According to my elementary metallurgy book, bronzes are mostly copper mixed with some aluminum, silicon, tin, or “some other metals”. (I think that I have some book on the history of metallugy, but don’t see it on my shelf here.) This book says that commercial copper-tin bronze has 12% or less of tin (I think they mean that if you could count the atoms, 12 out of every 100 were tin; that is number % not mass%). The wikipedia entry on copper-tin bronze says that the percentage that is tin is 40%. I don’t know why the discrepancy is so large. Wiki might be using the mass percent, but still—OK, enough of this, I don’t know what I’m talking about and it isn’t so relevant anyway…
About the orgins, wikipedia says that getting tin was the crux. They also mention that the southern part of the Korean penninsula had bronze knives around 700-600(?) BCE. Don’t know if these were knives for eating food or warfare. But I suppose that you have better info than that.
About processes, I read that copper is easy to work with because it melts at a lower temperature. But things get complicated when one mixes other elements with copper. When I was doing some experiments, I wanted a certain type of metal and found that beryllium copper was good. Turned out that it was a major hassle for the machinists though because beryllium copper is extremely hard. Now copper is super soft, as far as metals go, and the amount of beryllium in beryllium copper is only 1-2%, and yet that little bit makes the copper harder than many steels.
About the bell sound, I never really figured it out. I just found out that my first guess about that was wrong. I thought the length of the bell might determine the tone, like pipes for a church organ, but it is just not that simple…
Anyway, I hope someone else can help you out with the historical stuff. If I find that book, I’ll let you know if it has anything relevant.
Jon
