Casting aluminum bronze C95400

Discussion in 'Sand Casting' started by Tobho Mott, Aug 29, 2017.

  1. Tobho Mott

    Tobho Mott Gold Banner Member

    Thanks! Hoping to get it sanded, sharpened, and hardened by the weekend so I can chuck it at some jack-o'lanterns before they rot. :D

    Jeff
     
  2. I was talking to a guy today about cast bronze axes: he said they made some out of aluminium bronze and used Stellite hardfacing rod to build up an edge with oxy acetylene. There are many Stellite alloys and Stellite 1 is cobalt-chrome with a Rockwell C hardness of 51-56 which is the same as hardened steel hammers.

    Edit: On Ebay there's a range of conventional stick welding rods of various metals up to the high Rockwell C 60's..... probably fun to grind an edge on too.
     
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  3. Tobho Mott

    Tobho Mott Gold Banner Member

    Oh, that sounds really cool! One day I will learn how to do stuff like that. So far I have only done fluxcore welding, and that only just barely enough to build my furnace, its cart, and a few foundry tools.

    Jeff
     
  4. I have a love-hate relationship going with stick welding......It might be possible to do some trade with a welding guy: swap a bronze axe head for a hard facing job on another axe casting.
     
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  5. Tobho Mott

    Tobho Mott Gold Banner Member

    Good idea, I will have to look into that. You say that stuff can be stick welded to al-bronze, that is pretty cool. Does it have to be heat treated to get that hardness? I'm not sure how that would work. Haven't even figured out how to heat treat the bronze itself yet, I just know I've read that it is possible.

    Jeff
     
  6. He mentioned gas welding the stellite rod to the aluminum bronze. I'd be surprised if you could stick weld it. I hope I'm surprised.
     
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  7. There's flux cored MIG wire with a Rockwell C of 50: http://www.weldwire.net/wp-content/uploads/2013/08/ERCCoCr-C_Cobalt-1-Flux-Cored.pdf

    Here's the stick rod from the same people: http://www.weldwire.net/wp-content/uploads/2013/08/ECoCr-C_Cobalt-1-Coated-Electrode.pdf

    This is the TIG datasheet: http://www.weldwire.net/wp-content/uploads/2013/08/ERCoCr-C_Cobalt-1-Bare-Wire.pdf
    it has a Rockwell C hardness of 54. I'm surprised that you can obtain the hardfacing alloy in all three forms although it makes sense when you consider it's end use of repairing machinery wear.
    I'm certainly going to keep an eye out for the stuff to buy on the cheap. Over on Ebay there was also a tungsten carbide based stick rod too.


    I understand there's no need for heat treating, there's also a high carbon content so you get chrome and cobalt carbides forming which impart the hardness and wear resistance to the material.
     
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  8. Tobho Mott

    Tobho Mott Gold Banner Member

    Shows how much I know about welding... Sorry for the misunderstanding.

    I got some more work done on the pipe-hawk over the weekend.

    Before:

    20181031_071154-1040x780.jpg

    After sanding to 150 grit, sharpening, and peening to work harden the edge:

    20181104_121945_HDR-1040x780.jpg

    Still plan to show it a series of finer grits before I call it done.

    I tested it out a bit. Chopped down a small maple, threw it at a wooden target enough times to badly crack one of my handles, then kept throwing it at some left over pumpkins.

    I don't think YouTube would allow a video of all this to be published if no fruit was sacrificed. I will have to hide the footage of the real testing in among the pumpkin smashing nonsense using clever editing. Maybe it'll go viral if I can trick people into believing I am making something that is only good for hanging on a wall to look at. It's too bad I didn't think of casting it in beer can aluminum until it was too late... :rolleyes:

    Anyhow, the edge held up perfectly, here is a pic from after the chopping and throwing:

    20181104_122107_HDR_crop_276x428.jpg

    The flashing around the bowl was a real PITA to file off. Still isn't perfect, but maybe good enough... I still want to take a Dremel to the inner lip of the bowl to round off the edge, it's a little sharp there from grinding off the flashing.

    20181104_122333_crop_420x763.jpg

    Uh-oh, I was not supposed to be starting a collection...

    20181104_122206_HDR-1040x780.jpg

    Jeff
     
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  9. Tobho Mott

    Tobho Mott Gold Banner Member

    Just saw Mark's last post after submitting mine above. Great info, thanks Mark! Think my 80A fluxcore welder can make that first option work? Never would have thought that possible. What about with other bronzes? I also have some Everdur...

