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Bottini L (2021) Study of selective laser melting process parameters to improve the obtainable roughness of AlSi10Mg parts. Selected Topics in Manufacturing. pp 121–139. Springer, Cham. https://doi.org/10.1007/978-3-030-57729-2_9
Mirrors manufacturing with traditional computer numerical control (CNC) technologies have limitations on mass reduction. Additive manufacturing (AM) methods offer new concepts for production of metal optics that can overcome the specific limitations of CNC technologies. Internal structures can be designed with a variety of configurations, such as periodic structures [ 6], honeycomb cells [ 7, 8] , and topologically optimized structures [ 9, 10, 11]. The work underlines that the AM metal mirror fabrication can have an important progress by combining the geometrical design with new high performance MMC materials. However, the integration with the secondary finishing operation and the deformation induced by the assembly are of primary importance to assure the functionality. The modal analysis demonstrated the compliance with the requirements of a constrained modal response greater than 1100 Hz;
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Tan Q, Zhang J, Sun Q, Fan Z, Li G, Yin Y, Liu Y, Zhang MX (2020) Inoculation treatment of an additively manufactured 2024 aluminium alloy with titanium nanoparticles. Acta Mater 196:1–16. https://doi.org/10.1016/j.actamat.2020.06.026
Astronomers experimented with different recipes for speculum metal over the centuries, but the two main ingredients were copper and tin. Newton added small amounts of arsenic to his, arguing that it made the metal whiter and more reflective. He did at least take some basic precautionary measures when melting this poisonous substance to make his alloy, ‘bewaring in the mean time, not to draw in breath near the pernicious fumes’ ( Philosophical Transactions of the Royal Society, vol. 7 (1672)). Scientists agree that the beads are well-intentioned, but worry about their potential effects on the Arctic ecosystem. If they float around there indefinitely, “it’s just going to clog up the ocean and mess with the ecosystem,” says Cecilia Bitz, an atmospheric scientist at the University of Washington who specialises in Arctic sea ice. The prescreening simulation allowed the selection of a lattice structure with good compromise between mass reduction and maximum displacement;
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Artists Necole Schmitz, Stephen Coles and Katie Surridge took on the casting processes, melting the specially alloyed speculum metal in a chimney furnace at over 1000 degrees Celsius before pouring it into disc-shaped moulds. She did concede though that "rage" zombies through an anger-inducing virus could be possible: "There certainly are some microbes which can change behaviour and lead to aggression, with the rabies virus being the best known.
Rometsch PA, Zhu Y, Wu X, Huang A (2022) Review of high-strength aluminium alloys for additive manufacturing by laser powder bed fusion. Mater Des 219:110779. https://doi.org/10.1016/j.matdes.2022.110779 We must prioritise and put more funding behind scientific and multi-disciplinary research. At the moment, Arctic science is concentrated on its summer, with the Arctic winter which could tell us an enormous amount about the weather being under-studied. More collaboration is needed among UK universities to avoid repetition of scientific endeavours seeking out the same information, and with our international partners to learn and share resource." Milan B (2016) Laser additive manufacturing. Materials, Design, Technologies, and Applications. Woodhead Publishing, Cambridge
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Sahu R, Patel V, Singh S, Munjal B (2017) Structural optimization of a space mirror to selectively constrain optical aberrations. Struct Multidiscip Optim 55(6):2353–2363. https://doi.org/10.1007/s00158-016-1616-x It took Terry over 20 hours of grinding and polishing to produce our mirror – and no, thankfully, he didn’t do it non-stop! Left: Detail from a portrait of William Herschel published in 1835. He holds a diagram of Uranus labelled ‘The Georgian Planet’, the name which he originally chose in honour of his patron King George III. Credit: Science Museum Group Collection. Right: Reflecting telescope made by William Herschel, 1783-5. Credit: Science Museum Group Collection. Parry LA, Ashcroft IA, Wildman RD (2019) Geometrical effects on residual stress in selective laser melting. Addit Manuf 25:166–175. https://doi.org/10.1016/j.addma.2018.09.026 https://www.elementum3d.com/wp-content/uploads/2021/12/An-inside-look-at-how-AM-commercial-aluminum-alloys-are-made-possible-using-RAM-technology.pdf
A static balancing of this lightened mirror was provided. In particular, the original mass of 205 g was reduced to 154 g. Therefore, the mirror total mass was cut by 25% (from 415 to 311.8 g). Our speculum metal mirror is about the same size as that for the reflecting telescope with which William Herschel discovered the planet Uranus in 1781 – the first planet to be discovered with a telescope. We have a similar reflecting telescope made by Herschel on display in the Science City gallery, as well as the mirror which we had specially made.The main objective of the re-design is the weight reduction maintaining the strict mechanical constraints on deformation and static balance as the part rotates at high speed. For the scope, the mirror body and inner lattice structures are modeled using FEM. The chosen AM technology is the SLM. It belongs to the category of the powder bed fusion [ 20]. The process uses the thermal energy provided by a laser source to selectively melts regions of a powder bed. This way it is possible to fabricate layer by layer full dense metallic components characterized by very complex geometries and good mechanical properties [ 21, 22]. Many functionalities are demanded to this subsystem. Since it is under rotation, the mechanical balancing must be assured through an adequate stabilization to take care of the deformation which may affect the reflective surface. Modern LIDAR systems for aerospace applications require complex optical elements whose performance and lighter weight must be improved to meet growing application requirements. Metallic optics are a good choice to achieve the desired performance.
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