Mornin', Peter.
Depleted uranium has a coupla useful properties in a projectile, none of which has to do with anything nuclear. In fact, depleted uranium (after they refined out almost all of the tsaty crackly U-235) is only mildly radioactive.
Uranium metal is dense, better than 19 grams on the cc, I believe. Steel is less than eight. Uranium is the cheapest of the ultradense materials, cheaper than tungsten or gold (both also in the nineteen-and-heavier club). U is ductile and malleable, making machining a snap, and allowing the slug to shape itself to the cannon bore.
High bulk density gives a projectile good sectional density: the weight of the slug divided by its frontal area. Sectional density is the prime variable affecting penetration. A dense, sectionally dense, fast projectile is best for punching thru armor. No tank in the field today is strong enough to stop a 30mm uranium slug.
When a fast slug hits a thick steel plate, both act locally like liquids. The uranium literally melts and squeezes a deep crater into the steel. When the back of the steel plate ruptures, the hot compressed uranium squirts through like a shotgun blast. Bad news for the tank crew.
Finally, uranium is as flammable as the flint on a butane lighter. The uranium globs burn hot, adding an incendiary effect to the kinetic kill. That's why that great slo-mo footage on Wings shows the ricochets as starbursts of burning metal.
(Editorial note: Tom Clancy wrote up uranium as a nuke component in The Sum of all Fears. He said it was very hard and refractory. No. It's soft, kinda like aluminum, and it's very air-reactive. It is quite dense however.)
Hope I've helped. |
