Having been used by humans for thousands of years, copper is still widely used by industry. The addition of copper alloys, brass (copper and zinc) and bronze (copper and tin) have widened the uses for this non-ferrous metal further (see below for detail on these alloys).
The properties of copper and its alloys include high thermal conductivity, high electrical conductivity, good corrosion resistance, and high ductility.
These properties have allowed copper and its alloys to be used for heat exchangers and heating vessels, as an electrical conductor in wiring or motors, as a roofing material, for plumbing fittings, as well as for saucepans and statues.
Copper also oxidises to a green colour.
Aluminum is an important metal that is used in a wide range of applications due to its low weight and ease of machining. Despite being a relatively expensive material, aluminum is also the base metal for many alloys. Being corrosion resistant and a good conductor of heat and electricity (albeit less so than copper), as well as having good ductility and malleability, aluminum can require annealing as it becomes hard following cold working.
The light weight of aluminum makes it perfect for aerospace and automotive applications as well as for marine use in yachts. Aluminum is also found in bicycle frames, saucepans and drink cans.
Lead has been used over the centuries for a range of applications, including for bullets, in fuels and even in paint. However, it was found to be unhealthy when released into the atmosphere, while other applications also caused harm to users. Lead is the heaviest common metal and is resistant to corrosion. It also doesn’t react with many chemicals and is soft and malleable. Although many of its former uses are no longer allowed, lead is still widely used for batteries, power cables, and acid tanks.
Zinc has been used for centuries as an alloying element, particularly to alloy steel for a range of purposes as well as alloying copper to create brass.
Galvanising materials with alloying elements offers them a greater resistance to rust, affording it uses for chain-link fencing, guardrails, suspension bridges, lampposts, metal roofs, heat exchangers, and car bodies. Zinc is also used as a sacrificial anode in cathodic protection (CP) and as an anode material for batteries. Zinc oxide is also used as a white pigment in paints and to disperse heat during rubber manufacture.
Bronze has been used as a metal for centuries. Bronze is used in architecture for structural and design elements, for bearings because of its friction properties, and as phosphor bronze in musical instruments, electrical contacts, and ship propellers. It is naturally resistant to corrosion, making it a good metal to use in shipbuilding and other situations where exposure to seawater is a concern. Aluminum bronze alloy is used to make machine tools and some bearings.
Cobalt is a hard ferromagnetic, silver-white, hard, lustrous, brittle element. It is similar to iron and nickel in its physical properties. Cobalt, like iron, can be magnetized and so is used to make magnets. It is alloyed with aluminium and nickel to make particularly powerful magnets.
Other alloys of cobalt are used in jet turbines and gas turbine generators, where high-temperature strength is important.