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Materials and Manufacturing in
product design and development
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Product design Design a product considering its entire life cycle
Detail design (Concept detailing, engineering drawing, CAD/CAM, CAE..),material selection , manufacturing methods, Eco-design, DfX
Identifying customer needs
Initial design (Concept/idea generation,concept evaluation, selection..)
Prototyping
Manufacturing
Production
Marketing
Sales
Services
PurchaseUse
After use
Recycle, reuse, remanufacture
Discard (land fill)
Marketing dept.
Design dept.
Engineering dept.
R&D dept.
Manufacturing dept.
Mrf./Prod./industrial dept.
Marketing dept.
Sales dept.
Service dept.
Sales dept.
Sales dept.
Service dept.
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Engineering materials
Disclaimer: images are from the internet
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Materials classification
Elements Alloys
Elements and use
Steels (Ferrous)Carbon SteelsAlloy SteelsStainless Steels
Tool Steels
Non FerrousAluminum AlloysCopper Alloys..
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Common classification of engineering materialsCommon engineering materials that come within the scope of Material Science may be classifiedbroadly into the following three types:-
Metals (Ferrous and Non-Ferrous)CeramicsPolymersComposites
Please read Dr. Anupam Aggarwals previous course class slides
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Group Important Characteristics Common Examples of Engineering use
Metals and Alloys
Lusture, Hardness, Resistance toCorrosion, Thermal and ElectricalConductivity, Malleability,Stiffness and Property of Magnetism.
Metals: Ferrous metals and alloys (irons, carbon steels, alloysteels, stainless steels, tool and die steels)Nonferrous metals and alloys (aluminum, copper, magnesium,nickel, titanium, precious metals, refractory metals, superalloys)
Ceramics Thermal Resistance, Brittleness,Opaqueness to Light, ElectricalInsulation, High-temperatureStrength, abrasiveness, Resistanceto Corrosion.
GlassesGlass ceramics Graphite Diamond
Silica, Glass, Cement, Concrete, Refractories, Silicon Carbide,Boron Nitride abrasives, Ferrites, Insulators, Garnets, etc.
Organic Polymers
Soft, Light in weight,Dimensionally unstable, PoorConductors of Heat andElectricity, Ductile, Combustible,Low-thermal Resistance.
Thermoplastics plasticsThermoset plasticsElastomersPlastics Poly Vinyl Chloride, Poly Tetra Fluoroethylene,Polycarbonates.Natural and Synthetic Fibers Nylon, Terylene, Leather, etc.Other uses Explosives, Refrigerants, Insulators, Lubricants,Detergents, Fuels, Vitamins, Medicines, adhesives, etc.
Composites Hardness, Poor Conductors of Heat and Electricity, Non-combustible, high thermalregistance
Composites Reinforced plasticsMetal-matrix compositesCeramic-matrix compositesSandwich structuresConcrete
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Materials for special usage
Heat insulating materials: asbestos, glass wool, thermo Cole, cork,mica.
Electrical insulating materials . china clay, leather, bakelite, ebonite,glass wool, rubber, felt.
Sound insulating materials: Cork, fibre boards.
Fabrication materials : Wood, plywood, rubber natural andsynthetic, Glass plate glass, toughened glass, safety glass.
Refractory materials: General characteristics and uses of dolomite,ceramics.
Protective coating materials: Paints, primers, varnishes, enamels,putti, electroplating materials, rubasil, Teflon coating.
