An Introduction to Alloys, Part 3
Welcome back! Today we present our third and final primer on our most-used metals. We close out the series with aluminum. That’s al-YOU-min-ium for our British readers.
Unlike bronze or brass, aluminum is an honest-to-goodness element, atomic number 13, in the boron group.
There it is.
It is the third most abundant element in the earth’s crust after oxygen and silicon, but is so reactive that finding it naturally occurring in its elemental state is exceedingly rare. Instead, it is usually found in mineral ores, primarily bauxite, but there are over 250 others known that contain aluminum. Even though it is quite common, its introduction to industrial applications was much, much later than bronze or brass. In fact, it was not even produced in metal form until 1825, and until ore-extraction processes were refined in the 1880s it was more valuable than gold.
In 1884 the Washington Monument was capped with an approximately 9″ high by 5-1/2″ wide pyramid of the, at that point, extremely exotic metal. It originally cost $225, which works out to over $5500 in today’s money.
Today, the stuff is everywhere. Due to its reactivity it is almost always used in alloy form. The most common alloying metals are copper, magnesium, manganese, silicon, and zinc. Because of its light weight its used just about anywhere heaviness carries a penalty. You might find a scandium-aluminum in the skin of airplane you are flying in or the baseball bat you use for your rec league. There are multiple types of automotive aluminum alloys used in several parts of your car – from the engine block, to the frame, to the body panels. And of course there are aluminum alloys all over your kitchen from foil to cans to pans.
Yep, it’s up there too. Here at Progressive Bronze, we use it for situations requiring light weight or silver-colored applications where chrome plating won’t work. We can make just about anything from aluminum that we usually make in bronze or brass. It holds a mirror polish extremely well, and looks great in a satin/matte/brushed finish as well. We also construct our Excelsis Brand Memorial Lights (opens in a new window) of aluminum, which we also anodize. The anodizing process forms a thick layer of oxide on the surface, which increases aluminum’s corrosion resistance, and allows dyes to be introduced for color.
Hopefully we’ve enlightened you a bit about this lightweight metal. Next time you fly through the air or drive in a motorless carriage, give aluminum a little thanks for making your modern ways possible.
And as always, if you have any questions, or projects you’d like us to take a look at, send us an email.