Ceramic knives!

[andy]

Yes, really! A couple weeks ago my wife and I saw a documentation on the Science Channel about how they make knives from ceramics. Basically it's Circonia powder baked into a form and then sharpened.

Circonia?sp? is after diamond THE hardest material known to man AFAIK. And they make knives from it? Well long story short, since my wife is just visiting her mother I took the opportunity to order some of these knives in and she can't see them coming. They came in today.

One thing I can tell you: These things are SHARP! We'll see how long they last or if they brake easily. From what I have read as long as you don't try to twist the knife it'll last forever.

[Hog]

Boker's been making them for awhile. Pretty cool knife never need's to be sharpened, but it seem's like they would chip easily.
Dave

[Jim]

My son gave me one a few years back. Great knife. I only use it for veggies so it should stay sharp a long time. And, Diana doesn't use it. She is tough on knives. ;)

Only drawback it you have to send it back for sharpening, but with care that should be a while.

Don't cut yourself.

[andy]

In the description I got it says you can bring to the local knife sharpener as long as they have a motor driven DIAMOND wheel.

[RiderRay]

Heard of these back around 1993. Scary part is that, I am told, you can pass through security with them since they are not metal.

[andy]

HHmm Didn't think of that yet. But, yes, there is not a pice of metal on them. If you have that on your body I can't see how the metal detector could possibly see them.

[dshealey]

These have been around for over 25 years now. Started out only in Japan, but started making inroads to consumer use about 20 years ago. I worked for AVX Ceramics (Ceramic Capacitors) at the time, who was bought out by Kyocera. We could buy these knives at employee discount, but they were still awfully expensive at the time, so I never bought any.

They have come way down in price so I have considered them again in the last few years, but nothing was available over about 6" blade length last time I looked, about 4 years ago. Are they making longer ones now?

They are made from Stabilized Zirconia, which has the remarkable trait of resisting crack propagation. The molecular structure is such that a microscopic crack cannot progress, so they resist breakage very well. Of course if enough stress is applied they will certainly break.

They can be sharpened as sharp or sharper than the best steel knives, and hold the edge almost indefinitely if not mistreated.

Kyocera was the developer, and still is the largest producer by far. A couple other ceramics companies have been trying, but have not been able to match Kyocera's processes to date. Kyocera is the world's largest Ceramics company, and make just about anything that can be made from technical ceramics, including automoble engine and aerospace parts.

Where did you order your knives from Andy?

By the way, in the TV program which I also saw they mentioned that Kyocera adds metallic compounds to the ceramic so that they are detectable by security methods. I imagine this was pretty difficult still keeping the toughness and edge holding of pure Zirconia.

[andy]

Where did you order your knives from Andy?

I was too cheap to go for the Kyocera blades. I bought mine here (http://%3Cfont%20size=%22-1%22%3Ewww.%3Cb%3Eshenzhen%3C/b%3E%3Cb%3Eknives%3C/b%3E.com)

But you are right, 6 inch is the maximum I have seen as well.

[andy]

By the way, in the TV program which I also saw they mentioned that Kyocera adds metallic compounds to the ceramic so that they are detectable by security methods. I imagine this was pretty difficult still keeping the toughness and edge holding of pure Zirconia.

I must have missed that, because I was more interested in the product. But I guess it makes sense. Anyway, it looks kind of weird having a BRIGHT WHITE blade.

[tbarstow]

When I worked at Liquidmetal Technologies a few years ago, we were making blanks for some of the custom knife makers out of our amorphous alloys. They worked great, even garnered a few awards, held an edge great, and were pretty indestructible.

Then they found out that you could get them through a metal detector and if you sharpened them with a stone, the swarf was considered toxic due to the beryllium in the alloy.

You can catch a little bit about it on the Discovery Channel every few months (and see me on TV).