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Materials usage
Source: Galway technology service support service
http://www.google.co.in/url?sa=t&source=web&cd=4&ved=0CDAQFjAD&url=http%3A%2F%2Fwww.t4.ie%2FProfessional_Development%2FRD9_Technology%2FMaterials%2520Technology%2FClassification%2520of%2520Materials.ppt&ei=JoPkTeKaLIPjrAfPysSfBg&usg=AFQjCNE62x65YCGYwd3Nji4HIMDwCBzQrA
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Classification of Materials
Materials used in the design and manufacture of products
Plastics Wood Composites Ceramics Metals Fabrics Acrylic lensBalsa wood modelLayers of polycarbonate,
aluminium & acrylicTungsten carbide tool bitSteel, aluminiumLinen, cotton, nylon, Kevlar
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Classification of Materials (Plastics)
Plastics can be further classified as; Thermoplastic Thermoset Elastomers
Thermoplastics Thermosets ElastomersAcrylics Epoxy resins Rubbers
Nylons Phenolic SiliconesPVC Polyesters PolyurethanesPolyethylene
PolyethylenePVC guttersPhenol formaldehydeUrea formaldehyde
RubberRubber
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Classification of Materials (Wood) Wood can be further categorised as;
Hardwood Softwood Manufactured board
Hardwood Softwood ManufacturedBoardOak Pine Plywood
Ash Cedar BlockboardBeech Fir MDF
Sycamore Spruce Melamineboard
MahoganyOakAshBeechCedarChipboard with VeneerPlywood
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Classification of Materials (Composites)
A composite is a combination of two or more chemicallydistinct materials whose physical characteristics aresuperior to its constituents acting independently.
Because of their high strength/stiffness to weight ratiothey are widely used in the;
Aerospace industry Offshore structures Boats Sporting goods
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Classification of Materials (Composites)
Examples of composites include;
Reinforced Plastics Ceramic-matrix Metal-Matrix
Laminates
Kevlar, taffeta polyester sailsGlass reinforced plastic hullCarbon reinforced plasticThrust chamber for rocketCombustion chamber of jet engineCylinder liningsCylinder liningsOuter skin panels & fuselage A380
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Classification of Materials (Ceramics)
Ceramics are compounds of metallic and non-
metallic elements, examples include;
Oxides (alumina insulation and abrasives,zirconia dies for metal extrusion and abrasives)
Carbides (tungsten-carbide tools) Nitrides (cubic boron nitride, 2 nd in hardness todiamond)
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Classification of Materials (Metals)
Metals can be further classified as Ferrous &Non-Ferrous, some examples include;
Ferrous Non-Ferrous
Steels Aluminium
Stainless Steels Copper
High Speed Steels Brass
Cast Irons Titanium
AluminiumCopperBrassStainless SteelHigh Speed steel
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Classification of Materials (SmartMaterials)
Other more modern examples of smartmaterials include;
Shape memory polymers and alloys
Heat shrink tubing and packaging
Automatic actuators open/close greenhouse windows
Thermostats for heating control
Smart Wire
Actuators, linear, angular and rotary
Anthromorphic actuation human like robotic motion
Smart Link Silicone
Allows rotary motion between shafts up to 360 0 Smart Fluids
Motion control gel CD tray opening/closing, camera lensesFerro fluids earthquake dampers in buildings, hard disks
Piezoelectric MaterialsSensors, musical cards, motors, actuators, clocks Chameleon Colours
Car paints, printing inks, packaging
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The word, polymer , implies that polymers are constructed from pieces(monomers ) that can be easily connected into long chains ( polymer
Latin: Plasticus, that which can be molded. This name honors plastics useful property
of being easily molded.
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GlucoseStructural formula.
Straight chainglucose
H-C=O|
H-C-OH|
HO-C-H|
H-C-OH|
H-C-OH|CH 2 OH
Glucoseglucose bending
GlucoseTwo ring-shape
versions
alpha-glucose
beta-glucose
Glucose bends itself into 4different shapes millions of times
a second
1
4
6
2
3
5
Used inmakingcellulose
Used inmakingstarch
flips
eitherwaybends
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Why use plastics Plastic are easily formed materials.
The advantage to the manufacturer is that plastic products can be mass-produced and require less skilled staff .
Plastics require little or no finishing , painting, polishing etc. Plastic is referred to asa self-finishing material . Particular finishes can be achieved at relatively low cost.
