New Alloy Stronger Than Fe And Ti 448
SoCalChris writes "According to this article on MSNBC.com, researchers at CalTech have discovered a new alloy that is stronger than steel and titanium, can be cast in a mold like plastic, and sharpened like glass. The first plans for the new alloy are to be used in golf clubs, baseball bats, skis, and cell phone covers."
gah (Score:5, Informative)
Fe != Steel (Score:2, Informative)
Fatigue strength? (Score:5, Informative)
But materials like this tend also to be brittle, and do not do well in other kinds of loading. Take 'fatigue' loading, for instance. This measures how well it holds up to repeated loads, such as crankshaft in a car. Materials with uncrystalline structures not only tend to fail quickly under repeated loads, but also tend to fell catastrophically (breaking in two, instead of gradually bending).
The article doesn't give enough info to verify this - just my thoughts. In material science, you generally have to make a compromise - in this case, tensile strength against fatigue life.
Re:Wow, how revolutionary (Score:5, Informative)
Re:Cars (Score:4, Informative)
Let's take a 60 mph head-on collision with something massive enough that it doesn't move when the car hits it. Assuming that the car doesn't deform at all, the passengers will have to go from 60 mph to 0 in the distance of about an inch (liberal estimate for seat belt play and expansion).
'scuse me while I whip this [physics book] out:
v^2 = v0^2 + 2*a (x - x0)
Solve for a:
(v0^2-v^2)/(2*(x-x0))
v0 = 60 mph -> 26.8224 m/s
v = 0 mph -> 0 m/s
x = 0 in -> 0 m
x0 = i in ->
(26.8224 m/s ^ 2 - 0) / (2*(0 m -
(14162 m/s^2) / (9.8 m/s^2) = 1445 G's.
If you were unlucky enough to be in this car, you wouldn't just die. You would splash. I friend of mine just informed me that the tensile strength of a seatbelt is 15 tons, and a 150 lb person would exert 108 tons on the seatbelt and splash into the dashboard or steering wheel.
Moral of the story: if they ever do make a car that stiff, don't ever get in it.
Re:Liquid metal will not replace DU (Score:2, Informative)
Although the density of DU makes it good for armor, I believe the reason it is often used for armor piercing shells is its self sharpening property. Unlike lead bullets that mushroom out on impact, DU cleaves off at a certain degree, thus retaining a tip as it travels through the armor. A sharp tip of course concentrates the force, easing pentration. This is illustrated in the same domain as your link [osd.mil]
Actually tested this stuff out (Score:5, Informative)
Being a metallic glass, it has all sorts of crazy properites, as mentioned in the articles, but when it reaches the yeild strength it shatters (at least in non-composite form).
Also, because it is a metallic glass, it is inherently a meta-stable solid.... metals usually have relatively simple crystal structures, and thusly crystalize quickly with relatively small undercooling. The clever trick with this stuff is that it's a mix of four or five metallic elements that have a large span of atomic radii (this stuff is Zr-Ni-Cu-Ti-Be, various weightings of each, usually the Ni=Cu=Ti). Anyhow, when it finally does crystallize, whether due to heat, fatigue or constant strain, it forms a pretty complex crystal structure (I don't recall which one offhand) that allows very little motion of dislocations. Thus, it's super brittle when in it's thermodynamically stable state. Moreover, even with this clever alloying, it still requires high cooling rates to avoid crystallization from the melt, and is thusly hard to cast into large ingots.
Thus, whether it takes too hard an impact (can never be a tooling metal or knife, in pure form) or is under strain for too long (can never ever be a structural metal - too flaw sensitive in pure form and too expensive to process and machine in composite form) it will fail catastrophically.
Basically, this means it's pretty useless for most applications metals are required for (due to lack of crystal structure it's also a poor heat conductor - sorry overclockers). And because it is opaque, it can't be used for traditional glass applications. Liquid Metal has been around for a while trying to push the golf clubs, for at least three years, more like four or five, so I'm not sure what the sudden attention is for. We ran a back of the evelope calculation in my research group: Say you're on the links, and you mis-strike the ball, and hit a large rock in the ground with a non-composite liquidmetal club... basically you'll shatter the face of the head (only the face is amorphous due to process/cost/strength issues), sending shrapnel flying into your ankle. Yum.
Still, from a physics perspective, this stuff is really interesting due to its completely artificial nature (you'll never find anything close to this in nature) and odd mechanical properties (it's the metallic version of flubber). Commericially, in bulk form, I'd say they should shy away from structural applications and perhaps try transformers, where the thin film versions of amorphous metals have significant gains over silicon.
Another use (Score:2, Informative)
So many questions... (Score:5, Informative)
Actually.... (Score:2, Informative)
Re:Fatigue strength? (Score:2, Informative)
Re:Um... more info, please. (Score:1, Informative)
Tool steel(usually precipated hardened) and titanium are some of the strongest (not hardest like concrete, diamonds, or carbide) material available. They take stress very well, and that is why they are used in machines for cutting and what not.
Another strong material is Inkanel. Not as strong as titanium, but alot easier to machine.
Re:Don't let Smith & Wesson get a hold of this (Score:3, Informative)
as a Materials Scientist I flinch when it is said a material is stronger than another simply because strength can be measured in so many ways, and physical strength has components which are often inversely proportinal - e.g. toughness (ability to remain useful through fatigue and past the yeild strength) v.s. hardness.
this is harder than most metals, and has a higher yield strength, but zero ductility and probably really poor fatigue properties. Imagine a glass pistol... *shivers*
Metglass (Score:3, Informative)
BTW, the original patents have long ago expired so that anyone can work with metallic glasses.
What this guy did was develop an alloy that could be cooled into parts of thicker cross section than was previously possible.
Re:Fatigue strength? (Score:2, Informative)
Ballistics say: don't worry [was: only time ..] (Score:2, Informative)
Armor piercing is great for some applications. Most anti-personell weapons, however, don't want armor piercing. An armor piercing round from even a moderate velocity weapon will go all the way through a human, doing relatively minimal damage. If you want to cause damage, what you want are soft bullets that expand when they hit soft stuff. If they expand, they do more damage, and cavitation effects are worse. This is why hollow points exist. This is why bullets are made of lead, not steel. You're better off if you're hit with an armor piercing round.
Nato 5.56mm rounds (M-16 rounds, .22 cal) are designed to tumble very early. They do a massive amount of damage for a small round, because they are designed to tumble very early upon hitting the body, split in two, and produce some massive cavitation. Despite this, the 5.56 doesn't kill as fast as the 7.62 used by the M1 Garand or the AK-47. This is on purpose. The US small arms tactic is to prefer wounding over killing. This isn't because of some noble humanitarian ideal; the military figured out that one wounded soldier takes three other soldiers out of combat just to take care of the 1 wounded person. Wounded people are much more expensive to take care of than dead people.
In any case, all other things being equal, you'd be better off getting hit by a Liquid Metal bullet than most of the other options. You'd have a better chance of surviving, if you got to a hospital.