Jump to content

Aiden CC

Members
  • Content Count

    445
  • Joined

  • Last visited

  • Days Won

    6

Everything posted by Aiden CC

  1. Yes, quite! I probably should change the disk on the grinder the pad on the coarse polisher, which might help a bit. Are these pictures enough to tell that I’m looking at a roughly eutectoid steel?
  2. Just mounted and polished some samples of the saw blade, and I'm pretty happy with how it came out. It's hard to see in this picture, but the iridescent surface after etching is really cool, apparently that's why it's called pearlite (I wounder if it would be possible to get a blade to look like that...). A low magnification picture showing the decarburization around the surface (I probably should've wrapped this in foil before having it in a furnace so long). That would explain why the hardness measured so low (15-18) Closer up picture of the edge showing the decarb creeping into the sample (I'm assuming the white is ferrite). This is the picture I think speaks the most. Higher magnification, near the center. From what I can see, the structure is almost exclusively pearlite with little to no ferrite. Am I correct in thinking this means the sample is close to 0.77% carbon? Maybe it's some old form of 1060/1075 steel? The only metals are Fe and Mn according to XRF analysis. Same magnification, showing carbon loss at the pearlite grain boundries. Maximum magnification showing grains of pearlite, showing that there is essentially no ferrite between the grains in the center of the sample. I'm also still debating if I should re-harden some fillet knife blanks made from this stuff. They are currently 45 HRC, which seems a little soft for a knife, but I'm not sure.
  3. Thanks guys! I did a hardness test on the pieces I heat treated, and it turned out I forgot to hit save after entering the program into the furnace, so they only got brought up to 400C. Today I re-did it and confirmed that he furnace reached a maximum of 925C with a brief soak to make sure the pieces came up to temperature. The saw blade was 45 HRC and now measures between 15 and 18 HRC. Hopefully I'll get some pictures of some samples (which I'm hoping are pearlitic) before I leave for break. I got some budget from my school which I used to buy a piece of CPM 154, I'm going to try and make some blades out of it over break and heat treat them when I get back. Turns out I can also put in work orders on the water-jet for this kind of stuff, so I designed some fillet knife blanks and got them cut last week, which I may leave as is or re-harden, depending on how hard fillet knives ought to be (they are currently 45 HRC).
  4. That's good to know. I'm not sure if I could get my hands on any of those etchants, I would have to talk with the materials/chemistry lab director. The heat tinting might work, the mounting press runs at 180C to melt the resin, so it's possible I could color the steel by heating just the surface without degrading the mounting that much. The SEM was under repair when I started this project, but now I believe it is working, so I might look into that route for composition analysis as well. My hope is that the samples I'm actually analyzing are pearlitic (which would mean that my heat treatment of them worked). Would that be any different than the spherodite to analyze? It seems like I should at least be able to determine what side of the eutectic point it is by how the micrographs look (pearlite + ferrite vs pearlite + cementite).
  5. That would make sense, hopefully I'll get to see some pearlite in the samples I normalized this afternoon, plus I care more about their carbon content, this was just a test. Processed this using imagej, using the auto-threshold after finding edges. In this image the black portion (presumably ferrite) makes up 77% of the area. Using the densities of ferrite and cementite, as well as the weight percentage of carbon in cementite, I got a percent carbon in this image of 1.05% be weight, pretty close to the actual value of 1095.
  6. Thought about it more, and these might actually be spheroidized.
  7. Del, I'm definitely not an expert, but you might consider making a test blade, then carefully cutting/polishing a section of it for viewing. All of my pictures are taken on surfaces which are fairly flat, as they are mounted in resin then lapped/polished. I got a bit more done today. I mounted and polished some samples form 1095 and 440C as they came from the mill. I also learned how to program the furnaces and ran a single annealing cycle on some of the scrap steel I'm working with (also got my waterjet work order for the saw-blade fillet knives completed, but that's for another thread). Now for the pictures. This is the 1095. Looks like pearlite. A bit closer, also looks like pearlite, but I'm no expert. Here's the 440C, I think it needs a more aggressive etchant than the 2% nitric acid in ethanol I've been using. Do you think these pictures would be good enough (at least for the 1095) to use ImageJ to calculate carbon content? I can see what look like pearlite grains, but can't really see what's going on inside them. The plan is to polish some samples from the spring (which I found with XRF to contain a bit of chromium) and saw to calculate carbon content (probably just figure out if it's hyper or hypo-eutectic).
