Diamond impregnated steel blade

[Fireman]

I am not a material scientist but a am a tee shirt wearing knife steel nerd. What are the possibilities of a diamond impregnated steel? Think of diamonds distributed like carbides in a steel matrix. Could diamonds be used in conjunction with other carbides? Maybe cast like dendritic cobalt? I am naming this steel “Bling” steel. What would be the advantages and disadvantages? Help me Dr. Larrin!

[VooDooChild]

Buy a diamond saw blade and make a knife out of it.

As far as diamonds in the steel matrix I dont think they are strong enough for any sort of abuse. Im not sure they are strong enough for chopping on a hard surface.

Diamonds are hard but can still chip/break.

[Fireman]

Let’s say you added some diamonds to a tough CPM steel, say 3V for example, would it make the edge retention better or worse?

[JRinFL]

I know diamonds have been bonded to the surface of steel, but is it even possible to add diamonds to molten steel? Would diamonds survive in a PM type steel after the melt? I guess you'd need to know that before getting to your question.

[JRinFL]

Oh, my guess is that they would survive and you would have a very crumbly blade steel.

Edited to add: WRONG, see below

[Fireman]

They seem to have diamonds of incredibly small size for all purposes and diamonds melt at 7000 degrees where steel melts at less than half that. Add some diamond powder to the other carbide powders and add that to the powdered steel, do the powdered metallurgy alchemy and voila! Bling!

[Fireman]

They have some steels exceeding 20% carbides, let’s say you had a few percent diamonds. The diamonds would in theory wear less and cut more but the question is how would the diamonds do being held by the matrix?

[Granoo Fink]

They will dissolve in the melt and rise the carbon percentage.

[Fireman]

Hmmmmm. At what temperature will they melt? The internets say 7,000 degrees. Would cast in dendritic cobalt help?

[Granoo Fink]

They will not melt but dissolve, like salt in water. Table Salt melts at about 800°C .

[Naperville]

They seem to have diamonds of incredibly small size for all purposes and diamonds melt at 7000 degrees where steel melts at less than half that. Add some diamond powder to the other carbide powders and add that to the powdered steel, do the powdered metallurgy alchemy and voila! Bling!

This entire thread put a huge cheek to cheek smile on my face!

BRING ON THE DIAMONDS!!!

[JRinFL]

I just read that diamond will burn between 700-900 degrees C and that means Granoo Fink is correct. He already knew that, of course.
The heat treat range for something like M390 is well above the point at which diamonds burn.

[JRinFL]

I forgot to add, thanks for the question as it made me learn something today.

[JacksonKnives]

[edit: beaten already by quicker responses. ]

As noted by the others above above, solubility does not require melting the diamond, it happens readily at grinding temperatures.

After a quick search I found this whitepaper:
https://beckassets.blob.core.windows.ne ... pt_001.pdf

Carbon atoms easily diffuse into carbon-soluble metals such as Fe, Ni, Mo, and
rare-earth metals/alloys. These metals are ready to react with any source of free
carbon and absorb this carbon into their surface. Such a reaction is easily triggered
under the temperature and pressure conditions occurring in the diamond polishing process.
...
... the maximum carbon solubility in austenite is as high as 2.03 % C at 1147 °C. Therefore, such diffusion reaction is easily
triggered under the temperature and pressure conditions occurring in the thermochemical and dynamical polishing process.

This is one reason why CBN is becoming a popular alternative to diamond for high-speed polishing.

Specific temperature thresholds given in this source: https://gearsolutions.com/features/hard ... nd-or-cbn/

Diamond will oxidize above 600ƒC into carbon-dioxide
Diamond [will react with ferrous metals] above 700ƒC
Diamond reacts with carbides ... above 700ƒC...
Diamond will react with carbide formers (titanium and vanadium) above 800ƒC to convert into carbides.
Diamond could be dissolved in transition elements of iron group metals or their alloys above 900ƒC

[Naperville]

[Larrin]

Carbon is already added to steel. It goes into solution for hardness or forms various carbides. Getting diamonds to stick around in steel seems unlikely.

[Fireman]

Would be interesting to see if diamonds could survive. Is there any process that is could be cool enough?

[VooDooChild]

Would be interesting to see if diamonds could survive. Is there any process that is could be cool enough?

I assume for saw blades they are just bonded on in some way. Really good glue?

At that point your basically abrading something with diamonds. They will still chip, but they will also come off with use. So aside from no food prep, sharpening would be pointless, and once all the diamonds come off you just have a piece of whatever metal you stuck them to.

[Fireman]

OK, maybe this is a question for Roman but is there any reason diamonds can’t be added to cast ceramic?

[The Meat man]

Cool idea but how would you sharpen it?