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8/10/2019 Lubricants and Adhesives
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Welcome
to the
Monsoon Session 2014 @NIT Calicut
Enjoy the Pleasantness of Monsoon in the Campus!!!
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S7B. Tech. Monsoon 2014
CY 3011 LUBRICANTS AND ADHESIVES
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What is a lubricant ?
A substance introduced to reduce frictionbetween moving surfaces
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Lubricus= Slippery (Latin)
Early concept of lubrication was slipperiness
and a lubricant was considered as one
promoting sliding.
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Why is it needed?
Reduces friction
Helps to reduce tear and wear
Acts as a coolant Prevents corrosion
Keeps out dirt
Acts as a seal
http://www.google.co.in/imgres?q=lubrication+systems+in+cars&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=v3Z28ueNKgoFAM:&imgrefurl=http://www.english-online.at/travel/cars/cars-and-how-they-work.htm&docid=mXPx1KFQXuWWEM&imgurl=http://www.english-online.at/travel/cars/lubrication-system.gif&w=236&h=191&ei=2W_lUJ_-MILKrAeApoHoCg&zoom=1&iact=hc&vpx=837&vpy=175&dur=1076&hovh=152&hovw=188&tx=126&ty=90&sig=111074418618254241189&page=2&tbnh=144&tbnw=178&start=10&ndsp=15&ved=1t:429,r:14,s:0,i:1308/10/2019 Lubricants and Adhesives
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Major companies
.
http://www.google.co.in/imgres?q=lubricant+companies+in+india&start=335&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=Vohckiviq02LtM:&imgrefurl=http://topnews.in/companies/shell&docid=UoK6P4f98POesM&imgurl=http://topnews.in/files/Shell-Grand-prix-2010.jpg&w=400&h=400&ei=CXTlUP-4EY6Prgeb9IHYBw&zoom=1&iact=rc&dur=327&sig=111074418618254241189&page=19&tbnh=152&tbnw=170&ndsp=19&ved=1t:429,r:42,s:300,i:130&tx=125&ty=85http://www.google.co.in/imgres?q=lubricant+companies+in+india&start=375&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=1y9tU4_lvHGI6M:&imgrefurl=http://www.top10best.in/indian-companies-by-highest-revenue/&docid=L_X-Erb_g23ldM&imgurl=http://www.top10best.in/wp-content/uploads/2012/09/Hindustan-Petroleum.jpg&w=203&h=250&ei=CXTlUP-4EY6Prgeb9IHYBw&zoom=1&iact=rc&dur=499&sig=111074418618254241189&page=21&tbnh=148&tbnw=120&ndsp=19&ved=1t:429,r:81,s:300,i:247&tx=42&ty=77http://www.google.co.in/imgres?q=lubricant+companies+in+india&start=335&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=Vohckiviq02LtM:&imgrefurl=http://topnews.in/companies/shell&docid=UoK6P4f98POesM&imgurl=http://topnews.in/files/Shell-Grand-prix-2010.jpg&w=400&h=400&ei=CXTlUP-4EY6Prgeb9IHYBw&zoom=1&iact=rc&dur=327&sig=111074418618254241189&page=19&tbnh=152&tbnw=170&ndsp=19&ved=1t:429,r:42,s:300,i:130&tx=125&ty=85http://www.google.co.in/imgres?q=lubricant+companies+in+india&start=261&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=kB7TtEoaDEwE_M:&imgrefurl=http://www.exportersindia.com/indian-suppliers/industrial-lubricant.htm&docid=Ngo7wU2cn-7euM&imgurl=http://74.84.129.4/dynamic/company_logo/1179349.jpg&w=100&h=100&ei=o3PlUMDXAY6GrAeExoCgDg&zoom=1&iact=rc&sig=111074418618254241189&page=15&tbnh=80&tbnw=80&ndsp=18&ved=1t:429,r:73,s:200,i:223&tx=39&ty=37http://www.google.co.in/imgres?q=lubricant+companies+in+india&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=Wyep8xzmsoJdsM:&imgrefurl=http://www.bp.com/sectiongenericarticle.do?categoryId=9047472&contentId=7081136&docid=XSE9SAbzMgRVnM&imgurl=http://www.bp.com/liveassets/bp_internet/globalbp/STAGING/global_assets/images/locations/india/india_castrol_375x220.jpg&w=375&h=220&ei=I3HlUPi4CM3HrQfG5YDQCQ&zoom=1&iact=rc&sig=111074418618254241189&page=4&tbnh=139&tbnw=226&start=55&ndsp=18&ved=1t:429,r:58,s:0,i:268&tx=79&ty=71http://www.google.co.in/imgres?q=lubricant+companies+in+india&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=RkFhD2kme6s0wM:&imgrefurl=http://trade.indiamart.com/details.mp?offer=3489213912&docid=WOBK9wBSDr0d-M&imgurl=http://2.imimg.com/data2/XK/XB/MY-2222234/mak-lubricants-suppliers-in-chennai-250x250.jpg&w=250&h=250&ei=I3HlUPi4CM3HrQfG5YDQCQ&zoom=1&iact=rc&dur=234&sig=111074418618254241189&page=2&tbnh=145&tbnw=150&start=12&ndsp=19&ved=1t:429,r:17,s:0,i:139&tx=82&ty=114http://www.google.co.in/imgres?q=lubricant+companies+in+india&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=WzkqZGyXOpomUM:&imgrefurl=http://www.indiamart.com/ludhianaoil/profile.html&docid=zoCOhWAA6MbJwM&imgurl=http://2.imimg.com/data2/JL/WF/MY-/logo-250x250.gif&w=199&h=88&ei=I3HlUPi4CM3HrQfG5YDQCQ&zoom=1&iact=hc&vpx=144&vpy=307&dur=125&hovh=70&hovw=159&tx=86&ty=69&sig=111074418618254241189&page=2&tbnh=70&tbnw=159&start=12&ndsp=19&ved=1t:429,r:13,s:0,i:127http://www.google.co.in/imgres?q=lubricant+companies+in+india&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=kUQiebgkqF-iRM:&imgrefurl=http://www.indian-commodity.com/top-news/ioc-to-market-bio-lubricant-next-year.aspx&docid=4xKdw2lpsdGnaM&imgurl=http://www.indian-commodity.com/top-news/images/IOC-To-Market-Bio-Lubricant-Next-Year.gif&w=429&h=502&ei=I3HlUPi4CM3HrQfG5YDQCQ&zoom=1&iact=rc&dur=468&sig=111074418618254241189&page=2&tbnh=145&tbnw=125&start=12&ndsp=19&ved=1t:429,r:12,s:0,i:124&tx=42&ty=65http://www.google.co.in/imgres?q=importance+of+lubrication&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=sBkGuZuHsyGfBM:&imgrefurl=http://anikcorinstallations.com/the-importance-of-lubrication&docid=sn9GaL3u-tqyIM&itg=1&imgurl=http://anikcorinstallations.com/wp-content/uploads/2012/04/lubrication-service.jpg&w=224&h=224&ei=4CzlUJ2nFJHrrQeZh4Fg&zoom=1&iact=hc&vpx=846&vpy=95&dur=1342&hovh=179&hovw=179&tx=105&ty=79&sig=111074418618254241189&page=3&tbnh=133&tbnw=140&start=29&ndsp=19&ved=1t:429,r:34,s:0,i:1968/10/2019 Lubricants and Adhesives
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Adhesive
An adhesive is any substance that, when
applied to the surfaces of materials, binds the
surfaces together and resists separation.
