Unit 2. Materials Technology

1. The Islamic University of Gaza- Civil Engineering Department Technical English (ENGG 1305) Unit 2. Materials Technology By Husam Al-Najar

2. Outline of the unit • Describing specific materials • Categorising materials • Specifying and describing properties • Discussing quality issues 1. Describing specific materials: Exercise 1. Discuss the benefits and problems of recycling Scrapping cars A lot of metal, notably steel, can be recycled. Intact parts can be recovered and resold. Oil, brake fluid and battery acid are potential pollutants which need to be disposed of carefully. Tyres are more difficult to recycle. Recycling electronics Heavy metals such as lead, cadmium and chromium are potential pollutants and can also be recovered for recycling. The process of recycling electronic products is quite difficult due to the difficulty of breaking up and separating very small components. Breaking up ships Large amounts of steel can be recovered and recycled. Main pollutants are fuel oil from tanks and asbestos which was widely used as an insulation material inside ships. Demolishing buildings Structural steel can be recycled, concrete can be crushed and reused, for example in asphalt for road surfacing, copper in electrical wires can be recovered and recycled, good-quality bricks can sometimes be cleaned and reused. As with ships, asbestos is often found, requiring special precautions for its removal. The main difficulty is the time taken to demolish buildings meticulously.

3. Exercise 2.a. Use the following words to complete the sentences Glass Copper Aluminium Timber Rubber Plastic

4. vocabulary magnetism = force of attraction galvanised = coated with zinc (Zn) to prevent rusting recyclable= can be recycled chromium (Cr) and nickel (Ni) = metals added to steel to make stainless steel traces= small quantities scarcity= limited availability/rarity insulation= both electrical insulation and thermal insulation wire = single strand of metal scrap= waste material intended for recycling alloy= a mixture of metals sometimes containing a non-metal, for example carbon (C) in steel brass= an alloy of copper (Cu), zinc and, often, lead (Pb) bronze= an alloy of copper and tin (Sn) melting down = using heat to change the state of a substance from solid to liquid energy-intensive= using a lot of energy electrolysis= passing an electrical current through a liquid or solid in order to separate chemical compounds ore= mineral from which metal is extracted hardwood = timber from deciduous trees softwood= timber from pine trees ironmongery= collective term for small metal items commonly used in buildings, for example door handles, hinges, screws, nails

5. with from from with of of from

6. 2. Categorising materials

7. Exercise 5b. Answer the following questions. • Why do most braking systems waste energy? Because they use friction, which wastes energy as heat • What are regenerative braking systems, and how do they save energy? They recover heat and use it to power the car. • What characteristics are required of materials used for the brakes on racing cars? The ability to generate high levels of friction, and to resist the effects of friction and consequent heat. • What is meant by heat soak, and why is it a problem in racing cars? Heat from the engine being absorbed by the chassis, which can damage sensitive parts such as electronic components and plastic parts Exercise 5 c. Match the materials from the text (1-7) to description (a-g)

8. vocabulary automotive = related to vehicle design and manufacturing kinetic energy = energy in the form of movement, for example a spinning wheel deceleration = reducing speed acceleration = increasing speed asbestos = a fibrous material derived from rock that was used as an insulating material; it is no longer used as it damages the lungs if the fibres are inhaled composite = combined materials, consists of a bulk material called a matrix, reinforced with fibres or bars, for example glass-reinforced plastic = plastic matrix with glass fibres non-hazardous = not dangerous exhaust = system for evacuating smoke or gases, for example from an engine

9. 3. Specifying and describing properties Vocabulary: elasticity, toughness, abrasion resistance, thermal stability, lightweight, durable ideally, obviously, the key requirement, the last thing you want is …, a good degree of …

10. 8 abrasion resistance thermal stability durable lightweight

12. 4. Discussing quality issues

13. 14.b. True or False (T) (T) (F) It needs a protection coating (F) He says it’s fairly poor in terms of looks (F) (F) (T) (F)