Plastics can be easily printed, decorated or painted.
Plastics are corrosion resistant , and generally waterproof although certain typesof plastics such as UPVC can become brittle and it is possible for the suns rays tocause the colour of the plastic to fade. It becomes bleached.
Plastics are lighter than metals , giving deeper sections for a given weight, andhence stronger sections .
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Origins of Plastics - synthetic plastics . The main source of synthetic plastics is
crude oil .
Coal and natural gas are also used.
Petrol, paraffin, lubricating oils and highpetroleum gases are bi-products,produced during the refining of crude oil.
These gases are broken down into
monomers. Monomers are chemicalsubstances consisting of a single molecule.
A process called Polymerisation occurswhen thousands of monomers are linkedtogether. The compounds formed ascalled polymers .
Combining the element carbon with oneor more other elements such as oxygen,hydrogen, chlorine, fluorine and nitrogenmakes most polymers.
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Natural Plastics
Natural plastic products occur in such things as animals horns, animals milk,insects, plants and trees.
Animals horns - Casein (glue)
Animals milk - Formaldehyde (glue)
Insects - Shellac (French polishing)
Plants - Cellulose (table tennis balls), Cellulose acetate (cloth, photographic film,handles), Cellophane (wrapping), Bitumen (roads, flat roofs)
Trees - Latex (rubber)
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Common plastics
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A polymer madeform just one
monomer is polyethylene. It
is the mostcommon plastic
you see.It is used for
bottles, buckets, jugs, containers,
toys, evensynthetic lumber,
and many otherthings.
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LDPELow density polyethylene
Makes bottles that requires
flexibility
Produces grocery bags andgarbage bags, shrink andstretch film and the coatingfor milk cartons
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HDPEHigh Density Polyethylene
Used in milk, juice and watercontainers in order to take
advantage of its protectivebarrier properties
Its chemical resistance
properties make it a goodchoice as container forhousehold chemicals anddetergents.
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PETPolyethyleneTerephthalate
A clear, tough, polymer withexceptional gas and moisturebarrier properties.
PETs ability to contain carbondioxide (carbonation) make it agood choice in soft drinkbottles.
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Polythene (polyethelene)
High-density polythenehas been used tomanufacture milk
crates, bottles, buckets,bowl and gear wheels.
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VinylPolyvinyl chloride, or PVC
Excellent clarity, punctureresistance and cling
Film vinyl can breathe,making it ideal for meats
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PSPolystyrene
In its crystalline form, it is a colorlessplastic plastic that can be clear andhard.
It can also be foamed to provideexceptional insulation properties.Foamed or expanded polystyrene (EPS)
is used for products such as meat trays,egg cartons and coffee cups.
It is also used for packaging andprotecting appliances, electronics andother sensitive products
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Expanded polystyrene
This is used fordisposable foodpackaging, disposable
cups, heat insulationand protective packaging for electricalequipment.
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Clear Acrylic (Perspex)
It was first used to makeaircraft canopies. It isten times more impact
resistant than glass.
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Nylon
Nylon is hard, tough, self-lubricating, has a highmelting point and has verygood resistance to wear andtear.
It has been used to makeclothing, bearings andpropellers.
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PVC
The rigid type is used tomake pipes , guttering androofing. It is verylightweight and is resistantto acids and alkalis.
The plasticised type is usedfor suitcases, hosepipes,electrical wiring and floorcoverings.
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The favorite properties of plastics are that they are inert and won't reactwith what is stored in them. They also are durable and won't easilydecay , dissolve, or break apart. These are great qualities for things you
keep, but when you throw them away, they won't decompose .
h d d h l h
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Since they dont decompose, the answer is to recycle theplastics so they can be remade into something else. Herewe see a bunch of CDs getting recycled.
li l i
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Codes Descriptions Properties PackagingApplications
RecycledProducts
Polyethylene Terephthalate (PET, PETE). PET isclear, tough, and has good gas and moisturebarrier properties. Commonly used in soft drinkbottles and many injection molded consumerproduct containers. Other applications includestrapping and both food and non-food containers.
