Tuesday, August 18, 2009

Tuesday Tips Says Alloy, There, Matey!

What's an alloy? It is a combination of two metals that each enhance each others' properties. An example is stainless steel, which is a combination of iron, chromium and nickel metals. So here's some information for your Tuesday Tips on Metal Alloys and why something called "silver" might not have a bit of silver in it!

It can be confusing, talking about metal alloys.

For example, german silver, or nickel silver, which is an alloy of copper, nickel and zinc, doesn't have any silver in it, not at all. Many people who can wear silver but are allergic to nickel should avoid german silver because of its nickel content. Interestingly, musical instruments like the flute and french horn are frequently made of nickel silver.

Pure silver, or fine silver at .999 silver is what I use to create the fused silver chain links in these pictures. It's softer by nature than sterling silver (.925) which is an alloy of silver and copper. Those two metals together give the silver more strength while keeping the beautiful look of the silver metal.

Argentium sterling silver is a sterling silver alloy that replaces some of the copper with germanium, so that it is still 92.5% silver but the germanium give the silver a high resistance to tarnishing and prevents firescale during torch soldering.

Some people swear by argentium silver's properties, if they do a lot of torch soldering and don't want the firescale, or if they want their finished pieces to resist tarnishing.

You'll see lovely jewelry and charms these days made with shibuichi, which is an alloy of silver to copper that's higher in copper content. The word means "one-fourth" in japanese because the formulation of the alloy is one part silver to three parts copper. Because of the added copper, shibuichi will patina to lovely and muted shades of blue or green.

I haven't tried casting the shibuichi silver yet, but I've seen beautiful things made with it.

Many jewelry charms are made from pewter instead of sterling silver. Lead-free pewter is an alloy that's usually between 85 and 99 percent tin, with copper, antimony, bismuth and occasionally silver added in various proportions to the tin. To be a true pewter the alloy should be at least 90% tin. These days pewter is lead-free and nickel-free, and the finest quality English pewter contains at least 94% tin.

Britannia silver is an alloy of silver with 95.84% silver and the rest copper, used to replace sterling silver in England after an act of Parliament in 1697. It's a high-grade alloy of silver, even higher in silver content than sterling silver.

Britannia metal is different again from britannia silver. Britannia metal is a pewter-like alloy that doesn't contain any silver at all. It usually contains 93% tin, 5% antimony and 2% copper, and is often used as the base metal for electroplating with silver to create silver plated items like cutlery.

Brass is an alloy of copper and zinc, while bronze is an alloy of copper and tin. Each has a slightly different look because of the differing metals being used, but they have a warmer color tint than the silver alloys because of the high copper content in them.

So there you are - a list of alloys and their contents. Hope that's helpful and clears away any confusion about metals and mixtures of metals that are alloys.


SummersStudio said...

Clever title :) I can never remember all of the combinations of metals in even basic alloys. So here it is all in one tidy list. Thank you!

Narrative jewelry said...

Thank you so so much Llynn for these explanations.

I really need them, because, here in France, we have a lot of difficulties to find metal for jewelry, particularly sterling silver. And too, difficult to understand what is really this alloy, and the others of course...


Fanciful Expressions said...

Thank you for the wonderful explanations. And all in one place.I intend to print this out as a cheat sheet so when customers ask I'll have the answers at hand. I can never remember all of it.


The Joy of Nesting said...

Thanks Lynn!!!

As always Tues. Tips are always more then helpful and go straight to the Tues. Tip folder!! :)

I posted pictures of the mermaid on my blog wonder over when you have time. Sent you a couple via your email addresses :)I hope I did your incredible work at least a bit of justice!!

Pattie ;)