Under the microscope

connor · #141

Thanks Clip. I am sure rolled edges + your photographic skills will make a beautiful yet sinister work of art. :cool:

rodloos · #142

Thanks for your posts Chris. That is really neat what you can do with that microscope. I hate to ask, what does retail normally run for a microscope like you are using? Probably not something a "hobbyist" can afford to buy :D .

Clip · #143

I can't find any information on pricing, but looks like older models from the 70s-80s are going for $3-5k. I'd think this one is in the same range, not counting the light source, camera or software used to collect the data.

Clip · #144

Cut a good ways through some pallet planks (rough white pine) and sliced a few square feet of cardboard into extremely thin strips with the 154CM Manix2 today, and here is the resulting damage to the blade. I wasn't being easy on it either, using a good bit of force and twisting on the pallet trying to get the edge to deform with lateral loading.

50x

100x - detail from the above, looks like there might be a small inclusion as well

50x

100x

phillipsted · #145

Clip wrote:Cut a good ways through some pallet planks (rough white pine) and sliced a few square feet of cardboard into extremely thin strips with the 154CM Manix2 today, and here is the resulting damage to the blade. I wasn't being easy on it either, using a good bit of force and twisting on the pallet trying to get the edge to deform with lateral loading.

Sounds like you were having a bit of fun, Chris! :cool:

Thanks for the pics. Very interesting and educational as usual.

TedP

FroOchie · #146

You've got some really cool toys at work. Great pics and info!

Holland · #147

this thread is amazing, thanks for putting in the time to do this

Toddles · #148

I love this thread so very much.

Splice · #149

I have nothing to add other than that this is really really cool. I've learned a lot about edges here!

Lagrangian · #150

Hi Clip,

Wow, wonderful new pictures! :)

A couple of questions:
(1) What is a "Nomarski prism" ? Is that a conversion from bright-field imaging to dark-field imaging?
(2) For very high magnification, are you using immersion-oil between the microscope objective and the sample?

Sincerely,
--Lagrangian

Clip · #151

Thanks guys!

Lag, I believe it's a way to polarize the incoming light to create contrast where there is little to none. After a quick search, Wikipedia brought this which looks like the setup I'm using. http://en.wikipedia.org/wiki/Differenti ... microscopy

And at all magnifications, everything is dry. In school we used the oil immersion technique with an older microscope, but as this one's oriented so the lenses are looking upwards and the table sits the sample upside-down on top of the lens I imagine it'd be messy if not impossible to use that method. We did get some sharp pictures that way, though.

connor · #152

Very impressive pictures, Clip!
I especially like the almost-torn-off piece of metal on the last one.

Could you possibly add some edge-on pictures of damaged/used edges, please? These should be really interesting.

Clip · #153

connor wrote:Very impressive pictures, Clip!
I especially like the almost-torn-off piece of metal on the last one.

Could you possibly add some edge-on pictures of damaged/used edges, please? These should be really interesting.

I saw some edge damage near the tip, and decided to start photographing there. From that damage, I panned in the direction of the ricasso/handle and took micros of the bad sites. That last one surprised me, I'm not sure if it tore up at the bright spot and continued left, or if that's rolled directly towards or away from the lens to make it look like it's missing. Either way, that was a bad one. I was planning on sharpening that blade tonight, but it's no trouble at all to try and get some edge-on pictures of the damage to try and get the chips/rolls from another angle. It'll probably be Wednesday though before I get another chance.

connor · #154

If the edge doesn't look spectacular enough, you could do one or two light 90° cuts :eek: into a sharpening stone. This should certainly mess it up properly for our microscopic viewing pleasure. :-)

Clip · #155

connor wrote:If the edge doesn't look spectacular enough, you could do one or two light 90° cuts :eek: into a sharpening stone. This should certainly mess it up properly for our microscopic viewing pleasure. :-)

Maybe I'll see how it handles cutting some of our 70 HRC hardfacing :)

Lagrangian · #156

Clip wrote:Thanks guys!

Lag, I believe it's a way to polarize the incoming light to create contrast where there is little to none. After a quick search, Wikipedia brought this which looks like the setup I'm using. http://en.wikipedia.org/wiki/Differenti ... microscopy

And at all magnifications, everything is dry. In school we used the oil immersion technique with an older microscope, but as this one's oriented so the lenses are looking upwards and the table sits the sample upside-down on top of the lens I imagine it'd be messy if not impossible to use that method. We did get some sharp pictures that way, though.

Hi Clip,

Thanks! :)

Sincerely,
--Lagrangian

Donut · #157

Clip wrote: 100x

Wow, these pictures are great. I think we can see the carbides! Look at the edge and how many carbides we are seeing where there is wear. The carbides are definitely helping to stop it from wearing.

Clip · #158

Donut wrote:Wow, these pictures are great. I think we can see the carbides! Look at the edge and how many carbides we are seeing where there is wear. The carbides are definitely helping to stop it from wearing.

Donut, if you're talking about those spots on the very edge fading into the background, I think those are just artifacts produced by the software as I take a multi-layer image (noticed it heavily in the 1000x and sometimes 500x images). From the chemistry, 1 C and 14 Cr, there should only be chrome carbides and they appear acicular/needle-like or hexagonal when in a properly polished sample. At those low levels of carbon and chrome, 154CM shouldn't be showing any large formations of chrome carbides. Since this isn't polished to the extent we prepare other samples I can't say for certain that those raised spots in the micros are carbides, but I believe them to be carbide-rich areas.

Here's what I typically see when I'm looking at samples, but the page said that deposit was 4.8C and 32Cr, which is a very rich deposit. We also see these results with quite a bit less of each element:

http://www.kubesalloys.com/?page_id=282

Donut · #159

Ah, okay, that sounds reasonable. Thanks.

Clip · #160

More of the 154CM Manix2! I turned my light source all the way up, took the aperture to wide-open and was able to throw enough light to get some good pictures. This is the same edge as in post 143, just from a different angle.

100x - I think this might be a different view of the last picture in post 143

200x of above

100x

200x of above

100x - decent edge

200x of above