Cleaned, recycled PET flakes and pellets are ingreat demand for spinning fiber for carpet yarns,producing fiberfill and geo-textiles. Nickname:Polyester.
Clarity, strength,toughness, barrierto gas andmoisture,resistance to heat
Plastic soft drink,water, sports drink,beer, mouthwash,catsup and saladdressing bottles.Peanut butter, pickle,
jelly and jam jars.Ovenable film andovenable preparedfood trays.
Fiber, tote bags,clothing, film andsheet, food andbeverage containers,carpet, strapping,fleece wear, luggage
and bottles.
High Density Polyethylene (HDPE). HDPE is used tomake bottles for milk, juice, water and laundryproducts. Unpigmented bottles are translucent,
have good barrier properties and stiffness, and arewell suited to packaging products with a shortshelf life such as milk. Because HDPE has goodchemical resistance, it is used for packaging manyhousehold and industrial chemicals such asdetergents and bleach. Pigmented HDPE bottleshave better stress crack resistance thanunpigmented HDPE bottles.
Stiffness, strength,toughness,resistance to
chemicals andmoisture,permeability togas, ease of processing, andease of forming.
Milk, water, juice,cosmetic, shampoo,dish and laundry
detergent bottles;yogurt and margarinetubs; cereal box liners;grocery, trash andretail bags.
Liquid laundrydetergent, shampoo,conditioner and motor
oil bottles; pipe,buckets, crates, flowerpots, garden edging,film and sheet,recycling bins, benches,dog houses, plasticlumber, floor tiles,picnic tables, fencing.
Recycling plasticsThe table below shows the recycling codes for the most easily recycled plastics, anddescribes what functions they are useful for. All of these are thermoplastics this meansthat they can be reheated, softened and reformed.
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Codes Descriptions Properties PackagingApplications
RecycledProducts
Vinyl (Polyvinyl Chloride or PVC): Inaddition to its stable physical properties,PVC has excellent chemical resistance,good weatherability, flow characteristicsand stable electrical properties. Thediverse slate of vinyl products can bebroadly divided into rigid and flexiblematerials. Bottles and packaging sheet aremajor rigid markets, but it is also widelyused in the construction market for suchapplications as pipes and fittings, siding,carpet backing and windows. Flexible vinyl
is used in wire and cable insulation, filmand sheet, floor coverings syntheticleather products, coatings, blood bags,medical tubing and many otherapplications.
Versatility, clarity,ease of blending,strength,toughness,resistance togrease, oil andchemicals.
Clear food and non-food packaging,medical tubing,wire and cableinsulation, film andsheet, constructionproducts such aspipes, fittings,siding, floor tiles,carpet backing andwindow frames..
Packaging, loose-leaf binders,decking, paneling,gutters, mud flaps,film and sheet,floor tiles and mats,resilient flooring,cassette trays,electrical boxes,cables, trafficcones, garden hose,mobile home
skirting.
Low Density Polyethylene (LDPE).Usedpredominately in film applications due toits toughness, flexibility and relativetransparency, making it popular for use inapplications where heat sealing isnecessary. LDPE is also used tomanufacture some flexible lids and bottlesand it is used in wire and cableapplications
Ease of processing,strength,toughness,flexibility, ease of sealing, barrier tomoisture.
Dry cleaning, breadand frozen foodbags, squeezablebottles, e.g. honey,mustard.