The term "adhesive" may be used
interchangeably with glue, cement, mucilage
or paste.
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Why is it needed?
The use of adhesives offers many advantages over other binding
techniques such as sewing, welding, bolting etc.
These advantages include :
The ability to bind different materials together
The ability to distribute stress more efficiently acrossthe joint
Cost effectiveness of an easily mechanized process
Improvement in aesthetic(std) design
Increased design flexibility
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Major companies
United Gilsonite
Laboratories
(German)
MAPEI
http://www.logo-tape.de/en/index.htmhttp://www.uhu.com/de/produkte/korrektur-produkte.htmlhttp://www.ugl.com/http://www.brandsoftheworld.com/logo/fevicol?original=18/10/2019 Lubricants and Adhesives
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Surfaces
We need to know the features of surfaces
onto which the lubricant/ adhesive is to be
tried.
Let us initially go into it!
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Surfaces
Different surfaces
Metals, Ceramics, Polymers etc.
Evaluation of surface features Surface structure and properties
Substrate, work hardened layer, amorphous
layer, oxide layer, adsorbed gases,contaminants
http://www.google.co.in/imgres?q=surface+structure&um=1&hl=en&sa=N&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=HNpyFDyREQhCVM:&imgrefurl=http://icd.uni-stuttgart.de/?p=5655&docid=WiELfIXpRCmRnM&imgurl=http://icd.uni-stuttgart.de/icd-imagedb/Web_ICD_Research_ResponsiveStructure.jpg&w=640&h=480&ei=zyrlUMDWFs37rAf7nYHICw&zoom=1&iact=hc&vpx=766&vpy=118&dur=546&hovh=194&hovw=259&tx=148&ty=123&sig=111074418618254241189&page=1&tbnh=137&tbnw=192&start=0&ndsp=15&ved=1t:429,r:14,s:0,i:130http://en.wikipedia.org/wiki/File:Close_packing_box.svg8/10/2019 Lubricants and Adhesives
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Metals
o Metal (from Greekmtallon) - mine, quarry, metal
o The atoms of metallic substances are closely positioned to neighbouring
atoms in one of two common arrangements.
o The first arrangement is known as body-centered cubic. In this
arrangement, each atom is positioned at the centre of eight others.
o The other is known as face-centered cubic. In this arrangement, each
atom is positioned in the centre of six others.
o The ongoing arrangement of atoms in these structures forms a crystal.
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Hume-Rothery rules
Named after William Hume -Rothery
A set of basic rules describing the conditions
under which an element could dissolve in a
metal, forming a solid solution.
There are two sets of rules, one which refers
to substitutional solid solutions, and another
which refers to intertstitial solid solutions.
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Substitutional Solid Solution Rules
For substitutional solid solutions, the Hume-Rothery rules are:
The atomic radii of the solute and solvent atoms must differ by nomore than 15%
The crystal structures of solute and solvent must match
Complete solubility occurs when the solvent and solute have thesame valency
A metal will dissolve into a metal of higher valency to a greaterextent than one of lower valency.
The solute and solvent should have similar electronegativity.
(If the electronegativity difference is too great, the metals will tendto form intermetallic compounds instead of solid solutions.)
Foundations of Materials Science and Engineering, 4th ed., W. Smith and J.
Hashemi, pp.139-140 (2006).
http://www.clker.com/clipart-6994.htmlhttp://www.clker.com/clipart-11677.htmlhttp://www.clker.com/clipart-6994.html8/10/2019 Lubricants and Adhesives
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Interstitial solid solutions
Solute atoms must be smaller than the
interstitial sites in the solvent lattice.
The solute and solvent should have similar
electronegativity
Hume-Rothery Rules". Van Nostrand's Scientific Encyclopedia. John Wiley &
Sons, Inc. 2002.
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Metal Surface Texture
Lay
Shows the direction of the predominantsurface pattern
Flaws
Random irregularities
(cracks, holes, scratches)
WavinessRecurrent deviation from a flat surface , much likewaves on the surface.
http://www.google.co.in/imgres?q=surface+waviness&um=1&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=TCdlBeo7O7D5qM:&imgrefurl=http://procnc.com/resources/newsletter/august_2010_-_surface_roughness/&docid=PltloPXySljlUM&imgurl=http://procnc.com/images/content/texture.jpg&w=430&h=201&ei=0SvlUIbNGIWyrAeO8oCgAQ&zoom=1&iact=rc&dur=234&sig=111074418618254241189&page=2&tbnh=93&tbnw=200&start=15&ndsp=16&ved=1t:429,r:29,s:0,i:177&tx=116&ty=65http://www.google.co.in/imgres?q=surface+waviness&um=1&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=TCdlBeo7O7D5qM:&imgrefurl=http://procnc.com/resources/newsletter/august_2010_-_surface_roughness/&docid=PltloPXySljlUM&imgurl=http://procnc.com/images/content/texture.jpg&w=430&h=201&ei=0SvlUIbNGIWyrAeO8oCgAQ&zoom=1&iact=rc&dur=234&sig=111074418618254241189&page=2&tbnh=93&tbnw=200&start=15&ndsp=16&ved=1t:429,r:29,s:0,i:177&tx=116&ty=65http://www.google.co.in/imgres?q=surface+structure&um=1&hl=en&sa=N&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=spncrd6Kil074M:&imgrefurl=http://scriptedbypurpose.wordpress.com/participants/axel-kilian/&docid=9udR8MQNuhDYCM&imgurl=http://scriptedbypurpose.files.wordpress.com/2007/07/fish2m-g.jpg&w=400&h=253&ei=zyrlUMDWFs37rAf7nYHICw&zoom=1&iact=rc&dur=531&sig=111074418618254241189&page=1&tbnh=137&tbnw=242&start=0&ndsp=15&ved=1t:429,r:11,s:0,i:121&tx=109&ty=978/10/2019 Lubricants and Adhesives
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LAY
http://en.wikipedia.org/wiki/File:Surface_finish_lay_patterns.png8/10/2019 Lubricants and Adhesives
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Surface Roughness
Consists of closely spaced , irregular
deviationson a scale smaller than that for
waviness
Measured using a profilometer
http://en.wikipedia.org/wiki/File:Mechanical_filtering_of_surface_finish_trace.svg8/10/2019 Lubricants and Adhesives
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Roughness expressions
CLA
RMS
CLA = (ya+ yb+yc+)
n
a b c
de f
g h
y
x
Surface Profile
Central ( Datum) line
(Ya+ y
b+y
c+)
n(Ya+ yb+yc+)
n
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RMS = [ (ya2+ yb
2 + yc2++ yn
2)/n]1/2
122
RMS 63 is a smooth surface finish, RMS 125 is an average
manufacturing surface, RMS 25 is a very clean smooth surface
finish.
