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Ferrous & Non-Ferrous Materials

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Introduction

Metals form about a quarter of the earth crust by weightOne of the earliest material used dated back to

pre-historic time

Some of the earliest metals used include:

copper, bronze and iron

Stone age Bronze agediscovery of steel

Industrial Revolution in the 18th century

All metals except gold are generally found chemicallycombined with other elements in the form of

oxides and sulphates. Commonly known as ores.

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Metal is an element, compound or alloy that is a

good conductor of both electricity and heat

Metal crystal structure and specific metal

properties are determined by metallic bonding

force, holding together the atoms of a metal

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Other specific metal features are: luster or shine of theirsurface (when polished), their malleability (ability to behammered) and ductility (ability to be drawn).

These properties are also associated with the metallicbonding and presence of free electrons in the crystallattice.

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EngineeringMaterials

Metals

Ferrous

Iron

Steel

Pig iron

Cast iron

Wrought

iron

Non-Ferrous

Copper &

Alloys

Aluminium

Zinc

Tin

Lead

Non-Metals

Rubber

Plastics

Resin

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Pure Metals and AlloysMetal that are not mixed with any other materials are known

as pure metals. Metals listed in the Periodic Table are pure

metals

E.g. Iron (Fe), Copper (Cu) and Zinc (Zn)

Alloys are mixtures of two or more metals formed togetherwith other elements/materials to create new metals with

improved Mechanical Properties and other properties

of the base metal.

E.g. Brass (Copper and Zinc),

Stainless steel (steel and chromium)

Alloy = metal A + metal B + + other elements

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Ferrous Metals & Non-Ferrous Metals

Ferrous metals are metals that contain iron

E.g. Steel (iron and carbon)

Non-ferrous metals are metals that do not contain iron

E.g. Zinc (pure metal), Bronze (Copper and tin)(non-ferrous may contain slight traces of iron)

Ferrous Metal = alloy metals that contains iron

( Primary base metal is iron)

Non-ferrous Metal = alloy metals that do not contain iron

Primary base metal does not contain iron)

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Extraction of Iron

Iron is found in iron oxide in the earth.Three primary iron ores: magnetite, hematite, taconite

Iron is extracted using blast furnace

Steps in extraction of iron

Ores is washed, crushed and mixed with

limestone and coke

The mixture is fed into the furnace and is then melted

Coke(a product of coal, mainly carbon) is

used to convert the iron oxides to iron

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Blast Furnace

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Blast furnace

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Extraction of Iron

A blast furnace

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Blast Furnace Temperatures

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Ore, coke, and limestone are charged in layers into the top

of a blast furnace

Ore is the source of the iron , Coke is the source of the carbon(coke is derived from coal, by heating in a coking oven)

Limestone acts as a fluxing slag to remove impurities likesulphur and silica

1100-deg. air blown into bottom of furnace, burns oxygen offthe iron oxides, causing temperature in furnace to get above

the melting point of iron (approx 3000 degrees)

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Molten iron sinks to bottom of furnace, where

it is tapped off from furnace and cast into

large ingots called pigspigs contain high

carbon content (4% or so), plus manyimpurities, such as sulphur and silica which

wasnt removed by the limestone.

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Ferrous Metals - Iron and Steel

Pure iron is soft and ductile to be of much practical use.

BUT when carbon is added, useful set of alloys are produced.

They are known as carbon steel.

The amount of carbon will determine the hardness of the steel.

The carbon amount ranges from 0.1% to 4%.