    Jeff
     
  10. I have a fluxcore MIG but mostly use the stick welder as it lays the material down fast, but based on my stick experiences (316, Nickel) these alloys seem to use lower currents as their thermal conductivity is lower so the heat can't escape fast. I use 1/8" rods of 316 stainless in my small welder at currents more suited to thinner mild steel rods and I expect the exotic alloys would have similar poor thermal conduction.

    If I had a choice of welder types, I'd opt for a TIG to aim for a consistent deposit, stick and MIG can be erratic in my hands. Stick rods for hardfacing would be a lot more common on Ebay and Craigslist as they'd be used in the field to repair earthmoving machinery.
     
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  11. Tobho Mott

    Tobho Mott Gold Banner Member

    Hmmm. I'm currently limited to my little fluxcore machine, but I may ask around to see what some other guys in the area are using... Thanks.

    Jeff
     
  12. There'd have to be a welder who'd trade some beer or maybe barter a second axe head in exchange for a stellite hardfaced edge on your axe.
     
  13. Maybe I should clarify my statement. I will be really surprised if you can stick or MIG weld a hard surface alloy onto a copper based alloy. That's why we use copper backing plates where we don't want carbon steel rod to stick. I've welded lot's of hard surfacing but only on carbon steels. Most of them won't even stick to cast iron. And I am surprised you can TIG weld it but I don't doubt that, just surprised. TIG welding it would be a challenge because the rod will melt at such a much higher temperature than the aluminum bronze.
     
  14. I re-read your earlier post (in the morning) and fully comprehended it this time round.....:oops:. I really thought the aluminium bronze would be a lot more thermally conductive which would make it harder to stick as the heat would get sucked away. I had a look for aluminium brass thermal conductivity: https://www.engineeringtoolbox.com/thermal-conductivity-metals-d_858.html and according to that chart, aluminium bronze is 20% of the thermal conductivity of pure copper and close to cobalt and chrome. This is a lot different to what I expected, I would have thought it'd be close to copper. Jeff may have a fighting chance of stick welding it after all. I'll see if I can scare up some welding rods at this end and run the experiment with a big stick welder.

    There's still going to be the melting point difference you mentioned so it will be a tricky proposition.
     
    Last edited: Nov 5, 2018
  15. PatJ

    PatJ Silver

    Jeff-

    You may have to change your screen name to "Thor Mott".
    Edit: Or maybe Thor was the hammer guy, but seems like about the same thing.
     
  16. Tobho Mott

    Tobho Mott Gold Banner Member

    Blame Odin-Duck's pipe hawk thread on AA! That's what really got me going on this project. :D

    Edit - there is video...


    Jeff
     
    Last edited: Nov 21, 2018
  17. Tobho Mott

    Tobho Mott Gold Banner Member

    That last post should have read OddDuck, not Odin-Duck, lol. Too late to edit it now... Blame autocorrupt.

    I made another axe but forgot to update this thread...

    You may have seen this video before in the oversized Moya burner thread. Shows the molding and casting. Nothing much new there except the burner, but I don't think I ever posted the pictures:



    The weird little divots on the casting turned out to be caused by lumps of parting dust I failed to remove. D'oh! Lesson learned.

    I did the peening all over on this one, not just the edge. Also tried a liver of sulphur patina, but being an oxidation resistant alloy it fought me a bit as I suspected it might. But it did seem to work a little bit. I did all this because the guy I made it for really just wanted a wall hanger. I was aiming for 'functional in theory, but hopefully too pretty to use'.

    Pictures of the finished axe. Oh, actually not quite... Just realized I had not wedged in the handle yet when I took these. Almost finished:

    20191008_170828_copy_585x1040_1.jpg

    20191008_170815_HDR_copy_1040x585.jpg

    20191008_170739_HDR_copy_1040x585.jpg

    20191008_170414_copy_585x1040.jpg

    Now I have another friend who says he thinks he might want one too... :D

    Jeff
     
    Last edited: Aug 27, 2020
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  18. Jason

    Jason Gold

    Nice Axe!! I want one.. j/k...:p I know how much work goes into them. You need to stick the next one up on fleabay with a link to the video. $1000.00
     
  19. Tobho Mott

    Tobho Mott Gold Banner Member

    o_O
    I felt guilty about charging the "good friend for many years" price for the wall hanger above, and that was less than 1/3 of what you suggest.

    Can I get an independent sanity check on that number?

    Jeff
     
  20. rocco

    rocco Silver

    That is one damned pretty ax, well done!!
     

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