ESP Series
Audio files in MP3 format are available online at www.elionline.com
for MECHANICS & ELECTRONICS
Second Edition
FLASH on English
English for MECHANICS & ELECTRONICS
FLASH on English for MECHANICS & ELECTRONICS is specifically designed for students who are studying for a career in mechanics and engineering. It introduces the vocabulary and the language functions specific to this language sector, and includes practice exercises in all four skills.
Sabrina Richards Sopranzi
FLASH on
Sabrina Richards Sopranzi
ESP Series
FLASH on
English for MECHANICS & ELECTRONICS Second Edition
Downloadable MP3 Audio Files
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www.elionline.com
ESP Series
Sabrina Richards Sopranzi
FLASH on
English for MECHANICS & ELECTRONICS frontespizio
Contents Unit
1
Topic
Vocabulary
Skills
Materials
Types of materials: qualities, costs and properties Metal processes
Reading: properties of materials; basic metal processes Listening: descriptions of materials and metal processes Speaking: exchanging information about the qualities of materials Writing: a summary of the main types of materials
Properties of materials
Mechanical, thermal, electrical-magnetic and chemical properties
Reading: about properties of materials; insulators and conductors Speaking: asking and answering questions about materials properties
Technical drawing
Technical drawing tools Computer aided design system (CAD) Computer aided manufacturing program (CAM)
Reading: the basic tools of the drafter; from manual drawing to computerised drawing Listening: description of CAD/CAM systems
Machine tools
Machine tools: features and applications Computerised numerical control machines (CNC)
Reading: main features of machine tools; application of CNC machines to manufacturing processes Listening: automation of machine tools in manufacturing processes Writing: completing a table about the main features of metalworking processes
What is electricity?
Basic atomic structure Electricity and units of measurement Conductivity of materials
Reading: the atomic structure; types of current; units of measurement of electric current Listening: properties of conductors, semiconductors and insulators Writing: describing the main features of the atomic structure
Electric circuits
Circuit components Types of electric circuits Fuses and protective devices
Reading: description of the main circuit components; safety devices Listening: types of circuits Writing: describing the basic circuit components
How energy is produced
Conventional power plants Alternative power sources Electrical distribution system
Reading: types of power plants; alternative power sources Listening: different steps in the electrical distribution system Writing: completing a table about the advantages and disadvantages of alternative power sources Speaking: discussing the results of a quiz on energy saving
What is electronics?
Main electronic inventions Electronic circuits Mobile phones and radio signals
Reading: short history of the main inventions in electronics; types of electronic circuits Listening: mobile phones and radio signals Writing: describing the main advantages and disadvantages of an electronic device used everyday Speaking: exchanging information about mobile phones
pp. 4-7
2 pp. 8-11
3 pp. 12-13
4 pp. 14-17
5 pp. 18-19
6 pp. 20-21
7 pp. 22-25
8 pp. 26-28
Unit
9
Topic
Vocabulary
Skills
Telecommunications and networks
Means of transmission Ground and air transmission Main network components Network topologies
Reading: ground and air transmission; network components Listening: network topologies Writing: an article about the uses of computer networks Speaking: exchanging opinions on the use of everyday means of communication
Computer history
Terms related to the history of computers
Reading: a text about the computer evolution; about Steve Jobs Speaking: asking and answering questions about the computer evolution
Computer technology
Computer components: hardware and software USB flash drives Types of computers Internet connections
Reading: computer components; types of computers; different types of Internet connections Listening: USB flash drives Writing: a summary of the origins of the Internet Speaking: describing the features of your own computer
Automation and robotics
Automation technologies Robot applications Sensors and transducers
Reading: advantages and disadvantages of automation; applications of automation technologies; types of sensors Listening: robot applications; the optical mouse Writing: describing automation technologies Speaking: discussing the impact of automation on your life
Engines
Types of engines Types of fuel
Reading: a text about the drive train; the four-stroke and the two-stroke engines; the diesel engine Listening: a mechanic talking about the differential; the ignition process Writing: a short paragraph about the four-stroke and the two-stroke engines Speaking: a short presentation to the class; a presentation about the diesel engine
Technical assistance
Preventive and corrective maintenance Car components Auto maintenance
Reading: types of maintenance; car maintenance tasks Listening: a dialogue between a mechanic and his customer Writing: describing the features of different types of maintenance Speaking: comparing the results of a quiz about car maintenance
Health and safety at work
Health and safety regulations and objectives Safety signs and colours Safety equipment Fire safety plan
Reading: safety and welfare in the UK; safety sign categories and meanings; safety equipment Listening: safety rules and accident procedures; dialogues about safety equipment and how to prevent accidents Writing: describing health and safety regulations and objectives
pp. 29-33
10 pp. 34-35
11 pp. 36-41
12 pp. 42-45
13 pp. 46-53
14 pp. 54-57
15 pp. 58-62
p. 63 Appendix
Symbols, electrical units, conventional metric units
1 MP3 audio files downloadable from www.elionline.com
1
Materials
A mechanical engineer uses different materials to build machinery or tools. A specific knowledge of materials is required, concerning qualities, properties, costs and general characteristics.
