DT THEORY

DURALUMIN

________: Made from copper, magnesium and manganese Much more lightweight, ductile and harder as it is worked Machines and casts well Can become brittle through fatigue.

➢ MAHOGHANY

________: rich, dark red in colour, wood is expensive, contains interlocking grain, nice surface finish.

NON

________- FERROUS METALS: metals which do not contain iron and do not rust.

PVC

______WEATHER_ resistant, chemical resistant, gas impermeable, however forms HCL when broken down- toxic to environment.

▪ QUANTUM TUNELLING COMPOSITE

________: when GTC is in its relaxed state, it is a near perfect electrical insulator, but when it is stretched becomes an electrical conductor allowing electricity to flow through.

SOFTWOODS

________: Wood from coniferous trees, which generally originate from fast growing trees and take 30 years to mature, making it much more abundant and cheaper.

When reheated they can not soften due to the ________ forming rigid cross links which can not break.

polymer chains

❑

________ Mounting board: Made from compressed fine cotton to produce a rigid board- used to.

ZINC

________: Low melting point, weak material Very resistant to corrosion Uses: a coating on screws, steel buckets and to galvanise steel.

Advantages

________: good strength in all directions, no grain weakness, tough Disadvantages: can be damaged by water Application: structural work, desktops, indoor furniture, floorboards.

thermoplastic

a material which can only be heated and shaped once.

ALUMINIUM

________: lightweight, ductile, malleable, corrosion resistant, electrical and thermal conductor Uses: drink cans, aircraft bodies, bike frames, window frames, saucepans, cooking utensils, etc.

Linen

________: cool to wear, breathable, lightweight, high durability, creases badly, etc.

Box Board

multiple layers of pulp, good printing surface, can be creased, embossed, etc.

Hardboard

compressed wooden fibres, similar to mdf but denser and stronger.

MILD STEEL

________: Ductile and malleable, high tensile strength, tough, poor resistance to corrosion.

LIQUID CRYSTAL DISPLAY

________: LCD change colour when an electrical voltage is applied to it- the cells turn from light to dark.

ALLOY

________: Metals made form two or more elements to achieve desirable traits such as aesthetic appearance, conductivity, strength, ductility, etc.

Polyester resin PR

________: rigid, heat resistant, brittle Uses: castings, used in layering process for GRP for boat hulls.

Urea formaldehyde

________: hard, heat resistant, good electrical insulator, brittle.

THERMO CERAMICS

________: A metal powder is placed within a mould or die under high pressure, causing particles to fuse and bond with each other.

JELUTONG

➢ ________: Fine texture, straight grain, easy to cut, sand and carve, brittle, white or straw coloured.

Cotton

________: good absorption, breathable, low elasticity, tends to crease.

Polypropene

________: Doesnt absorb moisture, good chemical resistance, lightweight, not very breathable, flammable, cant be ironed.

CARBON FIBRE

________: ________ filament woven into a fabric set into a polyester resin matrix.

▪ THERMOCHROMIC MATERIAL

________: changes colour according to the temperature its subjected to.

Wool

________: warm to wear, absorbent, dries slowly, can shrink, not durable, good flame resistance.

➢ OAK

________: A very strong, hard, tough wood, good weather resistance, open grain.

Display

________ for the user: digital clocks, watches, computer screen, etc.

Nylon

________: warm to wear, absorbent dries slowly, crease resistant, not very breathable, can create static electricity.

Polyester

________: non absorbent, dries fast, good elasticity, can be recycled, low warmth.

Epoxy resin ER

________: Rigid, clear, hard, tough, chemical resistant Uses: Adhesives, surface coatings, encapsulation of electrical components, cardiac pacemakers.

TIN

________: Ductile, malleable, low melting point, corrosion resistant Bright silver appearance Uses: coating on food cans, ________ foil, soft solder.

MEDIUM FIBREBOARD MDF

________: compressed wooden fibres /dust with PVA Advantages: Available in large sheets at variable thicknesses, MDF has no grain, cheaper than most materials, consistent strength in all directions.

O Neoprene

________: good thermal resistance, toughness, good oil and chemical resistance.

COPPER

________: Good conductor, ductile, malleable, creep resistant.

good hardness

O Natural rubber: high tensile strength, electrical insulator, ________.

➢ BEECH

________: Tough, close grained, hard, light in colour, beech is also very easy to work with.

PLYWOOD

_____:thin layers of wood placed at 90 degree to each other and compressed with UF resin.

➢ BALSA

________: off white to pinkish colour, straight grain, low density lightweight.

➢ CEDAR

________: A pale yellow colour, fine even texture, lightweight, low density, cant corrode metals.

O ELASTOMER

________: Materials which at room temperature can be deformed under pressure and then upon release will return to their original shape.

▪ PHOTOCHROMIC MATERIAL

________: changes colour with light intensity, photochromic paints contain pigments which change colour according to the uv it is subjected to.

