In UNIT 2aao

Describing specifi c materiatsCategorising materialsSpecifoing and describingpropertiesDiscussing quatityr issues

ln pairs, discuss the benefits and problems ofrecycling. Use the following examples and your own ideas.

breaking up ships demol.ishing buitdings recycling electronics scrapping cars

Read the following web page and complete the missing headings using thewords in the box.

Aluminium Copper Gtass Plastic Rubber 5tecl Timber

T

- Describing specific materiats

2a

1 ííE c Y c L AB LE Li!ÁÍ E Rl ALst Sfeel Scrap can be sorted easily using magnetism. lf the metal is galvanised (coated

with zinc) the zinc is Íu||y recyc|ab|e' |Í it is stain|ess stee|, other meta|s mixed with the iron,such as chromium and nickel, can also be recovered and recycled. rE

2 - Soding is critical, as there are key differences between the clear and colouredmaterial used in bottles and Jars, and the high-grade material used in engineeringapplications, which contains traces of metals. y

3 - Scarcity makes recyc|ing especia|ly desirab|e, and justiÍies the cost of removing insulationÍrom e|ectric wires, which are a major source of scrap. Pure meta| can also berecovered from alloys derived from it, notably brass (which also contains quantities of zinc,and often lead) and bronze (which contains tin). t-

4 - The cost of melting down existing metal is significantly cheaper than theenergy-intensive process of electrolysis, which is required to extract new metal from ore. rE

5 - Hardwood and softwood can be reused, However, the frequent need toremove ironmongery and saw or plane off damaged edges, can make the process costly. y

6 - Tyres are the primary source oÍ recyc|ab|e materia|. These can be reused who|ein certain applications. They can also be ground into crumbs which have varied uses. y

7 - An obstacle to recycling is the need to son waste carefully. While some typescan be melted down for reuse, many cannot, or result in low-grade material. y

7 4 Unit 2 Materiats technology

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Match the materials from the web page (l-8) in Exercise 2 to thedefinitions (a-h).

1 stainless steet.,'' a a metal used to make brass, and in galvanised coatings on steel2 zinc I b the predominant metal in steel3 iron \c a \rpe of steel not needing a protective coating, as it doesn't rust4 bronze5 lead6 hardwood7 ore8 softwood

d a dense, poisonous metale rocks from which metals can be extractedf an a[[oy made from copper and ting timber from pine treesh timber from deciduous trees

Compf ete the following sentences using from, with or of .

I Bronze contains significant amounts o{ copper.2 Calvanised steel is steel coated -zinc.3 Steel is an alloy derived - iron.4 Pure metals can usually be recovered - alloys.5 To produce stainless steel, iron is mixed other metals.6 Stainless steel contains quantities chromium and nickel.7 Glass tableware contains traces - metals, such as lead.8 When new metal is extracted ore, the costs can be high.

ln pairs, ask and answer questions about different materials using thefollowing phrases.

3 a lrina, an ecological adviser, istalking to a group of engineerson a training course aboutenvironmentally friendly design.ln pairs, discuss the ideasfrom her slide and give someexamples.

ApplicationI electrical wires in vehicles2 external walls in houses

)z.t Listen to an extract from the talk and compare yourideas with what lrina says. What example does she use toil lustrate her main point?

)z.z lrina asks the engineers to do a simplifiedenvironmental audit. Their task is to compare steel andaluminium car bodywork from an ecological perspective.Listen to Sophia and Pete, two of the engineers, discussingthe topic and make notes of their ideas.

ln pairs, do an environmental audit for the followingapplications and materials. Use the words and phrases inthe box.

Materialscopper and aluminiumbricks and softwood

as far as I know ... I think so / I'd say so I'm (not) surethats an important consideration that needs to be researchedcoated derived mixed recovered recycled

- Categorising materials

5a

b

deceíeration. and stores it as asource of power for subsequentacceleration.

Regenerative brakes limitthe energy loss inherent intraditional braking systems. Inmost vehicles. conventionalbrakes comprise padspreviously made from asbestos-based composites, but nowconsisting of compounds*of exotic. non-hazardous

4 ceramics5 al.Loy6 non-metallic7 polymers

What do you know about braking systems? In pairs, discuss the followingquestions.

I Cenerally speaking, what do brakes do and how do they work?2 What kinds of material are used in brake pads and brake discs in different

vehicles?

Read the article on braking systems. In the title of the article, what do thecolours green and red refer to?

In pairs, answer the following questions.

I Why do most braking systems waste energy?2 What are regenerative braking systems, and how do they save energy?3 What characteristics are required of materials used for the brakes on racing cars?4 What is meant by heat soak, and why is it a problem in racing cars?

GREEN BrÜAKEs- A RED HOT TOPIC IN MOTOR RACINGAs motor racing goes green, materials, and discs made ofFormula I is aiming to lead feÜous metal. The resultingautomotive research in finding friction generates heat, whichhi-tech efficiency gains. One is wasted. In performance cars,of the keys to this ecological this phenomenon is takendrive is regenerative braking to extremes, and due to the(also known as kinetic energy high temperatures generated,recovery), which recovers brake discs are often made outenergy generated during of ceramics.

