Bronze is an alloy of copper with other metals, less commonly nonmetals. The most common name for bronze is an alloy of copper and tin. It gives the alloy hardness, resistance to abrasion and chemicals, and lowers the melting point.
Additional addition of lead increases the brittleness of bronze chips – it is useful for machining parts on metal cutting machines. Zinc is also added to bronze, which does not influence the properties of the alloy, but makes it considerably cheaper: tin is much more expensive than zinc.
There are dozens of varieties of bronze. Besides the usual tin bronzes, there are aluminum, beryllium, silicon, and phosphorus bronzes. There are bronzes with high content of magnesium, nickel, chrome, and iron. Each of them has its own special properties. For example, beryllium bronze is extremely strong.
Where do you use bronze?
Wherever parts are exposed to high mechanical stress, abrasion, and corrosive substances. Bronze is used for pipes for pumping chemically active liquids, bearing inserts, sanitary valves, propellers of marine vessels, valves, springs, and gears. If there are explosive and flammable substances somewhere in the workshop, bronze hammers and screwdrivers are used near them: they do not cause sparks.
Bronze is used to cast bells, and in the olden days, artillery pieces were made of special gun bronze.
Molten bronze fills complex shapes better than copper and steel. It has less shrinkage and does not form voids during cooling. Therefore, it is beloved by masters of artistic casting.
When and why the Bronze Age?
It took the place of the Copper Age and, in some places, bronze came directly from the Stone Age. In different places, the Bronze Age came at different times and varied in length. The oldest bronze articles are 6000 years old and have been found in Iran and Iraq.
Most likely, ancient metallurgists accidentally discovered ore containing tin besides copper. Smelting it, they unexpectedly got a new material and quickly came to appreciate its advantages.
Copper is soft and goods made of it quickly lose their sharp edges and become deformed. Bronze tools, weapons, utensils, and jewelry served better, more reliably, and longer.
Do they make bronze money now?
There are over three dozen countries that make bronze coins. These include Mexico, Singapore, Ukraine, Iran, Tanzania, Uruguay, and New Zealand. Some countries do bronze-only coating of coins or their outer ring (Canada, South Africa, Jordan, Venezuela, and others).
Bronze is a “mint” material: hard, rather light, and inexpensive. The latter makes it especially favorable for the state: its production costs are insignificant. Bronze does not need to be exported abroad, as it is neither gold nor silver. To cut weight and production costs, the coins are usually minted from aluminum bronze. Besides it is more durable, corrosion-resistant, and golden yellow.
What do you use to clean bronze pieces in the home?
You can restore the shine and brightness of bronze doorknobs, candlesticks, etc. by cleaning them with a pulp of lemon juice and baking soda or a “dough” of chicory powder mixed with water.
If the item is small or disassembled into parts, you can boil it with yellow peas for a few hours.
But experts advise simply wiping the bronze with a flannel flap with no “chemicals”. A clear darkish film on the surface of the metal will remain, but it is this that gives it the charm of antiquity.