What are the 4 main categories of materials?

• Polymers, composites, ceramics, metals

• Polymers, alloys, ceramics, metals

• Polymers, composites, alloys, metals

• Polymers, composites, ceramics, alloys

Why are metals different from plastics?

• Metals have covalent bonds, while plastics have metallic bonds.

• Metals are formed by small monomers, while plastics have a crystalline structure.

• Metals are chemically bonded, while plastics have free electrons.

• Metals have a crystalline structure, while plastics are formed by small monomers.

Which materials are used in micro engineering?

• micro processors

• Ceramics such as concrete and metals such as wrought steel

• Polymers and composites such as GRP, CFC

• Composites such as wood and metals such as wrought iron

Which materials are used in aviation engineering?

• Ceramics such as concrete

• Composites such as carbon fibre and lightweight metals

• Polymers such as plastics

• Mild steel

What types of bonds are in plastics?

• Hydrogen bonds

• Metallic bonds

• Ionic bonds

• Close compound bonds - molecular and covalent bonds

What types of bonds are in ceramics?

• Covalent and ionic bonds

• Metallic bonds

• Close compound bonds

• Hydrogen bonds

What is it called if carbon fibres are used instead of glass in polyester?

• Carbon compounds (CC)

• Glass reinforced fibre (GFR)

• Carbon fibre reinforced plastics (CFRP)

• Polyester fibre

What is the most common material used in car bumpers now?

• Carbon fibre

• Stainless steel

• Mild steel

• Polypropylene and ABS

Why are polypropylene and ABS used in car bumpers?

• cheaper than most metals, easily formed, malleable, ductile

• Heavier than most metals, difficult to form, expensive

• Tougher than most metals, easily formed, lightweight, non-oxiding

• heat insulating, weatherproof

What are cermets?

• Compounds of ceramic particles bonded with a metallic matrix.

• Compounds of metallic particles bonded with a ceramic matrix.

• Compounds of plastic particles bonded with a metallic matrix.

• Compounds of ceramic particles bonded with a plastic matrix.