advances in tribology and wear

8/13/2019 Advances in Tribology and wear

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SEMINAR ON

ADVANCES IN TRIBOLOGY

BY

APURV VERMA3RB09ME011

DEPARTMENT OF MECHANICAL ENGINEERING

BHEEMANNA KHANDRE INSTITUTE OF TECHNOLOGY, BHALKI


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INDEX

INRTODUCTION

PRACTICAL OBJECTIVES OF TRIBOLOGY

FRICTION

TYPESOFMOTION

TRIBOLOGYINPISTONRINGSANDCYLINDERLINER

WEAR AND ITS MECHANISM

LUBRICATION

SOYBEAN OILAS FUTURELUBRICANT OILFOR IC ENGINES

PVD

TRIBOLOGYCONCERNSINMEMS DEVICES

IMPACT OFTRIBOLOGY

ECONOMIC ASPECTS OF TRIBOLOGY


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INTRODUCTION

It is a GREEK word TRIBOS means rubbing processes.

Tribology is the science and technology of interacting surfaces in

relative motion.

Tribology tries to describe everything that happens when things

rub together.

TRIBOLOGY TRIANGLE


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PRACTICAL OBJECTIVES OF

TRIBOLOGY


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FRICTION What is friction?

5

Its a FORCE.

Occurs whenever two objects are IN CONTACT with each other.

Its the resistance to movement. It SLOWSobjects down.


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higher friction

lower friction

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FRICTIONLets 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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LUBRICATIONWhy do we need it?

friction

wear

remove heat and contamination

lower the friction

prevent wear


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WEAR

What is wear?

Its the removal of material

from a solid surface by the

action of another surface.

8


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WEARMECHANISMS

Adhesive

Low contact pressures

Augmented asperities

Abrasive

High contact pressures

Wear tracks


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TYPESOFMOTION

There are two types of motion between two

moving parts.

Sliding motion

e.g :- Piston in IC engine

Rolling motion

e.g :- Bearings, wheels of automobiles


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TRIBOLOGY IN PISTON RINGS AND

CYLINDER LINER Cylinder liner is fixed one

and piston will slide up

and down inside on it.

Friction exists between

these parts , it results in

wear.

It can be reduced by applyinglubricant.


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RECENT DEVELOPMENTS IN

TRIBOLOGY

Soybean oil as future lubricant for IC engines.

Chemical Vapor Deposition (CVD)

Physical Vapor Deposition (PVD)

Tribology concerns in MEMS devices

Diamond Coating

Ultrananocrystalline diamond (UNCD)

Self Assembled Monolayers (SAMs)

Cantilever Beam Array Technique


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SOYBEAN OIL AS FUTURE LUBRICANT

FOR ICENGINES

Soybean oil is a vegetable oil

extracted from soybean seeds.

It is easily available at low

price.PROPERTIES OF SOYBEAN OIL :-

> It has a high viscosity index up to 223.

> Has comparatively high flash point 610F.

> Has good fire point about 650F.

> It has high pour point, it can be reduced by winterizing the

soybean oil.


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MERITS OF SOYBEAN OIL

Soybean oil is biodegradable, in general it is

less toxic.

It is a renewable oil, so it reduces dependency

of foreign petroleum products.

Ease of processing.


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CHEMICALVAPOURDEPOSITION

CVD is used to grow a thin layer of advancedmaterials on the surface of a substrate.

Application:-

Integrated circuits, electronic devices and sensors.

Catalysts

Micromachines, fine powder and ceramic powderprotective coatings.


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CHEMICAL VAPOUR DEPOSITION

Thin film is formed from gas phase

components.


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CHEMICALVAPOURDEPOSITION

Two types of CVD:-

LPCVD (Low Pressure CVD):- Good

uniformity, Used for poly-Si, oxide, nitride.

PECVD (Plasma Enhanced CVD) :- Low

temperature process and high deposition rate.

Used for oxide, nitride, etc.