Shipping envelopes,garbage can liners,floor tile, furniture,film and sheet,compost bins,paneling, trashcans, landscapetimber, lumber
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Processing of plastics
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Processing of Plastics There are a wide variety of manufacturing processes that exist for plastic production. A wide variety of plastic
manufacturing processes exist
Extrusion Lamination (Calendaring) Thermoforming Casting Molding
Compression Molding Transfer Molding Rotational Molding Reaction Injection Molding Blow Molding Injection Molding
Expansion Foaming Spinning Solid-Phase Forming
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ExtrusionOne of the most common process for creating plastic for further processing isextrusion. The Extrusion process combines color pigments and performance additiveswith resin by pushing it through rotating screws. The heat and pressure producedwithin the screw barrels disperses and melts the ingredients into homogeneousmolten mixture. At the end of the mixture is usually cool die. The mixture is pushedthrough the die and onto the finishing operation such as pelletizing, calendaring, ormolding.
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Lamination (Calendering) In calendering, sheets of plastic are laminated together by rolling through heated
roller. Basically, warm or molten plastic (usually from an extruder) is fed through aseries of heated rolls as in this figure. The gaps between the rolls determine thefinal sheet size. Each additional roll would reduce the sheet thickness further.Then, once the laminated sheet is the correct thickness, the sheet is then strippedoff.
Schematic illustration of calendering. Sheets produced bythis process are subsequently usedin thermoforming.
Reinforced- plastic components for a Hondamotorcycle. The parts shown are front andrear forks, a rear swingarm, a wheel, and brakedisks.
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Casting Casting used for both thermosetting and thermoplastic materials. Basically, casting
places plastic in a mold then hardens it into a rigid article or form. In potting, the plastic is cast around a part, and the case becomes part of the final
component. In encapsulation, the component is covered with plastic and thecomponent and plastic are ejected from the mold. Both processes are usedextensively in electronics for insulation and dielectric properties
Schematic illustration of (a) casting,(b) potting, (c) encapsulation of
plastics.
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Molding Molding is the most common plastic forming or finishing method. There are many different methods in plastic
molding. Methods for molding include:
Compression Molding Transfer Molding Rotational Molding Reaction Injection Molding Blow Molding Injection Molding
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Blow Molding (Bottles) Blow molding is a modified extrusion and injection molding process, wherein a
tube is extruded (usually turned so that it is vertical) and clamped into a mold witha cavity much larger than the tube diameter. Air is blown inside the tube openingand the plastic expands to fill the mold cavity shape. Blow molding is similar toblowing up a balloon inside a bottle. Mostly, blow molding forms hollow plasticparts with relatively thin walls. Examples of blow molding products are bottles,bumpers, bags and ducting.
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Injection Molding The last and more popular process is injection molding. This process is used to
form complex plastic parts. Typical injection molded parts are fittings, containers,bottle tops, housings, and much more. Here is a pictorial of a typical injectionmolding machine and part. It is the most common of the plastic forming processestoday, accounting for approximately 30% of all plastics produced.
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Common Polymers ABS (Acrylanitrile Butadiene Styrene): amorphous, good Impact Strength, excellent appearance,
easy to process computer housings, small appliances, automotive interior, & medical components Acrylic : amorphous polymers, excellent clarity, excellent weatherability optical & outdoor
applications Cellulosics : among the first thermoplastics developed: smell funny, very flammable Nylon 6 : semi-crystalline polymer, good cost to performance ratio, lower numbered nylons, 6 ,6-6,
4-6, absorb moisture and change their properties as a result Polycarbonate : amorphous material, excellent Impact Strength, clarity, & optical properties
currently long lead times for this material. Polyethylene High Density : widely used, inexpensive, thermoplastic, easy to process, good to
excellent chemical resistance, soft & not for use above 150 F Polypropylene : semi-crystalline material, low temperature material, excellent chemical resistance
difficult to mold to extremely close tolerances Polystyrene High Impact (HIPS): few cents more than crystal styrene, to pay for the rubber
modifier, opaque & very widely used, lower modulus, better elongation, & less brittle than crystalstyrene
PVC Polyvinyl Chloride Rigid : properties similar to ABS (except appearance) at a slightly reducedcost primarily for water pipe and pipe fittings, occasionally for electrical enclosures *in plasticphase PVC is corrosive to molds & machines (non corrosive as a solid)
Why Design with Plastics?
