Study of Grease testing on SUJ2 material

1. BITS, PILANI – K. K. BIRLA GOA CAMPUS
Effect of Surface Finish On The Friction & Wear-Behaviour
Of SUJ2 Bearing Material at different velocity & viscosity.
Prepared By
P.N Uday
2010H141029G

2. Introduction(contd.)
1. Most greases are used in rolling elements with
lesser quantities in plain bearings, gear boxes & open
gears.
2. A satisfactory grease is expected to:
a)Provide adequate lubrication to reduce friction & to
prevent harmful wear of bearing components.
b)Protect against corrosion.
c)Act as a seal to prevent entry of dirt & water.
BITS, PILANI – K. K. BIRLA GOA 2
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3. Introduction
3. A grease typically consists of the following three
components :-
a)Base Oil
b)Thickener
c)Performance enhancing additives.
BITS, PILANI – K. K. BIRLA GOA CAMPUS 3

4. Introduction(contd.)
4)A base oil usually represents about 90% of the
total weight of the grease. It performs the
actual lubrication.
5)This is commonly a mineral oil, can be a
vegetable oil or a synthetic lubricating fluid.
6)In most greases refined petroleum oils are
used. They offer a good combination of
performance characteristics & price.
BITS, PILANI – K. K. BIRLA GOA 4
CAMPUS

5. Introduction(contd.)
7) The physical properties important for base-oil
selection are:-
a)Lubricating properties.
b)Viscosity (strength of the lubricating film).
c)Resistance to oxidation.(high temperature & life-
time).
d)Volatility.
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6. Methodology
1)Three different surface roughness of discs were
considered:-
a)Rough (Ra - 0.3-0.5 µm)
b)Medium (Ra - 0.1-0.3 µm)
c) Smooth(polished) (Ra - 0.01-0.09 µm)
2) Three greases with different viscosities were chosen:-
a)N6C (10cst)
b)Microlon (25cst)
c) Chemtura (20cst)
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7. Methodology(contd.)
3) Finally three different velocities of operation were
considered:-
a)V1 = 0.25 m/s
b)V2 = 0.5 m/s
c)V3 = 0.75 m/s
4) Hardware used :- the TRIBOMETER (CETR)
5) Software used :- UMT
6) Module used :- Ball on Disc
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8. Methodology(contd.)
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9. RESULTS
coeff of
Ra V D W T Grease Distance R.P.M d1 d2 Avg Scar Dia
friction
0.0389 0.25 30 400 66.66 N6C(10cst) 1000m 159.23 935 942 938.5 0.1234
0.49 0.75 50 400 22.22 N6C(10cst) 1000m 287 1101 1083 1092 0.1253
0.2531 0.25 30 400 66.66 Microlon(25cst) 1000 159.23 700 673 686.5 0.1244
0.012 0.75 50 400 22.22 Microlon(25cst) 1000 287 896 833 864.5 0.1255
0.2531 0.5 50 400 33.33 Microlon(25cst) 1000 191 875 876 875.5 0.1223
Chemtura
0.0118 0.25 30 400 66.66 1000 159.23 906 932 919 0.1142
sample1
Chemtura
0.0329 0.75 50 400 22.22 1000 287 705.7 653.6 679.65 0.09392
sample1
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10. Scar Images
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11. Scar Images(contd.)
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12. Conclusion
1)Selection of grease is very important.
2)Polished surfaces are the best for bearings.
3)The base oil of a grease has to be a good grade oil
especially mineral oil.
4)Chemtura has Calcium Sulphonate as the base oil
which is the best.
BITS, PILANI – K. K. BIRLA GOA 12
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13. Thanks
BITS, PILANI – K. K. BIRLA GOA CAMPUS 13