Material Conversion to D&D

[imp_fireball]

Aluminum

Aluminum is a silvery white low density metal, lighter than steel but strong, if not stronger.

Aluminum is non-corrosive, meaning it won't rust - meaning that it is invulnerable to the rust monster's special ability when weapons, armor and items are made purely of it. Aluminum has a lower melting point than steel, and thus for every 2 fire damage dealt, it suffers 1 damage.

Manufacturing armor with aluminum costs an additional 500gp which goes up in value for each class above light, in the same way that mithril does (2000gp for medium, 4500gp for heavy, etc.). Although common in its natural form, it is exceedingly difficult to extract, making it more valuable than gold.

Aluminum has 15hp/inch of thickness and hardness 10.

Titanium

Titanium is similar to aluminum in that it is low density, lighter than steel (as a material by itself) but even stronger.

Titanium is considered to be 1/3 lighter when used purely in armor. It imposes a 5% reduction in spell failure chance compared to steel and adds a +1 max dexterity bonus. Titanium has a higher melting point than steel, and thus for every 4 fire damage dealt, it suffers only 1; making it a desired mundane metal for the deepest of the forges.

Manufacturing armor with titanium costs an additional 800gp which goes up in value for each class above light, in the same way that mithril does (3200gp for medium, 7200gp for heavy, etc.).

Titanium has 25hp/inch of thickness and hardness 15.
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Just thought I'd include these values for the heck of it.

[Mongoose87]

From what I gather, aluminum is indeed light, but it's not actually all that strong.

[Mando Knight]

From what I gather, aluminum is indeed light, but it's not actually all that strong.

Yep. Its strength/weight ratio is a good bit worse than steel's.

[imp_fireball]

Yep. Its strength/weight ratio is a good bit worse than steel's.

So what would you say for aluminum?

[Leeham]

I'd say, "All hail the mighty tinfoil armour!"

[Calmar]

I'd say, "All hail the mighty tinfoil armour!"

Tin foil also protects you from mind control and mind reading. :smallbiggrin:

[Eldan]

So Aluminum Full Plate (with Helmet!) gives you a +5 circumstance bonus against mind-affecting? :smalltongue:

[Shpadoinkle]

Aluminum is extremely difficult to produce without electricity. I'd say it's only real use without being able to produce and process it en masse would be decorative. I can totally see a noble being proud of having a set of aluminum silverware or an aluminum goblet or something.

Because it's so weak is the reason we use it for stuff that functions better when made of metal, but not neccisarily a GOOD metal, like soda and beer cans, cheap silverware, etc.

[UserClone]

IIRC, 14ga AL is stronger than 16ga steel, but lighter still. So make the armor a bit thicker, and halve the weight or so.

Also, ProTip: There are oodles of spells that create electrical damage. It's not so hard to imagine producing a magic item whose express purpose is to refine AL.

[Silverscale]

Of course there is also the fact that given the fantasy nature of D&D, whose to say that we necessarily have to follow or even mimic real-world methods for extracting Aluminum ore? If we just say that it is relatively rare but otherwise relatively easy to extract once found, then the price can still be high due to it's rarity.

[Ashtagon]

Alternity's MagiTech setting had most military and para-militaries use aluminium for armour, because one of the core concepts in that setting was that iron (and steel, and any ferrous metal) are inherently non-magical, and cannot be enchanted. This unfortunately contradicts established D&D canon.

Traveller places aluminium as equal to very poor quality steel (hardness 1.7 compared to hardness 2 for good-quality steel), costs slightly more than twice as much (4000 vs 1600 credits), and noticeably lighter (material density 6 vs 8).

But really, there's no good reason to make body armour out of aluminium when steel is available, unless you invent properties that don't exist in the real world.

[Random832]

Yep. Its strength/weight ratio is a good bit worse than steel's.

That's pure aluminum, not alloys like are commonly used.