My cell phone has an RMS of around 32, smoother would make it too slippery.
A magazine cover is about 16.
A business card is between 32 and a 16..
A mirror or window is about 4.
RMS value is generally 11% higher than the Ra value for the same surfaceroughness.
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Density measurements
Crystalline areas are generally more densely
packed than amorphous(irregular) areas.
This results in a higher density, up to 15%
depending on the material.
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High quality surfaces
possess low coefficient
of friction.
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Contaminant ( 1-100nm)
Adsorbed gas ( 1nm)
Oxide ( 10-100 nm)
Amorphous ( 1-100 nm)
Work hardened
( 1-100 micron)
METAL SUBSTRATE
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Ceramics
A ceramic is an inorganic, non-metallic solid prepared by the
action of heat and subsequent cooling.
Ceramic materials may have a crystalline or partly crystalline
structure, or may be amorphous (e.g., a glass).
Bearing parts from ceramics
http://en.wikipedia.org/wiki/File:Ball_Bearing2.jpghttp://en.wikipedia.org/wiki/File:Israel-2013-Jerusalem-Temple_Mount-Dome_of_the_Rock-Detail_01.jpghttp://en.wikipedia.org/wiki/File:Si3N4bearings.jpg8/10/2019 Lubricants and Adhesives
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Most chip resistors are of the so-called thick film construction, where patterns of
inks containing glass frit and a mix of metals and oxides are printed onto a
ceramic substrate
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o Simple crystal structurescontaining ionic or
covalent bonds, or a mixture of the two.
o Magnesium oxide (used for furnace linings)- is
an ionic compound with cubic structure
o Silicon carbide- Covalent bonds and a
tetrahedral structure similar to that ofdiamond.
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o Complex silicate structures: The majority
of ceramic materials, in particular thosederived from clay, sand or cement,
contain the element silicon in the form of
silicates.
o The arrangements are many, involving
both chains of silicate ions, double chains
and links in sheet form
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Technical ceramics can be classified into three distinct
material categories:
Oxides: alumina, beryllia, ceria, zirconia
Nonoxides: carbide, boride, nitride, silicide
Composite materials: particulate reinforced, fiber reinforced,
combinations of oxides and nonoxides
Carbon-Ceramic ( SiC) Disk Brake
http://en.wikipedia.org/wiki/File:PCCB_Brake_Carrera_GT.jpg8/10/2019 Lubricants and Adhesives
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Grain size
The main disadvantage of Ceramicsas compared to Metals is their low fracture
toughness.
Toughness is a bulk mechanical property of a material; however it correlates
with its wear resistance particularly when the wear is a result of abrasive action
.
Fine grain structure allows to decrease the size of the surface micro-asperities
after the surface finish operation resulting in lower coefficient of friction.
Silicon nitride rocker thruster
( Left: on test stand ; Right :test with
propellants)
http://www.substech.com/dokuwiki/doku.php?id=ceramicshttp://www.substech.com/dokuwiki/doku.php?id=metalshttp://www.substech.com/dokuwiki/doku.php?id=fracture_toughness_tests_of_ceramicshttp://www.substech.com/dokuwiki/doku.php?id=fracture_toughness_tests_of_ceramicshttp://www.substech.com/dokuwiki/doku.php?id=mechanisms_of_wearhttp://en.wikipedia.org/wiki/File:Si3N4thruster.jpghttp://www.substech.com/dokuwiki/doku.php?id=mechanisms_of_wearhttp://www.substech.com/dokuwiki/doku.php?id=fracture_toughness_tests_of_ceramicshttp://www.substech.com/dokuwiki/doku.php?id=fracture_toughness_tests_of_ceramicshttp://www.substech.com/dokuwiki/doku.php?id=metalshttp://www.substech.com/dokuwiki/doku.php?id=ceramics8/10/2019 Lubricants and Adhesives
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Toughness
Toughness is a measure of the energy a
sample can absorb before it breaks.
If the height of a triangle is strength, and the
base of the triangle is strain, then the area is
proportional to strength times strain.
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Since strength is proportional to the force
needed to break the sample, and strain ismeasured in units of distance (the distance the
sample is stretched), then strength times strain
is force times distance. Force times distance is energy!
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Critical flaw size
Critical flaw size(the size of a flaw that results in rapid fracture)
Effect of flaw size on the fracture strength of a ceramic material is expressed by
the Griffith equation:
C=KIC/*Y( a)+where:
KICstress-intensity factor
athe flaw size;
Ygeometry factor
According to the equation flaws of lower size result in increased material
toughness and higher wear resistance.
Flaw size is generally proportional to the grain size.
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Homogeneous distribution of the matrix particles size and
pores size, second phaseparticles (toughening particles)
incorporated between the matrix particles, aid phase (binders,etc.) locating at the grains boundaries results in lowering the
flaw size and consequently in increase of the fracture strength
(according to the Griffith equation).
Higher fracture strength causes higher wear resistance.
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Polymer surface
Does not corrode but degrade.
Strength is low compared to metals
but has low frictional
characteristics.
Used to make bearings, gears, seals
etc.
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Hard, strong
Hard, tough
Soft, tough
http://www.google.co.in/imgres?q=polymers&start=184&um=1&hl=en&sa=N&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=-Jmvvwk8xP6b5M:&imgrefurl=http://www.snpinc.com/&docid=7KdD6iLAlQoZhM&imgurl=http://www.snpinc.com/images/home-promo-think-green.jpg&w=442&h=402&ei=ru_sUOO6B4PukQWFp4DYBw&zoom=1&iact=rc&dur=16&sig=111074418618254241189&page=12&tbnh=146&tbnw=160&ndsp=16&ved=1t:429,r:94,s:100,i:286&tx=86&ty=1058/10/2019 Lubricants and Adhesives
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Brinell Hardness Number
A steel or tungsten carbide ball of 10 mm dia is pressed against
a surface with a load ( kg).
The ratio of load P to the curved area of indentation is Brinell
Hardness
HB = 2P/{ (D) [ D- (D2 - d2)1/2 } kg/mm2
D is the diameter of the ball and d is the diameter of the
impression in mm
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Hardness and Resilience
H= cY
where Y is the yield stress, c= constant
Modulus of Resilience= Y2/2E
E= Youngs modulus
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A piece of steel has a hardness of 480 HB
( kg/mm2). Find the modulus of resilience
of this material , If E= 1400 MPa.
