UNIT 3 PROPERTIES OF MATERIALS COMPARISON

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UNIT 3PROPERTIES OF MATERIALSCOMPARISON
CONTRAST

• Vocabulary
• Properties of Materials (Adj / Nouns / Vbs)
• WORD FORMATION N/VB from ADJ
• Grammar and functions
• Comparison special structures
• ADJ vs ADV
• Comparing Contrasting connectors

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READING

• THERMOSETS
• Shaped only once
• Rigid, can be broken, not softened again
• TYPES UF, MF
• Toughness
• Electrical and thermal resistance
• Scratch resistant
• Dark colours and cheaper -gt PF

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thermoplastics

• - can be reshaped and can be softened again
• TYPES
• Polyethylene cheap / tough / light
• Low density transparent / flexible
• High density rigid
• Polypropylene resilient / less inclined to
  stress-cracking / not weakened by flexing /
  expensive / brittle
• Polystyrene cheap / light / rigid / brittle
• PVC rigid flexible / heavy
• Nylon tensile strength / thermal resistance
• PTFEcostly/ resistant to chemicals erosion
  /thermal resistance / low friction

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PROPERTIES - Matching

• It is hard but fractures easily when hit or
  worked BRITTLE
• It bends easily without breaking FLEXIBLE
• It has a high mass HEAVY
• It is easy to scratch SOFT
• It cannot be dented or scratched HARD
• It retains its new shape when force is applied,
  as opposed to elastic materials. PLASTIC
• It can be drawn or stretched into coils DUCTILE
• It is able to withstand a stretching load without
  breaking TENSILE STRENGTH
• It produces friction when rubbed ROUGH
• It returns to its original shape when the
  deforming force is removed ELASTIC

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PROPERTIES - Matching

• It has a low density LIGHT
• It is able to resist an impact load without
  breaking TOUGH
• It is difficult to bend RIGID/STIFF
• It burns easily COMBUSTIBLE
• You can see through it TRANSPARENT
• It can be hammered into a shape MALLEABLE
• It produces little friction SMOOTH
• It does not rust CORROSION RESISTANT
• It allows the flow of electricity GOOD CONDUCTOR
• It dissolves in water SOLUBLE

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PROPERTIES OF 4 MATERIALS

• COPPER
• A non-ferrous metal
• high electrical and thermal conductivity
• high tensile strength
• Ductile malleable
• ZINC
• A non-ferrous metal
• low hardness Very corrosion resistant
• A relatively heavy metal, but lower density than
  cast iron, copper or lead
• relatively high fusibility but lower than that of
  lead
• LEAD
• High density
• Melts very easily
• Low tensile strength
• ALUMINIUM
• Low density
• Ductile malleable
• Relatively low tensile strength

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WORD FORMATION

• FROM ADJ/ Noun to VERB
• ADJ/ Noun -EN to harden
• to strengthen
• EN Noun to encircle
• to enjoy
• FROM ADJ to NOUN
• LATIN ORIGIN ENGLISH (LATIN) ORIGIN
• -ITY activity -NESS hardness
• -NCE(Y) importance -TH/HT truth/height

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Word Formation (N/ADJ/VB)COPPER-NICKEL ALLOYS

•  The attractIVE corrosion resistANCE of
  copper-nickel alloys in sea water has led to
  their substantiAL use in marine services.
• They have good mechanicAL strenGTH and ductiLITY
  but cannot be hardENED by heat treatment.
• Of particulAR interest is their thermAL
  conductivITY this explains their popularITY for
  heat exchangers, where higher strenGTH is not the
  most importANT factor.
• They are also non-magneTIC and have a magneTIC
  permeabILITY close to uniTY

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TABLE
Glass Fe Al Cu Rubber Plastic
Good-Bad conductor D C B A D E
Hard-soft A B C C E D
Heavy-light C B D A E E
More-less Malleable E C/B C/B A D/E
Tough-Brittle E C B A B D
More-less Recyclable B D A D C B

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ADVERBS ADJECTIVES

• ADJECTIVES are used
• -BE(BECOME)ADJThis metal is weak / it is
  important.
• -ADJ NOUN a weak metal.
• -MAKE OBJECT ADJ this method makes the
  metal hard.
• ADVERBS are used
• -ADVADJ Aluminium is extremely light.
• -VERBADV Cool the bar slowly.
• -ADV Past Participle This alloy is highly
  recommended for propellers.

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Adj VS Adv

• 1.- Such a concentration of lead is highly
  dangerous for men.
• 2.- Hard steel is generally preferred when
  building huge bridges.
• 3.- Magnesium is known as a metal which burns
  easily.
• 4.- The cable is to be covered by a thin rubber
  coating.
• 5.- Stainless steel consists of slightly high
  proportions of chromium.
• 6.- If you put a pipe here, it should not be
  easily bent./
• 7.- This alloy performs well due to its
  exceptional electrical conductivity.
• 8.- Researchers found extremely rare compounds on
  Mars.
• 9.- Chalk is a good example of a soft material
• 10.- Protons are positively charged particles.