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Ken Youssefi Mechanical Engineering 58
Why Design with Plastics?
Cost
Relatively low cost compared tometals and composites
Density
Light weight, high weight to strengthratio, particularly when reinforced
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Properties Advantages
Light Weight High Strength-to-Weight Ratio Complex Parts - Net Shape Variety of Colors (or Clear) Corrosion Resistant Electrical and thermal Insulation
High Damping Coefficient Low pressures and temperature required
Disadvantages Creep Thermally Unstable- can not withstand Extreme Heat U-V Light Sensitive Relatively low stiffness Relatively low strength Difficult to Repair/Rework Difficult to Sort/Recycle
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Ken Youssefi Mechanical Engineering 60
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Metals
METALS
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METALSMetals are Solid at room temperature, except
mercury, which is liquid !
Metals have very high melting point.
Metals are shiny when they cut.
Metals are good conductors of heat and electricity.
Metals areusually strong & malleable so they can behammered into shape.
METALS
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METALS
METALS
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METALS
Materials used in the design and manufacture of products
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Materials used in the design and manufacture of products
Metals Non-Metals
Pure metals Alloys
Read classification of materials
Non-FerrousFerrous
Iron AluminumCopperSilverGoldZincTin
Steel (Iron+ carbon)
Brass (Copper +Zinc)Bronze (copper +Tin)Stainless steel (Steel+Chromium)
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Most popular
The Society of Automotive Engineers (SAE) has established standards for specific analysis of
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steels. In the 10XX series, the first digit indicates a plain carbon steel. The second digitindicates a modification in the alloys.
Classification of steels
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SAE - AISINumber
Classification
1XXX Carbon steels Low carbon steels: 0 to 0.25 % C Medium carbon steels: 0.25 to 0.55 % C High carbon steels: Above 0.55 % Carbon
2XXX Nickel steels 5 % Nickel increases the tensile strength without reducing ductility. 8 to 12 % Nickel increases the resistance to low temperature impact 15 to 25 % Nickel (along with Al, Cu and Co) develop high magnetic properties. (Alnicometals) 25 to 35 % Nickel create resistance to corrosion at elevated temperatures.
3XXX Nickel-chromium steels These steels are tough and ductile and exhibit high wear resistance , hardenability and highresistance to corrosion.
4XXX Molybdenum steels Molybdenum is a strong carbide former. It has a strong effect on hardenability and hightemperature hardness. Molybdenum also increases the tensile strength of low carbon steels.
5XXX Chromium steels Chromium is a ferrite strengthener in low carbon steels. It increases the core toughness andthe wear resistnace of the case in carburized steels.
86XX 87XX 93XX 94XX 97XX
98XX
Triple Alloy steels which include Nickel (Ni), Chromium (Cr), and Molybdenum (Mo). These steels exhibit high strength and also high strength to weight ratio, good corrosionresistance.
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METALS
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METALS & ALLOYSMetals are available in pure or alloy form.
Pure Metals such as pure aluminium or pure copper,contain only one type of metal. They are not mixed withany other metal.
Alloys are mixture of two or more pure metals.
Alloys tend to have better strength properties than puremetals.
Alloys and pure metals often have special physicalproperties .
PROPERTIES OF METALS
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1. Strength - The ability of a material to stand up to forces beingapplied without it bending, breaking, shattering or deforming in anyway.
2. Elasticity - The ability of a material to absorb force and flex indifferent directions, returning to its original position.
3. Plasticity - The ability of a material to be change in shapepermanently.
4. Ductility - The ability of a material to change shape (deform) usuallyby stretching along its length.
5. Tensile Strength The ability of a material to stretch withoutbreaking or snapping.
6. Malleability - The ability of a material to be reshaped in all directionswithout cracking.
7. Toughness - A characteristic of a material that does not break orshatter when receiving a blow or under a sudden shock.
