A friend of mine who fancies himself somewhat of a sword expert told me that steel (or a steel alloy) is the best known metal to use when making a sword. His reasoning was that while it wasn’t the hardest or densest, its malleability makes it ideal for swinging and striking. I had suggested titanium for hardness, or tungsten because I know its the densest metal (that I know of) but he said that if a sword was made of those materials, their properties makes them more likely to shatter when struck by a similarly hard object.
I dont know if thats true. Personally, I would think that the weak arm swing of a fragile creature such as ourselves wouldnt be enough to shatter metal. Is he right? Would harder and denser metals make swords shatter so much as to make them unreliable?
I brought up the “buckyball”, or whats scientifically known as the buckminster fullerene, as a substitute. Its light and the symmetric structure seems to exude strength and durability, but my friend said that it would also shatter
Does a sword really require some give to not shatter?
One of the most ideal materials is “pattern welded,” “forge welded” or laminated steel. Another name you’ll see for this is Damascus steel, even though it usually isn’t really Damascus steel. It’s made by sandwiching layers of steel with layers of softer metal - usually nickel, and then hours and hours of heating and beating, with successive doubling-over folds, resulting in dozens of layers in the final product. The ultimate result is something that can take an edge and be hardnened, yet still has some resiliency. A nice side effect is that it can result in beautiful patterns on the sides of the blade.
To answer your last question, yes, swords need a lot of “give” so they don’t shatter in use. I can’t find video clips, but some time ago, *Mythbusters *looked at the myth of cutting a sword with another sword. In the high-speed video, good swords flailed around as if they were made of cooked spaghetti, then came back to straight. Bad swords either snapped or stayed bent.
Never mind combat, you want a blade that can withstand being smacked against a table. This one…couldn’t. (Video with sound) My blacksmith friends would charitably call that a “wallhanger” sword. As in, it’s only good for hanging on the wall as decoration.
Tungsten would be wickedly heavy and ridiculously fragile.
Titanium would be too soft - it can’t be hardened sufficiently to take an edge, and surprisingly, a good steel blade would be able to slice through a similarly-sized titanium blade. Pure titanium is just silly-soft - it’s off the bottom end of the Rockwell scale. Swords need to be at around 50-55, and regular knife blades get hardened to the low 60s to be able to hold a keen edge. In terms of swordmaking, you may as well use aluminum instead of titanium - it’s cheaper and will take an edge about as well.
Of materials we can actually manufacture right now, steel is the best. A human arm can break even a steel sword, if it’s not treated properly, so I don’t see any reason to doubt that a human could break a less-suitable material. And heavy metals like tungsten would be terrible: A sword should be as light as possible.
Now, carbon nanofiber (which is related to but distinct from the “buckyball” form) might conceivably be suitable for sword use (maybe a hacksaw-like design, with the fiber stretched in place on some sort of frame), but our best current manufacturing techniques can only produce nanofibers a few centimeters long, so for the time being, carbon swords are out of the picture.
That looked good for about 6 stitches. Reminds me of a prybar I bought years ago. It snapped the first time I used it.
It would be worth watching how Japanese swords are made to understand what makes a good sword. It’s a combination of the right grade of steel, folded, peened, and tempered. Folding the steel over and over creates a grain in the steel, tempering it adjusts the hardness of the edge as well as the flexibility of the body, and peening adds hardness.
gotpasswords pretty comprehensively covered why steel has traditionally and remains to be the best available metal for sword and knife making, and why it is generally used for striking tools in general. Steel is readily allowable with a variety of elements to provide a wide range of properties, and while not the hardest material it has in many formulations a unique combination of hardness, tensile strength, and toughness (resistance to fracture and crack propagation), and reasonable corrosion resistance (when alloyed with chromium and nickel). Most steels are readily weldable via the common flux-cored arc welding (FCAW) process without protective inert gas, though gas metal arc welding (GMAW) is still often applied in automatic welding processes to reduce the incidence of voids and provide a faster weld. Iron is fortunately also readily available in the Earth’s crust and pretty easily separated from other elements. The only real downside to steel when compared with some other materials like nickel, tungsten, or tantalum (among others) is that it loses strength dramatically at high temperature (as do other common structural metals such as aluminum and magnesium), and so in high temperature application it has to be alloyed or substituted with a higher strength non-ferrous alloy.
One could make a sword from a composite of materials such as long carbon or silicate chain macromolecules (allowing high tensile and shear strength) with a metallic or ceramic filler to give hardness and sharpenability, but there is frankly little need for this, swords and other edged weapons being almost exclusively relegated to ceremonial and wall-hanger status in combat and warfare. Even the Pope’s Swiss Guard only carries their once-feared halberds for show, but each member is highly trained in the use of modern assault rifles and pistols for actual protective duty.
From what I’ve read, Japanese swords are a special case, in the sense that while the blade was most often made of a single kind of metal (steel folded over and over), a completed katana blade ended up with two different hardnesses : the edge was made extra hard through water tempering, but the back of the sword remained flexible. IIRC, they managed that by “painting” the back of the blade with clay before dousing it in water, so that it didn’t cool quite as fast.
The November 24, 2008 issue of The New Yorker had an article by Todd Oppenheimer on master bladesmith Bob Kramer that had lots of info on the eternal search for the ideal formulation and fabrication techniques for cutting implements (knives mostly, but some info on swords also).
How can metal shatter so easily? It seems against common sense. Is there no hard element that can be shaped to a blade and withstand some impact except steel?
How about if we can somehow take diamond and shape it into a sword? Would that be shatterproof (as far as human strength goes)?
More or less what’s already been said, but to recap:
To be any good, a sword has to have two properties- it’s edge, if not the whole sword, has to be very hard, and the sword as a whole has to be neither brittle nor too easily bent; “toughness” might be the term for what’s required. Glass is harder than steel, but you wouldn’t want to try to make a sword out of glass. Stone age flint knives had very hard very sharp edges, but they were replaced by metal because some metals were tougher. Gold, silver, lead and tin were hopelessly too soft to make practical knives and swords out of. Copper was just usable, bronze (alloyed copper) better, and mechanically tempered (“beaten”) bronze better still. Even better still was iron, and carbon-alloyed iron= steel far better.
Now that dozens of different metals are known, so far nothing unequivocally better than steel has been found. Harder and denser metals are known, but they’re usually very brittle. Aluminum and titanium can have better strength/weight ratios but are too soft. Ceramics may make a comeback as new ways of controlling their microstructure reduces their brittleness. Something like a buckyfiber rod with a diamond film edge might someday be the ultimate blade but we can’t make those yet.
Diamond is quite brittle; all it takes is a small (steel) tap hammer to shear it in planes to make a cut (faceted) jewel from a gemstone-quality diamond.
I doubt it–diamonds may be hard (as in they can scratch other materials), but they are breakable. They have “cleavage planes,” along which they will shear (http://en.wikipedia.org/wiki/Diamond#Toughness. I recall reading a story where a man crushes a grape sized diamond under his shoes.
Depends who you’re fighting. Steel for humans, silver for werewolves, kryptonite for Superman, diamond for golems, jade or obsidian for dragons, anything that’s been blessed for the undead, enchanted crystal for ethereal creatures, and fiery wrath for ice elementals.
Huh. I just got finished with the Iron Man DVD, and I distinctly remember the line at the end: “Of course, Iron Man isn’t really accurate, as it’s more of a gold-titanium alloy…”
And Tony Stark’s suit definitely takes some hard whacks (and bangs and crashes, etc.) Tsk, writers.
