Copper-Germanium Alloy

Discussion in 'Other metal working projects' started by mrhomescientist, Jun 15, 2021.

  1. Hey all, been a while since I've visited any hobby forums. I guess alloy avenue got shut down? That's a real shame. Hopefully you guys are keeping things alive over here.

    Recently I've done a little jewelry work with argentium silver. If you're unfamiliar, it's a silver alloy with germanium that's highly tarnish-resistant. The Ge forms a protective oxide layer on the surface that prevents things from attacking the silver. I wondered if it would be possible to make a copper-germanium alloy to give Cu some of that tarnish resistance. I found a few references to CuGe and some sellers of it, but little info on its properties. Does anyone know anything about it? Would it be a tarnish-resistant copper alloy?

    Ultimately, I'd like to incorporate germanium into aluminum bronze to get a golden colored alloy that would stay nice and golden. My Cu-Al alloy attempts so far have started out looking great but darken significantly over time. Thanks all.
     
    The Desert Yeti likes this.
  2. metallab

    metallab Silver

    I don't have experience with Cu-Ge only, but I do have experience with Argentium silver and I alloyed it myself by just adding some Ge pellets from ebay to copper and silver. The alloy indeed does not tarnish due to Cu2O which is the reddish copper(I)oxide which is barely formed when a few % of Ge is alloyed.
     
  3. What were the ratios you used to make your alloy? Did you add your Ge as big chunks that melted in, or did you have to grind it down?
    I'll try pure Cu and Ge, but if that doesn't alloy well I can try to add a little silver as a "bridge".
     
  4. metallab

    metallab Silver

    I just add 1.5% Ge and 5% Cu, rest silver and melt it together.
    But I don't know whether Cu dissolves Ge without Ag, you'll have to try. Melt some Cu and add Ge in small pieces to it.
     

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