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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Bournias-Varotsis, Alkaios, et al.
(författare)
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The effect of ultrasonic excitation on the electrical properties and microstructure of printed electronic conductive inks
- 2015
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Ingår i: 2015 38th International Spring Seminar on Electronics Technology (ISSE). - 9781479988600 - 9781479988594 ; , s. 140-145
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Konferensbidrag (refereegranskat)abstract
- Ultrasonic Additive Manufacturing (UAM) is an advanced manufacturing technique, which enables the embedding of electronic components and interconnections within solid aluminium structures, due to the low temperature encountered during material bonding. In this study, the effects of ultrasonic excitation, caused by the UAM process, on the electrical properties and the microstructure of thermally cured screen printed silver conductive inks were investigated. The electrical resistance and the dimensions of the samples were measured and compared before and after the ultrasonic excitation. The microstructure of excited and unexcited samples was examined using combined Focused Ion Beam and Scanning Electron Microscopy (FIB/SEM) and optical microscopy. The results showed an increase in the resistivity of the silver tracks after the ultrasonic excitation, which was correlated with a change in the microstructure: the size of the silver particles increased after the excitation, suggesting that inter-particle bonding has occurred. The study also highlighted issues with short circuiting between the conductive tracks and the aluminium substrate, which were attributed to the properties of the insulating layer and the inherent roughness of the UAM substrate. However, the reduction in conductivity and observed short circuiting were sufficiently small and rare, which leads to the conclusion that printed conductive tracks can function as interconnects in conjunction with UAM, for the fabrication of novel smart metal components.
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| 3. |
- Goulas, Athanasios, et al.
(författare)
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Additive manufacturing of physical assets by using ceramic multicomponent extra-terrestrial materials
- 2016
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Ingår i: Additive Manufacturing. - Amsterdam : Elsevier. - 2214-8604 .- 2214-7810. ; 10, s. 36-42
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Tidskriftsartikel (refereegranskat)abstract
- Powder Bed Fusion (PBF) is a range of advanced manufacturing technologies that can fabricate three-dimensional assets directly from CAD data, on a successive layer-by-layer strategy by using thermal energy, typically from a laser source, to irradiate and fuse particles within a powder bed.The aim of this paper was to investigate the application of this advanced manufacturing technique to process ceramic multicomponent materials into 3D layered structures. The materials used matched those found on the Lunar and Martian surfaces. The indigenous extra-terrestrial Lunar and Martian materials could potentially be used for manufacturing physical assets onsite (i.e., off-world) on future planetary exploration missions and could cover a range of potential applications including: infrastructure, radiation shielding, thermal storage, etc.Two different simulants of the mineralogical and basic properties of Lunar and Martian indigenous materials were used for the purpose of this study and processed with commercially available laser additive manufacturing equipment. The results of the laser processing were investigated and quantified through mechanical hardness testing, optical and scanning electron microscopy, X-ray fluorescence spectroscopy, thermo-gravimetric analysis, spectrometry, and finally X-ray diffraction.The research resulted in the identification of a range of process parameters that resulted in the successful manufacture of three-dimensional components from Lunar and Martian ceramic multicomponent simulant materials. The feasibility of using thermal based additive manufacturing with multi-component ceramic materials has therefore been established, which represents a potential solution to off-world bulk structure manufacture for future human space exploration. © 2016 Elsevier B.V.
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| 4. |
- Goulas, Athanasios, et al.
(författare)
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Investigating the additive manufacture of extra-terrestrial materials
- 2016
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Ingår i: Proceedings of the 2016 Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference. ; , s. 2271-2281
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Konferensbidrag (refereegranskat)abstract
- The Powder Bed Fusion (PBF) additive manufacturing process category, consists of a group of key enabling technologies allowing the fabrication of both intrinsic and complex structures for a series of applications, including aerospace and astronautics. The purpose of this investigation was to explore the potential application of in-space additive manufacturing/3D printing, for onsite fabrication of structures and parts, using the available extra-terrestrial natural resources as feedstock. This study was carried out by using simulants of terrestrial origin, mimicking the properties of those respective materials found extra-terram (in space). An investigation was conducted through material characterisation, processing and by powder bed fusion, and resultant examination by analytical techniques. The successful realisation of this manufacturing approach in an extra-terrestrial environment could enable a sustainable presence in space by providing the ability to build assets and tools needed for long duration/distance missions in deep space.
