Hard materials: Carbon nitride for tribological application

Sep 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: Airbrushing could facilitate large-scale manufacture of carbon nanofibers

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

add to favorites email to friend print save as pdf

Related Stories

Saws made of carbon

Aug 01, 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 ...

Antibacterial stainless steel created

Jul 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 ...

Recommended for you

A greener source of polyester—cork trees

Apr 16, 2014

On the scale of earth-friendly materials, you'd be hard pressed to find two that are farther apart than polyester (not at all) and cork (very). In an unexpected twist, however, scientists are figuring out ...

User comments : 0

More news stories

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.