1 What are these objects made of? Match the words in the box with the pictures, then read the text.
W
hen a machine or a tool is made, the most suitable material must be chosen by considering its properties, which can be classified as mechanical, thermal, electrical and chemical. The main types of materials used in mechanical engineering are metals, polymer materials, ceramics and composite materials. The most commonly used materials are metals, which can be divided into ferrous and non-ferrous. They can be used in their pure form or mixed with other elements. In this second case we have an alloy and it is used to improve some properties of the metals. The most commonly used ferrous metals are iron and alloys which use iron. Because iron is soft and pasty it is not suitable to be used as a structural material, so a small amount of carbon is added to it to make steel alloy. Non-ferrous metals contain little or no iron. The most common non-ferrous metals used in mechanics are copper, zinc, tin and aluminium. Some common non-ferrous alloys are brass (formed by mixing copper and zinc), bronze (formed by mixing copper and tin) and other aluminium alloys which are used in the aircraft industry. Other examples of materials used in mechanical engineering are plastic and rubber. PVC or polyvinyl chloride is a type of plastic and is used to insulate wires and cables. Rubber is a polymer and its best property is elasticity, as it returns to its original size and shape after deformation. Ceramic materials are good insulators: hard, resistant and strong, but brittle. Composite materials are made up of two or more materials combined to improve their mechanical properties. Concrete is reinforced with steel and is used in building engineering.
steel gold wood plastic glass ceramic
1
2
3
4
5
6
2
Read the text again and match the words with their definitions. 1 2 3 4 5 6 7 8
3
alloy steel PVC concrete brass ferrous materials ceramic iron
a b c d e f g h
Read the text again and answer the questions. 1 What is the basic classification of metals? 2 What are the characteristics of iron? 3 Why are alloys created?
4
a type of plastic used for insulation a combination of different metals an alloy formed by mixing iron and carbon an alloy formed by mixing copper and zinc metals containing iron a composite material used to build houses a metal not suitable as structural material a good insulator but brittle
4 Which materials are good insulators? 5 Is steel an alloy? Which metal does it contain?
1 4
1
Listen and complete the definitions with the words in the box. cooking coins alloy air copper wires steel carbon gold ferrum expensive ductile
Iron: I ts Latin name is (1) ferrum. It is magnetic and has a silvery colour. In prehistoric times it was used to make ornaments and weapons. If exposed to the (2) , it oxidises. (3) : It is one of the most widely used metals by humans. In prehistoric times it was used to make cooking utensils, (4) and ornamental objects. It is used in (5) and cables. (6) : It is the most (7) metal and is used to create precious jewellery. It is the most (8) metal. (9) : It is an (10) formed from iron and (11) . It can contain between 2.1% and 4% carbon. It is also used for (12) utensils and pans.
5
Complete the following diagram.
MATERIALS
polymer materials
plastic
ferrous
concrete
non-ferrous
alloy
6
Writing Write a summary of the texts in exercises 1 and 4 following the flow chart.
