This document discusses the use of nanoadditives in lubricants to improve tribological performance. It explains that nanoadditives such as oxides and sulfides can form protective transfer layers on metal surfaces in boundary lubrication regimes. The document discusses how functionalizing nanoadditives can improve their dispersion stability in lubricants. Test results show that lubricants with nanoadditives reduced wear rates in engines and bearings compared to conventional lubricants. In summary, nanoadditives provide improved lubrication and wear protection by forming protective surface layers at the interface of moving parts.

1. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Nanocomposite Materials: lubricants
Dr. Alberto Borghi
Tec Star Srl - President | CEO

2. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Summary
Nanoadditives for tribological
performance in lubricants
 How they work
 Dispersion and stability
 liquid and grease nanocomposite lubricants:
tribological properties: tribological properties
Example of applications

3. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
BOUNDARY LUBRICATION regime is critical for wear and friction. To work in this condition, people add to
lubricants chemical EP additives. Tipical additives are based on Chlorine, Sulfur, Phosphorus, Zinc, etc.
Main problems using these kind of chemical additives are due to chemical incompatibility, temperature
effect, pollution.
Nanoadditives for tribological performance in
lubricant: how they work

4. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Nanoadditives for tribological performance in
lubricant: how they work
sheared
transfer layers
arranged on
the surface for
boundary
layer
lubrication
Nanoparticles as additives for lubricants are:
 oxides and/or sulfides
 spherical or onion like structure
 functionalized or not
 chemically inert
 insensitive to temperature
 small dimensions: allow them to easly enter
the contact area
 low concentration

5. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Nanoadditives for tribological performance in
lubricant: dispersion and stability
Uncoated
DCG
S1-coated
DCG
S2-coated
DCG
S3-coated
DCG
Average
Agglomerate
size (µm2)
1.7 1.1 0.6 0.35
Sedimentation
time (days)
3 8 >14 4
Silane functionalization
S1 - Silane n°1 Long pol. chain
S2 - Silane n°2 Mid pol. chain
S3 - Silane n°3 Short pol. chain
DCG = dichalcogenide structure

6. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Nanoadditives for tribological performance in
lubricant: tribological properties
WR=V/(L·D)
DCG = dichalcogenide structure

7. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Nanoadditives for tribological performance in
lubricant: tribological properties of mineral oil
Tribological test: Wear Rate (WR) vs different
kinds of nanoparticles:
• Room Temperature
• Vertical Load = 500N
• Rotational Speed = 200 rpm
• Time = 30 min.
• Block Material = 39NiCrMo5
• Mineral Oil ISO 320 (M320)
• Nanoparticles Concentration = 0.05 wt.%
• Kind of Nanoparticles = variable
1. Best results = DCG2
2. Others kinds of nanofiller increase the WR
3. Main problem = Nanoparticles dispersion
and stability
4. DCG2 is more stable with respect to the
other ones

8. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Nanoadditives for tribological performance in
lubricant: tribological properties of mineral oil
Tribological test: WR vs Concentration of
Nanoparticles (NPs) :
• Room Temperature
• Vertical Load = 500N
• Rotational Speed = 200 rpm
• Time = 30 min.
• Block Material = 39NiCrMo5
• Mineral Oil ISO 320 (M320)
• NPs concentration = variable
• NPs = DCG2
WR doesn’t change with respect to the
concentration of DCG2 NPs.
The decrease of WR in roughly 35%.

9. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Tribological test: WR vs NPs concentration:
• Room Temperature
• Vertical Load = 700N
• Rotational Speed = 870 rpm
• Time = 30 min.
• Block Material = CuSn12
• Synthetic Oil PAG ISO320 (P320)
• NPs concentration = variable
• NPs = DCG2
WR decrease vs concentration of NPs.
WR decrease = roughly 80%.
Nanoadditives for tribological performance in
lubricant: tribological properties of synthetic oil

10. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Nanoadditives for tribological performance in
lubricant: tribological properties of synthetic oil
Tribological test: WR vs Vertical Load:
• Romm Temperature
• Vertical Load = variable
(low 470N, medium 700N, high 950N)
• Rotational Speed = 870 rpm
• Time = 30 min.
• Block Material = CuSn12
• Synthetic Oil PAG ISO320 (P320)
• NPs concentration = 1 wt.%
• NPs = DCG2
NPs decrease the WR with respect oil without NPs.

11. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Nanoadditives for tribological performance in
lubricant: tribological properties of grease
Weld Load (WL) measures were performed with a four-ball apparatus, according to ASTM D 2596.
The Weld Load is in kilograms and it represents the lowest applied load in kilograms force at which the rotating
ball seizes and then welds to the three stationary balls.
The four-ball Wear Rate (WR) test (ASTM D2266) is run for 60 min at 1,200 rpm with a load of 40 kg.

12. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Nanoadditives for tribological performance in
lubricant: example of applications
Bearing
Grease Nanoadditive has a positive impact on the bearing lubricity which led to:
1. Bearing friction reduction
2. Reduction in the operating temperature of bearings during the test
3. Significant improvement of the bearing service time (in about 100%),
4. Increasing of bearing dynamic load by about 30%.
Comparison of wear and tear of the inner
bearing rings.
Wear and tear of orbits is about the same
even though the bearing lubricated with
grease with the additive ran about a two
fold number of hours.

13. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Nanoadditives for tribological performance in
lubricant: example of applications
Worm gearbox
Yield and
Temperature vs
Synthetic Oil:
normal and
nanocomposite

14. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Nanoadditives for tribological performance in
lubricant: example of applications
WORK IN PROGRESS
Drawing Metal
We compare Chlorinated oil and Nanocomposite oil
Result: the speed of work increased by 15-20%

15. Tec Star S.r.l.
Viale Europa, 40 – 41011 Campogalliano (MO), Italy
Tel. +39059 526845 – Fax +39059 527000
Contacts
Dr. Alberto Borghi
borghi@tec-star.it
TEC STAR Srl
Viale Europa, 40
41011 Campogalliano (MO) - Italy
Tel (+39)059.526845
Fax (+39)059.527000