Thread: A quick slurry study

Originally Posted by niftyshaving

Very excellent images and data.
It might be interesting to look for and ID
swarf components as well. I fear that
iron and steel in the swarf would oxidize overnight.
But the carbides would not and perhaps the
morphology of the steel swarf might be
preserved (pseudomorph).

Do you also have access to an optical microscope?

I do but it does not have a camera on it.
As far as metal particles the grit for the images is taken from the supernatant of the grit suspension, leaving all the heavy stuff on the bottom of the vial.
Shapton slurry was not used to hone on so at best you can have a loose diamond or two from the Atoma.

very(!) interesting pictures. I´d love to see some pictures of the super cheap CHinese 12k for comparison.

But keep in mind, what you are looking at is the slurry.
How these particles are bond in the original stone (that is without slurry)
makes a whole lot of difference.

Also, is it me, or do I see some pretty large flakes in the Shapton 30k slurry,
like 2µm or so? These would explain the scratches the 30k leaves on a bevel, right?

Originally Posted by Lesslemming

very(!) interesting pictures. I´d love to see some pictures of the super cheap CHinese 12k for comparison.

But keep in mind, what you are looking at is the slurry.
How these particles are bond in the original stone (that is without slurry)
makes a whole lot of difference.

Also, is it me, or do I see some pretty large flakes in the Shapton 30k slurry,
like 2µm or so? These would explain the scratches the 30k leaves on a bevel, right?

The flakes are contamination from Nakayama, I used the same Atoma to raise slurry, I guess I did not scrub/rinse thoroughly enough between stones.

Originally Posted by niftyshaving

Very excellent images and data.
It might be interesting to look for and ID
swarf components as well. I fear that
iron and steel in the swarf would oxidize overnight.
But the carbides would not and perhaps the
morphology of the steel swarf might be
preserved (pseudomorph).

Do you also have access to an optical microscope?

I think they would begin to oxidize even quicker than that. I don't feel like that would be bad information because the iron oxide is not water soluble and it would still show up. Supposedly, the CaHPO4 in the Nakayama would turn that oxide into FePO4. That would be interesting in and of itself, don't you think so Tom?

Originally Posted by mainaman

I do but it does not have a camera on it.
As far as metal particles the grit for the images is taken from the supernatant of the grit suspension, leaving all the heavy stuff on the bottom of the vial.
Shapton slurry was not used to hone on so at best you can have a loose diamond or two from the Atoma.

Can you compare and contrast the material
from the bottom of the vial with the supernatant?

Stokes law will select material by size and
material for you perhaps confusing the conclusions.

Also how was the powder diffraction trace taken.
Stuff you already know, comes to mind...
A smear on a glass slide might generate data.
Dry material with a small amount of Duco Cement
can be rolled into a thread for a powder film camera.
On a glass slide the orientation will not be random
so the relative intensity of peaks will be odd
in a powder XRD trace.

Check the literature for information on natural
hones. There might be a topic for a short paper
or poster session in it.

Tom,
the x-ray results posted are not mine.
I just put the grit on a glass slide to see how it looks like.
A very thorough research will reveal a lot of interesting data, but it takes time, preparation and money. I basically smuggled my grit samples with my research samples, and took some quick pics.Private use of the SEM is in the range $160/hour so this out of question for me.
I'd imagine this study with more detail would be interesting topic for a geologist. For me the results are satisfying and explain how the grit works, I would be happy to hear further results on the subject if a person knowledgeable in rocks would be able to research more.

Originally Posted by mainaman

Tom,
the x-ray results posted are not mine.
...snip...
I'd imagine this study with more detail would be interesting topic for a geologist. For me the results are satisfying and explain how the grit works, I would be happy to hear further results on the subject if a person knowledgeable in rocks would be able to research more.

As a geologist/mineralogist I do have a biased list of things to ponder....

Thanks for the images...!

I know there was a lot of research into this back in the 30's
when fine optical microscopes surfaced and the microtome
folk got very interested in the edge they used to slice thin
samples for inspection.

I suspect that there is a gap between then and today with
electronic micro imaging and analysis tools. I am sure that
inside of the razor folk like Gillette and Schick there is a lot
more "secret" stuff.

Good stuff.

Originally Posted by niftyshaving

Can you compare and contrast the material
from the bottom of the vial with the supernatant?

Stokes law will select material by size and
material for you perhaps confusing the conclusions.

Also how was the powder diffraction trace taken.
Stuff you already know, comes to mind...
A smear on a glass slide might generate data.
Dry material with a small amount of Duco Cement
can be rolled into a thread for a powder film camera.
On a glass slide the orientation will not be random
so the relative intensity of peaks will be odd
in a powder XRD trace.

Check the literature for information on natural
hones. There might be a topic for a short paper
or poster session in it.

At these particles sizes, the quartz will likely drop right out during sedimentation. The clays will stay in suspension, but typically only if they are dispersed. Ideally, you'd want to remove any cementing agents first (in this case goethite and amorphous Si), but that's overkill for this (it might be easy to raise the pH to ~9.5-10 if you choose to pursue this, Stefan).

Well, fyi, the XRPD was done in reflection mode on a dried (powdered) slurry that was applied to a zero-background plate (a silicon wafer that was cut at an offset to (111) so that no Bragg reflections exist within the scan range). There is typically no need to use any cement these days with modern equipment, and use of film cameras are all but obsolete, even for single crystal work.

There is also little need to use a capillary (or rolled sample) because in this case, preferred orientation (potentially resulting in the ‘odd relative peak intensities’ that you mention) only would apply to the clays and is really fairly minimal in this case. This was measured. My analysis method was actually corrected for this as well, but you’re very observant. Btw - capillaries definately have their place, but usually not for routine characterization work such as this.

I'm thinking three things about these photographs and the speculations about them:
(1) where is the evidence of 'flaking'
(2) where is the evidence of 'break down'
(3) what is the definition of 'grit size' for a mixture of particles of different size

There are many reasons for the contrast in a SEM image, the challenge isn't taking pretty pictures, it's figuring out their meaning.
I'm still at loss at what these images mean, by themselves they can be interpreted in completely different ways, so at this point they're completely meaningless.

Originally Posted by gugi

I'm thinking three things about these photographs and the speculations about them:
(1) where is the evidence of 'flaking'
(2) where is the evidence of 'break down'
(3) what is the definition of 'grit size' for a mixture of particles of different size

There are many reasons for the contrast in a SEM image, the challenge isn't taking pretty pictures, it's figuring out their meaning.
I'm still at loss at what these images mean, by themselves they can be interpreted in completely different ways, so at this point they're completely meaningless.

Everyone can make their own conclusions looking at the pics, I certainly am not saying what happens, just what I think is happening. I stated that in at least one of my posts.