Scanning Electron Microscope Blade Edge Images

[Evil4blue]

First thing to understand about SEM technology is that it's not an optical image that you're seeing. What it is is a topographical map of the surface of your sample. An electron beam is fired at the sample, which excites the atoms on the surface, then these atom give off different energies which the detector in the SEM picks up. The software then makes sense of the data and draws the map that you see. The advantages of technology is that you can see detail to nearly the atomic scale, the disadvantages are that you sample needs to be conductive to work in a traditional SEM and that depending on the surface make-up, details you see optically, may not show up in the SEM.


Teflon is easy to spot because it's not conductive and will charge (basically, bounce back all the electrons shot at it). Charging particles will turn a brilliant white color in the SEM. The Gillette's don't appear to be Teflon coated, but may have a chrome coating or similar which will excite similarly to the stainless base and make it harder to distinguish in the SEM scan.


I'm learning a lot in this process and may revisit the first set of blades when I get time. It would be interesting to see if my improved technique changes what I initially recorded.

--Edit--

Also, what's the magnification factor of the USB microscope. The SEM images are at 150x and we're looking at a much smaller section of the edge. The roughness may smooth out as we get a closer look.

 

[gearchow]

For a view of optical imaging, Steve (SiBurning) did this series a while back:

Micrsoscope photography WARNING large pictures


-jim

 

[mblakele]

First thing to understand about SEM technology is that it's not an optical image that you're seeing. What it is is a topographical map of the surface of your sample. An electron beam is fired at the sample, which excites the atoms on the surface, then these atom give off different energies which the detector in the SEM picks up. The software then makes sense of the data and draws the map that you see. The advantages of technology is that you can see detail to nearly the atomic scale, the disadvantages are that you sample needs to be conductive to work in a traditional SEM and that depending on the surface make-up, details you see optically, may not show up in the SEM.


Teflon is easy to spot because it's not conductive and will charge (basically, bounce back all the electrons shot at it). Charging particles will turn a brilliant white color in the SEM. The Gillette's don't appear to be Teflon coated, but may have a chrome coating or similar which will excite similarly to the stainless base and make it harder to distinguish in the SEM scan.


I'm learning a lot in this process and may revisit the first set of blades when I get time. It would be interesting to see if my improved technique changes what I initially recorded.

--Edit--

Also, what's the magnification factor of the USB microscope. The SEM images are at 150x and we're looking at a much smaller section of the edge. The roughness may smooth out as we get a closer look.

Thanks for the explanation. The USB scope is supposed to be 200x but I think that is an exaggeration: probably includes digital zoom or something like that. Comparing the widths of the grinds with your images, I suspect 100x or less. You can see a better image of a similar texture on a Feather Super Pro in the photos by SiBurning at http://badgerandblade.com/vb/showth...-WARNING-large-pictures?p=2588873#post2588873 - however many of the photos in that thread are of straight razors or used blades, where I would not expect to see a coating. Later in that thread http://badgerandblade.com/vb/showth...-WARNING-large-pictures?p=4681505#post4681505 shows what I believe is a SEM image of a Feather blade, cross-sectioned and showing the rough-looking coating in detail.

The thing about a hardness coating (Cr, Pt, or a mix) is that I would expect that to be smooth at low optical magnification, and to adhere well to the steel substrate. According to what I have read those coatings are meant to counteract the edge softening that occurs when the anti-friction coating is sintered onto the blade. Hardness coatings are applied first, then the anti-friction coating goes on top. Sometimes there can be adhesion layer(s) in between, as in this Gillette diagram for cartridge edges.



The rough texture I see is omnipresent in the new blades I have looked at, and is pretty much gone after 3-7 shaves. So I concluded that it was an antifriction coating, something like sintered PTFE. But now I wonder if there is enough difference between different coating formulations to affect SEM visibility? Or maybe just a question of thickness?

Most of what I think I know about this comes from the patent literature. Over the years the Gillette and Schick patents went from talking about PTFE and fluorocarbon polymer to talking about (fluoro-)telomer layers. There were also some mentions in the 1990s about moving away from CFC-based solvents for the coating process. The general trend seems to be toward more and more highly refined processes for applying anti-friction coatings, and that may be the key to understanding these images.

 

[mata777]

Very interesting thread. Will keep an eye on this, thanks!

 

[Evil4blue]

Here's four more from this morning.

Perma-Sharp Super:





Wilkinson Sword (India):





Lord Platinum:





Sputnik:





Most od these blade have some sort of non-stick coating on them, be it Teflon or an oil/lubricant, which makes taking really high mag images difficult. The SEM has a really hard time getting a really crisp image when the sample surface has low conductivity. The Sputnik blade was relatively clean, even though it should have a Teflon coating. I tried grabbing an image of the razor's edge at 2500x. Here's the output. It's a little softer than I'd like, but it gives you some idea how uneven a razor edge can be.



Last thing to mention. The Lord Platinum blade didn't so any presence of platinum and may have been the dirtiest blade I've seen out of the package. This blade was manufactured in Egypt.