  8. Just got these cut out on the water jet! Tested the saw hardness this morning at 45 HRC, not sure if I should re-harden them. Also, debating if I should do a primary/secondary bevel or a scandi.
  9. The plan is one piece, should be working a bit more on that this Wednesday. Also, some renders of the other design, this time with matte textures for the wood.
  10. Been a little while, but I've had this on the back of my mind. The shop here doesn't have a single good sander, but there is a very nice waterjet cutter, so I've been thinking about CAD files to get some pieces cut for this. Also have something in the works for the ferrules, more on that will probably come later. Made a 3D model of one of the designs, and tweaked it until it should (barely) float. It's hard to make a knife that's less dense than water! Next I'll probably draw up a model of the third design, and probably get both cut, maybe even a third, just since these seem fairly doable with my current setup.
  11. Yeah, that seems to be the consensus. I re-polished (forgot to take pictures before etch, but no comet tails!) and did a gentler etch since it was a bit over-etched at the tooth end. Not sure if it's anything other than an uneven etch, but there is some un-evenness where the tooth was. 2.5x closer A picture showing some of the small particles which weren't removed by the etch this time. Not sure what they are. It's hard to see in this pictures, but there are little spheres throughout which looked like carbides to me and the professor I showed the sample to. X-ray fluorescence found only iron and manganese, maybe the steel is hypereutectic and they're iron carbides. XRF can't see carbon, it looks like the best thing I can do is anneal the sample and look at the relative amount of ferrite/cementite. Might be able to make a quick python script to do it for me...
  12. This morning the materials science lab director at my college trained me on the equipment to mount, polish and polish samples as well as look at hem with an optical microscope. My firs sample was a piece of saw-blade I plan on using for fillet knives. I am completely new to interpreting micrographs, (a little later on I'm planning on meeting with a professor who is specialized more in metallurgy to take a look at the sample), and if anyone has any ideas about these, I would love to hear them. Un-etched, low magnification. I think the comet tails mean I need a better polish. The scratches definitely mean that. A closer look at the little inclusions. Same magnification after the etch. Much higher magnification with an etch, maybe this is martensite? I'll probably re-polish and etch a little later on today. Thanks for looking!
  13. If you’re very careful, you can finish bevels nicely, the key I’ve found is minimizing the amount of work you need to do with the scotchbrite (good prep), and keeping things flat. I recently discovered you can do a no-hand-sand pre-etch finish for low layer (deep etch) pattern welding. Unfortunately, I don’t have access to my grinder right now, so the scotchbrite might be done by hand.
  14. Noted. There is some design/lettering on the saw I might try and preserve, maybe a scotchbrite finishing pad or something. Might just sand down to flat though. I may look into media blasting it, though if it's too aggressive, that could make a pitted surface which would rust/get dirty.
  15. I took a little bit of time to draw up some designs, the first two inspired by Rapala knives, the third a more general design. Would love to hear what people think. One and two both have ferrules, though 1 would be a custom. I'm also debating the surface finish for the knives, I thought it might be cool to leave the original patina, though I don't want it to hold dirt. Another option would be sand-blasting to have some original finish without losing too much material. My final option would be to sand it down to a clean finish and do my typical satin knife. Here are some materials I came across recently, cork and spalter birch. I went into the woods with some friends to get the springs off an overturned car and we happened on a dead birch tree which turned out to have some very nice spalting. Will probably dry out small pieces in the microwave and seal the ends of the longer pretier ones for a propper seasoning. Also ordered some virgin cork bark to make saw/sand into slices to make a stacked handle from.