The carbon discs and pads usedon Formula I cars generateso much heat that they glowred hot. High temperaturesare, in fact, necessary for theeffective operation of carbonbrakes. But there3 still plentyof potential for recovering thekinetic energy, rather thanmere|y dissípating it ín theform of heat.

The potential for recoveringenergy also extends to theheat generated by enginesand exhaust systems. Thisarea has also been discussedas a oossible area for futureexploitation in motor racing.Heat recovery might offer theadded benefit of reducingheat soak ítherma| absorptionby the chassisf as delicatealloy parts and sensitive non-metallic materials, such aspolymers, are susceptible toheat damage.

C Match the materiats from the text ( l-7) to the descriptions (a-g).

1 compounds 1 a materials that are not metal2 exotic \ U iron and steel\3 ferrous \ g combinations of materials

d mixture of metalse plastic materialsf minerals transformed by heatg rare or complex

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1 6 Unit 2 Materials technology

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ln pairs, take turns to describe an object using the words from Exercise 5cand the phrases in the box. Ask your partner to guess what it is.

comprise consist of made from made of made out of

6 a You are going to give a talk on composites technology at a constructionmaterials trade fair. In part of the talk, you focus on reinforced concreteas a well-known example of a composite material. Prepare your talk usingwords and phrases from this section and the following notes.

hmposite materials(ammon etample: reinforced concrete (very widely used composite)

Lement (derived fron lime)

ftgregate - f:i:r:fgrrg"te (und) + clarse aggregate (qravel or crushed

Water + chemical additives (e.9. plasticiser to improve w1rk^bility)

kinforcement (steel barq fixed together with steel tie wirQ

ln small groups, take turns to give your talk.

Margit, a sales engineer, is describing ahigh-voltage cable. Before you listen, labelthe cross-section with the parts (a-e).

a insulat ionb wateroroof membranec outer jacketd armoured protection 2e conductor

)z3 tisten to the description andcheck your answers in Exercise 6c.

Match the parts of the cable (a-e) inExercise 6c to the following categories ofmaterials (l -5). You will need to use some parts more than once.

non-metall ic at 4 non-ferrous metal

b

c

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metall icferrous metal -

5 polymer-based

Imagine you are presenting a product or appliance you know well to apotential client. Describe the categories of material used to make thedifferent parts.

Unit 2 Materiats technology t7

I Specifying and describing properties8a

b

9a

In pairs, discuss what you know about the properties of Kevlar@ and how itis used.

Read the following extract from DuPont'"'s technical guide to Kevlar@.Compare the information with your ideas from Exercise 8a.

\^/HAT IS KEVLAR,@?DtrPontÍl'1 KEVLAB@ is an orgarric fiberin the arornaiic polyanride fanri{y. Thelunique propert ies and dist inct chemicalCo|-1pos|Llon ot KEVLÁRe dist ingtr isnit Írom other cot-,rtllercia]' tllan nladeÍibers '

KEVLAR@ has a unique conrbinationof l ' rrgh nroduius, toughness, abrasionresrstance ar 'cr I lrernral stabi l ty. l t r ,vasdeveloped for der-nanciing industrialar ld advanced-technology applrcat ions.Currently. rrany types of KEVLAR@ areprocluced to rrreeT a oroad r irnge of enduses that require strong, l tghtwerght.c lt i rable rrater ia ls.

DuPont" and Kevtar@ are registered trademarks or trademarks of E.I.du Pont de Nemours Company or its affit iates

Find words in the text in Exercise 8b to match the following definitions.

1 foraghness : the opposite of fragil ity2 - : resistance to damage caused by friction3 - : r e S | S t a n c e t o p r o b l e m s c a u s e d b y t e m p e r a t u r e c h a n g e4 - : l ong - l a s t i ng5 - : the opposite of heavy

Match the automotive parts (l -5) to the descriptions (a-e).

t drive belts a sheets inserted between parts to prevent gas or fluid leakage2 brake pads b pneumatic envelopes in contact with the road surface3 tyres c flexible bands used in transmission systems4 sealing gaskets d protective barriers capable of resisting gunshots5 butlet-resistant armour e pads pressed against discs to induce deceteration

Read the information from DuPont'u on the following page explaining someof the automotive applications of Kevlar@. Complete the text using theautomotive parts in Exercise 9a.

Copyright DuPont de Nemours

18 Unit 2 Materiats technology

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Car and trr-rck (1) - have rncorporatedKevlar@ into their construction because it offers<r r no r l _ r n r r t a i r r r a eh r r c r n 'J u f r c v p u l l v ( u o . o u l o o l u l O r U l H O l ' g ) l ) i O l ! 8 ,

The hrgh |nodUIUS anc j abÍaS|o l l res|Sta l l ce o fKevlar@ help (2) retain their or ginalc ,h:np an. l lp r rc rnn n\/Ar lhe tT l r l l rgpt Ot

revolrrt,crrts tlteu no througn over lhe l itespan o{a venrcte.

