Prosperity Park, on 02 February 2012 - 09:18 PM, said:
Yup. Railgun rails are subjected to plasma scoring for each shot because the extreme amount of current flowing from anode rail->projectile-> the cathode rail causes serious electrical arcing between the projectile and the rails. When you make the rails you have to choose a material that's very electrically conductive, yet very resiliant in the face of extreme high-temperature operation and serious oxidation.
People who make their own Railguns at home typically use brass rails because brass, being a copper alloy, is very conductive so you lose little energy to heat, it's readily available on the market, fairly inexpensive compared to exotic alloys, and relatively durable for what it's worth.
You might think "Why not use Tungsten rails?" Tungsten is THE MOST heat-proof metal and it's very very very tough - tough enough to be the primary component of many armor-piercing munitions and many tank armor systems, themselves. There are 2 problems with Tungsten rails, though. 1.) Tungetsn is expensive. 2.) Tungsten has a fraction of the electrical conductivity of Copper and Silver which means Tungsten rails lose huge amounts of energy due to electrical resistance [in the form of heat, which further damages the system].
The best materials to build weaponized Railgun rails with, assuming that either money is not an issue or materials will be cheaper in the future, would be Tungsten-Silver alloys. Silver is the most conductive metal on the periodic table and Tungsten is the thermally- and oxidatively-toughest metal. These are currently available on the market, but too expensive to build weapons with. The next best bet would be CuproTungsten (Tungsten/Copper alloy) which is also available and slightly cheaper. Third best bet would be the kinds of high-temperature superalloys used to build turbine blades such as the ones marketed by Haynes International (their most "popular" product being named Hastelloy).
Or you could use a sacreficial metal like strait copper on the sides of the rails that touch the round and just replace it after a certain number of firings. The navy uses zinc anodes in their coolant systems to avoid cavitation from the electrical dicharge due to the friction between the water and the pipe.same principle you know your'e gonna lose metal so make it cheap and readily available.Also instead of replacing the whole set of rails you only need to replace the sleave whitch can be done from the end of the "barrel"
Edited by garx8, 02 March 2012 - 02:16 AM.
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