[UserClone]

Like I said before, I am reasonably sure that if you use a heavy enough gauge Al, it's stronger than normal steel, while still being lighter. something like 2 ga thicker or maybe 3. Hey, it could work. PS Mithral is Ti...just saying.

[Eloel]

Aluminum is extremely difficult to produce without electricity. I'd say it's only real use without being able to produce and process it en masse would be decorative. I can totally see a noble being proud of having a set of aluminum silverware or an aluminum goblet or something.

Because it's so weak is the reason we use it for stuff that functions better when made of metal, but not neccisarily a GOOD metal, like soda and beer cans, cheap silverware, etc.

Errr, irony much?

[DragoonWraith]

The aerospace industry uses aluminum very widely, mostly for its lightweight/high strength:

Pure aluminium has a low tensile strength, but when combined with thermo-mechanical processing, aluminium alloys display a marked improvement in mechanical properties, especially when tempered. Aluminium alloys form vital components of aircraft and rockets as a result of their high strength-to-weight ratio. Aluminium readily forms alloys with many elements such as copper, zinc, magnesium, manganese and silicon (e.g., duralumin).

Also, it basically doesn't rust or corrode, though this may not be true of an alloy strong enough to use as armor:

Aluminium is remarkable for its ability to resist corrosion due to the phenomenon of passivation and for the metal's low density. [...] Corrosion resistance can be excellent due to a thin surface layer of aluminium oxide that forms when the metal is exposed to air, effectively preventing further oxidation. The strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper. This corrosion resistance is also often greatly reduced when many aqueous salts are present however, particularly in the presence of dissimilar metals.

On the other hand, it is rather reactive:

Aluminium is too reactive chemically to occur in nature as a free metal. Instead, it is found combined in over 270 different minerals. [...] Its reactive nature makes it useful as a catalyst or additive in chemical mixtures, including being used in ammonium nitrate explosives to enhance blast power.

The conductivity of aluminum is also notable:

Aluminium is a good thermal and electrical conductor, by weight better than copper.

Oh, and it melts:

Another important property of aluminium alloys is their sensitivity to heat. Workshop procedures involving heating are complicated by the fact that aluminium, unlike steel, will melt without first glowing red. Forming operations where a blow torch is used therefore requires some expertise, since no visual signs reveal how close the material is to melting. Aluminium alloys, like all structural alloys, also are subject to internal stresses following heating operations such as welding and casting. The problem with aluminium alloys in this regard is their low melting point, which make them more susceptible to distortions from thermally induced stress relief. Controlled stress relief can be done during manufacturing by heat-treating the parts in an oven, followed by gradual cooling—in effect annealing the stresses

Also, it's very shiny:

Aluminium mirror finish has the highest reflectance of any metal in the 200–400 nm (UV) and the 3000–10000 nm (far IR) regions, while in the 400–700 nm visible range it is slightly outdone by tin and silver and in the 700–3000 (near IR) by silver, gold, and copper.

Finally, as noted, it's non-ferrous, so not affected by magnets. That doesn't really come up in D&D though.

So I'd go with light-weight, probably no bonus (but no penalty) to AC or hardness, and a resistance and/or immunity corrosion (a la the Rust Monster or whatever). Add in a vulnerability of something like "loses 1 AC for every 15 fire damage that it or its wearer is subject to" to reflect the melting, and some kind of effect where it makes the wearer more vulnerable to electricity, perhaps? You could also do something like "adds an extra 10 feet of bright illumination to any light source that the wearer carries" to do something with the reflectivity, maybe.

[imp_fireball]

That doesn't really come up in D&D though.

I read one scenario where it did for a GM. They included a giant magnet and plenty of sharp instruments that flew towards it. The PCs were blocking the way. You can guess what happened next. Of course, aluminum wouldn't help in that situation anyway (unless of course a sharp thing required attractive armor).

So yah, not being affected by the rust monster is a major plus I can bet.

Also for melting, I'd just make it melt from fire easier. Steel is already rather resistant to fire and cold. Say if fire damage ratio for steel is 3:1 I could make it 2:1 for aluminum.

