Materials Technology

Properties of Materials

Overview – Properties of Materials

OPTIONThe student will learn about…Grouping of materials according to properties of electrical and thermal conductivity, thermal expansion, optical, magnetic and mechanical properties

It is the arrangement of atoms within a material that greatly influences that materials behaviour and it’s properties

•Hardness•Ductility•Malleability•Conductivity•Thermal expansion•Optical properties•Magnetic properties•Melting point, etc.

Why would I need to know the properties of a material?

Overview – Properties of Materials

Materials listed in order of hardness:

•Diamond•Cubic boron nitride (ceramic)•Carbides•Hardened steels•Cast irons•Copper•Acrylic•Aluminium•Lead

Diamond’s are very hard. I wonder what else could I use them for besides jewellery?

Overview – Properties of Materials

Materials listed in order of ductility

•Gold•Silver•Aluminium•Copper•Steel

What property of a material is Ductility?

Overview – Properties of Materials

Materials listed in order of malleability

•Gold•Silver•Aluminium•Copper•Tin•Lead•Steel

What material are soft drink cans made from? Why is this material used for the can?

Overview – Properties of Materials

Materials listed in order of tensile strength

•Steel•Copper•Aluminium•Zinc•Lead

What material is used here to support the bridge & why?

Overview – Properties of Materials

Materials listed in order of electrical conductivity

CopperCobaltIronZincAluminumTitaniumMagnesium

GoldLeadPlatinumMercuryTinSilverNickelSilicon

What material is used in Electrical Wiring. Why is gold or lead not used in electrical wiring?

Overview – Properties of Materials

Materials in order of thermal conductivitySilverCopperGoldAluminumMagnesiumSiliconZincCobaltNickelIronPlatinumTinLeadTitaniumMercury

Overview – Properties of Materials

Overview – Testing Materials

Materials in order of magnetic properties

While most materials can be influenced in some way by a magnetic field, Iron, Nickel and Cobalt are thousands of times more susceptible than other materials

•Iron

•Nickel

•Cobalt

Compounds containing these elements are also magnetic

Selection of Materials

•Why are electrical wires generally made from copper?•Why are airplane bodies usually made from aluminium or composites?

•Why are cookware handles generally made from wood or plastic?•What properties make ash a suitable material for hurleys?

Selection of Materials

•Physical Properties•In answering the previous questions we have seen that the physical properties of a material have a large part to play in its selection for a particular application.

•Hardness, ductility, density, conductivity, melting point,

•cost of raw material, suitability for recycling, ease of manufacture, etc.