Product Design A-Level: Material properties and their uses

Compressive strength definition

The ability to withstand being crushed or shortened by pushing forces

Tensile strength definition

The ability to resist stretching or pulling forces (tension)

Bending strength definition

The ability to resist forces that may bend the material

Shear strength definition

The ability to resist sliding forces on a parallel plane

Torsional strength definition

The ability to withstand twisting forces from applied torque or torsion

Hardness definition

The ability to resist abrasive wear such as scratching, surface indentation, or cutting

Toughness definition

The ability to absorb impact force without fracture

Plasticity definition

The ability to be permanently deformed and retain the deformed shape

Ductility definition

The ability to be drawn out under tension, reducing the cross-sectional area

Malleability definition

The ability to withstand deformation by compression without cracking

Elasticity definition

The ability to be deformed and then return to the original shape when the force is removed

Electrical conductor definition

Allows the flow of electrical current through the material with little resistance

Electrical insulator definition

Doesn’t allow the flow of electricity through the material

Thermal conductor definition

Allows the transfer of heat energy through the material

Thermal insulator definition

Prevents the transfer of heat through the material

Thermal expansion definition

The increase in material volume in response to a heat input

Opaque definition

Prevents light from travelling through

Translucent definition

Allows light to travel through, but diffuses it so the image appears blurred

Transparent definition

Allows light to pass through easily

Density definition

The mass of the material in a standard volume of space

Fusibility definition

The ability of the material to be fused or converted from a solid to a liquid/molten state usually by heat. Good fusibility is essential in metal casting

Magnetism definition

The natural force between objects that causes the material to attract iron or steels

Corrosion/degradation resistance definition

The ability of the material to withstand environmental attack and decay

Ferrous metal definition

A metal containing mostly iron and carbon. They are magnetic and will rust

Low carbons steel

Ferrous

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

0.15-0.3% carbon content

Low carbon steel uses

Nuts, bolts, washers, screws, car bodies, outer panels for white goods

Medium carbon steel

Ferrous

Harder than low carbon steel but less ductile, malleable, tough

0.3-0.7% carbon content

Medium carbon steel uses

Springs, gardening tools (e.g. trowels, forks)

Cast iron

Ferrous

Hard outer-skin but brittle core, good under compression

3.5% carbon

Cast iron uses

Disc brakes, machine parts, engine blocks, sheet furniture (e.g. decorative bollards), bins, lighting

Non-ferrous metal definition

A metal that does not contain iron. They are not magnetic and do not rust

Aluminium

Non-ferrous

Lightweight, ductile, malleable, corrosion resistant, electrical and thermal conductor, can be MIG and TIG welded

Aluminium uses

Drinks cans, aircraft bodies, bike frames, window frames, packaging, baking foil

Copper

Non-ferrous

Ductile, malleable, tough, corrosion resistant, good electrical and thermal conductor, can be soldered and brazed

Copper uses

Electrical wires, printed electrical circuits, water pipes, hot water tanks, central heating pipes

Zinc

Non-ferrous

Low melting point, good corrosion resistance

Zinc uses

Galvanising steel as protective coatings (e.g. for dustbins, buckets, farm gates), intricate die castings

Silver

Non-ferrous

Malleable, ductile, corrosion resistant, can be soldered

Silver uses

Jewellery, electronic components, connectors, switch components

Gold

Non-ferrous

Malleable, ductile, corrosion resistant, can be soldered

Gold uses

Jewellery, electronic components, switch components

Titanium

Non-ferrous

Hard, similar strength to steels but more lightweight, high resistance to corrosion

Titanium uses

Joint replacements, tooth implants, spectacle frames, aircraft, spacecraft, golf clubs, bicycles, ship hulls

Tin

Non-ferrous

Ductile, malleable, low melting point, corrosion resistant

Tin uses

Soft solder, coatings for food cans

Alloy definition

A metal made from two or more metals, or by combining two or more elements where one of which is a metal. These alloys can be ferrous or non-ferrous

Stainless steel

Ferrous alloy

Tough, hard, corrosion resistant

18% chrome, 8% nickel

Stainless steel uses

Cutlery, sinks, kitchenware

High speed steel (HSS)

Ferrous alloy

Hard, tough, high level of resistance to frictional heat

18% tungsten, 4% chromium, 1% vanadium, 0.5-0.8% carbon

High speed steel (HSS) uses

Tool blades, drill bits, milling cutters, router bits

Die steel (Tool steel)

Ferrous alloy

Hard, tough

Die steel (Tool steel) uses

Blanking punches and dies, extruder dies, fine press tools

Bronze

Non-ferrous alloy

Tough, corrosion resistant, can be cast

90% copper, 10% tin

Bronze uses

Statues, coins, bearings

Brass

Non-ferrous alloy

Corrosion resistant, good electrical and thermal conductor, low melting point, casts well