Write about the importance in engineering of having a specific knowledge of materials.
List the materials and the main groups used in mechanics.
Tell the difference between ferrous and non-ferrous metals.
Say what an alloy is and why it is used.
Write a list of non-ferrous metals and alloys.
5
1 Metal processes 2 Listen and complete the texts about the different processes metals can go through. 7
8
Put the words in the correct order to make complete sentences. 1 taking their forms / fluid substances / into moulds / solidify ________________________________________ 2 drawing / room temperature / is done at
________________________________________
3 not essential / heat / is / in the drawing process
________________________________________
4 in the past / using / forging / a hammer / was done
________________________________________
5 can be / brittle materials / extrusion / done / with
________________________________________
6 many / is used / everyday objects / sheet forming / to make ________________________________________
9 Pairwork Read the texts again and write the correct processes that produce the objects listed below. Product
6
Process
10 Read the texts again and answer the following questions. 1 Which steps are included in casting? 2 What is the mould used for?
1 wires
_____________________
2 pasta
_____________________
3 sheet
_____________________
4 bricks
_____________________
5 tubes
_____________________
7 What does rolling consist of?
6 rods and bars
_____________________
8 What materials can be used in rolling?
7 golden leaves
_____________________
8 machine parts
_____________________
9 concrete
_____________________
3 What does drawing use in order to process metals? 4 What types of drawing are there? 5 What kind of process is forging? 6 How was forging done in the past?
9 What are the advantages of extrusion? 10 What materials can be used in extrusion? 11 What kind of process is sheet metal forming? 12 What can vary in sheet metal forming?
1
MY GLOSSARY alloy \"œlOI\____________________________________ aluminium \œljU"mIni´m\_________________________ bar \bA…“r‘\_____________________________________ bent \bent\_____________________________________ blacksmith \"blœksmIT\___________________________ brass \brA…s\____________________________________ brick \brIk\_____________________________________ brittle \"brItl`\____________________________________ bronze \brÅ…nz\_________________________________ cable \"keIbl`\___________________________________ carbon \"kA…bn\__________________________________ casting \"kA…stIN\_________________________________ concrete \"kÅNkri…t\_______________________________ copper \"kÅp´“r‘\________________________________ die \daI\________________________________________ drawing \"drO…IN\________________________________ extrusion \Ik"stru…Zn\_____________________________ flat \flœt\______________________________________ hammer \"hœm´“r‘\______________________________
hollow \"hÅl´U\__________________________________ to improve \tu… Im"pru…v\__________________________ to insulate \tu… "InsjUleIt\__________________________ machinery \m´"Si…n´ri\____________________________ mould \m´Uld\__________________________________ to oxidise \tu… "ÅksIdaIz\___________________________ pipe \paIp\_____________________________________ plastic \"plœstIk\_________________________________ rod \rÅd\_______________________________________ rolling \"r´UlIN\__________________________________ rubber \"røb´“r‘\_________________________________ shape \SeIp\____________________________________ sheet \Si…t\_____________________________________ steel \sti…l\_____________________________________ tin \tIn\________________________________________ tool \tu…l\______________________________________ tube \tju…b\_____________________________________ wire \"waI´“r‘\__________________________________ zinc \zINk\_____________________________________
7
2
Properties of materials
According to the reaction of some material to the appliance of a force, there are different materials properties which are included in the following categories: mechanical, thermal, electrical-magnetic, chemical.
Mechanical properties Strength The most common mechanical property is strength, or the ability of a material to resist forces without breaking, bending, shattering or changing in any permanent way. For example: if elastic material is stretched, the change will be temporary; but it will be permanent with plastic or metal materials. When a force is applied to a material, as when a weight is put on the end of a rope, certain forces inside the rope cause it to stretch. In mechanics, the weight that is applied is called the load. The force within the rope that causes it to stretch is called the stress. The actual change, in this case the stretching, is called the strain. A material can undergo three changes due to stress. It can stretch, it can get shorter, or it may divide into layers. The stress that causes a material to stretch is called tensile stress. The stress that causes a material to get shorter is called compressive stress, while the stress that causes a material to divide into layers is called shearing stress.
