Brevven, I Love your Mods, I'm ready for More.

I'm sure you've gotten many suggestions that I haven't read, So, I'm just going to write a few of them down here:

Aluminum: This is a hard one because it would be used in many of the same places that you've already used Titanium, making it feel redundent no?
Gold/Silver: Gold wire could be required for Red Circuits, and Silver wire for Blue Circuits. (this could be switched around.)
Platinum: Used in a air cleaning building using the same logic as a catalytic converter? maybe a 2nd teir of coal furnace that produces less polution.
Tungsten: Used in red bullets, artiliery, lights, nuclear power plants, and advanced crafting buildings (Tungsten carbide is a machining tool)

Thanks! Glad you enjoy them. I do definitely plan more.

I'm always open to suggestion, and much appreciate the ones you've provided. Agreed on Aluminum, it's probably something I'd like to do one day, but I'd need to differentiate from Titanium. I like all the other ideas, especially Tungsten, I hadn't really thought through the uses of Tungsten beyond lighting. Thank you!

I was quite inspired by the Tungsten suggestion, and have released an alpha version of such a mod (credited you with the initial ideas). If you like, let me know what you think:
https://mods.factorio.com/mod/bztungsten