Amorphous alloys

dano

dano

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Although they have been around for a while, it looks likes amorphous alloys, a.k.a. liquidmetals have started to enter the cutlery world.

www.vmatter.com is selling kitchen knives made from an amorphous alloy. There's technical info on their website, so the steel of the week folks can look into it, further.

I'd guess the stuff will eventually fall into a niche, similar to ceramic blades. Not too popular, but enough so to make production feasible and cheaper.
 
Looks like another name for metallic glass. It has no organized crystaline structure like conventional metals or ceramics, but is entirely disorganized like window glass. IIRC, it's very hard, has a very high yield strength, low hysterysis, and very low toughness. Because there is no organized crystaline stucture, there is no path for dislocations to migrate, which is the method of plastic deformation. Lacking the ability to plasticly deform means that the edge will chip or gall before it folds or flattens.

It's probably going to be useful in the same application as ceramics.

I'm still waiting for someone to come up with single crystal blades ($$$$$).
 
There's a nice article in the October NASA Tech Briefs about some work with amorphous metals that's been going on at JPL (Jet Propulsion Lab) and Cal Tech

http://www.techbriefs.com/component...ves-from-bulk-metallic-glasses-and-composites

They claim to have developed a Titanium amorphous metal that is blade steel hard, wear resistant, tough, and can be cast to near net shape so that it only needs final sharpening. The near net shape casting would bring the price down to something the average knife knut might dream of owning one some day.

Alloys have been developed based in titanium (and other metals), that exhibit high toughness, high hardness, excellent corrosion resistance, no ferromagnetism, edge-retaining self-sharpening, and the ability to be cast like a plastic using commercially available casting techniques (currently used by commercial companies
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I may yet get my vorpal blade (see sig line).
 
Twindog said:
How does the "self-sharpening" edge work?
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I once read a claim by a seller of a carbidizing machine that carbidizing just one side of an edge essentially makes an edge self-sharpening, as one side wears a bit faster than the other. It sounds like it makes a self-sharpening offset chisel grind, but I have good reason to believe that is more salesmanship than science - difference in wear resistance might make an edge last longer, but use would still wear the edge unevenly and would probably not be a flat keen edge. This is all speculation on my part based on a questionable claim, so feel free to correct and/or dismiss it.
 
I would love to see this "steel" cast into a paring knife that can be repurposed into a neck knife. The translucent green handles are quite sharp looking, they remind me of jade G10.

Now if only they had a more reasonable price...
 
I found that fascinating! I'd love to know more about the technology of it. I'm assuming it's not just the proportion of materials, but also has something to do with the processing. I'm wondering if there are high heat rate molds involved with some sort of cryogenic cooling to lock the material into its amorphous state before it can cool and self-organize into crystals. Seriously cool!
 
Clang! said:
Looks like another name for metallic glass. It has no organized crystaline structure like conventional metals or ceramics, but is entirely disorganized like window glass. IIRC, it's very hard, has a very high yield strength, low hysterysis, and very low toughness. Because there is no organized crystaline stucture, there is no path for dislocations to migrate, which is the method of plastic deformation. Lacking the ability to plasticly deform means that the edge will chip or gall before it folds or flattens.

It's probably going to be useful in the same application as ceramics.

I'm still waiting for someone to come up with single crystal blades ($$$$$).
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That seems odd considering they claim the alloy has a high amount of elasticity and can therefore cope with high amounts of strain (physical displacement in the form of bending) before reaching the point of possible plastic deformation or breaking. Perhaps it cannot plastically deform, but it supposedly is far more flexible than any steel or titanium. They argue the metal would be a good candidate for a spring material. I can't imagine a spring made from ceramic. I don't really see how this material is comparable to ceramics. But I'm certainly no expert in this.

But I see one gaping hole in this (in terms of being a good candidate for a cutlery material) is the lack of carbides. This stuff may be strong, but I'm not sure about wear resistance.
 
Sorry, I meant toughness in the materials science sense, not the lay sense. Toughness is a measure of how much energy it takes to break it. Elasticity is a measure of how much it can be deformed before it won't return to it's original shape.

http://en.wikipedia.org/wiki/Fracture_toughness

P.S. Strain is a measure of deformation per unit. It can be tension, compression, shear strain, or any combination. Refer to Mohrs Circle.

I agree with wear resistance. That could be a problem.
 
Comeuppance said:
I once read a claim by a seller of a carbidizing machine that carbidizing just one side of an edge essentially makes an edge self-sharpening, as one side wears a bit faster than the other. It sounds like it makes a self-sharpening offset chisel grind, but I have good reason to believe that is more salesmanship than science - difference in wear resistance might make an edge last longer, but use would still wear the edge unevenly and would probably not be a flat keen edge. This is all speculation on my part based on a questionable claim, so feel free to correct and/or dismiss it.
Click to expand...

I have no idea if what that guy was telling you was true or not about his process but what he describes is what happens with rodent teeth. One side is harder then the other so they wear differently and actually DO sharpen themselves.
 
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