Also, it's upsetting that titanium isn't better than mithril, isn't it? I was thinking it could be a cheaper alternative.

EDIT: I figured that since titanium is used in the construction of space ships and heat shields (I think), it's got a higher melting point than steel (like, much higher), so I made it more resistant to fire damage.


"adds an extra 10 feet of bright illumination to any light source that the wearer carries" to do something with the reflectivity, maybe.

That's more of a 'shininess' that interrupts light sources with its own reflective light source. It's a GM discretion thing - GM could rule that the PCs are temporarily dazzled and thus find a way to screw them over after realizing that his rust monster idea was foiled.

[Mando Knight]

The problem with aluminum armor is that it's not a material that's really cut out for that purpose: it's not as hard as steel, nor is it as stiff, and it has a much lower fatigue limit. In order to give aluminum armor the same properties valued in steel armor, you'd have to make it thicker than steel, which makes the armor bulkier. Steel and titanium (which is about as strong as steel for a comparable thickness, but much lighter) are thinner for the same amount of strength, but are heavier than aluminum. It's the thickness that would determine armor check penalties, spell failure, maximum dexterity, etc. since the thickness correlates to the bulkiness of the armor more directly than the sheer weight.

Titanium is better for armor, but it's a lot rarer than iron, and much harder to machine into a usable form, making it a lot more expensive.

[imp_fireball]

Well I removed the 'aluminum being light' factor since its assumed that effective enough armor is thicker. So now it's pretty much identical to steel except that it melts more easily and is non-corrosive. Also, it costs a little more. Titanium is even more expensive.

I mentioned that Titanium would be worked in the 'deepest of forges', meaning particularly hot and industrious places. Something for dwarves I bet. :smallwink:

[Rainbownaga]

So yah, not being affected by the rust monster is a major plus I can bet.



Pretty sure rust monsters can corrode stuff that doesn't even rust, like mithral and gold; they just don't like it as much.

[Shpadoinkle]

Errr, irony much?

Eh... for a specific kind of irony, I guess. Again, without being able to harness electricity (en masse at least) aluminum is very difficult to produce. Aluminum is essentially crap as far as metals go, but minus electiricty, it's RARE crap. It's kind of like an autographed photo. If there's onlly a handful of Bob Bobson photos autographed by the man himself, they're worth a lot because they're so rare. If Bob then decides to track down every photo of himself and autograph them all (for whatever reason) they go down in value because they're so much more common.

[I_Got_This_Name]

The range of strengths for alloys of aluminum is lower than the range for steels. Good aluminum might be stronger than weak steel, but you wouldn't make expensive armor out of bad steel anyway, and good steel is stronger than all aluminum. Aluminum sees most of its use nowadays because it's cheap; it just takes a lot of electricity, but aluminum ore is almost as common as dirt. Putting numbers on this:

To put some numbers on this:
Here's a site (http://www.onlinemetals.com/) selling steel and aluminum, with spec sheets up. I'm going to be using their numbers, since they trust their livelyhoods to them and Google rates them highly.
A36 steel (http://www.onlinemetals.com/alloycat.cfm?alloy=A36) is a weak steel. It has a tensile yield strength of just over 36 ksi, and an ultimate tensile strength of 58 ksi at least. That means that if you have a steel rod, for every square inch of cross section you have, you need to pull on it with 58 thousand pounds of force to break it, and if you pull with less than 36 thousand it will go back to its original length when you let go. You generally care about the yield strength, because that tells you, among other things, how hard it is to bend your steel out of shape.
1144 Steel (http://www.onlinemetals.com/steelguide.cfm) is a fair bit stronger. Its ultimate tensile strength is 115 ksi, and its tensile yield strength is 100 ksi. That's a hundred thousand pounds to stretch, and 115 thousand pounds to break, for a one square inch rod.
[url=http://www.onlinemetals.com/aluminumguide.cfm] Here are their aluminums. The strongest aluminum they have (7075 aluminum) is an aircraft-grade alloy with a yield strength of 73 ksi, and an ultimate strength of 83 ksi. There's a fairly strong mild steel with similar stats (A513 has 72/87 ksi).
Most aluminums they have are quite a bit lower. The most commonly used alloy (6061) is 40/45 ksi (yield/ultimate), and it's actually the strongest of the non-copper alloys.

