To begin with we have to define what it is you are trying to make with the material.
Armor has slightly different material requirements than a weapon.
Furthermore, swords, axes, and other cutting weapons have different needs than maces and war hammers.
It is useful to look at the weapon raws(..\raw\objects\item_weapons.txt
[ITEM_WEAPON:ITEM_WEAPON_AXE_BATTLE]
[NAME:battle axe:battle axes]
[SIZE:800]
[SKILL:AXE]
[TWO_HANDED:47500]
[MINIMUM_SIZE:42500]
[MATERIAL_SIZE:4]
The format is ATTACK:EDGE/BLUNT:contact area:penetration size:verb2nd:verb3rd:noun:velocity multiplier
Penetration size currently only matters for edged attacks.
[ATTACK:EDGE:40000:6000:hack:hacks:NO_SUB:1250]
[ATTACK:BLUNT:40000:6000:slap:slaps:flat:1250]
[ATTACK:BLUNT:1000:1000:strike:strikes:pommel:1000]
The number of [ATTACK:...] tags listed indicates the number of different modes of attack. In the case of the battle axe here, we have three, two blunt and one edge attack. The verbs and noun given are used in the attack declarations and are useful in guessing what the intention of the attack is. Bigger numbers on the [ATTACK:...] line are always better, the penetration number "shouldn't" mean anything for a blunt attack.
Which attack mode is used is, I think, primarily the top one and to some degree randomly chosen beyond that. I would have to do more research to be more specific.
For armor and edge based weapons the materials that are best are roughly as follows: Adamantine > steel > bronze = bismuth bronze > iron ~= copper > everything else. Depending on the specific use(such as armor), steel may be better than bronze and iron may be better than copper.
For primarily blunt damage weapons(mace, flail, war hammer, maul...), the density of a material seems to be the most important figure. This is partly because some of the inorganic_metal.txt numbers are wrong; however, that is a balance issue that Toady will have to deal eventually. For the moment, based on density being the most important attribute and limiting to materials that can be used to forge weapons in dwarf mode, silver > bronze = bismuth bronze ~= copper > Steel ~= Iron > Adamantine ~= everything else.
The
general consensus is that Axes are the best weapon in 0.31, with swords as second best. This is because of the tendency for Axes, and to a lesser degree swords, to remove limbs and promote massive blood loss. Additionally, one hit kills are much more likely with Axes(roughly 3 times as likely) and when you remove a limb that means you have removed the possibility of striking the already damaged limb a second time. Striking already broken limbs is very likely with blunt type weapons by comparison.
It is probably a good idea to carry a blunt type weapon along with your choice of either a battle axe or sword. This is because armor has a very good chance of deflecting an edge attack from a weapon of the same or lesser material, but a blunt attack will tend to carry through armor much more easily most of the time. Note: Blunt weapons tend to take a MASSIVE number of strikes to down an opponent, especially with a lowish weapon skill vs a larger opponent.
These are rough generalizations based on impressions gained from use and everything is subject to change based on any pending rebalance. As Toady has held off putting weapon/armor wear/damage in this version so things
do not seem to totally reflect reality. How all of the material properties matter to different damage modes and armor types isn't known.