Transparent ceramics made with aluminum
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Transparent ceramics made with aluminum
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Re: Transparent ceramics made with aluminum
#2Saying this is transparent Aluminum is the same as saying Glass is transparent Silicon. It's not, it's just a ceramic.
Re: Transparent ceramics made with aluminum
#3Metal will never be transparent. Metal means metal bonds which means free electrons. Free electrons are opaque to visible light.
Re: Transparent ceramics made with aluminum
#4This definitely looks like something that has the potential to be really useful, and gives the example of replacing gorilla glass. While I get that this is a very tough glass, I did not see anything about it's hardness in relation to gorilla glass, as hardness is the property that provides the scratch resistance that is so highly sought after in smartphone screens.
Toughness is how much energy a material can absorb, whereas hardness is the resistance to deformation. Think a rubber band vs. glass.
Re: Transparent ceramics made with aluminum
#5[deleted]
Re: Transparent ceramics made with aluminum
#6Metal will never be transparent. Metal means metal bonds which means free electrons. Free electrons are opaque to visible light.
Just to add on for others reading your comment: Although metals are opaque, conductors can still be transparent. A few techniques:
- Very thin layers (like graphene) such that absorption is on the order of a percent
- Narrow bandwidth materials that are opaque to infrared but transparent to visible
- Bad metals and non-band conductors that have correlated electron hopping from site to site
Transparent conductors like ITO are critical materials for displays and solar cells, since light needs to enter/exit one side of the device.
Re: Transparent ceramics made with aluminum
#7Metal will never be transparent. Metal means metal bonds which means free electrons. Free electrons are opaque to visible light.
See this experiment for a real transparent metal. Admitedly, the conditions are kinda extreme :)
https://www.youtube.com/watch?v=BIGMfai_ICg
Don't mind the intro, the interesting part starts at around 2:00
Re: Transparent ceramics made with aluminum
#8This definitely looks like something that has the potential to be really useful, and gives the example of replacing gorilla glass. While I get that this is a very tough glass, I did not see anything about it's hardness in relation to gorilla glass, as hardness is the property that provides the scratch resistance that is so highly sought after in smartphone screens. Toughness is how much energy a material can absorb,…
According to wikipedia's AlON page it has a knoop hardness of ~1800 which from my understanding of things (I may have misread sources or be mistaken, I'm not a material scientist or even amateur) looks to be about equivalent to sapphire glass and much higher than gorilla glass (~600).
edit: in fact while I skipped the intro it states specifically that AlON has ~85% the hardness of sapphire, which more or less checks out. Suffice to say it has excellent hardness, way beyond gorilla glass.
I could find no data on relative permittivity though, and I assume that would be a factor for touchscreens.
Re: Transparent ceramics made with aluminum
#9Metal will never be transparent. Metal means metal bonds which means free electrons. Free electrons are opaque to visible light.
I'd never realised the two were connected. What's a good learning reference for bandgap physics? It's something I've never quite understood properly.
Re: Transparent ceramics made with aluminum
#10Metal will never be transparent. Metal means metal bonds which means free electrons. Free electrons are opaque to visible light.
I don't think in quite understand. You mean they don't let photons to pass through? In which case do electrons in orbit? Or nuclei for example? Or does this need advanced physics knowledge?