The frictiona| Íorces that (3) - are designedto endure take less of a to l l orr t l \ose n 'dde wrt i rKerrlar@ pulp. The enhanced thernral stabil ityand inherent abrasion resistance of KevlariS

allolv thern to last loi 'rg and stop the rrelriclesaÍe|y and qrtietly.

Kev|ar@ provides an eÍÍectlrle' 1ightweight(4) - solutiorr for r. 'ehrcies that requrreprotection agains{ ball istic attack. allowing carsand light trucks to retain most of their originalhandiing characteristics.

Chernrc.r l s ta i l i i i t \ a1o l l re! !a ' s laD, l ' i ) re iomake (5) reinÍorced with Keviar@ pulpstrong ancj durable. The gaivanic corrosionresrstance of Kevlar'@ also contributes toirnproved iong ternr engrne perfonrance.

ln pairs, discuss why the properties of Kevlar@ are especially important foreach application described in the text.

)Z.q Listen to a conversation about the properties of materials used in aspecific type of tool and answer the following questions.

1 Where does the conversation take place?2 What tool is being discussed?3 Which materials can be used for its different oarts?

Complete the following extracts from the conversation using the propertiesin Exercise 8c. Listen again and check your answers.

1 The handle mustn't be heavy. ldeallg, Aou wont it to be2 Resisting friction is essential. The keg requirementis -5 The bur has to be built to last. Obviouslg, theg need to be verg4 Heat builds up in the bur. You need o good degree of -

Match the words and phrases ( | -5) from Exercise | 0b to the synonyms(a-e).

1 ideal.ty2 obviously3 the last thing you want4 the key requirement5 a good degree of

a iís clear thatb for the best resultsc the most important fuctord a lot ofl a high tevel ofe the worst situation

a You work for a manufacturer of .,-\hand tools and have ;;;';;n* a Harprme's a! Joi're"s' hatmme's (tov rattls)

investigate using alternative materials ro) Ltau'rp hatwrmets (fov uaatsorrvy chisels)

in your products. ln pui.., ."uá tr'" - -

Co\siáev the harr"rmer heotA at\A the harmwrev shart|.

notes and discuss the main properties Satws a| Wooá Sarws (€ov cta|tirrg wooá)

required of the materials used to make b) Harcksarws (fov craffirrg uaetatl)the too|s. Coqsiáev |he satw b|oA,e aúO, |v\e sarw hatr,tále o" €varrre.

Think of a product you know well.ln pairs, discuss the materials used in it and what properties make thematerials suitable. Discuss whether alternative materials could be used.

Unit 2 Materiats technology 79

I Discussing quality issues72

13a

b

14a

In pairs, answer the following questions.

I ln advertising, what hi-tech, high-performancesituations are often used to promote watches?

2 What messages are they intended to send about thequality of products?

3 What quality issues differentiate higher-quality watchesfrom lower-quality ones?

4 What is the difference between describing something aswater-resistant and waterproon

)ls touisa, a marketing executive for a watchmanufacturer, is discussing material selection withTom, one of her engineering colleagues. Listen to thediscussion and complete the four quality issues that arementioned in the meeting.

I - resistance2 -resistance3 -resistance4 -resistance

In pairs, discuss what is meant by each of the qualityissues in Exercise 13a.

)z.s tisten again and answer the following questions.

I What point does Tom make about the reasons for selecting materials?2 What does he say about submarine-grade steel to exemplify the above

point?3 What problem does he describe with regard to the marketability of many

materials?4 What hard commercial fact does Louisa give?

ln pairs, mark the following statements True fI) or False (F) according tothe views expressed in the conversation. Read the audioscript on page 87and check your answers.I Often, exotic-sounding materials are not that suitable, technically.2 People think that a submarine steel watch must be tremendously

water-resistant.3 The corrosion resistance of submarine steel is exceptionally good.4 Submarine-grade steel looks fairly good.5 Tom thinks submarine steel is particularly suitable for watches.6 The firm has often used materials that are not adequately durable.7 Often, the compositions of good watch materials are relatively complex.8 Materials with complicated names are pretty good for marketing.

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20 Unit 2 Materials technotogy

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C )z.O Listen to the following phrases from the conversation and undertine thestressed syllable. Practise saying the phrases.

I not patjeularly suitable 4 tremendously marketable2 exceptionally resistant 5 relatively complex3 not at all suitable 6 not all that good

d Complete the following table using the words in the box.

cxrcÉia*y fairty insufficientty not adequatety not (alt) thatnot partí.cularty pÍetty ntativety tetendousty

extremely quite not very not enough definitely notexcepfiohrrlly

15 In pairs, discuss the key properties and different types and grades ofthe following materials. Give examples of the properties that make eachmaterial good or bad for watch-making, from a quality perspective.

Materialssteel glass atuminium titanium gotd ptastic copper rubber

Propertieswater-resistant abrasion-resistant corrosion-resistant shock-resistant touqhbrittLe etastic durable heavy Lightweight thermalty stable

ln small groups, choose a well-known consumer product or appliance anddiscuss it from a quality perspective. How suitable are the materials used?How good is the product, compared with others sold by competitors?

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Unit 2 Materials technology 27