Take C = 3.
(MULTIPLY kg/mm2 WITH 9.807 TO CONVERT
INTO MPa)
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WE ARE GOING THROUGH AUGUST 2014!
Augusts birth flower is gladiolus or poppy,meaning:
beauty
strength of character and
love
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BASE OILS
Lubricants and adhesives are developed
based on different oils
Their flow features control the wetting of
the surfaces ( metal, ceramic or polymer)for effective application
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We now deal with:
Surface Tension
Viscosity Measurement
Newtonian and NonNewtonian Fluids
Melt Flow etc.
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Surface Tension
The force in Newton acting at right angles
along the surface of a liquid one metre in
length.
N/m
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Surface tension- Determination
Stalagmometer method Compares an experimental liquid with a reference
liquid
e = r x (nrde/ nedr)
ne = number of drops of experimental liquid in acertain volume
nr = number of drops of reference liquidde = density of experimental liquid
dr = density of the reference liquid
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Equal volumes of ethyl alcohol and water gave
50 drops and 30 drops respectively. Calculate
the surface tension of ethyl alcohol.
Given that surface tension of water is
7.2 x 10-2 Nm-1, density of water 996 kg/m3
and that of ethyl alcohol is 865 kg/m3.
How many times a water drop is heavier than a
drop of ethyl alcohol?
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3.75 x 10-2 N/m
mr/me = r/ e
= 1.92
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Capillary rise method
= rhdg/(2cos )
r= inner radius of capillary
h= height to which the liquid rises in the
capillary
d= density of the liquid
g= acceleration due to gravity= contact angle
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A liquid having density of 0.90 g/cm3 rises in a
capillary of radius 0.1 mm upto a height of 8
cm .Assume perfect wetting . Find the surface
tension.
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3.53 x 10-2 kg/s2 ( F= ma ; 1N= 1 kg m s-2)
3.53 x 10-2 N/m
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Viscosity- Capillary viscometers
These devices also are known as glass capillary viscometers
or Ostwald viscometers, named after Wilhelm Ostwald.Another version is the Ubbelohdeviscometer.
U-shaped glass tube held vertically in a controlled
temperature bath.. The time taken for the level of the liquid to pass between
two designated marks is proportional to the kinematic
viscosity
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Viscosity
Falling Sphere method
Stokes law is the basis of the falling sphere viscometer,.
The fluid is kept stationary in a vertical glass tube.
A sphere of known size and density is allowed to descend
through the liquid.
If correctly selected, it reaches terminal viscosity, which can
be measured by the time it takes to pass two marks on the
tube.
A series of steel ball bearings of different diameter is normally
used in the classic experiment to improve the accuracy of the
calculation.
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Viscosity
Stokes Law
= *2 g r2(ds - dl)]/ 9v
A steel ball ( density= 8 x 10 3 kg/m3) with 1 mm radius falls 10 cm
through a viscous liquid ( density = 2 x 10 3 kg/m3) in 20 seconds.
Find the absolute viscosity of the liquid.
2.6 kg m-1s-1
2.6 Pa s
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Newtons law
Laminar ( streamlined ) flow
The tangential force depends on:
Area of contact between two adjacent layers (A)
Velocity difference between the adjacent layers(dv)
The distance between adjacent layers (dx)
Hence F A dv/dx
F= A dv/dx
S l
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Supplementary notes..
Dimensions
F A dv/dx
F= A dv/dx
= F/ A (dv/dx)
= F dx/ A dv
= Nm/m2 ( m/s)
= N s m-2
= Pa.s
CGS: 1 Poise = 1 dynes s cm-2 = 0.1 Ns m-2
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Viscosity coefficients
Viscosity coefficients can be defined in two ways:
Dynamic viscosity, also absolute viscosity, the more usual one(typical units Pas, Poise, P);
Kinematic viscosityis the dynamic viscositydivided by thedensity (typical units cm2/s, Stokes, St).
Viscosity is a tensorial quantity that can be decomposed indifferent ways into two independent components. The mostusual decomposition yields :
Shear viscosity
bulk viscosity
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Shear viscosity, the most important one, often
referred to as simply viscosity, describing the
reaction to applied shear stress; simply put, it
is the ratio between the pressure exerted onthe surface of a fluid, in the lateral or
horizontal direction, to the change in velocity
of the fluid as you move down in the fluid (thisis what is referred to as a velocity gradient.).
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Volume viscosity(also called bulk viscosityorsecond viscosity) becomes important only forsuch effects where fluid compressibility isessential.
Extensional viscosity, a linear combination ofshear and bulk viscosity, describes the reaction toelongation, widely used for characterizingpolymers.
For example, at room temperature, water has adynamic shear viscosity of about 1.0103Pasand motor oil of about 250103Pas.
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Viscosities of materials
Substance Viscosity
( MPa s)
Air 10-5
Water 10-3
Glycerol 10
Polymer melts 102
-106
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Viscosity of blendsThe viscosity of the blend of two or more liquids can be estimated using the
Refutas equation.The calculation is carried out in three steps.
The first step is to calculate the Viscosity Blending Number (VBN) (also called the
Viscosity Blending Index) of each component of the blend:
where vis the kinematic viscosity in centistokes (cSt). It is important that the
kinematic viscosity of each component of the blend be obtained at the sametemperature.
The next step is to calculate the VBN of the blend, using this equation:
wherexX
is the mass fraction of each component of the blend.
Once the viscosity blending number of a blend has been calculated using equation
(2), the final step is to determine the kinematic viscosity of the blend by the equation
for v:where VBNBlendis the
viscosity blending
number of the blend.
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shear stress
shear rate
According to
Newton
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r
Pseudoplastic : shear-thinning fluids
Dilatant : shear-thickening fluids
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n> 1 Dilatants
log n=1 Newtonian
n
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Time dependa(e)nt and time independa(e)nt
fluids
Rheopectic fluid: increases with increasing t
Thixotropic fluid, decreases with increasing t
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Leonardo da vinci (1452-1519)
Proposed the fundamental principles
of friction and lubrication
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Classical laws of friction
Frictional force is proportion to the appliedload
Coefficient of friction is independent of the
apparent area of contact Static coefficient is greater than dynamic
coefficient
Coefficient of friction is independent of slidingspeed
Coefficient of friction is material dependent
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Types of lubrication
Thick-film lubricationInterposing a fluid film that completely
separates the sliding surfaces.
Hydrodynamic lubrication.
In this, the two moving parts are separated by a thick film of
lubricant, about 1000A thick.
This type of lubrication occurs in machine parts of low load and
high speed such as in clocks, sewing machines (delicateinstruments).
The coefficient of friction is low; typically 0.001 to 0.03.
