Hard materials: Carbon nitride for tribological application

September 25, 2013
Fig.1 Plasma assisted pulsed laser deposition with substrate heating.

Carbon nitride is an attractive material for its expected hardness of the hypothetical compound β-C3N4. On the other hand, amorphous carbon nitride (CNx) exhibits a low friction coefficient under certain conditions, a property that is promising for tribological application.

However, it is difficult to deposit on steel substrates due to adverse effects associated with carbon/ diffusion into the steel substrate at elevated temperatures during deposition.

Now, Toshiaki Yasui and colleagues at Toyohashi Tech show that thick layers of CNx can be coated onto steel substrate at elevated temperatures, and describe the mechanical characteristics of coating.

The CNx coatings were deposited on steel substrates by radio frequency plasma assisted pulsed with substrate heating. A pulsed Nd:YAG laser (532 nm, 30 mJ) was irradiated onto high purity graphite target. RF power (13.56 MHz, 60 W) was applied to substrate to generate nitrogen plasma around it. Polished steel substrates were heated up to 673 K by a ceramic heater.

The friction coefficient of the CNx coating decreased with RF power and substrate temperature. The minimum friction coefficient of 0.072 was achieved for SUJ2 substrates by high hardness of the CNx coating.

Hard materials: Carbon nitride for tribological application
Fig.2 Friction coefficient of CNx coating.

CNx coating could find applications as tribological materials for mechanical instruments.

Explore further: Interaction of free falling copper droplets with heated substrates

More information: Yasui, T. et al. Carbon nitride deposition onto steel substrate by radio frequency plasma assisted pulsed laser deposition with substrate heating, Thin Solid Films, 523, 20-24 (2012). DOI: 10.1016/j.tsf.2012.05.060

Related Stories

Antibacterial stainless steel created

July 19, 2011

Materials scientists at the University of Birmingham have devised a way of making stainless steel surfaces resistant to bacteria in a project funded by the Engineering and Physical Sciences Research Council which culminated ...

Saws made of carbon

August 1, 2013

More material could be saved when manufacturing wafers in future. Ultra-thin saws made of carbon nanotubes and diamond would be able to cut through silicon wafers with minimum kerf loss. A new method makes it possible to ...

Recommended for you

New method facilitates research on fuel cell catalysts

October 8, 2015

While the cleaning of car exhausts is among the best known applications of catalytic processes, it is only the tip of the iceberg. Practically the entire chemical industry relies on catalytic reactions. Therefore, catalyst ...

Better fluorescent lighting through physics

October 8, 2015

General Electric (GE), Lawrence Livermore National Laboratory (LLNL) and Oak Ridge National Laboratory (ORNL) have created new kinds of fluorescent lighting phosphors that use far less rare-earth elements than current technology.

Porous material holds promise for prosthetics, robots

October 8, 2015

Cornell researchers have developed a new lightweight and stretchable material with the consistency of memory foam that has potential for use in prosthetic body parts, artificial organs and soft robotics. The foam is unique ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.