 

[jwilock]

Look at the bottom of the first post. There is a Voskhod scan there.

I also have a Sputnik blade to scan. I believe is also from the St Petersburg plant,

Ah didn't see that one there. The Rapira blades, including the Voskhods come from a plant in Moscow, not St. Pete like many of the Gillette blades. I wonder if there is anything in your tests that can distinguish between the St. Pete blades and the ones made in Moscow.

 

[Evil4blue]

I managed to mount a Personna Med Prep on edge and took a couple pictures of the edge.



Here's one at 1100x:



I added some lines to show the different sections of the edge:



The inner most area is the actual edge, the next set of lines show the area coated with Teflon, the next set of lines is the secondary bevel, and the last set is the primary bevel. The 1.36um in the corner is the width of the actual edge.

The blade is right at 100um wide, the secondary bevel is about half the width (50um), and the Teflon coated area was about 16um wide.

 

[KodiakAttack]

This is very interesting. Im a huge fan of the gillette blacks, but they don't appear nearly as sharp/smooth as the yellows, and yellows are my second choice. I'm surprised by the Voskhod's too, those look scary as hell but are incredibly comfortable for me.
Thanks for the educating post!

 

[mblakele]

Nice! Comparing this to the previous med prep image, it seems like the coating is much more visible. Is that basically because the electron beam hits a thicker layer of it edgewise than it does from the side? Or are there other factors?

With my cheap optical scope I seem to see the coating impinging on the secondary bevel. But it is probably a thinner layer there, and thickest near the ultimate edge.

I know, I know - another post about coatings. Thanks again for posting these images.

 

[Evil4blue]

To tell you the truth, I'm not sure why it's more visible. The first photo is at 3x the magnification of the side profile, so I'm sure that helps, but it probably has more to do with the way the electrons are hitting the surface and the detector is picking up the response. I'm also using a higher voltage with these. Voltage is a weird setting and you sometimes have to rob Peter to pay Paul. Some things look great a high voltage, while other become invisible. I'm always tweaking things to try and get a formula that works for what I'm looking at.

 

[lindyhop66]

What is the frosty looking residue, soap residue? Maybe clean with alcohol and compare.

 

[lindyhop66]

You should try a straight razor at different stages of honing or polishing. A jagged looking edge can still give a great shave.

 

[StraightEdge]

That's Excellent! I have to admit, I was slightly disappointed with some of the results (I thought I had found "The One"),, Guess I will be trying some Crystals, etc. hahaha!! Thank you so much for posting this!

So with your "Study" what blade is in your Razor now??

 

[5savages]

That's Excellent! I have to admit, I was slightly disappointed with some of the results (I thought I had found "The One"),, Guess I will be trying some Crystals, etc. hahaha!! Thank you so much for posting this!

Your face is a far better judge of which blade is "the one" than the SEM is. These images are cool as hell, but only your face can tell you which blade is best.

 

[captaincaveman]

Your face is a far better judge of which blade is "the one" than the SEM is. These images are cool as hell, but only your face can tell you which blade is best.

+1

I imagine the SEM could explain why and perhaps help identify other blades that would work for you.

 

[StraightEdge]

Agreed, I was very surprised by some of the results/photos, but the blades I've been using are great! Will have to try some of the others to see how they feel now though hahaha!

 

[Evil4blue]

Please, please, please, don't judge any blade by these photos solely. All these blades were fresh out of the package (no cleaning or rinsing of any kind) because I'm using that as a baseline. Some manufactures obviously take a little more time to clean their product than others, but we all rinse our blades prior to us, even if it's just a quick dunk in the sink. I'm going to clean a few of the more popular blades and rescan at some pont in the future to see the difference if any in the blade.

My favorite blades are Personna labs/meds, Voskhods, Polsilver SI, and Gillette Blacks. Some of those blades look pretty bad out of the box, but my face says differently and I get fantastic shaves from all of them.

This whole thread is meant for displaying some interesting information and stoking some good conversation. I think its accomplished that so far. It was never meant to be used and the be-all, end-all on what blades are best.

As for the request of the straight razor, although I think it would be interesting, I don't straight razor shave, so I don't have one or access to the tools to accomplish that kind of testing. Sorry.

 

[Galaktus]

That Med Prep looks like an axe at that magnification.

 

[malocchio]

I'm not surprised at the lack of platinum in the Lord ,or any other blade...I think many use the word in the same context of "gold" standard , it is a description of their highest standard,rather than true content.The crap on that blade shows the care in the manufacturing process,although I readily admit,I get good shaves from the Lord line-up of blades,and I always rinse my blade in hot water before the first stroke.The Perma-Sharp and Sputnik blades look extremely clean.This is really a fascinating photo journey,and greatly appreciated.

 

[StubbleTrouble]

Many, many thanks for sharing this, Evil4Blue. I think this may be a first in our community.?.?.

Some scans of various stages of blade degradation would be extremely interesting to see!