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: Towards controlled dislocations

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

Triplet threat from the sun

8 hours ago

The most obvious effects of too much sun exposure are cosmetic, like wrinkled and rough skin. Some damage, however, goes deeper—ultraviolet light can damage DNA and cause proteins in the body to break down ...

Towards controlled dislocations

Oct 20, 2014

Crystallographic defects or irregularities (known as dislocations) are often found within crystalline materials. Two main types of dislocation exist: edge and screw type. However, dislocations found in real ...

Chemists tackle battery overcharge problem

Oct 17, 2014

Research from the University of Kentucky Department of Chemistry will help batteries resist overcharging, improving the safety of electronics from cell phones to airplanes.

Surface properties command attention

Oct 17, 2014

Whether working on preventing corrosion for undersea oil fields and nuclear power plants, or for producing electricity from fuel cells or oxygen from electrolyzers for travel to Mars, associate professor ...

User comments : 0