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Boundary lubrication
A condition that lies between unlubricated sliding and fluid
film lubrication is referred to asboundary lubrication. Thin film lubrication
It occurs in machine parts of high load and low speed. Here
thick film of lubricant cannot be maintained between the
moving surfaces but the lubricants are adsorbed physically /
chemically on the metal surfaces. The lubricant film thickness is
as low as 2-3-molecule thickness with the frictional coefficient
being 0.05 to 0.15.
Extrerme pressure lubrication
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Extrerme pressure lubrication
This mechanism occurs under conditions of high load and high speed.
Under these conditions, the lubricant may vaporize / decompose due
to local heat. Special additives called extreme pressure additives are used with
lubricants to overcome this difficulty.
Organic compounds containing active groups such as chlorine,
phosphorous, sulphur are used as extreme pressure additives.
At high temperatures, the additives react with metals giving metallic
chlorides / sulphides / phosphides possessing high melting points.
Variation of (viscosity)
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Variation of (viscosity)
with temperature T
Viscosity
Temperature
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Too Thick
whencold
Viscosity / Temperature Relationship
Thick
SAE 40
SAE10W40
SAE
10W
Too Thinwhen
hot
Increasing
Viscosity
Thin
Winter starting
temperature
Engine operating
temperature100oc0oc
Viscosity index
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Viscosity index
Measure of fluids change of viscosity with
temperature.
Empirical number
Higher the VI lower will be the change of viscositywith temperature
Indicator of temperature range of operations
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SUV ( Saybolt Universal Viscosity)
Cylindrical brass cup in the bottom of which
is an orifice of specific dimension.
The cup is surrounded by an oil bath.
At the test temperature, the time requiredfor 50 mil of the liquid to run down through
the orifice is noted.
Unit is sec.
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Calculation
VI= [( L-U)/ (L-H) ] x 100
VI = Viscosity Index of the oil under test
L= Viscosityof a low viscosity standard oil
having a low VI at 100 F ( Typically gulfoil)
H = Viscosityof a high viscosity standard oil
having a high VI at 100 F ( Typically Pennsylvanian
oil)
U = Viscosity of the test oil at 100 F
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Try it
An oil has a SUV of 600 seconds at 100 F.
Pennsylvanian oil has a SUV of 500 sec at 100 F
while gulf oil has a SUV of 800 sec at 100 F.
Find the viscosity index of the experimental oil.
VI = 66.67
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API gravity
A measure of how heavy or light a petroleumliquid is comparedto water.
If its API gravity is greater than 10, it is lighter and floats on
water; if less than 10, it is heavier and sinks.
API gravity is thus an inverse measure of the relative density of a
petroleum liquid and the density of water, but it is used to
compare the relative densities of petroleum liquids.
For example, if one petroleum liquid floats on another and is
therefore less dense, it has a greater API gravity.
http://en.wikipedia.org/wiki/Petroleumhttp://en.wikipedia.org/wiki/List_of_crude_oil_productshttp://en.wikipedia.org/wiki/List_of_crude_oil_productshttp://en.wikipedia.org/wiki/Petroleum8/10/2019 Lubricants and Adhesives
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The formula to obtain API gravity ofpetroleumliquids, from specific gravity(SG), is:
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Effect of additives
Hydrodynamic effect
1. Einstein Equation (1906)
Viscosity of a dispersion can be represented as:
f = u(1+2.5C)
C= volume fraction of spheres
u= viscosity of the liquid where uniformly spherical
particles are distributed
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2. Guth and Gold Equation ( 1938)
f = u(1+2.5C+14.1 C2)
3. Guth Equation ( 1945) [ For non-spherical
particles]
f = u(1+0.67 f C+ 1.62f2C2)
f is the shape factor, the ratio of the longest
to the shortest diameter of the particles
Flash Point
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Flash Point
Lowest temperature at which the vapor above theliquid will ignite under flame
Indicated safe maximum temperature of
operation. Indicator of volatility
Measured in C
h ?
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Why is it important?
The flash pointof a volatilematerial is the
lowest temperatureat which it can vaporize to
form an ignitable mixture in air.
Measuring a flash point requires an ignitionsource.
At the flash point, the vapor may cease to burn
when the source of ignition is removed.
h ?
http://en.wikipedia.org/wiki/Volatility_(chemistry)http://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Airhttp://www.google.co.in/imgres?imgurl=http://images.wisegeek.com/motor-oil-being-poured-out.jpg&imgrefurl=http://www.wisegeek.org/what-are-the-different-types-of-lubricants.htm&usg=__s7R1CZGP0EFC1PYcANhnvhiurOk=&h=1302&w=1000&sz=65&hl=en&start=263&zoom=1&tbnid=MrF_EXSRD_A3wM:&tbnh=150&tbnw=115&ei=y54kUZbeAZHorQeU-4H4CA&prev=/search?q=lubricating+oils-+cartoon&start=260&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CC0QrQMwAjiEAghttp://en.wikipedia.org/wiki/Airhttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Volatility_(chemistry)8/10/2019 Lubricants and Adhesives
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Why is it important.?
The flash point is not to be confused with the
autoignition temperature, which does not require an
ignition source, or the fire point, the temperature at
which the vapor continues to burn after being ignited.
Neither the flash point nor the fire point is dependent
on the temperature of the ignition source, which is
much higher.
h i i i ?
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Why is it important?
The flash point is often used as a descriptive characteristicof liquids, and it is also used to help characterize the fire
hazards of liquids.
Flash point refers to both flammableliquids and
combustibleliquids. There are various standards for
defining each term.
Liquids with a flash point less than 37.8 C (100 F) areconsidered flammable, while liquids with a flash point
above it are considered combustible.
H i fl h ?
http://en.wikipedia.org/wiki/Flammabilityhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Flammabilityhttp://www.google.co.in/imgres?imgurl=http://abiramiengg.com/transformer/flashpoint.jpg&imgrefurl=http://abiramiengg.com/transformer-oil-test-lab.htm&usg=__vKRPhfLTQb87irT68Mhd_RW7Ruo=&h=241&w=250&sz=78&hl=en&start=66&zoom=1&tbnid=jKthbrMSmX_GqM:&tbnh=107&tbnw=111&ei=Gl4kUaeyDIz9rAeXkYGAAg&prev=/search?q=flash+point+of+lubricating+oils&start=60&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CDMQrQMwBTg88/10/2019 Lubricants and Adhesives
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How it flashes?Every liquidhas a vapour pressure, which is a functionof that
liquid's temperature.
As the temperature increases, the vapour pressure increases.
As the vapor pressure increases, the concentration of vapor of
the flammable liquid in the air increases. Hence, temperaturedetermines the concentration of vapour of the flammable
liquid in the air.
A certain concentration of vapour in the air is necessary tosustain combustion, and that concentration is different for each
flammable liquid. The flash point of a flammable liquid is the
lowest temperature at which there will be enough flammable
vapour to ignite when an ignition source is applied.
