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The special properties of ceramics are what? Disc brakes and ball bearings are all I know. In neither of these situations is brittleness a problem. Given brittl

The special properties of ceramics are what? Disc brakes and ball bearings are all I know. In neither of these situations is brittleness a problem. Given brittleness is a problem I cannot see iphones being ceramic any time soon even as a back inlay. However that could be done and the assumptions of this article all wrong. As an inlay the tolerances might be fine, no army of robots needed. The aluminium band holding it together could be an extrusion, hydroformed to have strength.

xanderstrike 10y ago
> Given brittleness is a problem I cannot see iphones being ceramic any time soon even as a back inlay. This is the company that put glass on the back of their phones for aesthetics we're talking about here. Nothing is out of the question.
- alayne 10y ago
  It's one company of many. Samsung, Sony, Oppo, Huawei, BLU, and Xiaomi also manufactured glass back phones.
LeifCarrotson 10y ago
Ceramics are extremely hard and tolerant of great heat (the latter not being particularly relevant). They can also be lightweight for their strength, at least in compression. They can also have a nice, smooth, cool feel in the hand (partially as a result of their temperature insulation properties). They're also a huge variety of materials, it's like asking why plastic is a good material - do you mean silicone rubber, ABS, or Teflon?
- noir_lord 10y ago
  > Ceramics are extremely hard and tolerant of great heat (the latter not being particularly relevant). Tell that to samsung, joking aside a ceramic case might be useful if a battery cooks off.
  - ygra 10y ago
    The heat still has to go somewhere. Ceramic just won't melt or fail in the heat, but it will conduct it well enough to your skin.
- DannyBee 10y ago
  "Ceramics are extremely hard and tolerant of great heat (the latter not being particularly relevant)" But very rarely are they not brittle upon impact. This is why you don't see ceramic saw blades - carbide, even though brittle, is much less brittle than ceramics. (this is also why they don't use diamond saw blades except for abrasive cutting - the diamonds we make are too brittle to be used to cut wood).
  - mrob 10y ago
    >carbide, even though brittle, is much less brittle than ceramics To clarify, "carbide" here is short for "cemented carbide", i.e. ceramic carbide particles sintered together in a metal binder. It's tougher than the pure ceramic although still somewhat brittle. https://en.wikipedia.org/wiki/Cemented_carbide https://en.wikipedia.org/wiki/Cemented_carbide
    - DannyBee 10y ago
      Yes. They rely on the metal binder to provide some help here. But ceramic still wouldn't work. (at least what we are talking about here. In theory, cemented carbide can be a ceramic, depending on the exact terminology used).
saosebastiao 10y ago
You're likely to get some generalizations, but the question is about as vague as asking about the special properties of metal. Some metals are strong, some are not. Some are tough, some are not. Some are toxic, some are antiseptic, some are explosive, etc. Some exhibit specific properties in specific conditions but nearly opposite properties at nano-scales or in composition with some other substrate. The most common ceramics are strong but brittle and lightweight. I wouldn't assume that these would make good choices (for example, weight alone is a reason to choose aluminum over plastic...it weighs more and thus feels more expensive). But there are still some interesting alternatives out there that would be cool to consider. Like possibly monolithic and completely waterproof circuits with near perfect insulation that can be cast instead of printed/assembled. Or possibly structural batteries? Who knows?

xanderstrike 10y ago

> Given brittleness is a problem I cannot see iphones being ceramic any time soon even as a back inlay. This is the company that put glass on the back of their phones for aesthetics we're talking about here. Nothing is out of the question.

alayne 10y ago
It's one company of many. Samsung, Sony, Oppo, Huawei, BLU, and Xiaomi also manufactured glass back phones.

LeifCarrotson 10y ago

Ceramics are extremely hard and tolerant of great heat (the latter not being particularly relevant). They can also be lightweight for their strength, at least in compression. They can also have a nice, smooth, cool feel in the hand (partially as a result of their temperature insulation properties). They're also a huge variety of materials, it's like asking why plastic is a good material - do you mean silicone rubber, ABS, or Teflon?

noir_lord 10y ago
> Ceramics are extremely hard and tolerant of great heat (the latter not being particularly relevant). Tell that to samsung, joking aside a ceramic case might be useful if a battery cooks off.
- ygra 10y ago
  The heat still has to go somewhere. Ceramic just won't melt or fail in the heat, but it will conduct it well enough to your skin.
DannyBee 10y ago
"Ceramics are extremely hard and tolerant of great heat (the latter not being particularly relevant)" But very rarely are they not brittle upon impact. This is why you don't see ceramic saw blades - carbide, even though brittle, is much less brittle than ceramics. (this is also why they don't use diamond saw blades except for abrasive cutting - the diamonds we make are too brittle to be used to cut wood).
- mrob 10y ago
  >carbide, even though brittle, is much less brittle than ceramics To clarify, "carbide" here is short for "cemented carbide", i.e. ceramic carbide particles sintered together in a metal binder. It's tougher than the pure ceramic although still somewhat brittle. https://en.wikipedia.org/wiki/Cemented_carbide https://en.wikipedia.org/wiki/Cemented_carbide
  - DannyBee 10y ago
    Yes. They rely on the metal binder to provide some help here. But ceramic still wouldn't work. (at least what we are talking about here. In theory, cemented carbide can be a ceramic, depending on the exact terminology used).

saosebastiao 10y ago

You're likely to get some generalizations, but the question is about as vague as asking about the special properties of metal. Some metals are strong, some are not. Some are tough, some are not. Some are toxic, some are antiseptic, some are explosive, etc. Some exhibit specific properties in specific conditions but nearly opposite properties at nano-scales or in composition with some other substrate. The most common ceramics are strong but brittle and lightweight. I wouldn't assume that these would make good choices (for example, weight alone is a reason to choose aluminum over plastic...it weighs more and thus feels more expensive). But there are still some interesting alternatives out there that would be cool to consider. Like possibly monolithic and completely waterproof circuits with near perfect insulation that can be cast instead of printed/assembled. Or possibly structural batteries? Who knows?