Hello everybody!
I was reading the modding forum the other day and noticed a few mods that add fictional metals to sort of "bridge the gap" as one modder put it, that exist between the properties of steel and adamantine. While i have nothing against adding fictional materials, it made me wonder why would you make materials up when we have plenty of unimplemented non-fictional materials.
I immediately thought of osmium and wolfram. Both are dense metals with attractive mechanical properties, and thus would probably make fine weapons. (Osmium is perhaps my favorite metal due to its spiffy blue tinge) I got mildly exited and started digging more information about metals, and I'll now share with you what I think is relevant.
I assume that dwarfs produce their metals mostly either by directly melting (or forging) native metals, or by thermal reduction of their ore. I couldn't quite ascertain the peak temperatures achievable by dwarven smelters, but its quite safe to assume that they can at least reach 1111°C, the temperature of magma. Most likely they can reach higher temperatures, such as 1538°C, the melting point of iron, otherwise it would be hard to make pig iron. Perhaps they can reach higher, like 1769°C to melt platinum. This might however be bit of a stretch, as dorfs could just forge the nuggets directly into ingots, rather than melting them. (Perhaps one day a more advanced forge might be added, one that would need something like mechanism and refractory bricks [for example from graphite, it would work better than one might think, adamantine would definitely work] in order to be built, but that's another topic)
I use terms like stiffness, tensile yield strength (TYS, unit MPa), ultimate tensile strength (UTS,MPa), toughness and hardness, you should have a basic idea of what they mean, otherwise the texts might be hard to read. I use Young's modulus (E,GPa) for stiffness. For things like collisions between weapons and armor, I feel that tensile strength is the most relevant. Well, actually compressive strength, but the values are identical as I only talk about metals, which can be considered isotropic. Hardness is a poorly defined term that describes the materials ability to resist deformation. I refer to a material that is fairly stiff and has high yield strength as hard. All these are important for weapons and armor, UTS less so for weapons, and stiffness for armor. Toughness tells us how much energy the material can absorb before it breaks; it proportional to strength and inversely proportional to stiffness.
Take everything with a grain of salt, I'm no expert. If something I write sounds completely idiotic, it quite likely is. Most of the numbers I state are either just form memory, of from my notes, both of which are pretty poorly sourced, but I think could find sources for most of them, so ask if you're interested. Also, the numbers are not directly comparable as there are differences in hardening, composition, etc, and some might just be false. I just add them to give you something to work with, otherwise this post would be a chain of “strong, even stronger, even...”, you get the idea.
Metals I list here could be divided into three rough categories: ones that definitely could be produced by dwarves and would definitely have some utility, to those that could be produced, but whose usefulness would be dubious, and those that would be sweet, but need some convoluted techniques to be produced. I however just spew them out in nonspecific order.
Nickel:
As we all know, dwarves can already make nickel in DF, they just don't really use it in ways they could. Nickel is one of those materials that should make dorfs drool all over their beards. On its own commercially pure nickel is about as dense, somewhat softer and less stiff than iron, but has higher ultimate tensile strength (up to 370 vs 450 annealed), and thus is tougher. Sounds like something I'd use for armor. It is also readily work hardened, to UTS beyond common steel.
However main dwarfiness of nickel is in its alloys. Cupronickel, alloy of copper and nickel (duh), offers high tensile strength (up to around 550 yield and 650 UTS in copper with around 1/4 nickel, when properly worked), thus making a fairly tough material potentially harder than DF steel, although not as strong. If alloyed with iron as alloy with around 1/3 nickel (Fe-36Ni, or Invar 36) could have TYS of 240-720 and UTS of 450-800 (annealed-hardened), and thus superior to common steel. It is less stiff (E≈140 vs.205GPa), and thus tougher. This would make fine weapons and even finer armor.
Chromium:
Extremely hard, strong, stiff and quite light (7.19 g/cm^3), chromium would seem like an extremely nice material for weapons. It's not very tough and is brittle at room temperature, but has impressive enough TYS (~950) compared to it's stiffness, that it could still absorb energy from blows. Brittle materials tricky in this sense, as they usually break suddenly, well below their potential strength. I sadly could not find a value for its compressive strength. Then again, due to its brittleness, extreme hardness and very high melting point (1907°C), pure chromium would be very hard to work with.