STRENGTH OF MATERIALS (in pounds per square inch) Material Aluminium
Tensile
Compressive
Shearing
58,000
35,000
35,000
Brick
1,500 – 3,000
Bronze
85,000
Cast iron
60,000
Concrete Copper
8
70,000
2,000 50,000 – 70,000
Stone Wrought iron
145,000
8,000 48,000
25,000
38,000
2 Plasticity This is the ability of a material to be permanently changed in shape. For example, the plasticity of molten aluminium can be demonstrated by pouring it into a mould. Once the aluminium has cooled down, it can be removed from the mould and has a new shape. Malleability, which occurs when metals are hammered or rolled into thin sheets, is also a property associated with plasticity. Gold, for example, is one of the most malleable metals. Other common metals in order of malleability are silver, copper, aluminium, tin, zinc, and lead. Ductility, which is the ability of certain solid substances to undergo permanent changes in shape without breaking usually by stretching the length is another property. For example, a piece of copper can be stretched to make a thin wire, but the shape of a brick cannot be permanently changed except by breaking it. Ductility is a valuable property of many metals including aluminium, gold, iron, nickel, and silver. The term malleability is often used in place of ductility when describing the property of metals that allows them to be hammered into thin sheets. Elasticity This is the ability of a substance to return to its original shape or volume after it has been changed by a force. All substances have some elasticity. Some familiar uses of elasticity are the springs in vehicles and the rubber and air in balls. Hardness This is the resistance of a material to surface abrasion, scratching and indentation. The standard scale of hardness is as follows: soapstone, gypsum, chalk, fluorite, apatite, porcelain, quartz, topaz, corundum, diamond. Brittleness This is the property of a material that is hard but easily broken. Fatigue This is the ability to resist repeated stress cycles and tension.
1 Read the text and decide if the statements are true (T) or false (F). 1 2 3 4 5 6 7 8
The ability of a material to resist forces is the most common mechanical property. Strain means the weight applied to a material. A material doesn’t undergo any changes when under stress. Shearing is the stress that divides materials into layers. Aluminium is less tensile than bronze, but more than brick. Cast iron is as compressive as concrete. The ability of metals to be hammered or rolled into thin sheets is called plasticity. Diamond is the hardest and chalk is the softest.
________ ________ ________ ________ ________ ________ ________ ________
2 Match the words with their definitions. 1 2 3 4
brittleness strain plasticity hardness
a b c d
n the state of a material which is distorted by forces acting on it n resistance to cutting, indentation, abrasion n the tendency to fracture without appreciable deformation and under low stress n a property of certain materials by which deformation due to a stress is largely retained after removal of the stress
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2 Thermal properties Thermal properties describe how a material behaves when its temperature changes. Thermal conductivity, thermal expansion and melting point are among the main thermal properties. Thermal conductivity In physics, thermal conductivity is the ability of a material to conduct heat. Metals in general have high thermal conductivity, as they are able to transmit heat energy. Thermal conductivity is important in materials science, research, electronics, building insulation and related fields, especially when high operating temperatures are achieved. Cooling solutions for electronics or turbines usually use high-thermal conductivity materials such as copper, aluminium, and silver to cool down specific elements. However, applications in buildings or furnaces use low thermal conductive materials such as polystyrene and alumina for insulation purposes. Thermal expansion This is the change in dimensions that occurs with most materials as the temperature is increased or decreased. Heat causes expansion because it increases the vibrations of atoms or molecules in a material. Different materials expand by different amounts when the temperature is raised by one degree. For example: aluminium expands twice as much as iron under the same temperature increase. Melting point The temperature at which a material turns suddenly from solid to liquid. For metals the maximum operating temperature is usually around two thirds of the melting temperature.
3 Read the text and answer the questions. 1 What is the property of thermal conductivity? 2 Which materials are more able to transmit heat energy? 3 What is meant by thermal expansion?