65% copper, 35% zinc

Brass uses

Boat fittings, door furniture, cast valves, and taps, ornaments

Duralumin

Non-ferrous alloy

Equivalent strength properties to low carbon steel but more lightweight, ductile, becomes harder as it is worked

4% copper, 1% magnesium and manganese

Duralumin uses

Aircraft parts, vehicle parts

Pewter

Non-ferrous alloy

Malleable, low melting point, casts well

85-99% copper and antimony

Pewter uses

Tankards, flasks, goblets, photo frames, decorative items, candlesticks, sports trophies

Hardwood definition

A wood from a broad-leafed tree that is generally slow growing. Hardwoods are dense and heavy due to their close grain

Oak

Hardwood

Hard, tough, attractive grain, good weather resistance

Contains tannic acid which will corrode steel screws or fittings

Oak uses

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

Ash

Hardwood

Tough, attractive open grain pattern which makes it more flexible

Ash uses

Tool handles, ladders, sports goods, laminating

Mahogany

Hardwood

Rich, dark-red colour

Can contain interlocking grain which makes it harder to work with

Mahogany uses

Indoor furniture, shop fittings and cabinets, veneers

Teak

Hardwood

Hard, tough, straight grain, natural oils resist moisture and acids/alkalis

Birch

Hardwood

Hard, straight close grained, resists warping

Birch uses

Furniture, indoor panelling, veneers

Beech

Hardwood

Tough, close grained, hard, available in steamed (white colour) and unsteamed (pink colour), does not impart a taste to food

Softwood definition

A wood from a coniferous (cone bearing) tree that is generally fast growing. Softwoods are generally cheaper due to the speed of the wood growth

Pine

Softwood

Straight grain, knotty

Can cause resinous knots

Pine uses

Construction work, roof beams and timber frame construction, interior joinery

Spruce

Softwood

Straight grain, resistant to splitting

Spruce uses

Indoor furniture

Douglas fir

Softwood

Straight or slightly wavy grain, few knots, stable, good resistance to corrosion

Douglas fir uses

Veneers, plywood construction, joinery and construction work

Larch

Softwood

Hard, tough, good resistance to moisture

Attractive grain pattern fades to silver upon exposure outside

Larch uses

Garden furniture, cladding, decking, fencing

Cedar

Softwood

Straight grain, low density, good sound dampening, good resistance to moisture

Can corrode ferrous metals due to acidic nature

Cedar uses

Exterior cladding, sheds, greenhouses, beehives, interior panelling

Manufactured board definition

A man-made wood-based composite material which is available in much larger sizes than solid wood

Plywood

Manufactured board

Thin layers of wood are placed and glued perpendicular to each other and compressed to form the board. Always uses an odd number of layers

Good strength in all directions, no grain weakness

Plywood uses

Structural work, desk tops, interior furniture, floorboards

Marine plywood

Manufactured board

Thin layers of wood are placed and glued perpendicular to each other and compressed to form the board. Gap and void-free, and uses specialist water and boil proof (WBP) glue to provide moisture resistance

Some high-quality marine plywood is also resistant to fungal attack

Marine plywood uses

Boat dashboards, boat lockers and panelling

Aeroply

Manufactured board

Thin layers of wood are placed and glued perpendicular to each other and compressed to form the board. These layers are from a high-quality timber such as birch

Available in very thin sheets, lightweight, easy to bend around a support frame

Aeroply uses

Gliders, laminated furniture, laser cut projects, jewellery items

Flexible plywood

Manufactured board

An odd number of layers glued together with the two outer layers made from open grained timber which allows the sheet to flex. Bent and glued around a former to achieve a solid complex

Flexible plywood uses

Laminated furniture, curved panels

Chipboard

Manufactured board

Wood chips compressed with a resin such as urea formaldehyde

Chipboard uses

Often veneered or covered with polymer laminate

Kitchen worktops and units, shelving and flat-pack furniture

Medium density fibreboard (MDF)

Manufactured board

Compressed wood fibres, but may include urea formaldehyde as an additional resin

Two smooth faces available in either standard grade or veneered with a layer of timber

MDF uses

Model/mould making, furniture items, cabinets and desks

Veneers

Thin slices of wood less than 3mm thick

Veneer uses

Decorative coverings for manufactured board

Melamine formaldehyde (MF) laminates

Thin sheets of MF polymer

Hard, tough, chemical resistant

MF laminates uses

Decorative covering for chipboard for kitchen worktops

Thermoplastic definition

A polymer that can be heated and reshaped multiple times, allowing it to be recycled