UNCLASSIFIED
UNCLASSIFIED
EXPERIMENTAL METHODS FOR MULTI-GENRE NETWORKS
Raman Spectra, 144-960, 300℃-600℃ analysis(8)
Sb2O3
MoS2
MoO3 • MoS2 peaks detected up to 500℃
• Molybdenum oxide peaks form at 600℃
h-MoS2 (2)orthorhombic-MoO3 (7)
2MoS2 + 9O2 → 2MoO3 + 4SO3(9)
Lubrication and Phase Analysis of an Adaptive Coating at Elevated Temperatures
Alex BerendtMaterials Science & EngineeringUniversity of North Texas
ARL Mentor: Dr. Jon-Erik MogonyeDirectorate / Division: VTD / VICTOR ERP Project Duration: 06/01/2020 to 08/21/2020
Materials Problem• Coating delamination failure leading to loss of power generation • Elevated optimal liner working temperature can reduce friction and power loss but leads to
increased asperity contact and potentially more wear(1)
1.
Cyl
inde
r Pre
ssur
e, k
Pa
Objectives• Explore Ti-Si-O ceramic PEO + Chameleon BN/MoS2/Sb2O3
architecture for high temperature tribological use in cylinder applications
• Provide understanding of the conditions and materials failure mechanisms of coating materials in severe engine conditions of UAS operation
BN/MoS2/Sb2O3 Transfer film
BN/MoS2/Sb2O3chameleon coating
Ti-Si-O PEO(4)
Titanium substrate
Si3N4 counter body20 N
h-MoS2 (2) h-BN (3)
Wear Teasting and Raman Spectrscopy• Wear testing against a Ti PEO-Chameleon coating with a
Si3N4 cylinder with a tribometer • Coefficient of Friction data is a measure of lubricity
• Raman spectroscopy used for phase detection• Scattered photon are of higher or lower energy than the
incident photon caused by rotational and vibrational energy of the molecule(6)
Results
0 1000 2000 3000 40000.000.050.100.150.200.250.300.350.400.450.50
Coefficient of Friction Temperature (C)
Cycles
Coe
ffici
ent o
f Fric
tion
Ti5, Sb2O3-MoS2-BN
300
400
500
600
Tem
pera
ture
(C)
COF vs. Cycles, Si3N4 cylinder against Chameleon coating
• COF increases at temp. > 500℃
• COF represents coating failure (high COF) at 600℃
Wear track against Si3N4 cylinder, 50x
wear track
wear track100µm
Si3N4 wear track, 600x
Transfer film
Si3N4 counter body and transfer film, 1200x
50µm
Conclusion• Coating has good tribological properties,
being enhanced by transfer film until MoS2 oxidizes above 500℃
• The role of hexagonal BN is still under investigation
• Good lubrication up to 500℃, good indicator for engine application
Future Work• Study phase transformations of Chameleon
coating phases at elevated temperatures• Investigate role of hexagonal BN at high
temperature in detail • Investigate if low COF is recoverable in
temperature cycling
Acknowledgements• Dr. Jon-Erik Mogonye• Dr. Samir Aouadi• Dr. Andrey Voevodin
• Dr. Stephen Berkebile• Dr. Diana Berman • Asghar Shirani• Euan Cairns
References1. Rahmani, Ramin, et al. "The effect of cylinder liner operating temperature on frictional loss
and engine emissions in piston ring conjunction." Applied energy 191 (2017): 568-581.2. Wu, M. hong, Li, L., Liu, N., Wang, D. jin, Xue, Y. cheng, & Tang, L. (2018). Molybdenum
disulfide (MoS2) as a co-catalyst for photocatalytic degradation of organic contaminants: A review. Process Safety and Environmental Protection, 118, 40–58. https://doi.org/10.1016/j.psep.2018.06.025
3. Uddin, M. R., Doan, T. C., Li, J., Ziemer, K. S., Lin, J. Y., & Jiang, H. X. (2014). Electrical transport properties of (BN)-rich hexagonal (BN)C semiconductor alloys. AIP Advances, 4(8). https://doi.org/10.1063/1.4894451
4. Tekin, K. C., Malayoglu, U., & Shrestha, S. (2016). Tribological behaviour of plasma electrolytic oxide coatings on Ti6Al4V and cp-Ti alloys. In Surface Engineering (Vol. 32, Issue 6, pp. 435–442). https://doi.org/10.1179/1743294415Y.0000000075
5. Shirani, A., Joy, T., Rogov, A., Lin, M., Yerokhin, A., Mogonye, J.-E., Korenyi-Both, A., Aouadi, S. M., Voevodin, A. A., & Berman, D. (2020). PEO-Chameleon as a potential protective coating on cast aluminum alloys for high-temperature applications. Surface and Coatings Technology, 397(June), 126016. https://doi.org/10.1016/j.surfcoat.2020.126016
6. Kudelski, A. (2008). Analytical applications of Raman spectroscopy. Talanta, 76(1), 1–8. https://doi.org/10.1016/j.talanta.2008.02.042
7. Rao, M.C. & Koutavarapu, Ravindranadh & Kasturi, A. & Shekhawat, Manoj. (2013). Structural Stoichiometry and Phase Transitions of MoO3 Thin Films for Solid State Microbatteries. Research Journal of Recent Sciences. 2. 67-73.
8. Search RRUFF Sample Data. (n.d.). Retrieved July 21, 2020, from https://rruff.info/molybdate/display=default/
9. Spychalski, W. L., Pisarek, M., & Szoszkiewicz, R. (2017). Microscale Insight into Oxidation of Single MoS2 Crystals in Air. In Journal of Physical Chemistry C (Vol. 121, Issue 46, pp. 26027–26033). https://doi.org/10.1021/acs.jpcc.7b05405
Example of Raman Spectra(5) Tribometer with in situ Raman(5)