4 Do all materials expand in the same way? 5 What happens when the temperature reaches melting point?
4 Pairwork Take turns with your partner at asking and answering questions about thermal properties. • What is heat energy? • How is energy transferred?
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• Which are main conductors of energy?
2 Electrical-magnetic and chemical properties Electrical conductivity This is the ability of a material to conduct electrical charge. All materials conduct electricity, but some materials such as rubber and glass allow so few electrons to get through that the current is hardly noticeable. These materials are called insulators. Other materials, such as metals, conduct current readily. These materials are called conductors. Metal, in general, is the best conductor, and silver, copper, gold, and aluminium are among the best metallic conductors. Electrical resistivity This is the ability of a material to resist, or oppose, the transport of electrical charge in response to an external electrical field. A chemical property is any of the properties of a material that become evident during a chemical reaction. Chemical properties can be useful to identify an unknown substance or to purify it or separate it from other substances. Resistance to chemicals This is the ability of a material to resist chemical attack and to withstand corrosion processes such as oxidation. Atomic volume This is the volume occupied by a gram-atom of an element in the solid state. Density This is the mass of material per unit volume (kg/m3).
5 Read the text and find the following information. • Difference between insulators and conductors. • Best electrical conductors.
• Properties useful to identify unknown substances. • One of the chemical properties.
6 Complete the text about insulators and conductors with the words from the box. heat wire
conductors
insulators
thermal
material
hot dangerous electricity copper
Some materials let heat pass or flow through easily and these are called (1) _________________ conductors. Other materials don’t let (2) _________________ pass or flow through them and these are called thermal insulators. Among the best (3) _________________ are carbon and most metals (especially silver and copper). Think about metal saucepans; they allow the heat from the cooker to pass through easily to heat up the water and food inside them. The best (4) _________________ include wood, cork, concrete, plastic and fabrics such as thermal vests and oven gloves. If a (5) _________________ is a good insulator then it’s a poor conductor. Heat only moves from (6) _________________ things to colder things. As well as conducting or insulating against heat, materials can also conduct or insulate against (7) _________________. As a general rule, materials that conduct heat well are also good conductors of electricity (e.g. metals such as copper, iron, steel and aluminium). Wood, plastic, glass and rubber are both thermal and electrical insulators. These are very important and have really essential uses. For example, (8) _________________ wires allow electricity to flow through them, but each (9) _________________ is covered in plastic and all are encased in plastic tubing so electricity won’t flow out and give you a shock; it’s insulated. Remember, electricity can be (10) _________________ . It can even be conducted through the sweat on your body!
7 Pairwork Take turns with your partner at asking and answering questions about electrical and magnetic properties. MY GLOSSARY brittleness /"brIt(´)ln´s/ _____________________________ conductivity/kÅndøk"tIvIti/__________________________ density /"dEnsIti/ __________________________________ ductility /døk"tIlIti/ ________________________________ elasticity /Ela"stIsIti/ _______________________________ expansion /Ik"spanS(´)n/ ____________________________ fatigue /f´"ti…g/ ____________________________________ hardness /"hA…dn´s/ ________________________________ layer /"leI´/ _______________________________________
malleability /malI´"bIlIti/ ____________________________ plasticity /pla"stIsIti/ _______________________________ resistivity /ÆrIzI"stIvIti/ _______________________________ to melt /t´ mElt/ __________________________________ to shear /t´ SI´/ ___________________________________ to shutter /t´ "Sat´/ _________________________________ to strain /t´ streIn/ _________________________________ to stretch /t´ strEtS/ ________________________________
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3 1
Technical drawing
Read the text about technical drawing and label the pictures. Technical drawing, also known as drafting, is the act and discipline of composing plans. The main purpose of technical drawing is to describe or explain all the characteristics of a product, giving all the necessary information that will help a manufacturer to produce that component. The visual image should be accurate in terms of dimensions and proportions, and should provide an overall impression of what an object is or does. It is a precise task requiring a high level of skill and suitable engineering tools. A drafter is the person who makes a drawing and who requires a wide knowledge of geometry, trigonometry and spatial comprehension, and in all cases must be precise and accurate and give great attention to detail. People who communicate with technical drawings use a visual language and technical standards that define practical symbols, perspectives and units of measurement. What are the tools and instruments used by a drafter in manual drafting? A T-square, a protractor, a compass, rulers, and triangles. Paper is also important and can be divided into layout paper, which is thin and fragile, and cartridge paper, which is heavier and more suitable for final drawings. Pencils used in drawing are graded from H to F depending on the hardness. The final drawing is made using a technical pen, graded according to the point, which must maintain the same line width. They are used with a range of stencils to add symbols, letters and patterns to the drawing. Rubbers remove pencils or pen writing when mistakes are found. Correction fluid is used to mask text errors.
