Question

what metal, alloy, polymer or any other material would you suggest which has a favourable combination of the following properties-

1. it should be corrosion resistant (the maximum you can think of).
2. fireproof
3. waterproof
4. not brittle
5. cost effective

(we are supposed to research on a material which can be used for marking weapons so as to have permanent records and to prevent their illicit trade)???

Answer 1

You could try Teflon or ETFE. cost-effective basically rounds down a lot. ETFE is very resistant to chemical attack, thermosetting, waterproof, flexible, and very cost effective.

Answer 2

You are leaving out the most important property of the material, which is its strength, usually expressed as various moduli for compression, bending, et cetera. Since you're talking about making weapons, I would assume you need something pretty strong. In that case, you pretty much need a metal. Corrosion resistance is a little vague -- it would be better to say what kind of environment you expect it to tolerate, because just lying around in a damp garage is different from being submerged in sea water.

Titanium would be very good here, but doesn't fit cost effective. Carbon fiber composites are another good choice, if you don't need the strength and resilience of a metal (composites tend to be more brittle). This, too, can be expensive, however. Not the materials so much as the manufacture, which tends to be labor-intensive. Aluminum is a good choice, except that it's not a very hard metal, so it may not be hard enough for you.

My first pass guess would probably be one of the many varieties of stainless steel that are made. You can get varying strengths and corrosion resistance, and the cost varies appropriately. It isn't especially light, but you didn't mention that.

Answer 3

Though I'm curious. How are you going to mark those weapons?

Answer 4

sir, it is not exactly a physics project.
we have to propose an international system for tracing of small arms and light weapons in illicit regulation. what i wished to know was that the unique national and international codes should be imprinted in which material to prevent falsification or removal.

Answer 5

@callisto can u help me? ryt now!

Answer 6

well you could always use laser etching. It can be done on the weapon it self without affecting the main body. small holes of varying depth and complexity are etched on the pattern. It can be etched anywhere. This considerably increase the difficulty of trading it in the black market.

Answer 7

Ah, I see. Unfortunately, your project strikes me as hopeless. No one has ever succeeded in marking anything, from diamonds to automobiles, in a way that defeats falsification. If it were possible, then people who want to stop automobile theft or software piracy would already be doing it.