Level 2 Certificate in Engineering Unit 202: Handout 1 202: Principles of Engineering Technology Know Requirements for Materials in Engineering Handout 1: Range of Materials Outcome: 202.1.1 – State the Range of Materials used in common Engineering Applications Materials commonly used in engineering Material grouping Group description Ferrous metals and alloys contain the element iron. Ferrous metals Steels are alloys of iron and small amounts of other elements, particularly carbon and manganese. Do not contain iron. Each metal has its own properties and uses. Non-ferrous metals In general, with the exception of copper, nonferrous metals are mixed to form alloys. Group members Low, medium and high carbon steels Stainless steel Cast iron Aluminum and aluminum alloys Copper Brass Bronze Many are corrosive resistant. Lead Thursday, 03 January 2019 Member description Versatile and widely used. Higher carbon steels are harder and can be used as cutting tools Contains high proportion of chromium to provide corrosion resistance. Used in catering to maintain hygiene standards. Contains iron and carbon. Does not need high cost refinement. Can be easily cast into complex shapes. Lightest of commonly used metals. Very good thermal & electrical conductivity. Good corrosion resistance. Mechanically weak – difficult to weld and solder. Very good thermal & electrical conductivity. Good corrosion resistance. Easy to solder and braze. Relatively strong. Used in electrical cables. Alloy of copper (60%) and zinc (40%). Corrosion resistant. Used for plumbing fittings. Alloy of copper (97%), zinc (2.5%) and tin (0.5%). Used for coins. Soft, heavy, toxic and malleable. Used in batteries due to its high resistance to corrosion by acids. Poor electrical conductivity. Used in solder with tin (60% tin & 40% lead) for electrical/electronic work. 1 Level 2 Certificate in Engineering Material grouping Group description Unit 202: Handout 1 Group members Hard & soft woods Composites Plastics materials Diverse in their make-up. Non-metallic materials They can be plastic, organic, mineral, or synthetic materials. Glass Ceramics Laminates Rubber Thursday, 03 January 2019 Member description Natural material. Soft woods used for mould patterns for casting. Hardwoods used for tool handles. Bonded components combined to gain advantages of each component’s properties. Examples: reinforced concrete, plywood, corrugated cardboard, motor vehicle belts and glass reinforced plastic. Lightweight, strong relative to weight. Good electrical insulators. Good resistance to corrosion especially acids. Two types – thermoplastics (set/reset by heating) and thermosetting (set by chemical reaction and cannot be reset). Hard, brittle, transparent solid. Used for lenses in optical instruments and spirit level vials. Very good thermal resistance. Chemically bonded metal and nonmetal combination and have a very rigid structure. Used for grinding wheel grit, cutting-tool tips and high-voltage insulators. Constructed by uniting two or more layers of material together. The layers can be made from the same or different materials. Plywood is an example of an laminate. Vehicle windscreens using laminating to improve safety in case of an accident. A natural product known for its flexibility and durability. Used for belts, tyres, ant-vibration mountings and drive couplings. 2 Level 2 Certificate in Engineering Material grouping Reinforcing materials Group description A combination of materials that if used on their own would failure to perform. Unit 202: Handout 1 Group members Glass fibres Carbon fibres Exploit combined strengths of composite materials. Thursday, 03 January 2019 Aramid Member description Can be used with plastics. Combined material is very strong and lightweight. Corrosion resistant. Used for aircraft and car bodies. Tough lightweight material. Used in aerospace, bicycles & motorbikes, sailboats, fishing rods, sports rackets, etc. Heat- resistant and strong synthetic fibres. Used in aerospace and military applications – body armor. Flame-resistant clothing and helmets. 3