Measurement-
http://en.wikipedia.org/wiki/Liquidhttp://en.wikipedia.org/wiki/Vapor_pressurehttp://en.wikipedia.org/wiki/Function_(mathematics)http://en.wikipedia.org/wiki/Temperaturehttp://www.google.co.in/imgres?imgurl=http://abiramiengg.com/transformer/flashpoint.jpg&imgrefurl=http://abiramiengg.com/transformer-oil-test-lab.htm&usg=__vKRPhfLTQb87irT68Mhd_RW7Ruo=&h=241&w=250&sz=78&hl=en&start=66&zoom=1&tbnid=jKthbrMSmX_GqM:&tbnh=107&tbnw=111&ei=Gl4kUaeyDIz9rAeXkYGAAg&prev=/search?q=flash+point+of+lubricating+oils&start=60&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CDMQrQMwBTg8http://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Function_(mathematics)http://en.wikipedia.org/wiki/Vapor_pressurehttp://en.wikipedia.org/wiki/Vapor_pressurehttp://en.wikipedia.org/wiki/Vapor_pressurehttp://en.wikipedia.org/wiki/Liquid8/10/2019 Lubricants and Adhesives
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Measurement
open cup and closed cup
There are two basic types of flash pointmeasurement: open cup and closed cup.
In open cup devices the sample is contained in anopen cup which is heated, and at intervals a flame isbrought over the surface. The measured flash pointwill actually vary with the height of the flame abovethe liquid surface, and at sufficient height the
measured flash point temperature will coincide withthe fire point. The best known example is theCleveland open cup(COC).
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Closed cup testers
There are two types of closed cup testers: non-equilibrium,such as Pensky-Martens where the vapours above the liquidare not in temperature equilibrium with the liquid, andequilibrium, such as Small Scale (commonly known asSetaflash) where the vapours are deemed to be in
temperature equilibrium with the liquid.
In both the above types, the cups are sealed with a lidthrough which the ignition source can be introduced.
Closed cup testers normally give lower values for the flash
point than open cup (typically 5
10 C lower, or 9
18 F lower)and are a better approximation to the temperature at whichthe vapour pressure reaches the lower flammable limit.
ASTM D93 ISO 2719 DIN 51758
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ASTM D93, ISO 2719, DIN 51758
Methods for determining the flash point of a liquid arespecified in many standards. For example, testing by the
Pensky-Martens closed cupmethod is detailed in ASTM D93,
ISO 2719, DIN 51758.
Fuel Flash point
http://en.wikipedia.org/wiki/Pensky-Martens_closed_cuphttp://www.google.co.in/imgres?imgurl=http://www.infovisual.info/05/img_en/002%20Anatomy%20of%20an%20automobile.jpg&imgrefurl=http://www.mahjoob.com/en/forums/showthread.php?t=204338&usg=__zPu6_llPCJ7Eqe4Q_hkIZSv_oDs=&h=391&w=682&sz=98&hl=en&start=18&zoom=1&tbnid=VFyMQXRpC2qmHM:&tbnh=80&tbnw=139&ei=mpokUfymIcPtrAf2pIDwBQ&prev=/search?q=lubrication+system+in+ic+engines&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CEsQrQMwEQhttp://en.wikipedia.org/wiki/Pensky-Martens_closed_cuphttp://en.wikipedia.org/wiki/Pensky-Martens_closed_cuphttp://en.wikipedia.org/wiki/Pensky-Martens_closed_cup8/10/2019 Lubricants and Adhesives
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p
Ethanol(70%) 16.6 C (61.9 F)
Diesel>62 C (144 F)
Jet fuel>60 C (140 F)
Kerosene(paraffin) >3872 C (100162 F)
Vegetable oil(canola) 327 C (621 F)
Cloud Point and Pour Point
http://en.wikipedia.org/wiki/Ethanolhttp://en.wikipedia.org/wiki/Diesel_fuelhttp://en.wikipedia.org/wiki/Jet_fuelhttp://en.wikipedia.org/wiki/Kerosenehttp://en.wikipedia.org/wiki/Vegetable_oilhttp://www.google.co.in/imgres?imgurl=http://lh4.ggpht.com/_EhOQGW2GHBg/SmA9_aji8tI/AAAAAAAAHoc/Ix8sdLWEpno/clip_image0063.gif?imgmax=800&imgrefurl=http://www.meadinfo.org/2009/07/design-and-fabrication-of-ic-engine.html&usg=__XH3flnrdT51qhzZleFSfprYmpew=&h=330&w=499&sz=62&hl=en&start=55&zoom=1&tbnid=QQoQdplcc4-6rM:&tbnh=86&tbnw=130&ei=2ZokUcOiNsn3rQe7yoEI&prev=/search?q=lubrication+system+in+ic+engines&start=40&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CEUQrQMwDjgohttp://en.wikipedia.org/wiki/Vegetable_oilhttp://en.wikipedia.org/wiki/Kerosenehttp://en.wikipedia.org/wiki/Jet_fuelhttp://en.wikipedia.org/wiki/Diesel_fuelhttp://en.wikipedia.org/wiki/Ethanol8/10/2019 Lubricants and Adhesives
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Cloud point- Temperature at which cloudinessappears
Pour Point -Lowest temperature at which a fluid
will flow Latter indicates lowest operating temperature
Measured in C
A d l b i t
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A good lubricant possesses ..
:
High boiling point ( Flash point)
Low freezing point ( Pour point)
High viscosity index
Thermal stability
Hydraulic StabilityDemulsibility
Corrosion prevention
High resistance to oxidation
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Degradation/Combustion
Calculations
Flue gas analysis
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Essentially an exothermic reaction
Oil + Oxygen = Products + Heat
More heat content Lower heat content
Typically,
C(S) + O2 (g) CO2(g) + 97 kcal
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Combustion Wt. of oxygen needed
(g)
Volume of oxygen ( m3)
C + O2 CO2
a g or m3
(a x 32)/ 12 a x 1
H2 + O.5 o2 H2oy g or m3
(y x 16)/2 Y x 0.5
CO + O.5 o2 CO2
z g or m3
(z x 16)/28 Z x .0.5
S+ O2 SO2
p g or m3
(p x 32)/32 P x 1
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3. Air contains 21 % of oxygen by volume and 23 % oxygenby mass.
1kg of oxygen is supplied by (1 x 100)/23 = 4.35 kg of air
1 m3 of oxygen is supplied by (1 x 100)/21 = 4.76 m3 ofair
4. 28.94 g/ mol is taken as the molar mass of air
5. Minimum oxygen required for combustion is:Theoretical oxygen - Oxygen present in the fuel
FUNCTIONAL POLYMERS 2011
Problem 1
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Problem 1
What could be the weight and volume of airrequired for the combustion of 1 kg of
carbon?