Chromite already exist in DF, but there are 2 hurdles to overcome. The smaller one is that chromite is also an ore of iron, thus any product would likely be an alloy of iron, and the iron would be hard to separate. Then again alloying into steel is the most like use for the metal so this is not a very big problem. The bigger problem is that in order to reduce chromite with carbon, you need very high temperature (perhaps around 1850°C), which would need some dwarven science to achieve, On the bright side you could also process chromite with an aluminothermic reaction (or possibly by utilizing sodium, but I'll get to that later). This would practically be sacrificing the preposterously valuable aluminum in order to get something with more applications. Dwarfy. Chromium does occur as a native metal in volcanic environments, probably formed much like native aluminum. As Cr is not as reactive as Al it might be slightly more abundant, but still very rare.
Alloying pure chromium with nickel (Cr:Ni 3:2) creates a brittle alloy with UTS up to 1000 (=TYS as brittle), thus potentially even better weapon material than pure chromium. When added to steel chromium makes it harder and easier to harden, it is quite hard to find specific values for alloys containing large amounts of only chromium. As a side mention adding cobalt to the mixture makes even more weaponariffic metal, Cr-Co-Fe-Ni (1:2:1:1) alloys can have TYS>1000 and UTS>1300. Cobaltite exist DF, and it too can be formed into the metal via aluminothermic reaction.
Gah, all this writing is making my head spin..
Platinum metals:
Platinum is just one metal in a group of chemically similar metals. They all have more or less interesting properties, but I'll concentrate mostly on the two most interesting: Iridium and Osmium.
They have several notable properties, Osmium is the densest material known and Iridium the second densest by a very small margin. They are both very hard, strong, stiff (E≈529-550, 2.5 times that of steel!) and brittle. Work hardened iridium can reach UTS>2200, and platinum wire alloyed with 30% iridium can reach 2480, compared to that of pure platinum, 392. I could not find tensile strength values for osmium, which is a pity, but its Brinell hardness of 3920MPa gives a hint (iridium has mere 1670) I do have a note that says osmium has reached over 10GPa in compressive strength, but it doesn't mention the scale (materials are generally stronger at small scale). Why I introduce these metals together is because they occur together as a native alloy. They are also found alloyed with platinum. Dorfs could utilize the native metal or separate it from platinum, which is not as hard as one might imagine. Both metals are insoluble to aqua regia, which dissolves platinum. Thus the crazy buggers could dissolve platinum and forge the residue into ingots, and perhaps later extract the platinum from the water of gods that is left behind (it's easy, just heat it). The powder would not actually be just iridium and osmium, it would also contain ruthenium and rhodium, two other platinum metals that are insoluble to aqua reqia. Producing aqua regia would need capability to make spirit of nitre and spirit of salt, well within the ability of dwarven alchemy I presume (as soon as it gets implemented). The resulting powder would however be preposterously hard to work into anything. Perhaps it could be alloyed into platinum to create the final product.
I actually modded this alloy into my DF as uristium ( I didn't have the heart to call it osmiridium or iridosmrhodruthenium, and also I didn't want to specify the composition). Its pretty effective, clearly better than steel, but worse than adamantine in edged weapons and armor. I haven't really modded the production in yet (if ever), I just made a reaction that produces 3 platinum and 1 uristium bar from 4 native platinum and a bucket of lye (close enough, its corrosive isn't it
). I haven't gotten to test the reaction yet but dwarven traders have blessed me with the material.
So many metals to go and I have depleted my sanity, for now I hope. If there is interest, I could still do tungsten (hard, tough, strong, stiff & dense), arsenic & antimony (alloys for copper/bronze, cups for elves), sodium (interesting applications), perhaps some others too. Tell me what do you think? Now I must rest, I cant remember when I last produced this much text, certainly never of my own volition.
(EDIT: fixed some errors)