Nanocomposite Coating w/ Self-healing, Low-friction & Anti-wear Diamond-like Carbon Film

Researchers at Argonne National Lab (ANL) recently reported new nitride nanocomposite catalytic coatings that can generate a diamond-like carbon (DLC) low-friction film on the surface of the coating. Lux Research spoke with Osman Levent Eryilmaz, a co-author on the paper and co-discoverer of the coating’s functionality. The molybdenum nitride-copper (MoNx-Cu) and vanadium nitride-nickel (VNx-Ni) nanocomposite coatings form this soft and amorphous DLC film when exposed to lubricating oils and elevated temperatures and/or pressures commonly found in automotive engines. DLC film formation during engine part operation is a significant step towards lubrication for life, and may increase oil change intervals.

The nanoscale copper and nickel components in the coatings catalyze the breakdown of hydrocarbon chains in engine oils to continuously create the low-friction DLC films as they wear away. This film prevents adjoining surfaces from wearing thanks to its low-shear. The underlying nanocomposite coating, however, has a high Vickers hardness of 2000 (19.6 GPa) characteristic to other physical vapor deposited (PVD) nitride coatings. Ball-on-disc friction and wear experiments demonstrate MoNx-Cu coating in poly-alpha-olefin 10 has a 20% lower coefficient of friction and less wear than a high-carbon, chromium-containing, low-alloy steel in the same poly-alpha-olefin 10 or in ILSAC-5 5W-30 engine oil. The coating’s improved performance over anti-wear additives found in ILSAC-5 motor oils is attributable to DLC film formation, and proven using various characterization techniques.

Levent spoke to the technology’s commercial potential in the automotive industry, describing the coating as an alternative to the environmentally unfriendly anti-wear and low-friction additives used in modern motor oils. These additives form low-friction inorganic films inside the engine, but can also cover catalytic converter active sites that limit converter function. Although ANL’s nanocomposite coating would need to coat all engine components to effectively replace these additives, Levent said that there would be no negative effects on coating or additive functionality if used simultaneously. He also noted that many automotive parts manufacturers and specialty coating companies already employ nitride coatings applied using PVD equipment, significantly reducing barriers to production-scale adoption. Research on this technology continues to focus on fine-tuning various properties as well as other applications, such as large-scale natural gas compressor leak mitigation. Those interested in protective anti-wear, low-friction coatings should consider partnering with ANL to support engine-scale validation and related applications of this early, yet promising technology. The methodology for producing these coatings is patented and available for licensing, with consideration given to application-specific agreements.


Dayton Horvath is a Research Associate on the Advanced Materials Intelligence team at Lux Research, which provides strategic advice and on-going intelligence for emerging technologies. For more information, visit Lux Research.