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12 g of C needs 32 g of oxygen.
1kg of carbon needs (32/12) x 1000= 2667 g =
2.667 kg
Wt of air required = (100/23) x 2.667 = 11.59
kg
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32 g of oxygen occupies 22.4 l.
2667 g will occupy 22.4/32 x 2667 = 1866.9 L
Volume of air = (100/21) x 1866.9 = 8890 L =
8.89 m3
Carbon residue
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Carbon residue
Weighed amount of lubricant is heated in asilica crucible having a close fitting cover with
a small opening.
Carbon residue= (wt of residue/wt of sample)
x 100
Liquid lubricants
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Liquid lubricants
Liquid lubricants are fluidsthat preventfriction and wear between two machine
parts. Common liquid lubricants include water-
based lubricants and synthetic oils.
Many liquid lubricants can pollute theenvironment, so proper disposal of used
lubricant is essential.
Mineral Oils
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Mineral oils are usually made from
crude(impure) petroleum, which can beprocessed to create fluids with varying
viscosity.
TYPICAL COMPOSITION OF
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AN ENGINE OIL
Components Base oils
Dispersants
Detergents
Anti-wear
Anti-oxidant
Pour point depressant
Anti-foam
Viscosity Improver
Quality oil
%
>70
0 to 7
0 to 3
0 to 20 to 3
0.2
0.001
5 to 15
100%
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SMART LUBRICANTS
SAE Coding
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SAE Coding
The Society of Automotive Engineers (SAE) has established anumerical code system for grading motor oils according to theirviscosity characteristics.
SAE viscosity gradings include the following, from low to highviscosity: 5, 10, 15, 20, 25, 30, 40, 50 or 60.
The numbers 5, 10, 15 and 25 are suffixed with the letter W,designating they are "winter" (not "weight") or cold-startviscosity, at lower temperature.
Ref: Thomas R. Lynch, Process Chemistry of Lubricant Base Stocks,CRC Press, Boca Raton, FL, 2008.
NR + SAE
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ISNR -5 was dissolved in SAE OilSample Code Amount of SAE 30 Oil
(ml)
Amount of NR
(g)
A1 250 5
A2 250 10
A3 250 15
A4 250 20
A5 250 25
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SAMPLE POUR
POINT (c)
SAE
30(TURBO)
-9
A1 -11
A2 -14
A3 -17
A4 -19
A5 -21
SAE 60 -29
Synthetic Oils
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Synthetic oils are man-made lubricants that have
greater operating ranges than mineral oil lubricants.
As a result, synthetic oils are better choices than
mineral oils in certain circumstances. Esters, silicone fluid and fluorocarbons are examples
of synthetic oils.
Silahydrocarbonsare synthetic oils composed, as the
name suggested, from hydrogen, silicon and carbon.Silahydrocarbons have the potential to provide fluidity
and lubrication in space machinery.
Vegetable-Based Liquid Lubricants
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Liquid lubricants can also be manufactured from
plant life. Sources of vegetable-based lubricants
include:
canola
palm oil
rapeseed
sunflower seed.
While more environmentally friendly than mineral and
synthetic oils, vegetable-based liquid lubricants are
rarel used in vehicles or machiner
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Semi-solids
Grease
Grease is defined as a solid or semi-fluid
product which is a dispersion of athickening agent in a liquid lubricant alongwith some additives.
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Greaseis a semisolidlubricant.
It generally consists of a soapemulsified
with mineralor vegetable oil.
The characteristic feature of greases is that
they possess a high initial viscosity, which
upon the application of shear, drops with
time. This change in viscosity, as we have
seen earlier , is called thixotropy.
Why use a Grease?
http://en.wikipedia.org/wiki/Quasi-solidhttp://en.wikipedia.org/wiki/Lubricanthttp://en.wikipedia.org/wiki/Soaphttp://en.wikipedia.org/wiki/Emulsionhttp://en.wikipedia.org/wiki/Mineral_oilhttp://en.wikipedia.org/wiki/Vegetable_oilhttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Thixotropyhttp://www.crystalgraphics.com/powerpictures/Image.Search.Details.asp?product=cg3p9776293chttp://en.wikipedia.org/wiki/Thixotropyhttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Vegetable_oilhttp://en.wikipedia.org/wiki/Mineral_oilhttp://en.wikipedia.org/wiki/Emulsionhttp://en.wikipedia.org/wiki/Soaphttp://en.wikipedia.org/wiki/Lubricanthttp://en.wikipedia.org/wiki/Quasi-solid8/10/2019 Lubricants and Adhesives
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Why use a Grease?
Grease offers unique characteristics which makes it
particularly useful in machine elementsStay where it is putAllows unattended service for long periods(sealed for life)Requires less frequent application for areas ofpoor accessibilitySeals out contaminantsOperate over a wide temperature rangeSolid additives can be used without concern of
settling outLow leakage means they are effective in wornequipment
Advantages over Oil
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g
Grease stays in place because of semisolid nature
whereas oils flow awayBearing designs simplified and maintenance workreduced as there is no oil pump/sump
For long time or packed for life applications grease ispreferred e.g.. electric motors, wheel bearings of new
generation passenger cars, etc.Grease works as a sealant in -
Dusty environment, cement plants, mining industriesetc.
Corrosive water in paper mills
Corrosive gases/liquids in chemical industries.
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Sodium Based Calcium Based
Lithium Base Non-Soap / Synthetic
Greases
Scheme
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Scheme
Oil
Soap
Grease -Additives
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Teflonis added to some greases to improve their lubricating properties.
Gear greases consist of rosinoil, thickened with limeand mixed with mineral oil,with some percentage of water. Special-purpose greases contain glycerolandsome esters. They are used, for example, in low-temperature conditions.
Some greases are labeled "EP", which indicates "extreme pressure". Under high
pressure or shock loading, normal grease can be compressed to the extent thatthe greased parts come into physical contact, causing friction and wear.
EP grease contains solid lubricants, usually graphite and/or molybdenumdisulfide, to provide protection under heavy loadings. The solid lubricants bondto the surface of the metal, and prevent metal-to-metal contact and theresulting friction and wear when the lubricant film gets too thin.
Copperis added to some greases for high pressure applications, or wherecorrosion could prevent dis-assembly of components later in their service life.