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Non-ferrous metals

Copper

Aluminium

Zinc

Tin

Lead

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Copper & Alloys

CopperLatin cuprum(Cu) ranks next to iron inimportance and wide range of application

good heat and electrical conductivity

resistance to corrosion

Alloys: brass, bronze, cupro- nickel (copper nickel)alloys

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Copper

Moderate strength in the pure state

Malleable and ductile

Very good electrical and thermal conductor Good corrosion resistance

Alloys with Zinc to give brass

Alloys with Tin and others to make bronze

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Copper as a Heat Exchanger

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Aluminium

Aluminium (BrE) or aluminum (AmE) Al,atomic number 13

whitish with bluish cast

the third most abundant element (afteroxygen and silicon), and the most abundantmetal in the Earths crust

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Aluminium

low density and ability to resist corrosion;

good conductivity

structural components made from aluminium

and its alloys are vital to the aerospace

industry and are important in other areas of

transportation and structural materials

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Aluminium

A large Aluminium billet

from which wrought

products will be

produced.

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Boat Hulls

Aluminium boat hulls

offer corrosion

resistance and light

weight.

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Aluminium Engine Blocks (Lupo)

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Audi A2 engine block

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Forged Aluminium Wheels

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Al heat transfer components

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Zinc

Zinc(Zn), atomic number 30

bluish white

corrosion resistant in air due to a thin oxide film formingon its surface

used as a coating for protecting steel - galvanisation (orgalvanisation) is the process of applying a protective zinccoating to steel or iron, in order to prevent rusting

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Zinc

No structural engineering uses in pure state

Used as sacrificial anodes to protect steel.

Used as an alloy with copper to producebrass

Used to corrosion coat steel by:

Galvanising or Plating

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Brass Components

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Tin

Tin Latin stannum (Sn), atomic number 50

white, lustrous, soft, malleable, ductile, resistantto corrosion

used as coating for steel and sheet iron

white metal tin based alloy with amounts oflead, copper and antimony lining material

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Tin

Soft and corrosion resistant.

Used to alloy with lead to make solder

Used to alloy with copper to produce bronzes,

e.g. Bell metal

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Bell Metal

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Lead

Lead Latinplumbum (Pb), atomic number 82

metallic lead has a bluish-white colour after

being freshly cut, but it soon tarnishes to a dull

grayish color when exposed to air

has a shiny chrome-silver luster when it is melted

into a liquid

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Lead

soft, malleable, has little ductility

usage: plates for storage batteries, covering

for electrical cables

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Magnesium

Light weight S.G. of 1.7

Burns easily when being machined

Used with Aluminium to make lightweight

alloys.

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Non-Metals

Non-Metals are poor conductors of heat and electricity whencompared to metals as they gain or share valence electronseasily (as opposed to metals which lose their valence

electrons easily)

usually have lower densities than metals;

they have significantly lower melting points and boiling pointsthan metals

brittle, non-ductile, dull (do not posses metallic luster)

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Titanium

Low density (S.G. of 4.5, as compared to steel

at approx 8)

Similar strengths to steels

Highly corrosion resistant

Melts at 1670C

Use restricted to


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Titanium

Used in

Aerospace parts

Racing cars, motorcycles and bicycles

Pipework and heat exchangers in chemical

plants and oil installations.

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Tit i h t


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Titanium heat-

exchangers

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Nickel

Corrosion resistant forms strong oxide layer.

Brittle in the pure state

Used in stainless steels

Alloyed with copper to produce cupronickelsfor coinage and Monel for corrosion-resistantvalve parts.

Used in Nimonic and superalloys foraerospace engine parts.

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Nickel-based superalloys

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Single-crystal blades

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Chromium

Corrosion resistant forms strong oxide layer.

Brittle in the pure state

Used in stainless steels

Used with Ni & Mo to produce strong steel

alloys for bicycle and motorcycle frame tubes.

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Non-Metals

Plastics

Thermosetting polymer

Epoxy resin

Thermoplastic

Rubber

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Plastics

Plastics:

immune to corrosion

insulator

unsuitable for higher temperatures

to improve their properties additives are given

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Thermosetting plastic

A thermosetting plastic, also known as a

thermoset, is polymer material that

irreversibly cures. The cure may be donethrough heat (generally above 200 C),

through a chemical reaction (two-part epoxy,

for example).

