Refine
Year of publication
Institute
- Fachbereich Maschinenbau und Mechatronik (4)
- Fachbereich Chemie und Biotechnologie (3)
- Fachbereich Wirtschaftswissenschaften (3)
- IaAM - Institut für angewandte Automation und Mechatronik (3)
- Fachbereich Bauingenieurwesen (1)
- Fachbereich Elektrotechnik und Informationstechnik (1)
- Fachbereich Energietechnik (1)
- Fachbereich Gestaltung (1)
- IBB - Institut für Baustoffe und Baukonstruktionen (1)
Has Fulltext
- no (14)
Document Type
- Article (6)
- Book (4)
- Conference Proceeding (3)
- Report (1)
Keywords
- 3D-printing (1)
- Additive manufacturing (1)
- Glass powder (1)
- L-PBF (1)
- Laser processing (1)
- Melting (1)
- additive manufactureing (1)
- body imaging at 7 T MRI (1)
- glass (1)
- laser based powder fusion (1)
Development of an epithermal and fast neutron target station for the High Brilliance Neutron Source
(2025)
The conceptual design of an epithermal and fast neutron target–moderator–reflector (TMR) unit for the High Brilliance Neutron Source (HBS) project is presented. A total of 450 simulations with the Monte Carlo code PHITS were analyzed to explore different combinations and thicknesses of pre-moderator and moderator materials. For each case, the highest epithermal outgoing neutron current at the end of an extraction channel was obtained. Analysis of the outgoing current density showed that the neutron spectra are independent of the proton pulse width, while the integral outgoing current is proportional to the pulse width, indicating a trade-off between the time resolution obtained and the neutron flux per pulse expected at the sample position. The neutron time distribution analysis showed that D₂O as pre-moderator, combined with D₂O, 7LiF or graphite as moderators, will provide a competitive epithermal neutron current. The averaged epithermal and fast values obtained for the 96 Hz station and 167 μs proton pulse width are 9x10⁹ cm⁻² s⁻¹ and 2x10¹⁰ cm⁻² s⁻¹ for the epithermal and fast neutron extraction channels, respectively, with reductions expected for short proton pulses in burst-mode operation.
Laser-based Additive Manufacturing (AM) processes for the use of metals out of the powder bed have been investigated profusely and are prevalent in industry. Although there is a broad field of application, Laser Powder Bed Fusion (LPBF), also known as Selective Laser Melting (SLM) of glass is not fully developed yet. The material properties of glass are significantly different from the investigated metallic material for LPBF so far. As such, the process cannot be transferred, and the parameter limits and the process sequence must be redefined for glass. Starting with the characterization of glass powders, a parameter field is initially confined to investigate the process parameter of different glass powder using LPBFprocess. A feasibility study is carried out to process borosilicate glass powder. The effects of process parameters on the dimensional accuracy of fabricated parts out of borosilicate and hints for the post-processing are analysed and presented in this paper.
This paper presents the laser-based powder bed fusion (L-PBF) using various glass powders (borosilicate and quartz glass). Compared to metals, these require adapted process strategies. First, the glass powders were characterized with regard to their material properties and their processability in the powder bed. This was followed by investigations of the melting behavior of the glass powders with different laser wavelengths (10.6 µm, 1070 nm). In particular, the experimental setup of a CO2 laser was adapted for the processing of glass powder. An experimental setup with integrated coaxial temperature measurement/control and an inductively heatable build platform was created. This allowed the L-PBF process to be carried out at the transformation temperature of the glasses. Furthermore, the component’s material quality was analyzed on three-dimensional test specimen with regard to porosity, roughness, density and geometrical accuracy in order to evaluate the developed L-PBF parameters and to open up possible applications.