Scheme
http://en.wikipedia.org/wiki/Teflonhttp://en.wikipedia.org/wiki/Rosinhttp://en.wikipedia.org/wiki/Calcium_oxidehttp://en.wikipedia.org/wiki/Glycerolhttp://en.wikipedia.org/wiki/Glycerolhttp://en.wikipedia.org/wiki/Molybdenum_disulfidehttp://en.wikipedia.org/wiki/Molybdenum_disulfidehttp://en.wikipedia.org/wiki/Molybdenum_disulfidehttp://en.wikipedia.org/wiki/Copperhttp://www.google.co.in/imgres?imgurl=http://cache1.asset-cache.net/gc/152407287-monkey-holding-test-tube-gettyimages.jpg?v=1&c=IWSAsset&k=2&d=eVIekUjLgTIytqnpQqTIv1pquk67ezOQ34U7wp501Q/5r+K8bG7obO5kHlFJrUL9&imgrefurl=http://www.gettyimages.com/detail/illustration/monkey-holding-test-tube-royalty-free-illustration/152407287&usg=__XJztIXLkm00k9AG6PqM5lL-oZRg=&h=463&w=370&sz=62&hl=en&start=7&zoom=1&tbnid=B3HfkYJ4eFUjzM:&tbnh=128&tbnw=102&ei=ZrAkUeuBOYKJrAelqYGoAQ&prev=/search?q=monkey+with+a+test+tube&um=1&hl=en&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CDUQrQMwBghttp://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Molybdenum_disulfidehttp://en.wikipedia.org/wiki/Molybdenum_disulfidehttp://en.wikipedia.org/wiki/Glycerolhttp://en.wikipedia.org/wiki/Calcium_oxidehttp://en.wikipedia.org/wiki/Rosinhttp://en.wikipedia.org/wiki/Teflon8/10/2019 Lubricants and Adhesives
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Scheme
Oil
Polymer
GREASES COMPOSITION
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BASE OIL + THICKENER+ADDITIVES
( 75-85%) ( 10-15 %) ( 0-5%)
MINERAL
SYNTHETICVEGETABLE
SOAP BASE
NON-SOAPPOLYMERS
ANTI-OXIDANT
ANTI-CORROSIONEP/ANTI-WEAR
TACKINESS AGENT
SOLID FILLER
METAL DEACTIVATOR
STRUCTURE MODIFIER
Silicone grease
http://www.google.co.in/imgres?imgurl=http://img.photobucket.com/albums/v51/MarieAlice/cartoon-car-rhs.jpg&imgrefurl=http://www.ayearfromoakcottage.org/2009_03_01_archive.html&usg=__Eqa6GinFKBXVWmAYLAmuPr9eGlw=&h=427&w=490&sz=32&hl=en&start=65&zoom=1&tbnid=fyc9NAASXJ0fnM:&tbnh=113&tbnw=130&ei=KbAkUYLfLoHPrQfbhICgAQ&prev=/search?q=greased+car+cartoons&start=60&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CDEQrQMwBDg88/10/2019 Lubricants and Adhesives
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Silicone grease
It is a waterproof greasemade by combining asilicone oilwith a thickener.
Most commonly, the silicone oil is
polydimethylsiloxane and the thickener isamorphousfumed silica.
Using this formulation, silicone grease is atranslucent white viscous paste, with exact
properties dependent on the type andproportion of the components.
http://en.wikipedia.org/wiki/Grease_(lubricant)http://en.wikipedia.org/wiki/Silicone_oilhttp://en.wikipedia.org/wiki/Polydimethylsiloxanehttp://en.wikipedia.org/wiki/Amorphoushttp://en.wikipedia.org/wiki/Fumed_silicahttp://en.wikipedia.org/wiki/Fumed_silicahttp://en.wikipedia.org/wiki/Fumed_silicahttp://en.wikipedia.org/wiki/Fumed_silicahttp://en.wikipedia.org/wiki/Amorphoushttp://en.wikipedia.org/wiki/Polydimethylsiloxanehttp://en.wikipedia.org/wiki/Silicone_oilhttp://en.wikipedia.org/wiki/Silicone_oilhttp://en.wikipedia.org/wiki/Silicone_oilhttp://en.wikipedia.org/wiki/Grease_(lubricant)8/10/2019 Lubricants and Adhesives
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Silicone grease is commonly used forlubricating and preserving rubber parts, suchas O-rings.
Additionally, silicone grease does not swell orsoften the rubber, which can be a problemwith hydrocarbonbased greases.
It functions well as a corrosion-inhibitor and
lubricant for purposes that require a thickerlubricant.
Dropping point
http://en.wikipedia.org/wiki/O-ringhttp://en.wikipedia.org/wiki/Hydrocarbonhttp://en.wikipedia.org/wiki/Hydrocarbonhttp://en.wikipedia.org/wiki/O-ringhttp://en.wikipedia.org/wiki/O-ringhttp://en.wikipedia.org/wiki/O-ring8/10/2019 Lubricants and Adhesives
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Dropping point
The lowest temperature at which a grease , whenheated under specific conditions, becomes
sufficiently fluid so that a drop will fall from a cup
having a hole of specific dimensions.
Shows the thermal stability of grease.
Lime soap greases have lower dropping point
than greases of sodium, lithium.
Can be increased by adding thickeners such as
carbon black.
Solid lubrication
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Solid lubrication
Solids such as graphite and molybdenum
disulfide are widely used when normal
lubricants do not possess sufficientresistance to load or temperature
extremes.
How is a Lubricant made?
http://www.google.co.in/imgres?imgurl=http://www.pexashop.com/images/uploads/cog-sml.jpg&imgrefurl=http://www.pexashop.com/dry-film-lubricants/cat_3.html&usg=__sKtq9SX6USMnFhsGWWvRmvfHXyo=&h=150&w=150&sz=4&hl=en&start=146&zoom=1&tbnid=yar4IGhB7MS0DM:&tbnh=96&tbnw=96&ei=aqEkUfejJITJrAeHyYG4Dw&prev=/search?q=solid+lubricants-+graphite+and+molybdenum+sulphide&start=140&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CDMQrQMwBTiMAQhttp://www.google.co.in/imgres?imgurl=http://i00.i.aliimg.com/photo/v1/489227460/MoS2.jpg_140x140.jpg&imgrefurl=http://www.alibaba.com/showroom/mos2.html&usg=__yfseDcB-q0-638Ox6rEdwflAdQE=&h=140&w=140&sz=6&hl=en&start=84&zoom=1&tbnid=RL-GqF3NTEfSnM:&tbnh=93&tbnw=93&ei=BKEkUb7nBs7MrQeo34DYAQ&prev=/search?q=solid+lubricants-+graphite+and+molybdenum+sulphide&start=80&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CC8QrQMwAzhQ8/10/2019 Lubricants and Adhesives
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How is a Lubricant made?
BASE MATERIAL + ADDITIVES
FINISHED LUBRICANT
Peer reviewed
JOURNALS
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JOURNALS
Tribology Transactions
Journal of Synthetic Lubricants
Tribology Letters
Lubrication Science
AN INTERESTING SITE BY TOTAL
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AN INTERESTING SITE BY TOTAL
http://www.total-
s.com/lub/content/NT0012EE62.pdf
Sense the true engineering!
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Se se t e t ue e g ee g
Indias first indigenousaircraft carrier gets
launched for Indian
Navy at CochinShipyard
(12/8/2013)
VIKRANT