would life be possible without tribology ????? dr a. karpinska 1

Would Life Be Possible Without

Tribology?????

Dr A. Karpinska

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Tribology is the science and engineering of interacting surfaces in relative motion

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SO WHAT IS TRIBOLOGY?Tribology tries to describe everything that

happens when things rub together

TRIBOLOGY TRIANGLE

FRICTION What is friction?

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It’s a FORCE.Occurs whenever two objects are IN CONTACT with

each other.It’s the resistance to movement. It SLOWS objects

down.

higher friction

lower friction

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FRICTIONLet’s use THE SAME FORCE to move the box on:

wooden floor

ice

Which one will slide further?In which case friction is higher?

WHY?

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THE AMAZING FRICTION

CHALLENGE!

Pick up thousands of rice grains with a single chopstick.

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THE AMAZING FRICTION

CHALLENGE!

Pull apart two books with interwoven pages.

30 s

3 min

MAKING CORNFLOUR SLIME

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Cornflour Water Ratio

50 ml 25 ml 2:1

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Cornflour is made up of lots of tiny (<0.01mm) angular starch particles, these are very attracted to water so the water gets in amongst them very quickly.

The water acts as a lubricant, so when you move it slowly the particles have time to move past each other and they can flow like a liquid. However if you apply a rapid force it causes the particles to move slightly causing the particles that are almost touching to jam together. and the water that was between them moves sideways slightly into the gaps.

Now instead of having lots of lubricated individual particles you have a solid structure of lumps touching each other which can't flow.

foods

WHERE IS TRIBOLOGY?

corn flour + water

920 s

HIGH FRICTION

10good bad

HIGH FRICTION

11bad

LOW FRICTION

12good bad

sport

WHERE IS TRIBOLOGY?

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sport

WHERE IS TRIBOLOGY?

leather or ... synthetic?

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cosmetics

WHERE IS TRIBOLOGY?

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cosmetics- hair conditioners

WHERE IS TRIBOLOGY?

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WHERE IS TRIBOLOGY?

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mechanisms: gears, bearings, rail wheels

WHERE IS TRIBOLOGY?

18According to specifications, the bearings were to have a life of more than 50 years.

nature and human body

WHERE IS TRIBOLOGY?

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WEAR What is wear?

It’s the removal of material from a solid surface by the action of another surface.

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WEAR

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good bad

LUBRICATION

Why do we need it?

↓ friction

↓ wear

remove heat and contamination

lower the friction prevent wear

LUBRICATION Types of lubricants

OIL

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LUBRICATION Types of lubricants

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GREASE

LUBRICATION Types of lubricants

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AIR

Load

Pressurized air

LUBRICATION Types of lubricants

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SOLID

LUBRICATION Types of lubricants

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SPECIAL SUBSTANCES

just look around !!!

TRIBOLOGY IS EVERYWHERE !!!

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Dr A. Karpinska

29 Thank you