The vikings have journey far and wide, they have discovered the secret to produce vast quantity of depleted uranium and also how to forge weapon with it in short period of time. Will the vikings dethrone Genghis Khan as the world most powerful conqueror or their legacy is only one tiny pebble in the never-ending river of time?
Depleted uranium has a few features that make it useful for modern projectile weapons:
- It's one of the densest substances known. For high-speed impacts, one of the key parameters for penetration depth is the ratio of the projectile's density to the target's density.
- It's self-sharpening. As a DU projectile penetrates a target, it tends to fracture in a way that maintains the shape of the projectile.
- It's flammable. Uranium dust tends to spontaneously ignite, and after shooting an armored vehicle, there's plenty of dust flying around.
- If you've got a nuclear weapons program, it's dirt-cheap. DU is a waste byproduct of uranium enrichment, so if you're willing to spend the money to build nuclear weapons, you get a large supply of depleted uranium essentially for free.
DU is used for armor because of the density and cost factors mentioned above.
Now, let's look at it in the context of medieval combat.
Swords, arrows, and other weapons are moving at slow-enough speeds that the strength of the material matters. Uranium isn't very good for that: it has a tensile strength of around 500 MPa and a yield strength of 170 MPa; for comparison, basic carbon steel is around 900 MPa/500 MPa, good spring steel is 1400 MPa/1000 MPa, and even bronze is better at around 700 MPa/650 MPa.
The self-sharpening ability is nice, but your arrows and swords probably aren't hitting metal often enough for it to matter.
Flammability is bad if it's your armor or your sword that is catching fire.
Density? You can get some seriously effective maces that way, by concentrating a huge weight into a small area. For weapons such as swords, where strength comes as much from the shape as from the material, a denser material simply means a heavier weapon, causing the user to tire faster.
If your Vikings decide to concentrate on depleted-uranium weapons, they'll probably be remembered as suicidally-aggressive warriors who tire easily and whose weapons shatter with a good blow.
Uranium is a very dense metal, so a sword, axe head or even spear tips and arrows would be mush heavier than standard steel models. The weapons would be very unwieldy and tiring even to carry into battle, much less use in a physically demanding bout of hand to hand combat.
If any enemy were to discover the massive weight of the weapons, their best course of action would be to feign running away and encourage the Vikings to chase them, then turn and cut down the exhausted Vikings as they tried to catch their breaths.
Perhaps the only possible advantage is the weapon would cleave through most shields and armour with a single stroke, assuming anyone is unfortunate enough to be standing in front of a well rested Viking right at the start of a battle.
Even the pyrophoric effects of DU (it self ignites at a high enough temperature in an oxygen atmosphere) only come into play when the piece of DU passes through a piece of metal at supersonic speeds and the frictional energy heats the metal to the point of ignition.
The Great Khan will have a mild chuckle as his mounted warriors ride around the exhausted band of Vikings toiling on the road to Kiev and supposed safety with the rest of the Rus....