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I've read that when using diamond wheels to grind ferrous metals, at high temperatures the carbon in the diamond becomes soluble in the iron thus damaging the diamond wheel.

Is it okay to use a diamond wheel to grind a non-ferrous alloy like Tantung? Is there some similar solubility issue? It's an alloy that has:

  • ~40% Cobalt
  • ~30% Chromium
  • ~15% Tungsten
  • ~4% Carbon
  • ~5% Nickel
  • ~5% Iron

So it does have a small amount of iron in it but I am not sure how big an issue this is. Nor do I know if there are solubility issues with the other elements.

I ask because I have a diamond wheel and a CBN wheel, and although CBN wheel will work, it is was more expensive and generally more useful than the diamond wheel. The diamond wheel is harder and wears less, and does not get anywhere near as much use so I want to use it when I can.

DKNguyen
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1 Answers1

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I thought I heard of everything but not this, so I did a net search. Apparently this is a new less expensive way to put tungsten carbide into a cobalt matrix. One source describes it as cobalt matrix and a few describe as a casting. Apparently nickel and iron are low because some sources do not mention them. Regular tungsten carbide tools are WC powder mixed with cobalt powder, compacted very low porosity and sintered at about 2000 F. Some WC inserts are silver soldered into tools like drill bits and saw teeth. Chrome carbide may be added. The matrix is Co, occasionally with Ni, but the total is only several per-cent ( such as 12 % max). The Co and Ni do not dissolve any carbides during sintering. The Tantung is directly cast; the Co,Ni,W,Cr and C are melted together, that gives little control of the shape and size of the WC and CrC particles. The traditional WC is ground with diamond wheels however there is essentially no iron present. I doubt very much if diamond dissolves into iron during grinding. I suspect some other factor is causing the diamond wheel wear.

blacksmith37
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