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CHEMICAL VAPOUR DEPOSITION

Si Wafers

Quartz tube

Resistance-heated furnacePressure sensor

Gas control

Sourcegases

Pump

TrapexhausTo

s stem

LPCVD Systems


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PHYSICALVAPOURDEPOSITION

PVD is a fundamentally a vaporization coating technique,involving transfer of material on an atomic level.

It is an alternative process to electroplating.

The process is similar to chemical vapor deposition (CVD)except for the raw materials.

i.e.the material that is to be deposited starts in solid form,whereas inCVD the precursors are introduced to the reaction

chamber in gaseous state.


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APPLICATIONSOFPVD

PVD coatings are used to improve Hardness,

Wear Resistance, Oxidation Resistance.

Thus, such coatings used in variety of applications

such as :-

Aerospace

Automotive

Surgical/medical Dies and moulds for all manner of material processing

Cutting tools

Fire arms


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TRIBOLOGY CONCERNS IN MEMS

DEVICES

Friction and Wear are the biggest issuesin blocking advances of MEMStechnology.

Once SAMS and Diamond Coatings aremore fully developed, MEMS technologywill be able to more completely realize itspotential.


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DIAMONDCOATINGS

Diamond has a variety of useful properties compared toSilicon

Low wear, low coefficient of friction, thermallystable, isotropic hardness

Diamond cannot be simply made into smaller andsmaller flakes, then deposited on MEMS devices

Diamond (or diamond-like) film must be grown onsurface.


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UNCDULTRANANOCRYSTALLINE DIAMOND

A better method for producing diamond-like films.Grain size is 2-5nm.

Unlike conventional diamond film CVD, C60isintroduced into the reaction along with CH

4.

C60collides with itself, creating C2(carbon dimers)

These C2molecules enter the diamond lattice.

An abundance of C2is the goal of the UNCD creationprocess.


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SELFASSEMBLED

MONOLAYERS(SAMs)

O O O OSi Si Si SiO O O OSi Si Si Si

O O O

O O O OSi Si Si SiOH OH OH OH

Deposition

Two Types

Silane deposits on silicon

Thiol deposits on gold

Deposition Formations

Densely Packed

Amorphous Structure

Functional group determines:

applications

hydrophilicity/hydrophobicity

Used as:

binders for subsequent moleculeslubricants

Common hydrophobic SAMS:

OTS (long chain hydrocarbon)

FDTS (long chain fluorocarbon)


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Cantilever beams are fabricated of

different lengths

Cantilevers are put into contact with

surfaceLonger beams adhere to surface

Longest beam that does not stick

signifies adhesion force

SAM coated beams adhere after

longer lengths than oxide surface

Beam Structures

CANTILEVERBEAMARRAY

TECHNIQUE


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ECONOMICASPECTS OF TRIBOLOGY

The LUBRICANT REPORT estimated an amount exceeding

500 million pounds can be saved in the civilian sector of

UKby research in tribology.

The estimated 11 % total savings in annual US energyconsumption is equivalent to some 16 billion US dollars

by an expenditure in research and development o f an

estimated twenty-four million dollars.

Analysis of the failure of boiler tubes indicate that aboutone-third of all occurrences were due to erosion.

In UK, the application of tribological principles can effect

national energy savings. These are estimated at 468 to

700 million poundsper annum.


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IMPACTOFTRIBOLOGY

Since the publication of the Lubrication Report there has beenan increasing awareness throughout industry of the subject oftribology.

In the UK the National Centre for Tribology and IndustrialUnits of Tribology have been set up to provide advice t oindustry on the utilisation of existing knowledge.

Tribology is now recognized universally and President Carterof U.S.A. declared it to be a generic technology underlyingmany industrial sections and the prospectus for an IndustrialTribology Institute at Rensselaer Technology Center has beenpresented.


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REFERENCES

Mr. RAJSHEKHAR MATHAPATI

www.wikipedia.com

www.slideshare.com www.google.com

Tribology In Industries by SUSHIL KUMAR

Engineering Tribology by G.W. STACHOWIAK

Industrial Tribology by M.H. JONES
http://www.wikipedia.com/http://www.slideshare.com/http://www.google.com/http://www.google.com/http://www.slideshare.com/http://www.wikipedia.com/


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ANYQUERIES


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