Brass Metalurgy

Discussion in 'General foundry chat' started by HT1, May 19, 2024.

  1. HT1

    HT1 Gold Banner Member

    for those that don't know, business is booming, I've had three reels go having serious difficulty locating enough brass to melt at a reasonable price , I paid $3.12 at a scrap yard , Alro was selling brass drops at $7/Lb(Full retail)

    I'm getting desperate

    Now for those that dont know im making ornamental pieces with no requirement other then Shiny,

    can a I get away with adding say 5% aluminum to my Scrap yellow Brass, the 5% number comes from nordic gold , I know aluminum bronzes have less then .5% zinc, does Zinc and Aluminum do something bad together?

    any input would be appreciated

    V/r HT1
  2. FishbonzWV

    FishbonzWV Silver Banner Member

    The Zamak family is mostly Zinc with Al as the alloying element. Ranges from Zamak 3 to Zamak 27.
    Don't know how it affects Cu though.
    HT1 likes this.
  3. HT1

    HT1 Gold Banner Member

    Good point and leads me to believe that Cu, Zn and Al probably all play together well.
    i'm hoping someone with more metallurgy than I will pop in with some obscure actual alloy that will really set me at ease ,

    it would also be cool if someone had metal for sale at a fair price

    V/r HT1
  4. I've heard a small amount of aluminium makes molten brass a nice, very fluid pour but causes micro porosity and that it will permanently contaminate your crucibles.....all as secondhand advice so I haven't set out to try it myself. Aluminium bronze has a few percent iron and has low machinability rating compared to brass. Aluminium bronze alloys all seem to want the zinc content below 0.5% for some reason almost as an undesirable contaminant.
  5. I had a steel pot over a gas burner melting used zinc anodes and casting ingots that assayed 1-2% iron with an XRF gun. Later while trying to alloy 3-5% aluminium to zinc I added some aluminium scrap to the molten zinc and it dissolved in quickly despite being below aluminium's melting point. Later on I was enthusiastically skimming the melt and the resulting ingots were 100% zinc on the XRF gun as the aluminium was semi solid at molten zinc temps and floated. I later found an old article where researchers were removing iron from zinc as an undesirable contaminant using aluminium which floated to the surface and took the iron with it. Iron prevent anodes from working well as it passivates the zinc surface.

    Of course at brass temps keeping aluminium in solution won't be a problem.
  6. Jammer

    Jammer Silver Banner Member

    List of copper alloys - Wikipedia
    This has 4 different Manganese Bronze alloys that have Zinc, Aluminum, Manganese and some Iron. The lower Copper amount may make it less expensive. I have several pounds of Mn if you need any to play with. Send me a PM if you want. You may try to contact Lou, he comes around sometimes. He had a bunch of an Everdur alloy that casts great and is a beautiful gold color. Are you getting plumbing fittings, Red Brass from the scrap yards? I think you would be lucky to find any brass for less than $5 a pound. Scrap is crazy right now.
    HT1 likes this.
  7. HT1

    HT1 Gold Banner Member

    I worked professionally in several scrap yards, so I can get Proper prices, i Just paid $3.12/ Lb for Yellow brass, no more then 5% fe

    From what your showing me, I can probably add 5% Al to Brass By weight safely which given the twos densities would increase my volume 15 % ... Im very tempted
  8. I asked again about aluminium in brass and my friend Peter said he was taught to add small amounts of aluminium to brass to increase fluidity by an old timer who did it all the time. Peter said the professionals were horrified at the idea and just told him any fittings made from it wouldn't be pressure tight. He drilled a chunk of brass runner with aluminium in it and filled it with oil and overnight the oil had leaked out. So you should be fine making ornamental items from it it may even be more tarnish resistant.
    HT1 likes this.
  9. HT1

    HT1 Gold Banner Member

    so it creates microsporocyte, which is why lead was added to "red brasses" it fills spaces in the lattice making the material watertight, this si also a reason thinner material is often more watertight, thick material has a larger space lattice so if you make a chunky part and then machine it, it may weep liquads, this can be overcome with a little lead in the alloy, or if after the fact by peening the part

    Thank you

    V/r HT1

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