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Thermosetting plastic

Thermoset materials are usually liquid or

malleable prior to curing and designed to be

molded into their final form, or used asadhesives. Others are solids like that of the

molding compound used in semiconductors

and integrated circuits (IC).Once hardened, a thermoset resin cannot be

reheated and melted back to a liquid form.

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Epoxy resins

Epoxy resin thermosetting plastic

usage: chocking materials

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Thermoplastic

Thermoplastic, also known as athermosoftening plastic is a polymer that

turns to a liquid when heated and freezes to avery glassy state when cooled sufficiently.

Thermoplastic polymers differ fromthermosetting polymers in that they can beremelted and remoulded.

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Rubber

Rubber

rough, elastic material

unaffected by water

attacked by oil and steam

usage: gaskets, flexible couplings, vibration mount

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Non-Ferrous Metals and their alloys.

Non-ferrous metals are those which do not contain iron. In general they

have excellent resistance to corrosion. Copper, reputed to be the first metal

used by mankind, includes some very useful and interesting properties, it

is malleable and ductile. It is for this reason is was of such interest to our

ancestors. Another non-ferrous metal, aluminium, has only featured in

engineering terms in the last 75 years.

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CopperCopper as an engineering metal came to prominence during the industrial revolution, up tothen it was considered only for its decorative value and utensils value and on roofing.

Properties of copper include

Malleability - the ability to be beaten or rolled into shape.

Ductility - The ability to be drawn into shape as in the manufacture of copper wire.

Copper is a good conductor of heat and electricity.

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Copper production in modern timesCopper production has a strong link with an Irishman called Marcus Daly, from Co. Cavan.

As a consequence of his mining in Montana USA he was the first to exploit the metalwhen he sent a shipment to Wales for smelting just at the time when it was becoming a

prominent metal in the electrical industry. He was really trying to find a better use for the

mineral which was a by-product of the silver mines in the region.

Copper ore Copper matte Blister Copper pure copper

Reverberatory furnace Converter Furnace Electrolysis

Flowchart of copper ore to pure copper

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Copper production


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Copper production

Copyright Microsoft Encarta

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The production of copper.There are three distinct stages to the production of copper;

1 Copper Matte - The first stage of the production of copper is with matte. It is a mixture of

30% to 40% copper. Ore is first concentrated at the mining site by crushing and thenleaching or floatation.

The ore is then roasted or smelted in an oil fired furnace at a temperature below the melting

point of copper, [1083oC]

The resultant matte contains high levels of sulphur and iron from the chalcopyrite (Cu Fe S2)

2 Converting - Iron and sulphur are removed by blowing air through the molten matte in aconverter vessel, similar to the Bessemer converter. The matte is placed in the converter

and held at the temperature for about 8 hours.Blowing continues until only copper

sulphide remains. This is what is referred to as Blister Copper. It is up to 99% pure. This is

then refined by further heating to remove the oxygen. It is then cast into ingots known as

Anodes.

3. Refining by Electrolysis: - For copper to be used in the electrical industry it has to have

99.99% purity. This can only be achieved by electrolytic refinement.

Pto.

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Refined blister copper anodes are attached to the positive DC supply, while a thin cathode

plate is connected to the negative supply. An electrolyte, a mixture of copper sulphate and

sulphuric acid at 50O C is poored into the tanks.

Acurrent density of around 200 amps is passed between the anode and the cathode,

depositing pure copper onto the thin cathodes

Application of copper

Over half of all copper produced is used in the electrical industry. Copper wire fortransmission accounts for a large amount of this use.

Central heating and plumbing are the major applications of copper. Cylinders, copper piping

etc are the most widely used.

Recycling of copper is an industry in itself and accounts for 40% of all copper used.