1
2
6
5
2
12
4
3
Read the text again and choose the correct answer. 1 Technical drawing is needed to... A make a scale of the product. B practise pens, rulers and stencils. C let the manufacturer understand the requirements.
4 Pencils are graded according to... A hardness. B hardness and colour. C hardness and point.
2 The drafter needs... A some paper and a pencil. B a wide range of technical instruments. C the final product.
5 A technical pen... A makes regular lines. B maintains the same line width. C draws lines of the same length.
3 Paper is chosen considering... A what sort of drawing the drafter is going to make. B the pencils he/she is going to use. C the drafter’s preference.
6 When mistakes are found... A we can’t correct them. B they’re removed with correction fluid. C stencil can cover them.
3 3
3 Listen and complete the text with the words in the box. creation advantages boards drawings software defects faster instructions traditional reduce modification electronically
CAD/CAM systems Drawing (1) and manual drawing are not always precise and rapid: (2) design is usually slow, especially in its revision and (3) . For this reason manufacturing firms have replaced manual drawing with computer-aided design (CAD) to carry out functions related to design and production. This computer technology assists the designer in the (4) , modification and analysis of a physical object. Nowadays computer (5) can easily provide a three-dimensional drawing, which allows engineering designers to see how mechanical components may fit together without making models thus saving a lot of time. CAD is much (6) and more accurate than manual drawing; designs can be quickly modified, reproduced and transmitted (7) . Computer simulated analysis of the model helps experts find problems and (8) without building prototypes, in this way saving a lot of money and time. When the design is ready, the CAD system can generate the detailed (9) needed to start product manufacturing. When CAD systems are linked to manufacturing equipment controlled by computers, they form an integrated CAD/CAM system. Computer-aided manufacturing (CAM) offers significant (10) over traditional approaches by controlling manufacturing equipment with computers instead of human labour. CAM converts the design of a component into computer language and it gives (11) to the computer regarding machine operations. Thanks to CAD/CAM systems it is possible to eliminate operator errors and (12) manufacturing costs.
4
Read the text again and match each sentence with its ending. 1 2 3 4 5 6 7 8
CAD helps designers By using a CAD technology Unlike manual drawing, CAD CAD allows us to save CAD designs can be CAM is the use of computer software The CAM system turns CAD/CAM systems
a b c d e f g h
seen from any angle and are easily manipulated. to draw, modify and correct designs. the design into computer language. defects can be easily found. provides three-dimensional drawings. time and money. minimise errors and manufacturing costs. to control machine tools in the manufacturing process.
MY GLOSSARY to carry out \t´ "kœri aUt\_________________________ drafter \drA…ft´“r‘\_______________________________ drafting \"drA…ftIN\________________________________ to fit \t´ fIt\____________________________________ hardness \"hA…dnes\______________________________ point \pOInt\____________________________________ prototype \"pr´Ut´taIp\____________________________ protractor \pr´"trœkt´“r‘\__________________________
to replace \t´ rI"pleIs\_____________________________ ruler \""ru…l´“r‘\__________________________________ skill \skIl\______________________________________ technical drawing \"teknIkl "drO…IN\__________________ to save \t´ seIv\_________________________________ triangle \"traIœNgl`\_______________________________ T-square \ti…skwe´“r‘\____________________________ width \wIdT\___________________________________
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