I was reading an item about ceramic gun barrels, and wondered if any ceramics are tough enough that you could make an entire gun out of ceramic materials.
The ammo can be standard ammo in this case.
Do you want it to be usable more than once? If you just want a one-shot <heh> weapon, I don’t think there’d be a problem.
Hit send too soon… There are ceramics out there that are plenty tough - Kyocera’s been making chefs knives from the stuff for years, and Lockheed is making ceramic rocket nozzles. We’re probably not too far from reusable ceramic weapons.
What about the Glock 7 ?
I don’t see why they couldn’t. I can see why they won’t, cost. Unless you can get a process that is cheaper than making them out of metal I don’t see why you would. Anyone who has fired a M-60 can see the reason for making a ceramic barrel. I don’t see the point in a handgun, the heat factor isn’t that important.
The Master speaks, at least as of the mid-nineties.
I’m not a materials scientist, but I think that the deal with metals is not just that they are strong. They are also elastic. So for a split second, they can withstand a phenomenal amount of pressure without failing. Instead, they expand a little and then go back into place.
As far as I know, even strong ceramics generally lack this property.
The only part where that would matter is the barrel. As for the barrel it is then only a matter of having a material which can withstand the pressure without cracking. They have non-metalic material which is much stronger than steel. I don’t see why they couldn’t make a barrel that was strong enough that it wouldn’t need any give. But the cost would be very high compared to a metal gun. And the only customers would be terrorists and maybe James Bond.
I am not talking from any actual knowledge, just pushing along the OP waiting for the answer from someone with the facts and background.
Do you have a better link than urban dictionary for the glock 7? Wiki seems to think that glocks are not ceramic guns at all.
Whoosh.
Are you implying he sneaked a ceramic gun joke past my security systems?
I’d be willing to bet more than a Dulles International Airport Police Chief makes in a month.
Ceramics are indeed elastic. I even saw an article long ago (maybe in Technology Review) showing how someone had constructed a working coil spring from ceramic. One key, as I recall, is to eliminate bubbles. For any particular clay composition, the strength of a ceramic object is inversely proportional to its largest bubble.
What ceramics generally are not is malleable. If you exceed steel’s yield strength it will usually stretch or bend some before it breaks. Ceramic just breaks. A steel gun barrel is damaged if you exceed its yield strength, but you might get away with it a few times before it fails visibly.
Regarding detection, X-ray machines measure a material’s density, not necessarily whether it is metal or not. If you create a ceramic gun barrel that’s dense enough to take a discharge, you may well make it dense enough to show up in an X-ray anyway. But the ceramic gun would probably sneak through an induction-type metal detector. (BTW: Inductive metal detectors don’t detect metal oxides, do they? Refractory ceramics can contain lots of alumina.)
Couldn’t you use the same sort of space age polymer they use for making model race cars? :dubious:
Wouldn’t you at least need metal for a spring, unless I’m missing something wouldn’t it be difficult to aim the weapon and strike the primer otherwise?
Elastic materials like rubber, polybutadiene, silicones etc. are common examples of non-metallic “springs”. A mechanical assembly based on them could approximate a metal spring.
Also, I think that shock, more than the absolute pressure, is the issue for ceramics. A tumbler may support 100 lbs or more of static weight, but break if dropped.
Not sure what space age polymer msmith537 is referring to, but this made me think about carbon fiber.
How about making the barrel out of layers and layers of carbon fiber composite, with the strands oriented in a way to take the stress?
I suspect it wouldn’t be good for many shots, but if you are using one of these you probably don’t care if it is worn out after one magazine.
The problem with carbon fiber (or e-glass fiber, or Kevlar, or whatever) in shock loading applications is that the fiber is embedded in a matrix of some stiff binder. Usually the first time you load it up you crack the binder (called “crazing”), and it continues to craze somewhat through every load cycle (hence why uncoated fiber composites are sensitive water contamination). This isn’t a big deal in situations where the part in question is loaded in pure tension or primary bending as long as you’ve designed the lay or wind such that the load is taken in tension, but if the part sees multi-axial loads it’ll literally come apart into a big mess of string.