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| 5. |
- Goulas, Athanasios, et al.
(författare)
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Mechanical behaviour of additively manufactured lunar regolith simulant components
- 2019
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Ingår i: Proceedings of the Institution of mechanical engineers. Part L, journal of materials. - London : Sage Publications. - 1464-4207 .- 2041-3076. ; 233:8, s. 1629-1644
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Tidskriftsartikel (refereegranskat)abstract
- Additive manufacturing and its related techniques have frequently been put forward as a promising candidate for planetary in-situ manufacturing, from building life-sustaining habitats on the Moon to fabricating various replacements parts, aiming to support future extra-terrestrial human activity. This paper investigates the mechanical behaviour of lunar regolith simulant material components, which is a potential future space engineering material, manufactured by a laser-based powder bed fusion additive manufacturing system. The influence of laser energy input during processing was associated with the evolution of component porosity, measured via optical and scanning electron microscopy in combination with gas expansion pycnometry. The compressive strength performance and Vickers micro-hardness of the components were analysed and related back to the processing history and resultant microstructure of the lunar regolith simulant build material. Fabricated structures exhibited a relative porosity of 44–49% and densities ranging from 1.76 to 2.3 g cm−3, with a maximum compressive strength of 4.2 ± 0.1 MPa and elastic modulus of 287.3 ± 6.6 MPa, the former is comparable to a typical masonry clay brick (3.5 MPa). The additive manufacturing parts also had an average hardness value of 657 ± 14 HV0.05/15, better than borosilicate glass (580 HV). This study has shed significant insight into realising the potential of a laser-based powder bed fusion additive manufacturing process to deliver functional engineering assets via in-situ and abundant material sources that can be potentially used for future engineering applications in aerospace and astronautics. © 2018, IMechE 2018.
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| 6. |
- Ursby, Thomas, et al.
(författare)
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BioMAX the first macromolecular crystallography beamline at MAX IV Laboratory
- 2020
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Ingår i: Journal of Synchrotron Radiation. - Chichester : Wiley-Blackwell. - 0909-0495 .- 1600-5775. ; 27, s. 1415-1429
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Tidskriftsartikel (refereegranskat)abstract
- BioMAX is the first macromolecular crystallography beamline at the MAX IV Laboratory 3 GeV storage ring, which is the first operational multi-bend achromat storage ring. Due to the low-emittance storage ring, BioMAX has a parallel, high-intensity X-ray beam, even when focused down to 20 μm × 5 μm using the bendable focusing mirrors. The beam is tunable in the energy range 5-25 keV using the in-vacuum undulator and the horizontally deflecting double-crystal monochromator. BioMAX is equipped with an MD3 diffractometer, an ISARA high-capacity sample changer and an EIGER 16M hybrid pixel detector. Data collection at BioMAX is controlled using the newly developed MXCuBE3 graphical user interface, and sample tracking is handled by ISPyB. The computing infrastructure includes data storage and processing both at MAX IV and the Lund University supercomputing center LUNARC. With state-of-the-art instrumentation, a high degree of automation, a user-friendly control system interface and remote operation, BioMAX provides an excellent facility for most macromolecular crystallography experiments. Serial crystallography using either a high-viscosity extruder injector or the MD3 as a fixed-target scanner is already implemented. The serial crystallography activities at MAX IV Laboratory will be further developed at the microfocus beamline MicroMAX, when it comes into operation in 2022. MicroMAX will have a 1 μm × 1 μm beam focus and a flux up to 1015 photons s with main applications in serial crystallography, room-temperature structure determinations and time-resolved experiments.
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