I'd love to see poisoned weapons, though I'm not sure how/if they'd work. Would a sword made of a toxic syndrome material affect things that it cuts? Hopefully it wouldn't affect the weilder too , haha, as that would be bad.
Another suggestion I have...is please change the names of the advanced alloys! Welded Metal seems so plain for some of the best metals in the game. Slademantine is fine of course, but the others could do with cool name upgrades.
It's up to you ultimately, but I had some suggestions if you don't feel like thinking them up.
Orihalcum could be in there somewhere, either as the Cobalt alloy or the Mithril one. It's another mythological metal. Technically it was supposed to be an alloy of bronze, but we can use poetic license. It was historically coloured pink from the copper if you wanted to keep the colour.
Silver-Steel was another word in Tolkien for Mithril. Mithril was in fact just the elven word for the metal, Silver-Steel presumably being the human word for it.. Seeing how our alloy is made from mithril and steel, it seems fitting.
Varium is just Varia + -ium, Varia being the greek word for heavy. This could do for the wolfram alloy. In fact you could do with for all the metals. Greek and Latin sound cool and vaguely mythic no matter the word. Nitidus is the latin word for shiny, that sounds cool as heck for the chrome alloy, doesn't it?
Awemedinite, from the story of Cacame Awemedinade obviously.
Anyhow, upto you to name them, if indeed you want to change the names at all.
While I'm on the topic though:
Iridium in real life is a highly radioactive substance: Is this the same material as in the mod? I'm a little put off by the name, draping my dwarves in radioactive cloaks and whatnot (personally I changed the name my self to orichalhum so it seemed a little more mystical).
I haven't found any meteoric iron at all in my last few forts. Is anyone else not encountering it?