In the case of a gun barrel, the barrel sees both radial pressure loads plus the axial load from the bullet forcing its way through the lands (which is necessary both to impart stabilizing spin and to contain the expanding gas pressure which propells the bullet) which will apply local shear to the matrix. You also are not going to be able to machine grooves into a barrel, and polygonal “forging” of tough fibers will force them into right angle turns that will cause them to break. You could (and a few guns have) made barrels that comprised of a steel liner overwrapped by a fiber composite; in this case, however, the fiber is in pure tension and doesn’t need to display any real shear resistance. A barrel (or for that matter, a slide or mechanical striking parts) made of a carbon fiber composite would be a very poor choice. On the other hand, short fiber composites (like fiberglass, only with a much stronger matrix) are commonly used in handgun and rifle frames because of their light weight and durability. Again, most modern manufactures line the sliding parts (frame rails) with steel for wear resistance. You could potentially make a firearm capable of a few cycles from some kind of omni-directional short-fiber composite capable of firing low pressure rounds, but I’d let someone else test it.
Ceramics suffer from a different problem; they don’t tend to resist fracture well. This is independent of the hardness (even simple fired ceramics are much harder than non-refractory metals), and is typically characterized as toughness or fracture resistance, K[sub]c[/sub], which is a function of stress intensity (how localized the stress tends to be around a hypothetical small crack) and elasticity. If the applied load creates a stress that is beyond the limit of the material to distribute stress evenly, it will be focused on the crack tip and the crack will propogate. In some materials like mild steel or nickel, this isn’t a big deal becuase the crack propogation is slow and linear, and cracks tend to show up long before they compromise the main structure. It can be more of a concern in aluminum because even though this material will tolerate a certain amount of cracking the act of cracking work hardens the material significantly and makes it more prone to faster cracking. In really hard materials like hardened steel or ceramics, the crack propogation is extremely nonlinear and it is hard to predict just how long it will take a crack, once initiated, to grow; hence any cracking may rapidly cause failure.
For steel, this requires alloy selection heat treatment to make the microstructure resistant to crack formation to begin with; for ceramics all you can really do is try to reinforce them. Ceramics are also more sensitive than other materials to thermal stress cycling, because without careful composition control they tend to expand and contract at different rates (hence, why you don’t want voids or air pockets in a ceramic material) and this can cause rapid crack propogation even if the article itself is not highly stressed.
There are a few ceramic materials that might be suitable to make a gun barrel from, although they would be more bulky than a steel part, and as previously noted, hardly undetectable via modern security scanners. Other working parts of the gun could probably be made from ceramic materials, though I don’t think they’d have the longevity of metal parts.
Springs are another issue entirely; there just isn’t really a good mechanical replacement for metal coil or cantilever springs, and I’m not sure how you’d make a working gun without springs of some kind. Rubber and plastic just don’t have enough energy storage density to replace steel for these applications.
And no, the mythological Glock 7 doesn’t exist except in the minds of bad Hollywood screenwriters. The firearm featured in the film was a Glock 17, which is a conventional short recoil pistol using a modified Browning linkless lockup with a composite frame and a steel slide and barrel. It’ll show up just fine on airport scanners. But frankly, that it is the least problematic aspect of that film.
Stranger
I ran a ceramic knife through an airport x-ray machine just to see if it was detectable (with the knowledge and cooperation of the x-ray machine operators). It looked like a metal knife.
Of course if you tried to get it through that way it would show up. If you had it on your body does it set off the metal detector? I don’t think so.
It wasn’t TSA’s x-ray machine, it was Agriculture’s. They don’t have a metal detector. I agree that it probably would not be detected by a metal detector.
If you get away from conventional ammo and have a non-reloadable gun which is fired using electrical squibs, you could get away from that problem. I believe that is how the troika pistol worked (it was supposed to have steel barrel liners though). That is assuming the troika was even real.
FWIW,
Rob