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Transparent aluminum–from Star Trek to (almost) reality
- pkaye 7y agoWhat is the difference between this and sapphire?
- xref 7y ago> Transparent aluminum, also known as aluminum oxynitride, is a transparent polycrystalline ceramic with a cubic spinel crystal structure made of nitrogen, oxygen and aluminum. It is optically transparent in the near-ultraviolet, visible and infrared regions. It is four times harder than fused silica glass, 85% harder than sapphire and 15% harder than magnesium aluminate spinel. The material remains solid up to 1200°C (2190°F). It has good corrosion resistance and resistance to damage from radiation and oxidation. It is about three times harder than steel of the same thickness. https://www.azom.com/article.aspx?ArticleID=8095 https://www.azom.com/article.aspx?ArticleID=8095
- Tagbert 7y agoso.... not really aluminum, just another ceramic with a high aluminum content.
- grzm 7y agoFrom the article: > "We cannot create transparent aluminum in real life, but we can get close with two transparent ceramics made from aluminum compounds"
- xref 7y agoArticle is upfront about it not being “elemental transparent aluminum” (a distinction not made in the Star Trek movie I believe?) I mean, even aluminum aircraft bodies are mostly alloys but we call it aluminum
- saagarjha 7y agoAlloys are most certainly metal, though.
- deleted 7y ago[deleted]
- dbetteridge 7y agohttps://doi.org/10.1117/12.960761 https://doi.org/10.1117/12.960761 TLDR: Sapphire is weaker, the optical finishing process is longer and more difficult. Sapphire however exhibits less optical distortion
- jiggawatts 7y agoIt's technically a different ceramic because it also has nitrogren in it, but it's the same "transparent aluminium" rabid-trek-fan idiocy. It's aluminium in the same sense that table salt is sodium. "I made transparent sodium!" -- said exactly nobody, ever.
- je_bailey 7y agoYou've obviously never googled for "transparent sodium" there's multiple articles about it
- ISL 7y agoI don't think it is pedantic to state that aluminum oxynitride is clearly not aluminum. This material, while it sounds super interesting is almost-certainly not a metal. Furthermore, among aluminum's key properties is its machineability. This stuff sounds like it would destroy an end mill or shatter. It is exceedingly difficult, if not impossible, to make a transparent metal. If charge-carriers are free to move, a defining property of a metal, then they will move in response to the electromagnetic field of a light wave. That movement will act to either attenuate or reflect the light wave.
- supernova87a 7y agoSuper interesting that they can now achieve an transparent quality with a powder pressing technique. And yes, the name is terrible. It's a composite material that contains aluminum. Obviously it's not aluminum metal.
- Scaevolus 7y agoAluminum Oxynitride was described before Star Trek IV's "transparent aluminum" in 1986, so the suggested causative direction is backwards: Hartnett, T. M., Maguire, E. A., Gentilman, R. L., Corbin, N. D. & McCauley, J. W., Aluminum oxynitride spinel (ALON): A new optical and multimode window material. Ceram. Eng. and Sci. Proe., 3(1-2) (1982) 67.