, Plasma electrolytic oxidation, Ti6Al4V
National Category
Materials Engineering
Identifiers
urn:nbn:se:miun:diva-49288 (URN)10.1016/j.heliyon.2023.e19289 (DOI)001069182600001 ()2-s2.0-85169475451 (Scopus ID)
Available from: 2023-09-13 Created: 2023-09-13 Last updated: 2023-10-23Bibliographically approved
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