  16. Sounds like the thin filet knife is a doable project. I'll see how the original finish looks, but I'll probably end up sanding it down/using one of my coarse stones. Probably test the hardness, see if it warrants re-hardening. I'm trying to get trained on some of the mat-sci equipment, so I may try to figure out what's in the saw steel just for fun. I'll probably get a design drawn at some point.
  17. I like that thickness for kitchen knives, I've gone down to around 0.055" for my thinnest paring knife. I'm currently back at my college, which means I don't have any good grinders or general knife making equipment, however I do have the advantage of a materials science lab with a director who likes to help students with passion projects. The saw blade ought to be heat treated already, I can test the hardness at some point and see exactly what it is, if needed, I could use a proper kiln to re-harden it. I may try something like that, though I'm afraid if I remove too much material I'll end up making it too flexible. Did you do a primary and secondary bevel or just a single one? I really like very thin knives, they can do a lot. I'm worried this might be a bit too thin. I'll probably leave essentially the initial finish on the flats so I don't lose too much mass.
  18. A few weeks ago I bought some old hand saw blades (measured at 0.042" thick with my micrometer), and I was wondering if that would bee too thin to make a filet knife out of. The plan would probably be to do a small scandi grind as the stock is already so thin. I've wanted to try making a knife that floats and I figure this would be a good bade type to give that a shot, so I ordered some cork flats to do a stacked handle with. Anyways, do you all think 0.042" would be thick enough for a filet knife or should I look for some thicker stock?
  19. This seax speaks to the past with it's style based on millennia old originals as well as the wrought iron it its pattern from a 150 year old window bar. In addition to a wrought iron spine, the blade also has a central bar of twisted 15n20 and 1095 and an edge bar of W1 tool steel, sharpened to a working edge. There is also the shadow of an auto-hamon reveled by the etch. The handle is made from a beautiful piece of curly maple stained and burnished to bring out the figure. The knife comes with a leather sheath with brass fittings configured for edge up carry as it is believed may have been the case on originals. Dimensions are: -Blade: 7” (178mm) long, 1 1/4” (32mm) wide, 5/16” (8mm) thick. -Overall length: 12 3/4” Price is SOLD plus shipping, if you're interested you can send me a PM here or check it out on my Etsy shop here: https://www.etsy.com/listing/574263574/pattern-welded-broken-back-seax-knife
  20. My most recent puukko, in 80crv2 and birds-eye maple with traditional Scandinavian wedged handle construction. The blade has a rhombic cross section with a high scandi grind polished/sharpened on a surface plate to ensure flatness. I find these little blades excel at wood working, and all sorts of other tasks. The blade is held into the handle with a pair of pine wedges along with eposy to increase strength and water resistance. The knife comes with a custom fit leather sheath with a wooden blade liner and a "dangler" style belt loop. Here are the dimensions: -3” (76mm) blade-7/8” (22mm) wide -3/16” (4mm) thick spine at the thickest point- 7 1/8” (181mm) overall length Price is $120 plus shipping, if you are interested you can PM me here or find it in my Etsy shop at https://www.etsy.com/listing/588066369/hand-forged-puukko-knife-with-birdseye Thanks for looking!
  21. Coming in handy already!
  22. Thanks guys! I tried to get four months of knife making compressed into a few weeks. I also found a new polishing process I like a lot which saves some time using emery on a buffing wheel.
  23. I had about two and a half weeks of my month of winter break to make knives and I think I set a personal record. Someone got a forge set up at my school, but the grinders are pretty lacking and I won't have time for filing, so these 12 will probably be my last ones until May. Also, I discovered that taking photos of big sets of knives is fun, so there are a lot of pictures. Sorted by size By the order I made them in I sharpen the knives in the shared kitchen every month or so, but they're pretty lacking, so I made myself a kitchen set. Woods are laurel from Costa Rica and cherry from a dead tree someone had me cut down a few years ago in the middle. The knife second from the right isn't from this month, but these are all of the "gaucho" knives I made based on the ones I saw in Chile. Finally, sheaths which I spent the last few days making. Sheaths on the kitchen knives are mostly for transport, I also like this style a lot. Thanks for looking!
  24. Cleaned off the scale with an angle grinder, and did some profiling. The recurve came from the positions of the hay knife teeth, but I think it makes it look pretty wicked and mimicks the wear pattern of repeated sharpening. This is going to be a beast to grind. Also, turns out my shopvac was filled all the way to the brim with dust.
×
×
  • Create New...