You can bypass the energy requirements to refine aluminum with Fabricate, but that doesn't help you with the fact that you're using a weaker metal, especially if you don't have modern metallurgical science to tell you how to alloy it (you're basically just doing blind experimentation).

That said, there are applications of aluminum to D&D. Not as armor, though. For instance, if you needed metal arrowshafts for some reason, aluminum is strong enough for them to be hollow, saving you weight over a solid shaft. Wood does catch fire more easily than aluminum melts, so if you're going to be trying to shoot through walls of fire or whatever, aluminum arrows might be advantageous.

On the other hand, Titanium is basically just mithral.

[Mulletmanalive]

Having lived with an engineer, it's worth pointing out:

Aluminium on it's own is not used for much. Aeroplanes are made of Duralumin or similar materials which are only between 60 and 80% aluminium and usually have a moderate Titanium content. Undoped aluminium is only really used for cans and foil because of its oxide skin. It's not even easier to recycle than steel, just that there's much more of a reason to use balast in a modern aluminium rig than most stages of iron smelting [which is about 30-40% scrap].

Titanium itself, raw, is useless. Yes, that's right, more or less useless; its almost as brittle as graphite pure. Lightly doped, to the stakes of steel, it's ok but it's still got very little impact resistance. Titanium's primary advantages are tensile strength [not something you worry about in armour] and its heat resistance. On the other hand, the term titanium is usually used for anything with more than about 20% titanium [much to the annoyance of my friend] and included Titanium Steel and Titanalumin, both of which are very strong building materials.

For actual game terms, Aluminium has about a hardness of 4 because it's soft, with about twice the hp of steel because of its tendency to bend, but it would reduce armour values by about 2 against Bludgeoning weapons because of the same tendency. Excellent armour against HEAT shells though...

Titanium, assuming it's an alloy of some sort, would be steel [Hardness 12] but about half the weight. It'd be most useful as Titanium Steel, which would have about Hardness 14 and 20% more hp per inch. That'd probably equate to a +1 enhancement bonus.

Overall, Titanium would be an intensely rare thing that you could add to your armour to give it a boost and a snazzy blue sheen; Aluminium is probably best ignored unless you're building vehicles.

One useful combination to Fabricate would be Iridium with a 5% Osmium dope. So hard that it can penetrate most materials; 9.something on the Moh's scale.

[Amadi]

Ugh.. Aluminium does rust. Further, it rusts really, really fast. The layer on top of the aluminium can IS rust. This layer cannot rust further, and stays on top of the aluminium, protecting the rest from rusting. :smallwink:

[SlyGuyMcFly]

Ugh.. Aluminium does rust. Further, it rusts really, really fast. The layer on top of the aluminium can IS rust. This layer cannot rust further, and stays on top of the aluminium, protecting the rest from rusting. :smallwink:

Indeed. 'Course, as soon as that layer of rust is scratched off (say, by being hit with a sword) the aluminium under it rusts and so on and so forth. Aluminium armour or weapons would not last very long. At all.

[imp_fireball]

Damn son, you guy's should homebrew something appropriate involving this since most of you know more than me.


On the other hand, Titanium is basically just mithral.

But better because it's non-magical! Seriously, how often does something that effect time/space permeate the world. It's not healthy. Better to go with a mundane alternative.

[Shpadoinkle]

I always figured titanium was analogous to adamant, or adamantine, or adamantium or adamantite or whatever you call it.

[imp_fireball]

I always figured titanium was analogous to adamant, or adamantine, or adamantium or adamantite or whatever you call it.

No, adamantium is analogous to diamond (hardest naturally occurring element on earth). At least that's how I read it in wikipedia.