8. Conductivity - The ability of a material to conduct electricity.9. Hardness The ability of a material to resist scratching, wear and
tear & indentation.
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Common metals
FERROUS-METALS
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1. Mild SteelComposition: Iron alloy with 0.3% carbon
Properties: Malleable and ductile, and therefore bends fairly easilyUses: nuts, bolts, screws, tubes etc.
Methods of Identification
Appearance: Bright drawn mild steel has a smooth, bright surface;black mild steel is covered with a blue-grey oxideDropping: Gives out a ringing note
Grinding: Gives off a shower of long white sparksEffect of Heating: Slightly tougher but little change
FERROUS-METALS
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2. Tool Steel / cast steel / carbon steelComposition: Iron alloy with 0.5%-1.5% carbon
Properties: Tough rather than hard, and fairly ductileUses: Springs and most tools such as hammer heads, drills, chisels,shears etc
Methods of Identification
Appearance: Has a smooth skin of black oxideDropping: Gives out a high ringing note
Grinding: Moderate number of red sparksEffect of Heating: Becomes hard and brittle
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Use of non-ferrous metals
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Aluminium:Aluminium is a widely used non ferrous metal. It is Grayish-Whitein colour, soft and malleable. This non ferrous metal is conductiveto heat and electricity. It is corrosion resistant. Aluminium can bewelded but this is difficult. Special processes need to be adoptedin order to weld it properly. Due to its light weight, it is used inthe manufacturing of aircrafts and boats. Its other uses arewindow frames, saucepans, packaging and insulation, pistons andcranks.
Aluminium alloys (Duraluminium): Aluminium alloys (Duraluminium) is composed of Aluminium,Copper and Manganese. Its also Ductile, Malleable, WorkHardens. It is used in the manufacturing of aircrafts and vehicleparts.
Source: http://www.bracebridgeengineering.co.uk/engineering_non_ferrous_metal.asp
Non Ferrous metals are those metals which does not contain iron . They are not magneticand are usually more resistant to corrosion than ferrous metals. Most commonly used nonferrous metals are Aluminum, Copper, Brass, Lead, Tin, Gilding Metal and Zinc.
Copper :
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Copper is another very important pure non ferrous metal. Its red incolour, tough and ductile. It is very good electrical conductor andoffers great resistance to corrosion. Copper can work hard or coldbut it needs frequent annealing. Copper is mostly used in themanufacturing of electric wires, cables and conductors. Its otheruses are water and central heating pipes and cylinders, Printedcircuit boards and manufacturing of special roofs.
Brass :Another important non ferrous metal is Brass which is not a puremetal but combination of Copper and Zinc. It contains 65% copperand 35% Zinc. This non ferrous metal is very corrosive, yellow incolour, tarnishes very easily. It is harder than copper and its goodelectrical conductor.
Lead :Lead is a pure and an important non ferrous metal. It is the heaviestcommon metal. The other characteristics are its softness,malleability and brightness. It is shiny metal when new but quicklyoxidizes to a dull grey. It has resistant to corrosion. Its uses aredifferent than other non ferrous metals. It is used in protection
against X-Ray machine, Paints, roof coverings, flashings etc.
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Zinc :Lead is also a pure and an important non ferrous metal. Alayer of oxide protects it from corrosion. It is bluish-white
in colour and easily worked. It is used to makes brass bymixing and processing with Copper. It is used as coatinglayer for steel galvanized corrugated iron roofing, tanks,buckets, rust-proof paints etc.
Tin :
Tin is a pure non ferrous metal. It is white in colour, softand corrosion resistant. It is used in Tinplate and makingbronze.
Gilding metal:This non ferrous metal comprises of 85% copper and 15%
zinc. It is corrosion resistant, golden in colour and enamelswell. Its uses are Beaten metalwork and artificial jewellerymanufacturing.
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