HARDWOOD

________: A hardwood is a type of wood originating from a deciduous tree, generally much more expensive than softwoods due to them taking about 100 years to mature.

REACTIVE GLASS

________: ________ is a smart glass, changes in response to temperature fluctuations by changing the tint of the material.

➢ LARCH

________: hard, tough, attractive grain a pattern, resistant to rot when in contact with the ground.

❑ Foil

________ lined board: board with foil applied either one side or both sides, provide water resistant and heat insulating layer.

Flame resistance

________: dipped in chemicals to create a barrier between the fibre the flame.

HARDWOOD

A hardwood is a type of wood originating from a deciduous tree, generally much more expensive than softwoods due to them taking about 100 years to mature

➢ OAK

A very strong, hard, tough wood, good weather resistance, open grain

USES

Furniture, flooring, boat buildings, cladding, interior and exterior joinery

➢ MAHOGHANY

rich, dark red in colour, wood is expensive, contains interlocking grain, nice surface finish

USES

Indoor furniture, shop fittings and cabinets

➢ BEECH

Tough, close grained, hard, light in colour, beech is also very easy to work with

USES

Chairs, chopping boards

➢ JELUTONG

Fine texture, straight grain, easy to cut, sand and carve, brittle, white or straw coloured

➢ BALSA

off white to pinkish colour, straight grain, low density lightweight

SOFTWOODS

Wood from coniferous trees, which generally originate from fast growing trees and take 30 years to mature, making it much more abundant and cheaper

➢ PARANA PINE

Hard and straight grained, almost knot free, fairly strong and durable, expensive

➢ SCOTS PINE

A straight grained softwood, knotty, easy to work with, cheap and highly abundance

➢ REDWOOD

Strong, knotty, cheap, durable when preserved

➢ LARCH

hard, tough, attractive grain a pattern, resistant to rot when in contact with the ground

➢ CEDAR

A pale yellow colour, fine even texture, lightweight, low density, cant corrode metals

FERROUS METALS

metals which rust and hence contain iron

MILD STEEL

Ductile and malleable, high tensile strength, tough, poor resistance to corrosion

USES

nuts, bolts, washers, screws, car bodies, etc

USES

springs, gardening tools chisels

COPPER

Good conductor, ductile, malleable, creep resistant

Uses

plumbing electric components, cookware, etc

ALLOY

Metals made form two or more elements to achieve desirable traits such as aesthetic appearance, conductivity, strength , ductility, etc

DURALUMIN

Made from copper, magnesium and manganese Much more lightweight, ductile and harder as it is worked Machines and casts well Can become brittle through fatigue

Uses

aircrafts and vehicle structure, bicycle and engine parts, precision tools

Thermoplastic

can be heated and shaped many times

Thermosetting plastic

a material which can only be heated and shaped once

PVC Weather resistant, chemical resistant, gas impermeable, however forms HCL when broken down

toxic to environment

Urea formaldehyde

hard, heat resistant, good electrical insulator, brittle

Uses

electrical fittings, adhesives

o ELASTOMER

Materials which at room temperature can be deformed under pressure and then upon release will return to their original shape

o Natural rubber

high tensile strength, electrical insulator, good hardness

Uses

tyres, footwear, belts, toys, hoses, etc

o Neoprene

good thermal resistance, toughness, good oil and chemical resistance

Uses

laptop cases, hose covers, shock absorbers

CARBON FIBRE

carbon fibre filament woven into a fabric set into a polyester resin matrix

%% Advantages

lightweight, corrosion resistant, tough, excellent strength to weight ratio, good tensile strength

%% Disadvantages

expensive materials, only available in black, highly specialised manufacturing process, cannot be easily repaired, cannot be recycled

Applications

sport equipment, bicycle, tennis rackets, etc

GLASS REINFORCED PLASTIC

glass fibres mixed with polyester resin

Advantages

excellent strength to weight ratio, resistant to corrosions and water, colours available, good compressive strength, etc

Application

flat pack furniture, model making

HARDBOARD

compressed wooden fibres, similar to mdf but denser and stronger

PLYWOOD

thin layers of wood placed at 90 degree to each other and compressed with UF resin

❑ Corrugated board

protective packaging for fragile goods, they have excellent impact resistance, and excellent strength

Uses

protective packaging, takeaway boxes, prototype ideas, etc

❑ Foam board

two outer layers of card with foam in the middle, varies in thickness, expensive

❑ Foil lined board

board with foil applied either one side or both sides, provide water resistant and heat insulating layer

Uses

drink packaging, milk cartons

❑ Box board

multiple layers of pulp, good printing surface, can be creased, embossed, etc

uses

Supermarket food packaging, cereal boxes

Cotton

good absorption, breathable, low elasticity, tends to crease

Uses

denim jeans, t shirts, coloured and non coloured clothing