Francis Gastellu Posted March 3, 2021 Share Posted March 3, 2021 (edited) Hey everyone! I thought I would share my latest failure, because ... well because there's always something to learn from failure. Besides, I'm still somewhat pleased about this blade, and I wanted to share. This all started when I decided to slice a piece of Campo Del Cielo meteorite, a fairly common iron-nickel meteorite, with your typical widmanstatten and neumann bands, kamacite, taenite, plessite, and the odd troilite inclusion (Group I: 6.68% Ni, 0.43% Co, 0.25% P, 87 ppm Ga, 407 ppm Ge, 3.6 ppm Ir) Cutting that ended up ruining a bandsaw blade by the way, but ultimately I ended up with a couple of flat pieces that I could integrate into a larger billet. Here comes my first mistake in this project. From left/right to center: 15n20 (1/4"), meteorite (~1/4"), wrought iron (~1/2"), 15n20 (1/16th), 1095(1/4" x 2). Let's skip why I would use so many different materials in the first place (let's say i'm experimenting) and move on to forge welding. This billet will be drawn out and cut in two halves. Each half will be twisted (one clockwise and one counter clockwise) and then flattened to eventually serve as a san mai cladding layer. Did you catch the issue? Why on earth would I put the most valuable material, the meteorite, near the *outside* of a twist? Spoilers: by the end of this build, there will not be much meteorite left on this blade, and most of it will be invisible. We're getting ahead of ourselves tho, let's catch up... we're forge welding. ... and drawing ... and cutting the billet in halves ... and having a peak, because we can't resist. We never can. I wasn't sure exactly what of the meteorite's visible features would survive the forge welding heats. I knew that the widmanstatten bands wouldn't but I was hoping for ... something. I wasn't disappointed. What looks like little fractures here are actually taenite crystals, which are found at the meteorite's grain boundary. They survived! At that point I'm ecstatic, this is going to look awesome right?! (spoiler: these will basically disappear). But for now, we're twisting. And flattening the twisted bars... (yes, I had a peek at the pattern again) Ok, I'm about to make my second really dumb mistake. Here I have a 1/4" piece of 1095 to serve as the blade's core, and a couple of pieces of thin 15n20 (1/16") to serve as a contrasting layer (and maybe to limit carbon migration? who knows). Except these aren't 15n20, they're actually 1095, which I'm only going to find out once I etch the final blade. I'm literally about to forge weld 1095 to itself for no good reason. Whoohoo! This is the resulting san mai billet (ok, technically this is 5 layers, not 3... I'm sure there is a name for that... then again do those 3 x 1095 layers really count as 3? and what is the meaning of life?) We're ready to forge the blade proper. Cleaning up the forge scales... Shaping... More shaping... Heat treating... This is where I'm going to lose some of you I'm sure. No clay, no differential heat treatment, no water quench, just a simple Parks 50 quench. Once you see the blade I think you'll agree there would have been no point in attempting a hamon: no room for it, and a blade that's way too busy already. After cleanup, polishing and etching. This is as-etched out of the ferric chloride tank, before cleaning up any oxides. Notice the lack of a contrasting layer next to the 1095 core? Yep, those "contrasting layers" were not 15n20, they were 1095, and they're indistinguishable from the core (save for a very faint weld line). I can't believe I picked up the wrong steel... I really suck. And here you can see the consequences of my very first mistake in this project. After so much profiling and sanding, and because the meteorite was on the outside of the twisted billets, there are very few areas where the meteorite is still visible: The irony is there is plenty more meteorite left than in these spots, but most of it sits right between the cladding and the core... And... as you can see, the taenite has been thinned out to oblivion, too It is still visible under the microscope, tho: Now for the mistake that really sealed this blade's fate: Yep, these are two very visible delaminations between the core and the cladding (and more of them on the tang). What happened is that I ran out of propane pressure during this forge weld, and I lost temperature at the worst possible moment. I worked as fast as I could and I thought I got away with it, but I didn't. At this point I'm heartbroken I pick myself up, telling myself that I made other mistakes anyway and this is really good practice for the next blade, so I decide to finish it anyway. The original plan, because of the meteorite, had been to inlay "Star Iron" in gold on the tang. Instead, I go for "Shimatta" in copper ("damn it" in Japanese). This was a really fun project. I feel silly for making so many mistakes (including some I have not mentioned here) that should have been easy to avoid, but I learned my lessons: - In a twisted billet, put the interesting material near the center - make sure to use the steel you mean to (duh) - make sure there is enough propane for forge welding, when in doubt, assume there isn't. I will eventually do another one of these, hopefully without the above issues. In the meantime, this will hang on the mistake wall as a reminder that I should really think before I act. Cheers! Edited March 3, 2021 by Francis Gastellu 8 Link to comment Share on other sites More sharing options...
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