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STRUCTURES OF COMPARISON

• There is AS MUCH water AS we thought
  uncountable TANTO COMO
• There are AS MANY people AS we thought.countable
  TANTOS COMO
• It is SO GOOD/SO MUCH(MANY) that SENTENCE
  TAN(TO/S) QUE
• TOO ADJ gt TOO BIG / TOO MUCH money /TOO MANY
  products.
• DEMASIADO(S)
• This box is THE SAME size AS that one.
• This box is TWICE larger THAN /HALF AS large AS/
  EL DOBLE DE
• This box is TWICE THE SIZE of the other box.
• Technology is becoming MORE AND MORE
  sophisticated.
• MOST (OF THE) METALS are good conductors.
• The most/very WIDELY/COMMONLY/FREQUENTLY USED
  metals are steel and copper. (SE USA MUCHO/ ES EL
  MAS USADO)
• THE GREATER the amount of carbon added, THE LESS
  SOFT the steel becomes (cuanto mayor/menor
  mayor/menor).
• This car is QUICKER (Adj). This car runs MORE
  QUICKLY (Adv)
• THE FORMER THE LATTER (El primero .. El
  último)

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EXCERCISE Comparison

1. As copper has become RARER and MORE EXPENSIVE,
   aluminium has come into use even though it has a
   HIGHER resistance THAN copper.
2. In early days, people thought that the electric
   current flowed in THE SAME way AS water
3. In Volta's cell, one of the metals is chemically
   MORE ACTIVE THAN the other and gives off
   electrons which are attracted by THE LESS ACTIVE
   metal.
4. If we let the bar cool FASTER than before, we
   obtain a metal which is HARDER and MORE EASILY
   machineable.
5. Hydrogen is one of THE LIGHTEST elements while
   uranium is one of THE HEAVIEST.
6. Electrons orbiting FARTHER from the nucleus are
   those which are MORE EASILY drawn away.
7. In generators, THE FASTER the wires move, THE
   GREATER the generation of emf.
8. Thermoplastics can be reheated AS MANY times AS
   required.
9. MOST (OF THE) metals are alloyed to get better
   properties.
10. Oil is THE MOST WIDELY USED energy source
11. If the layer is TOO thin it will not protect the
    metal below
12. We spend SO MUCH energy in producing electricity
    that we should concentrate our efforts on other
    possibilities to generate it

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LISTENING (6 metals)

• Cast IRON FERROUS metal, 3C, HARD but BRITTLE,
  will not BEND
• Spring STEEL TOUGH. Uses springs, e.g. in
  CLOCKS, car ENGINE piston rings
• Mild STEEL MUCH LESS CARBON than cast IRON,
  SOFTER but not BRITTLE, though very TOUGH can be
  worked into different SHAPES

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LISTENING (6 metals)

• ALUMINIUM base or PURE METAL, LIGHT RESISTANT
  TO CORROSION THOUGH SOFT easily SHAPED,
  NEVERTHELESS very STRONG. Uses PISTONS in CAR
  ENGINE.
• COPPER easily BENT STRETCHED GOOD CONDUCTOR
  of HEAT ELECTRICITY. Uses ELECTRICAL WIRING,
  water PIPES
• ZINC a PURE METAL, RESISTANT TO CORROSION,
  easily CAST, used for making COMPLEX SHAPES

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COMPARISON AND CONTRAST

• We compare X with/to Y
• X, in comparison with/to Y, has advantages over
  other elements
• as regards (size)
• regarding (size)
• with regard to (size)
• with respect to (size)

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SIMILARITIES

• As ADJ as X The same Noun as
• identical TO X
• A is similar TO X in (that)
• like X
• A resembles X
• A, like X, is a (gas)
• A and X have their elasticity in common
• Similarly (to X), In the same way (as), In this
  way

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DIFFERENCES

• COMPARATIVES
• A differs FROM X in (that)
• A is different FROM X in (that)
• The differences between A and X are...
• differentiate
• We can distinguish between A and X
• make a distinction
• tell the difference
• A can be distinguished FROM X by....(its shape)
• unlike X,
• A, as distinct FROM X,
• in contrast TO X A DIFERENCIA DE,
• as opposed TO X,

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DIFFERENCES

• CONJUNCTION SENTENCE (Subject VB)
• ON (the) one hand.........., ON the other
  (hand).......
• But / although though(even though)/ whereas /
  while
• However/ /nevertheless/ yet sin embargo, no
  obstante
• Otherwise (if not) o si no .... De lo contrario
• ON the contrary/Contrarily(TO this/the examples
  given) / BY/IN contrast(TO this/the examples
  given) Por el contrario
• PREPOSITION ( NOUN/ -ING VB)
• Instead (of)/ rather (than) en vez de, / en su
  lugar
• In spite of /Despite NOUN/ VB-ING a pesar de
• In spite of /Despite the fact that SENTENCE a
  pesar de que
• IN SPITE OF/DESPITE its low density/ THE FACT
  THAT it is light

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EXERCISE expressions

• If we...COMPARE.. wrought iron and cast iron, we
  may find some...SIMILARITIES..
• Both of them are ..SIMILAR IN THAT....they
  contain iron wrought iron, . LIKE/IN THE SAME
  WAY AS/SIMILARLY TO cast iron,
• HOWEVER..., .ALTHOUGH they are very....SIMILAR IN
  .... their composition, we may notice some
  ...DIFFERENCES... REGARDING/WITH RESPECT TO/ AS
  REGARDS their properties
• thus ,wrought iron is very malleable,
  WHEREAS/WHILE cast iron is THE LEAST MALLEABLE of
  all ferrous metals
• .. ON THE OTHER HAND, cast iron ...DIFFERS FROM
  wrought iron in elasticity because WHEREAS/WHILE
  the former has a very poor elasticity, the latter
  is very elastic.
• The..DIFFERENCE between these two metals comes
  from the different amount of carbon content THE
  HIGHER the content of carbon, THE LESS MALLEABLE
  AND ELASTIC these metals are.