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AluminiumAluminium is one of the most versatile of metals. It is only of engineering significance sincethe late twenties, when it became possible to produce it in commercial quantities. Next tosteel it is the most used metal in the world. Yet the production of aluminium is only 6% that ofsteel.Aluminium has a wide range of uses, from cooking foil to aircraft. Its properties make itsuitable for many applications. It is light does not corrode, is a good conductor of electricityand heat and is cheaper than copper.Aluminium can be cast, extruded, rolled, forged, drawn,etc., to give us the numerous shapesof the aluminium objects that we see everyday.

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Mining

Aluminium is the most abundant metal on the earths crust. About 8% of the earths crust ismade up of aluminium.

So why is it not the most abundant metal in use? There is great difficulty and cost attached to

refining aluminium. It does not exist as a pure metal in nature, but is combined with other

elements. The Ore of aluminium is called Bauxite,[hydrated aluminium oxide].

Bauxite is mined in many countries, France, Australia, Guinea, Brazil, Russia and china being

the more common.

Mining Methods;-Open-cast mining is carried out using very large scale plant. After the overburden of topsoil is

removed the ore is excavated out and loaded into giant dumper trucks. The ore is crushed and

washed close to the mining site to save on transport costs.

Production of Aluminium from Barxite;-It requires a huge amount of energy to extract aluminium from its ore. The energy is supplied

in the form of electricity. Because of the large amount of electricity involved the production

of aluminium is generally in countries with large amounts of cheap electricity, such as Canada,

Norway and Brasil.

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A Two-stage process.

Purification;-Before aluminium can be made the ore has to be purified. After being mixed with caustic soda

solution the bauxite is sent to heated pressure vessels where the alumina hydrated aluminium

oxide dissolves in the caustic soda. The impurities are removed as red mud. As the alumina

cools alumina hydrate forms crystals. It is then roasted or calcined. In the Bayer process. This

process is what is carried out in Aughinis in the Shannon Estuary outside Limerick.

Reduction of Alumina to Aluminium;-Electrolysis is used to convert alumina to aluminium. Alumina has a melting point of 2000oC.

To reduce the temperature at which conversion takes place cryolite is added and hence

reduces the amount of energy required to convert the alumina to aluminium.

It takes about 2 tonnes of alumina , 15000 units of electricity to make one tonne ofaluminium.

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Recycling of AluminiumRecycling accounts for about 25% of the total world production of aluminium.

As the amount of bauxite is limited, it makes good sense to recycle the metal. The cost of

recycling a tonne of aluminium is 5.3% the cost of its initial production.

Aluminium and its uses;Aluminium is often used in transmission cables for high tension systems in place of copper

because of cost factors. It is also better in national grid transmission because of the reduction

of weight.

Aluminium is often alloyed with other metals such as copper, magnesium, nickel and zinc to

produce metals with special properties.

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LeadLead is one of those metals which have been used for many ages. The Romans used lead to

duct water to their baths. Batteries are the main users of lead nowadays as it has found to be

dangerous in many other applications. Petrol used lead to aid the lubrication of the fuel

system.

Lead is a toxic material and is being replaced by other materials in places like drainpipes,

guttering etc.

Lead-tin alloys of solder are essential to the electrical industry and are known as soft-

solders(approx 60%tin-40% lead). Other uses of lead include the sheathing of underground

telecommunication cables, bearing matals, radiation protection shields (X-ray and Nuclear).

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TinTin is mainly used in the production of tinplate( sheet steel coated in tin for corrosion

protection.

Tin was mined mainly ion Britain in Cornwall which attracted the Romans to Britain.

Tinplate is produced by dipping sheet steel into baths of molten tin. The canned or tinned

food industry is based on the tinplate can. The tin makes up just 1% of the tincan.

ZincZinc is a white silvery metal which is a poor conductor of both electricity and heat. It is mostly

used as a source of protecting steel I the form of galvanised steel. It is usually applied by hot-

dipping the steel in vats of molten zinc, But is also applied by electroplating.

Zinc is used in dry-cell batteries such as those for torches and radios etc. It is alloyed with

other metals to make die castings.

One of its main uses is its alloy with copper to make brass.

Non Ferrous 2

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