ALUMINIUM ALLOY WHEELS

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• Invented in 1948.

• First Al wheel – forged.

• Used initially because of aesthetic appeal.

• Today 50% wheels are Al wheels.

• Lighter while providing same strength.

• Components

Wheel hub.

Spokes.

Rim.

• Reasons for using Aluminium

Improved car handling and riding

comfort.

Improved grip.

Reduced fuel consumption.

Better braking performance.

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Processes used for manufacture of Al wheels.

Casting

Forging

Sheet Metal Process

Final finishing operations.

Painting

Varnishing

Polishing followed by a clear coating

Chrome Wheel Finish

Stiffness.

Yield Strength.

Temperature & Corrosion

resistance.

Fatigue Strength.

Impact Resistance.

Reduced Weight.

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LOW PRESSURE DIE CASTING

• Metal stored in crucible.

• Air at Pressure(15-100

kPa) introduced.

• Molten metal rises into the

cavity between the dies.

• The metal solidifies.

• The pressure is released

after which the die is

opened and casting taken

out.

PERMANENT MOLD CASTING

• Permanent molds made of

carbon steels or grey cast

iron.

• Molten metal poured into

the permanent mold.

• Molten Al pressurized into

negative cavity of mold.

• Ensures no voids created

in the cast.

FLOW FORMING (RIM ROLLING)

• Begins with LPDC.

• Temp. increased to 300-

3500C.

• Steel rollers push against

the rim area to its final

dimension.

• Produces light and strong

wheels at reasonable costs.

Setup for LPDC4

Single block of high strength alloy.

Forged into basic wheel shape with 8000 ton press.

Strength maximized by heat treatment.

Machined to ensure desired shape.

Drilling of holes and ventilation.

Polishing to give a shine.

Etching and painting. 5

SHEET METAL PROCESS

Large strip cut into two round shapes.

Ends welded together.

Rims shaped by rolling.

Nave produced by deep drawing/stamping.

Joining of nave and rims.

Surface treatment and coating.

FINISHING OPERATIONS

Machining and finishing to remove

protruding parts and defects during initial

processes.

Fine polishing to enhance shine of surface.

Chrome wheel finish.

Polished clear coat finish.

Painting and varnishing.

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• Difficult step in casting – mold preparation – high complexity of shapes.

• Some properties may get compromised while reducing weight – wheel blank heated under

pressure.

• Grains get aligned along one direction during forging – gives better damage tolerance,

increased strength and toughness.

• Forged wheels are non – porous and have fine

microstructure. Hence they have high fatigue resistance.

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CAST WHEELS

• Low cost of production.

• Mediocre fatigue performance.

• Could fail due to sudden impacts ( hitting

curbs and potholes).

• Can perform at par with forged wheels

under normal loading conditions.

FORGED WHEELS

• Relatively expensive.

• Better mechanical properties than cast

wheels.

• Higher safety due to absence of pores and

cavities.

• Can bear higher loads than cast wheels.

• Large variety of surface finishes can be

applied.

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• AIR INSIDE Technology

Hollow chambers and spokes.

Reduces weight – better driving experience and comfort.

Increases load bearing ability by up to 60%.

• CERAMIC POLISHING

Very good surface finish.

High strength ceramic particles used.

Removes brittleness to a certain extent.

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• NANO PAINTWORK

Heat and scratch resistant.

Repels dirt, dust, water and other liquids.

• FABRICATION

Assembly of multiple components to produce finished wheel.

Titanium bolts which impart high strength and minimize failure chances are used.

Easy replacement of components.

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• Aluminium wheels are most widely used in the world.

• Aluminium alloy wheels better than conventional steel wheels.

• Most widely used processes - casting and forging.

• Forged wheels are better than those made by Casting.

Better impact resistance.

Fatigue performance.

High durability.

Lightweight.

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THANK YOU !!

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