Metals

Josh Ricketts says:

There are 4 main types of metals;

Ferrous - These metals contain iron and carbon and therefore rust and can be brittle.

Non-Ferrous - As the name suggests, these metals contain no iron and corrode, not rust.

Ferrous Alloy - A ferrous alloy is a mix of metals which contain iron and carbon

Non-Ferrous Alloy - An alloy which is a mix of non-ferrous metal and contains no iron or carbon.

An alloy is a mix of metals to create and combine properties to suit the function or form. An alloy is usually to keep one property, strength for example, and get rid of another, like rust, an example of this is stainless steel.

By combining them you can change the:

-Resistance to corrosion

-Melting Point

-Colour

-Strength

-Electrical properties

-Thermal properties

-Flow of the melted metal

Rust is a huge problem when concerning ferrous metals. The metal oxidises with the air and then flakes off the metal, which exposes more metal for rusting. Another way to avoid rusting is galvanising. This covers the metal in a thin layer of more reactive zinc which corrodes rather than the iron.

Ferrous Metals

Mild Steel - Has a 0.3% carbon content and as a result is strong but rusts easily. The metal is tough and can't be hardened.

High-Carbon Steel - Is brittle but strong. The high carbon content means it is tough to impact, but easier to break. High-carbon steel can be hardened and tempered.

Cast Iron - Is hard but brittle. It has a hard skin but a soft core. Used for manhole covers and other applications which the weight of the product is not very important as cast iron is very heavy.