Metals

Metals

1. Non-ferrous

   • Are metals that do not contain iron and do not rust.
   • Examples
     • Aluminium MP is 660 degrees. Has good strength to weight ratio. Light, soft, ductile, good conductor of heat and electricity. Used for kitchenware and overhead cables.
     • Copper MP is 1083 degrees. Is malleable and ductile. Good conductor of heat and electricity. Resistant to corrosion. Used for domestic pipe work and jewellery.
     • Lead MP is 330 degrees. Very soft but heavy metal used for flashing between roofs and adjoining brickwork. It's very durable.
     • Titanium MP 1675 degrees. Has good strength to weight ratio. Lightweight. Very clean material, making it suitable for surgical applications such as hip replacements.
     • Tin MP is 232 degrees. Applications include food wrapping (foil) and coating for steel plate in manufacture of food cans. Soft, malleable, ductile and resistant to corrosion.

2. Ferrous

   • Metals that contain iron and carbon.
   • Examples
     • Iron is generally soft and ductile. So carbon is added to harden the metal.
     • Mild steel, is iron made up with <0.3% carbon. It has high ductility, low hardness and high toughness. Used for Nuts, bolts, washers, car bodies etc.
     • Medium carbon steel is made up with 0.3-0.6% of carbon. It has relatively high ductility, low hardness, an is relatively tough. Used for springs, and general gardening tools.
     • High carbon steel is made up of 0.6-1.7% has relatively low ductility, relatively hard, not very tough. Used for hand tools, chisels and plane blades.
     • Cast iron is made up of Iron and 3.5% carbon. Very low ductility, very hard, but brittle. Used for machine parts, brake discs and engines.

3. Alloys

   • An alloy is a mixture of two or more metals with the aim of enhancing particular properties.
   • Examples
     • Brass. Composition is copper and 35% zinc. Used for cast valves and taps, boat fittings and ornaments. Has good conductivity, and is easily manipulated into the desired shape.
     • Bronze. Composition is copper and 10% Tin. Uses include statues, coins and bearings. Bronze has good wearability, machinability, corrosion resistant and is ductile.
     • Nitinol. Composition is Nickel and Titanium. Smart metal used for springs, braces, glasses. Shape memory and superelasticity are main properties.
   • Benefits of alloying
     • Increases strength, hardness and ductility.
     • Enhances resistance to corrosion and oxidation.
     • Changes electrical/thermal properties.
     • Improves flow properties, producing better castings.